Endoplasmic Reticulum: A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)Endoplasmic Reticulum Stress: Various physiological or molecular disturbances that impair ENDOPLASMIC RETICULUM function. It triggers many responses, including UNFOLDED PROTEIN RESPONSE, which may lead to APOPTOSIS; and AUTOPHAGY.Endoplasmic Reticulum, Rough: A type of endoplasmic reticulum (ER) where polyribosomes are present on the cytoplasmic surfaces of the ER membranes. This form of ER is prominent in cells specialized for protein secretion and its principal function is to segregate proteins destined for export or intracellular utilization.Sarcoplasmic Reticulum: A network of tubules and sacs in the cytoplasm of SKELETAL MUSCLE FIBERS that assist with muscle contraction and relaxation by releasing and storing calcium ions.Endoplasmic Reticulum, Smooth: A type of endoplasmic reticulum lacking associated ribosomes on the membrane surface. It exhibits a wide range of specialized metabolic functions including supplying enzymes for steroid synthesis, detoxification, and glycogen breakdown. In muscle cells, smooth endoplasmic reticulum is called SARCOPLASMIC RETICULUM.Golgi Apparatus: A stack of flattened vesicles that functions in posttranslational processing and sorting of proteins, receiving them from the rough ENDOPLASMIC RETICULUM and directing them to secretory vesicles, LYSOSOMES, or the CELL MEMBRANE. The movement of proteins takes place by transfer vesicles that bud off from the rough endoplasmic reticulum or Golgi apparatus and fuse with the Golgi, lysosomes or cell membrane. (From Glick, Glossary of Biochemistry and Molecular Biology, 1990)Unfolded Protein Response: A cellular response to environmental insults that cause disruptions in PROTEIN FOLDING and/or accumulation of defectively folded protein in the ENDOPLASMIC RETICULUM. It consists of a group of regulatory cascades that are triggered as a response to altered levels of calcium and/or the redox state of the endoplasmic reticulum. Persistent activation of the unfolded protein response leads to the induction of APOPTOSIS.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Protein Transport: The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.Molecular Chaperones: A family of cellular proteins that mediate the correct assembly or disassembly of polypeptides and their associated ligands. Although they take part in the assembly process, molecular chaperones are not components of the final structures.Sarcoplasmic Reticulum Calcium-Transporting ATPases: Calcium-transporting ATPases that catalyze the active transport of CALCIUM into the SARCOPLASMIC RETICULUM vesicles from the CYTOPLASM. They are primarily found in MUSCLE CELLS and play a role in the relaxation of MUSCLES.Tunicamycin: An N-acetylglycosamine containing antiviral antibiotic obtained from Streptomyces lysosuperificus. It is also active against some bacteria and fungi, because it inhibits the glucosylation of proteins. Tunicamycin is used as tool in the study of microbial biosynthetic mechanisms.Calnexin: A lectin found in ENDOPLASMIC RETICULUM membranes that binds to specific N-linked OLIGOSACCHARIDES found on newly synthesized proteins. It may play role in PROTEIN FOLDING or retention and degradation of misfolded proteins in the endoplasmic reticulum.Transcription Factor CHOP: A CCAAT-enhancer binding protein that is induced by DNA DAMAGE and growth arrest. It serves as a dominant negative inhibitor of other CCAAT-enhancer binding proteins.Calcium-Transporting ATPases: Cation-transporting proteins that utilize the energy of ATP hydrolysis for the transport of CALCIUM. They differ from CALCIUM CHANNELS which allow calcium to pass through a membrane without the use of energy.Intracellular Membranes: Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Calreticulin: A multifunctional protein that is found primarily within membrane-bound organelles. In the ENDOPLASMIC RETICULUM it binds to specific N-linked oligosaccharides found on newly-synthesized proteins and functions as a MOLECULAR CHAPERONE that may play a role in PROTEIN FOLDING or retention and degradation of misfolded proteins. In addition calreticulin is a major storage form for CALCIUM and functions as a calcium-signaling molecule that can regulate intracellular calcium HOMEOSTASIS.Thapsigargin: A sesquiterpene lactone found in roots of THAPSIA. It inhibits CA(2+)-TRANSPORTING ATPASE mediated uptake of CALCIUM into SARCOPLASMIC RETICULUM.Brefeldin A: A fungal metabolite which is a macrocyclic lactone exhibiting a wide range of antibiotic activity.Protein Folding: Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Microsomes: Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)Activating Transcription Factor 6: One of the BASIC-LEUCINE ZIPPER TRANSCRIPTION FACTORS that is synthesized as a membrane-bound protein in the ENDOPLASMIC RETICULUM. In response to endoplasmic reticulum stress it translocates to the GOLGI APPARATUS. It is activated by PROTEASES and then moves to the CELL NUCLEUS to regulate GENETIC TRANSCRIPTION of GENES involved in the unfolded protein response.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Glycosylation: The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Biological Transport: The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Heat-Shock Proteins: Proteins which are synthesized in eukaryotic organisms and bacteria in response to hyperthermia and other environmental stresses. They increase thermal tolerance and perform functions essential to cell survival under these conditions.Caspase 12: A long pro-domain caspase that contains a caspase recruitment domain in its pro-domain region. Caspase 12 is activated by pro-apoptotic factors that are released during cell stress and by CARD SIGNALING ADAPTOR PROTEINS. It activates APOPTOSIS by cleaving and activating EFFECTOR CASPASES.Protein Sorting Signals: Amino acid sequences found in transported proteins that selectively guide the distribution of the proteins to specific cellular compartments.Protein Processing, Post-Translational: Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.COP-Coated Vesicles: TRANSPORT VESICLES formed when cell-membrane coated pits (COATED PITS, CELL-MEMBRANE) invaginate and pinch off. The outer surface of these vesicles is covered with a lattice-like network of COP (coat protein complex) proteins, either COPI or COPII. COPI coated vesicles transport backwards from the cisternae of the GOLGI APPARATUS to the rough endoplasmic reticulum (ENDOPLASMIC RETICULUM, ROUGH), while COPII coated vesicles transport forward from the rough endoplasmic reticulum to the Golgi apparatus.Protein Disulfide-Isomerases: Sulfur-sulfur bond isomerases that catalyze the rearrangement of disulfide bonds within proteins during folding. Specific protein disulfide-isomerase isoenzymes also occur as subunits of PROCOLLAGEN-PROLINE DIOXYGENASE.Subcellular Fractions: Components of a cell produced by various separation techniques which, though they disrupt the delicate anatomy of a cell, preserve the structure and physiology of its functioning constituents for biochemical and ultrastructural analysis. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p163)Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Stress, Physiological: The unfavorable effect of environmental factors (stressors) on the physiological functions of an organism. Prolonged unresolved physiological stress can affect HOMEOSTASIS of the organism, and may lead to damaging or pathological conditions.Calcium Signaling: Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.Cytosol: Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.Calcium-Binding Proteins: Proteins to which calcium ions are bound. They can act as transport proteins, regulator proteins, or activator proteins. They typically contain EF HAND MOTIFS.COS Cells: CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). They are used for transfection and cloning. (The CV-1 cell line was derived from the kidney of an adult male African green monkey (CERCOPITHECUS AETHIOPS).)Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Cell Fractionation: Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Recombinant Fusion Proteins: Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.Inositol 1,4,5-Trisphosphate Receptors: Intracellular receptors that bind to INOSITOL 1,4,5-TRISPHOSPHATE and play an important role in its intracellular signaling. Inositol 1,4,5-trisphosphate receptors are calcium channels that release CALCIUM in response to increased levels of inositol 1,4,5-trisphosphate in the CYTOPLASM.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Transfection: The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.Vesicular Transport Proteins: A broad category of proteins involved in the formation, transport and dissolution of TRANSPORT VESICLES. They play a role in the intracellular transport of molecules contained within membrane vesicles. Vesicular transport proteins are distinguished from MEMBRANE TRANSPORT PROTEINS, which move molecules across membranes, by the mode in which the molecules are transported.Saccharomyces cerevisiae Proteins: Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.Cytoplasm: The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)Cell Compartmentation: A partitioning within cells due to the selectively permeable membranes which enclose each of the separate parts, e.g., mitochondria, lysosomes, etc.HeLa Cells: The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.Microscopy, Fluorescence: Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.Endoplasmic Reticulum-Associated Degradation: A degradation process whereby incorrectly folded proteins are selectively transported out of the ENDOPLASMIC RETICULUM and into the CYTOSOL. The misfolded proteins are subsequently ubiquitinated and degraded by the PROTEASOME.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.Activating Transcription Factor 4: An activating transcription factor that regulates the expression of a variety of GENES involved in amino acid metabolism and transport. It also interacts with HTLV-I transactivator protein.Mitochondria: Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)Apoptosis: One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.Kinetics: The rate dynamics in chemical or physical systems.Cercopithecus aethiops: A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Microscopy, Confocal: A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.eIF-2 Kinase: A dsRNA-activated cAMP-independent protein serine/threonine kinase that is induced by interferon. In the presence of dsRNA and ATP, the kinase autophosphorylates on several serine and threonine residues. The phosphorylated enzyme catalyzes the phosphorylation of the alpha subunit of EUKARYOTIC INITIATION FACTOR-2, leading to the inhibition of protein synthesis.Proteasome Endopeptidase Complex: A large multisubunit complex that plays an important role in the degradation of most of the cytosolic and nuclear proteins in eukaryotic cells. It contains a 700-kDa catalytic sub-complex and two 700-kDa regulatory sub-complexes. The complex digests ubiquitinated proteins and protein activated via ornithine decarboxylase antizyme.CHO Cells: CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.Membrane Glycoproteins: Glycoproteins found on the membrane or surface of cells.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Secretory Pathway: A series of sequential intracellular steps involved in the transport of proteins (such as hormones and enzymes) from the site of synthesis to outside the cell. The pathway involves membrane-bound compartments through which the newly synthesized proteins undergo POST-TRANSLATIONAL MODIFICATIONS, packaging, storage, or transportation to the PLASMA MEMBRANE for secretion.Calcium Channels: Voltage-dependent cell membrane glycoproteins selectively permeable to calcium ions. They are categorized as L-, T-, N-, P-, Q-, and R-types based on the activation and inactivation kinetics, ion specificity, and sensitivity to drugs and toxins. The L- and T-types are present throughout the cardiovascular and central nervous systems and the N-, P-, Q-, & R-types are located in neuronal tissue.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.HSP70 Heat-Shock Proteins: A class of MOLECULAR CHAPERONES found in both prokaryotes and in several compartments of eukaryotic cells. These proteins can interact with polypeptides during a variety of assembly processes in such a way as to prevent the formation of nonfunctional structures.Protein Biosynthesis: The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Microscopy, Immunoelectron: Microscopy in which the samples are first stained immunocytochemically and then examined using an electron microscope. Immunoelectron microscopy is used extensively in diagnostic virology as part of very sensitive immunoassays.Ryanodine Receptor Calcium Release Channel: A tetrameric calcium release channel in the SARCOPLASMIC RETICULUM membrane of SMOOTH MUSCLE CELLS, acting oppositely to SARCOPLASMIC RETICULUM CALCIUM-TRANSPORTING ATPASES. It is important in skeletal and cardiac excitation-contraction coupling and studied by using RYANODINE. Abnormalities are implicated in CARDIAC ARRHYTHMIAS and MUSCULAR DISEASES.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Green Fluorescent Proteins: Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.Reticulum: The second stomach of ruminants. It lies almost in the midline in the front of the abdomen, in contact with the liver and diaphragm and communicates freely with the RUMEN via the ruminoreticular orifice. The lining of the reticulum is raised into folds forming a honeycomb pattern over the surface. (From Concise Veterinary Dictionary, 1988)Taurochenodeoxycholic Acid: A bile salt formed in the liver by conjugation of chenodeoxycholate with taurine, usually as the sodium salt. It acts as detergent to solubilize fats in the small intestine and is itself absorbed. It is used as a cholagogue and choleretic.Mannosidases: Glycoside hydrolases that catalyze the hydrolysis of alpha or beta linked MANNOSE.Organelles: Specific particles of membrane-bound organized living substances present in eukaryotic cells, such as the MITOCHONDRIA; the GOLGI APPARATUS; ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.Lysosomes: A class of morphologically heterogeneous cytoplasmic particles in animal and plant tissues characterized by their content of hydrolytic enzymes and the structure-linked latency of these enzymes. The intracellular functions of lysosomes depend on their lytic potential. The single unit membrane of the lysosome acts as a barrier between the enzymes enclosed in the lysosome and the external substrate. The activity of the enzymes contained in lysosomes is limited or nil unless the vesicle in which they are enclosed is ruptured. Such rupture is supposed to be under metabolic (hormonal) control. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)Fluorescent Antibody Technique: Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.Adenosine Triphosphate: An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.PhenylbutyratesProtein PrecursorsMicrosomes, Liver: Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.Fungal Proteins: Proteins found in any species of fungus.Eukaryotic Initiation Factor-2: Eukaryotic initiation factor of protein synthesis. In higher eukaryotes the factor consists of three subunits: alpha, beta, and gamma. As initiation proceeds, eIF-2 forms a ternary complex with Met-tRNAi and GTP.Vacuoles: Any spaces or cavities within a cell. They may function in digestion, storage, secretion, or excretion.Cyclopentanes: A group of alicyclic hydrocarbons with the general formula R-C5H9.Recombinant Proteins: Proteins prepared by recombinant DNA technology.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Coatomer Protein: A 700-kDa cytosolic protein complex consisting of seven equimolar subunits (alpha, beta, beta', gamma, delta, epsilon and zeta). COATOMER PROTEIN and ADP-RIBOSYLATION FACTOR 1 are principle components of COAT PROTEIN COMPLEX I and are involved in vesicle transport between the ENDOPLASMIC RETICULUM and the GOLGI APPARATUS.Homeostasis: The processes whereby the internal environment of an organism tends to remain balanced and stable.Calsequestrin: Acidic protein found in SARCOPLASMIC RETICULUM that binds calcium to the extent of 700-900 nmoles/mg. It plays the role of sequestering calcium transported to the interior of the intracellular vesicle.Caffeine: A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling.Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Caspases, Initiator: A subtype of caspases that contain long pro-domain regions that regulate the activation of the enzyme. The pro-domain regions contain protein-protein interaction motifs that can interact with specific signaling adaptor proteins such as DEATH DOMAIN RECEPTORS; DED SIGNALING ADAPTOR PROTEINS; and CARD SIGNALING ADAPTOR PROTEINS. Once activated, the initiator caspases can activate other caspases such as the EFFECTOR CASPASES.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Nuclear Envelope: The membrane system of the CELL NUCLEUS that surrounds the nucleoplasm. It consists of two concentric membranes separated by the perinuclear space. The structures of the envelope where it opens to the cytoplasm are called the nuclear pores (NUCLEAR PORE).Luminescent Proteins: Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.Hexosaminidases: Enzymes that catalyze the hydrolysis of N-acylhexosamine residues in N-acylhexosamides. Hexosaminidases also act on GLUCOSIDES; GALACTOSIDES; and several OLIGOSACCHARIDES.Immunoblotting: Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.Ryanodine: A methylpyrrole-carboxylate from RYANIA that disrupts the RYANODINE RECEPTOR CALCIUM RELEASE CHANNEL to modify CALCIUM release from SARCOPLASMIC RETICULUM resulting in alteration of MUSCLE CONTRACTION. It was previously used in INSECTICIDES. It is used experimentally in conjunction with THAPSIGARGIN and other inhibitors of CALCIUM ATPASE uptake of calcium into SARCOPLASMIC RETICULUM.Cathepsin A: A carboxypeptidase that catalyzes the release of a C-terminal amino acid with a broad specificity. It also plays a role in the LYSOSOMES by protecting BETA-GALACTOSIDASE and NEURAMINIDASE from degradation. It was formerly classified as EC 184.108.40.206 and EC 220.127.116.11.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Receptors, Peptide: Cell surface receptors that bind peptide messengers with high affinity and regulate intracellular signals which influence the behavior of cells.Coat Protein Complex I: A protein complex comprised of COATOMER PROTEIN and ADP RIBOSYLATION FACTOR 1. It is involved in transport of vesicles between the ENDOPLASMIC RETICULUM and the GOLGI APPARATUS.Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase: A group of related enzymes responsible for the endohydrolysis of the di-N-acetylchitobiosyl unit in high-mannose-content glycopeptides and GLYCOPROTEINS.Membrane Transport Proteins: Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Inositol 1,4,5-Trisphosphate: Intracellular messenger formed by the action of phospholipase C on phosphatidylinositol 4,5-bisphosphate, which is one of the phospholipids that make up the cell membrane. Inositol 1,4,5-trisphosphate is released into the cytoplasm where it releases calcium ions from internal stores within the cell's endoplasmic reticulum. These calcium ions stimulate the activity of B kinase or calmodulin.Adenosine Triphosphatases: A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.Cell Line, Tumor: A cell line derived from cultured tumor cells.Disulfides: Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.Precipitin Tests: Serologic tests in which a positive reaction manifested by visible CHEMICAL PRECIPITATION occurs when a soluble ANTIGEN reacts with its precipitins, i.e., ANTIBODIES that can form a precipitate.HEK293 Cells: A cell line generated from human embryonic kidney cells that were transformed with human adenovirus type 5.Enzyme Inhibitors: Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.rab1 GTP-Binding Proteins: A genetically related subfamily of RAB GTP-BINDING PROTEINS involved in vesicle transport between the ENDOPLASMIC RETICULUM and the GOLGI APPARATUS and through early Golgi compartments. This enzyme was formerly listed as EC 18.104.22.168.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.IndolizinesAutophagy: The segregation and degradation of damaged or unwanted cytoplasmic constituents by autophagic vacuoles (cytolysosomes) composed of LYSOSOMES containing cellular components in the process of digestion; it plays an important role in BIOLOGICAL METAMORPHOSIS of amphibians, in the removal of bone by osteoclasts, and in the degradation of normal cell components in nutritional deficiency states.Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Terpenes: A class of compounds composed of repeating 5-carbon units of HEMITERPENES.Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Mannosyltransferases: Enzymes that catalyze the transfer of mannose from a nucleoside diphosphate mannose to an acceptor molecule which is frequently another carbohydrate. The group includes EC 22.214.171.124, EC 126.96.36.199, EC 188.8.131.52, and EC 184.108.40.206.Organoids: An organization of cells into an organ-like structure. Organoids can be generated in culture. They are also found in certain neoplasms.Endoribonucleases: A family of enzymes that catalyze the endonucleolytic cleavage of RNA. It includes EC 3.1.26.-, EC 3.1.27.-, EC 3.1.30.-, and EC 3.1.31.-.Protein Synthesis Inhibitors: Compounds which inhibit the synthesis of proteins. They are usually ANTI-BACTERIAL AGENTS or toxins. Mechanism of the action of inhibition includes the interruption of peptide-chain elongation, the blocking the A site of ribosomes, the misreading of the genetic code or the prevention of the attachment of oligosaccharide side chains to glycoproteins.Biological Transport, Active: The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Viral Envelope Proteins: Layers of protein which surround the capsid in animal viruses with tubular nucleocapsids. The envelope consists of an inner layer of lipids and virus specified proteins also called membrane or matrix proteins. The outer layer consists of one or more types of morphological subunits called peplomers which project from the viral envelope; this layer always consists of glycoproteins.Cricetulus: A genus of the family Muridae consisting of eleven species. C. migratorius, the grey or Armenian hamster, and C. griseus, the Chinese hamster, are the two species used in biomedical research.alpha-Mannosidase: An enzyme that catalyzes the HYDROLYSIS of terminal, non-reducing alpha-D-mannose residues in alpha-D-mannosides. The enzyme plays a role in the processing of newly formed N-glycans and in degradation of mature GLYCOPROTEINS. There are multiple isoforms of alpha-mannosidase, each having its own specific cellular location and pH optimum. Defects in the lysosomal form of the enzyme results in a buildup of mannoside intermediate metabolites and the disease ALPHA-MANNOSIDOSIS.Mutagenesis, Site-Directed: Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.Signal Recognition Particle: A cytosolic ribonucleoprotein complex that acts to induce elongation arrest of nascent presecretory and membrane proteins until the ribosome becomes associated with the rough endoplasmic reticulum. It consists of a 7S RNA and at least six polypeptide subunits (relative molecular masses 9, 14, 19, 54, 68, and 72K).Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Oligosaccharides: Carbohydrates consisting of between two (DISACCHARIDES) and ten MONOSACCHARIDES connected by either an alpha- or beta-glycosidic link. They are found throughout nature in both the free and bound form.Isomerases: A class of enzymes that catalyze geometric or structural changes within a molecule to form a single product. The reactions do not involve a net change in the concentrations of compounds other than the substrate and the product.(from Dorland, 28th ed) EC 5.DNA, Complementary: Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.Histocytochemistry: Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.HSP40 Heat-Shock Proteins: A family of heat-shock proteins that contain a 70 amino-acid consensus sequence known as the J domain. The J domain of HSP40 heat shock proteins interacts with HSP70 HEAT-SHOCK PROTEINS. HSP40 heat-shock proteins play a role in regulating the ADENOSINE TRIPHOSPHATASES activity of HSP70 heat-shock proteins.Pancreas: A nodular organ in the ABDOMEN that contains a mixture of ENDOCRINE GLANDS and EXOCRINE GLANDS. The small endocrine portion consists of the ISLETS OF LANGERHANS secreting a number of hormones into the blood stream. The large exocrine portion (EXOCRINE PANCREAS) is a compound acinar gland that secretes several digestive enzymes into the pancreatic ductal system that empties into the DUODENUM.Fibroblasts: Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.Microscopy, Electron, Transmission: Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.Immunoprecipitation: The aggregation of soluble ANTIGENS with ANTIBODIES, alone or with antibody binding factors such as ANTI-ANTIBODIES or STAPHYLOCOCCAL PROTEIN A, into complexes large enough to fall out of solution.Mannose: A hexose or fermentable monosaccharide and isomer of glucose from manna, the ash Fraxinus ornus and related plants. (From Grant & Hackh's Chemical Dictionary, 5th ed & Random House Unabridged Dictionary, 2d ed)Amino Acid Motifs: Commonly observed structural components of proteins formed by simple combinations of adjacent secondary structures. A commonly observed structure may be composed of a CONSERVED SEQUENCE which can be represented by a CONSENSUS SEQUENCE.Glycoside HydrolasesDithiothreitol: A reagent commonly used in biochemical studies as a protective agent to prevent the oxidation of SH (thiol) groups and for reducing disulphides to dithiols.Glucose-6-Phosphatase: An enzyme that catalyzes the conversion of D-glucose 6-phosphate and water to D-glucose and orthophosphate. EC 220.127.116.11.Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)alpha 1-Antitrypsin: Plasma glycoprotein member of the serpin superfamily which inhibits TRYPSIN; NEUTROPHIL ELASTASE; and other PROTEOLYTIC ENZYMES.Mice, Inbred C57BLalpha-Glucosidases: Enzymes that catalyze the exohydrolysis of 1,4-alpha-glucosidic linkages with release of alpha-glucose. Deficiency of alpha-1,4-glucosidase may cause GLYCOGEN STORAGE DISEASE TYPE II.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Receptors, Autocrine Motility Factor: Cell surface receptors for AUTOCRINE MOTILITY FACTOR, which is the secreted form of GLUCOSE-6-PHOSPHATE ISOMERASE. The receptor has an unusual composition in that it shares some structural similarities with G-PROTEIN-COUPLED RECEPTORS and functions as an ubiquitin protein ligase when internalized.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Cell Death: The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.Centrifugation, Density Gradient: Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)PolysaccharidesDNA Primers: Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.Ribosomes: Multicomponent ribonucleoprotein structures found in the CYTOPLASM of all cells, and in MITOCHONDRIA, and PLASTIDS. They function in PROTEIN BIOSYNTHESIS via GENETIC TRANSLATION.Leupeptins: A group of acylated oligopeptides produced by Actinomycetes that function as protease inhibitors. They have been known to inhibit to varying degrees trypsin, plasmin, KALLIKREINS, papain and the cathepsins.Cysteine Endopeptidases: ENDOPEPTIDASES which have a cysteine involved in the catalytic process. This group of enzymes is inactivated by CYSTEINE PROTEINASE INHIBITORS such as CYSTATINS and SULFHYDRYL REAGENTS.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Ubiquitin: A highly conserved 76-amino acid peptide universally found in eukaryotic cells that functions as a marker for intracellular PROTEIN TRANSPORT and degradation. Ubiquitin becomes activated through a series of complicated steps and forms an isopeptide bond to lysine residues of specific proteins within the cell. These "ubiquitinated" proteins can be recognized and degraded by proteosomes or be transported to specific compartments within the cell.Oxidative Stress: A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Membranes: Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.RNA, Small Interfering: Small double-stranded, non-protein coding RNAs (21-31 nucleotides) involved in GENE SILENCING functions, especially RNA INTERFERENCE (RNAi). Endogenously, siRNAs are generated from dsRNAs (RNA, DOUBLE-STRANDED) by the same ribonuclease, Dicer, that generates miRNAs (MICRORNAS). The perfect match of the siRNAs' antisense strand to their target RNAs mediates RNAi by siRNA-guided RNA cleavage. siRNAs fall into different classes including trans-acting siRNA (tasiRNA), repeat-associated RNA (rasiRNA), small-scan RNA (scnRNA), and Piwi protein-interacting RNA (piRNA) and have different specific gene silencing functions.Cytoplasmic Granules: Condensed areas of cellular material that may be bounded by a membrane.beta-Fructofuranosidase: A glycoside hydrolase found primarily in PLANTS and YEASTS. It has specificity for beta-D-fructofuranosides such as SUCROSE.Lipid Metabolism: Physiological processes in biosynthesis (anabolism) and degradation (catabolism) of LIPIDS.Egtazic Acid: A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID.Monomeric GTP-Binding Proteins: A class of monomeric, low molecular weight (20-25 kDa) GTP-binding proteins that regulate a variety of intracellular processes. The GTP bound form of the protein is active and limited by its inherent GTPase activity, which is controlled by an array of GTPase activators, GDP dissociation inhibitors, and guanine nucleotide exchange factors. This enzyme was formerly listed as EC 18.104.22.168Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Muscles: Contractile tissue that produces movement in animals.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Glycosylphosphatidylinositols: Compounds containing carbohydrate or glycosyl groups linked to phosphatidylinositols. They anchor GPI-LINKED PROTEINS or polysaccharides to cell membranes.Protein Isoforms: Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.Receptors, Cytoplasmic and Nuclear: Intracellular receptors that can be found in the cytoplasm or in the nucleus. They bind to extracellular signaling molecules that migrate through or are transported across the CELL MEMBRANE. Many members of this class of receptors occur in the cytoplasm and are transported to the CELL NUCLEUS upon ligand-binding where they signal via DNA-binding and transcription regulation. Also included in this category are receptors found on INTRACELLULAR MEMBRANES that act via mechanisms similar to CELL SURFACE RECEPTORS.RNA Interference: A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.Ribonucleoproteins: Complexes of RNA-binding proteins with ribonucleic acids (RNA).Inclusion Bodies: A generic term for any circumscribed mass of foreign (e.g., lead or viruses) or metabolically inactive materials (e.g., ceroid or MALLORY BODIES), within the cytoplasm or nucleus of a cell. Inclusion bodies are in cells infected with certain filtrable viruses, observed especially in nerve, epithelial, or endothelial cells. (Stedman, 25th ed)Histocompatibility Antigens Class I: Membrane glycoproteins consisting of an alpha subunit and a BETA 2-MICROGLOBULIN beta subunit. In humans, highly polymorphic genes on CHROMOSOME 6 encode the alpha subunits of class I antigens and play an important role in determining the serological specificity of the surface antigen. Class I antigens are found on most nucleated cells and are generally detected by their reactivity with alloantisera. These antigens are recognized during GRAFT REJECTION and restrict cell-mediated lysis of virus-infected cells.Myocardium: The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.Molecular Weight: The sum of the weight of all the atoms in a molecule.Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase: An amidohydrolase that removes intact asparagine-linked oligosaccharide chains from glycoproteins. It requires the presence of more than two amino-acid residues in the substrate for activity. This enzyme was previously listed as EC 22.214.171.124.Tobacco: A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.
Structural and functional changes in acute liver injury. (1/12813)Carbon tetrachloride produces liver cell injury in a variety of animal species. The first structurally recognizable changes occur in the endoplasmic reticulum, with alteration in ribosome-membrane interactions. Later there is an increase in intracellular fat, and the formation of tangled nets of the ergastoplasm. At no time are there changes in mitochondria or single membrane limited bodies in cells with intact plasmalemma, although a relative increase in cell sap may appear. In dead cells (those with plasmalemma discontinuties) crystalline deposits of calcium phosphatase may be noted. Functional changes are related to the endoplasmic reticulum and the plasma membrane. An early decrease in protein synthesis takes place; an accumulation of neutral lipid is related to this change. Later alterations in the ergastoplasmic functions (e.g., mixed function oxidation) occurs. Carbon tetrachloride is not the active agent; rather, a product of its metabolism, probably the CC1, free radical, is. The mechanisms of injury include macromolecular adduction and peroxide propagation. A third possibility includes a cascade effect with the production of secondary and tertiary products, also toxic in nature, with the ability to produce more widespread damage to intracellular structures. (+info)
The Saccharomyces cerevisiae CWH8 gene is required for full levels of dolichol-linked oligosaccharides in the endoplasmic reticulum and for efficient N-glycosylation. (2/12813)The Saccharomyces cerevisiae mutant cwh8 was previously found to have an anomalous cell wall. Here we show that the cwh8 mutant has an N -glycosylation defect. We found that cwh8 cells were resistant to vanadate and sensitive to hygromycin B, and produced glycoforms of invertase and carboxypeptidase Y with a reduced number of N -chains. We have cloned the CWH8 gene. We found that it was nonessential and encoded a putative transmembrane protein of 239 amino acids. Comparison of the in vitro oligosaccharyl transferase activities of membrane preparations from wild type or cwh8 Delta cells revealed no differences in enzyme kinetic properties indicating that the oligosaccharyl transferase complex of mutant cells was not affected. cwh8 Delta cells also produced normal dolichols and dolichol-linked oligosaccharide intermediates including the full-length form Glc3Man9GlcNAc2. The level of dolichol-linked oligosaccharides in cwh8 Delta cells was, however, reduced to about 20% of the wild type. We propose that inefficient N -glycosylation of secretory proteins in cwh8 Delta cells is caused by an insufficient supply of dolichol-linked oligosaccharide substrate. (+info)
The role of oocyte transcription, the 5'UTR, and translation repression and derepression in Drosophila gurken mRNA and protein localization. (3/12813)The establishment of the major body axes of the Drosophila egg and future embryo requires strict regulation of gurken mRNA and protein localization. Here, we show that grk mRNA and protein localization is dependent on synthesis of grk transcripts in the oocyte nucleus and on RNA localization elements in the 5' portion of the transcript. We also show that gurken mRNA and protein localization is dependent on region-specific translation of gurken transcripts and identify K10 as a probable negative regulator of gurken translation. (+info)
Re-entering the translocon from the lumenal side of the endoplasmic reticulum. Studies on mutated carboxypeptidase yscY species. (4/12813)Misfolded or unassembled secretory proteins are retained in the endoplasmic reticulum (ER) and subsequently degraded by the cytosolic ubiquitin-proteasome system. This requires their retrograde transport from the ER lumen into the cytosol, which is mediated by the Sec61 translocon. It had remained a mystery whether ER-localised soluble proteins are at all capable of re-entering the Sec61 channel de novo or whether a permanent contact of the imported protein with the translocon is a prerequisite for retrograde transport. In this study we analysed two new variants of the mutated yeast carboxypeptidase yscY, CPY*: a carboxy-terminal fusion protein of CPY* and pig liver esterase and a CPY* species carrying an additional glycosylation site at its carboxy-terminus. With these constructs it can be demonstrated that the newly synthesised CPY* chain is not retained in the translocation channel but reaches its ER lumenal side completely. Our data indicate that the Sec61 channel provides the essential pore for protein transport through the ER membrane in either direction; persistent contact with the translocon after import seems not to be required for retrograde transport. (+info)
Cloning of the peroxiredoxin gene family in rats and characterization of the fourth member. (5/12813)Peroxiredoxin (PRx) exhibits thioredoxin-dependent peroxidase activity and constitutes a family of proteins. Four members of genes from rat tissues were isolated by PCR using degenerated primers based on the sequences which encode a pair of highly conserved Cys-containing domains, and were then cloned to full-length cDNAs. These included two genes which have previously been isolated in rats, PRx I and PRx II, and two rat homologues of PRx III and PRx IV. We showed, for the first time, the simultaneous expression of all four genes in various rat tissues by Northern blotting. Since a discrepancy exists regarding cellular distribution, we further characterized PRx IV by expressing it in COS-1 cells. This clearly demonstrates that PRx IV is a secretory form and functions within the extracellular space. (+info)
Characterization of elementary Ca2+ release signals in NGF-differentiated PC12 cells and hippocampal neurons. (6/12813)Elementary Ca2+ release signals in nerve growth factor- (NGF-) differentiated PC12 cells and hippocampal neurons, functionally analogous to the "Ca2+ sparks" and "Ca2+ puffs" identified in other cell types, were characterized by confocal microscopy. They either occurred spontaneously or could be activated by caffeine and metabotropic agonists. The release events were dissimilar to the sparks and puffs described so far, as many arose from clusters of both ryanodine receptors (RyRs) and inositol 1,4,5-trisphosphate receptors (InsP3Rs). Increasing either the stimulus strength or loading of the intracellular stores enhanced the frequency of and coupling between elementary release sites and evoked global Ca2+ signals. In the PC12 cells, the elementary Ca2+ release preferentially occurred around the branch points. Spatio-temporal recruitment of such elementary release events may regulate neuronal activities. (+info)
Lectin receptor sites on rat liver cell nuclear membranes. (7/12813)The presence and localization of lectin receptor sites on rat liver cell nuclear and other endomembranes was studied by light and electron microscopy using fluorescein and ferritin-coupled lectin conjugates. Isolated nuclei labelled with fluorescein-conjugated Concanavalin A (Con A) or wheat germ agglutinin (WGA) often showed membrane staining, which sometimes was especially bright on small stretches of the nuclear surface. Unlabelled nuclei and nuclei with a complete ring fluorescence were also seen. The nuclear fluorescence corresponded in intensity to that seen on the surface of isolated rat liver cells. Con A-ferritin particles were seldom detected on the cytoplasmic surface of the intact nuclear envelope. However, at places where the 2 leaflets of the envelope were widely separated or where the outer nuclear membrane was partly torn away, heavy labelling was seen on the cisternal surface of both the inner and outer nuclear membranes. Labelling with Con A-ferritin was also found on the cisternal side of rough endoplasmic reticulum present in the specimens. No labelling was seen on the cytoplasmic surface of mitochondrial outer membrane. The results demonstrate the presence of binding sites for Con A and WGA in nuclei and an asymmetric localization of these sites on the cisternal side of ribosome-carrying endomembranes in rat liver cells. (+info)
Missense mutations in SGLT1 cause glucose-galactose malabsorption by trafficking defects. (8/12813)Glucose-galactose malabsorption (GGM) is an autosomal recessive disorder caused by defects in the Na+/glucose cotransporter (SGLT1). Neonates present with severe diarrhea while on any diet containing glucose and/or galactose . This study focuses on a patient of Swiss and Dominican descent. All 15 exons of SGLT1 were screened using single stranded conformational polymorphism analyses, and aberrant PCR products were sequenced. Two missense mutations, Gly318Arg and Ala468Val, were identified. SGLT1 mutants were expressed in Xenopus laevis oocytes for radiotracer uptake, electrophysiological experiments, and Western blotting. Uptakes of [14C]alpha-methyl-d-glucoside by the mutants were 5% or less than that of wild-type. Two-electrode voltage-clamp experiments confirmed the transport defects, as no noticeable sugar-induced current could be elicited from either mutant . Western blots of cell protein showed levels of each SGLT1 mutant protein comparable to that of wild-type, and that both were core-glycosylated. Presteady-state current measurements indicated an absence of SGLT1 in the plasma membrane. We suggest that the compound heterozygote missense mutations G318R and A468V lead to GGM in this patient by defective trafficking of mutant proteins from the endoplasmic reticulum to the plasma membrane. (+info)
Inf2-formin that polymerizes and depolymerizes actin on endoplasmic reticulum. :: Dartmouth Dissertations
INF2 -FORMIN THAT POLYMERIZES AND DEPOL YMERIZES ACTIN ON ENDOPLASMIC RETICULUM A Thesis Submitted to the Faculty in partial fulfillment of the requirements for the degree of cfnifi;s ·K. Barlowe, Ph.D. Dean of Graduate Studies Doctor of Philosophy In Biochemistry by Ekta Seth Chhabra DARTMOUTH COLLEGE Hanover, New Hampshire May 23rd ,2008 Examining Committee: • u» Henry N. Higgs, PhP - - 1 Duane A. Compton, Ph.D D~ R. Madden, Ph.D Jennifer Lippincott-Schwartz, Ph.D ...
Q96DN0 | ERP27 | Endoplasmic reticulum resident protein 27 | Druggability | Cancer
casSAR Dugability of Q96DN0 | ERP27 | Endoplasmic reticulum resident protein 27 - Also known as ERP27_HUMAN, ERP27, C12orf46. Specifically binds unfolded proteins and may recruit protein disulfide isomerase PDIA3 to unfolded substrates (PubMed:16940051, PubMed:23192347). Binds protein substrates via a hydrophobic pocket in the C-terminal domain (PubMed:16940051, PubMed:23192347). May play a role in the unfolded stress response (PubMed:23192347). Interacts with PDIA3.
Endoplasmic Reticulum Stress-Mediated Apoptosis Involved in Indirect Recognition Pathway Blockade Induces Long-Term Heart...
Implementation of dendritic cell- (DC-) based therapies in organ transplantation can reduce dependency on nonspecific immunosuppression. Despite extensive research, mechanisms of equipped DCs inducing transplant tolerance remain incomplete. Here, we applied RNA interference technique to inhibit CD80 and CD86 expression in host bone marrow-derived DCs. This approach could specifically and effectively knock down CD80 and CD86 expression. T cells primed by these DCs inhibited allogeneic responses. Administration of recipient DCs loaded with alloantigen after CD80 and CD86 blockade prolonged cardiac allograft survival. We also found a higher percentage of apoptotic T cells in lymph tissues and grafts than that detected in control group. In addition, these T cells expressed high expression of GRP78 than controls, indicating activation of unfolded protein responses. Upregulation of CHOP expression among these cells suggested that the endoplasmic reticulum stress (ERS) response switched to a proapoptotic
Mif1: A Missing Link between the Unfolded Protein Response Pathway and ER-Associated Protein Degradation? | BenthamScience
Title: Mif1: A Missing Link between the Unfolded Protein Response Pathway and ER-Associated Protein Degradation?. VOLUME: 2 ISSUE: 2. Author(s):Theo van Laar, Alex J. van der Eb and Carrol Terleth. Affiliation:MGC-Department ofRadiation Genetics and Chemical Mutagenesis, Leiden University MedicalCenter, P. O. Box 9503, 2300 RA Leiden, the Netherlands. Keywords:Eukaryotic cells, ER-Associated Protein Degradation, Alzheimers disease, protein disulfide isomerase (PDI), ER-lumenal part, UPR-independent functions, multi-membrane spanning ER, RING-domain, E3 Ubiquitin Ligase, ER-stress. Abstract: Eukaryotic cells have three different mechanisms to deal with the accumulation of unfolded proteins in the endoplasmic reticulum: (1) In cells in which unfolded polypeptides accumulate, translation initiation is inhibited to prevent further accumulation of unfolded proteins. (2) Expression of proteins involved in polypeptide folding is strongly enhanced by a process called the Unfolded Protein Response (UPR). ...
Endoplasmic reticulum resident protein - Wikipedia
ER retention refers to proteins that are retained in the endoplasmic reticulum, or ER, after folding; these are known as ER resident proteins. Their localization to the ER often depends on certain sequences of amino acids located at the N-terminus or C-terminus. The classical ER retention signal is the C-terminal KDEL sequence for lumen bound proteins and KKXX for transmembrane localization. These signals allow for retrieval from the Golgi apparatus by ER retention receptors, effectively maintaining the protein in the ER. Other mechanisms for ER retention are being studied but are not as well characterized as signal retention. ...
Endoplasmic reticulum stress-mediated apoptosis in pancreatic beta-cells. - PubMed - NCBI
In Vivo Action of the HRD Ubiquitin Ligase Complex: Mechanisms of Endoplasmic Reticulum Quality Control and Sterol Regulation |...
Fig. 4. Hrd1p/Hrd3p cross-linking to Hmg2p did not require the presence of Ubc7p or Cue1p. (a) Hrd3p cross-linking to Hmg2p in the presence of either the hrd1Δ, ubc7Δ, orcue1Δ allele. The appropriate null alleles of each gene required for Hmg2p degradation were introduced into the strain coexpressing 1myc-Hmg2p and 3HA-Hrd3p. Cross-linking assay was performed as in Fig. 1. (b) Hrd1p cross-linking to Hmg2p in the presence of either the hrd1Δ, ubc7Δ, orcue1Δ allele. The appropriate null alleles of each gene required for Hmg2p degradation were introduced into the strain coexpressing 1myc-Hmg2p and 3HA-Hrd1p, and the cross-linking assay was performed. (c) Hrd3p function was required for Hrd1p cross-linking to Hmg2p under normal Hrd1p expression levels. Cells expressing 1myc-Hmg2p and 3HA-Hrd1p from its native promoter and coexpressing either the wild-type HRD3 allele (wt), the hrd3Δ allele, or the truncated hrd3 allele (hrd3357-833 ) were subjected to the cross-linking assay. (d) Expression ...
PERK (Inhibitors Agonists Modulators Antagonists)-MedChemExpress.com
Protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) is a type I endoplasmic reticulum transmembrane protein containing a stress-sensing domain facing the endoplasmic reticulum lumen and a cytosolic kinase domain. PERK is a major component of the unfolded protein response (UPR), which promotes the adaptation of cells to various forms of stress. PERK is activated in response to a variety of endoplasmic reticulum stresses implicated in numerous disease states. PERK regulates proliferation of beta cells during embryonic and neonatal development and is essential for viability of acinar cells in mouse exocrine pancreas, neither of which is associated with endoplasmic reticulum stress response. PERK is also required for endoplasmic reticulum functions including proinsulin trafficking and quality control in beta cells. Similarly, PERK modulates proliferation and differentiation of osteoblasts as well as secretion of type I collagen. PERK phosphorylates α subunit of the translation ...
Gentaur Molecular :EIAab \ CLIA 58 kDa glucose-regulated protein,58 kDa microsomal protein,Disulfide isomerase ER-60...
Gentaur molecular products has all kinds of products like :search , EIAab \ CLIA 58 kDa glucose-regulated protein,58 kDa microsomal protein,Disulfide isomerase ER-60,Endoplasmic reticulum resident protein 57,Endoplasmic reticulum resident protein 60,ER protein 57,ER protein 6 \ U1497r for more molecular products just contact us
Segregation of the polypeptide translocation apparatus to regions of the endoplasmic reticulum containing ribophorins and...
Ribophorins I and II, two transmembrane glycoproteins characteristic of the rough endoplasmic reticulum (ER) are thought to be part of the translocation apparatus for proteins made on membrane bound polysomes. To study the stoichiometry between ribophorins and membrane-bound ribosomes we have determined the RNA and ribophorin content in rat liver microsomes or in microsomal subfractions of different density (i.e., ribosome content). The specificity of antibodies against the ribophorins was demonstrated by Western blot analysis of rat liver rough microsomes separated by 2-dimensional gel electrophoresis. The ribophorin content of microsomal subfractions was determined by indirect immunoprecipitation and for ribophorin I by a radioimmune assay. In the latter assay a molar ratio of ribophorin I/ribosomes approaching one was calculated for total microsomes as well as in the gradient subfractions. We therefore suggest that ribophorins mediate the binding of ribosomes to endoplasmic reticulum ...
Hepatoprotective Effect of Quercetin on Endoplasmic Reticulum Stress and Inflammation after Intense Exercise in Mice through...
Oxidative Medicine and Cellular Longevity is a unique peer-reviewed, Open Access journal that publishes original research and review articles dealing with the cellular and molecular mechanisms of oxidative stress in the nervous system and related organ systems in relation to aging, immune function, vascular biology, metabolism, cellular survival and cellular longevity. Oxidative stress impacts almost all acute and chronic progressive disorders and on a cellular basis is intimately linked to aging, cardiovascular disease, cancer, immune function, metabolism and neurodegeneration. The journal fills a significant void in todays scientific literature and serves as an international forum for the scientific community worldwide to translate pioneering
ERLEC1 - Endoplasmic reticulum lectin 1 precursor - Homo sapiens (Human) - ERLEC1 gene & protein
Eldorado: Endoplasmic reticulum membrane potassium channel dysfunction in high fat diet induced stress in rat hepatocytes
In a previous study we reported the presence of a large conductance K+ channel in the membrane of endoplasmic reticulum (ER) from rat hepatocytes. The channel open probability (Po) appeared voltage dependent and reached to a minimum 0.2 at +50 mV. Channel activity in this case was found to be totally inhibited at ATP concentration 2.5 mM, glibenclamide 100 μM and tolbutamide 400 μM. Existing evidence indicates an impairment of endoplasmic reticulum functions in ER stress condition. Because ER potassium channels have been involved in several ER functions including cytoprotection, apoptosis and calcium homeostasis, a study was carried out to consider whether the ER potassium channel function is altered in a high fat diet model of ER stress. Male Wistar rats were made ER stress for 2 weeks with a high fat diet. Ion channel incorporation of ER stress model into the bilayer lipid membrane allowed the characterization of K+ channel. Our results indicate that the channel Po was significantly ...
Marchf6 (membrane associated ring-CH-type finger 6) - Rat Genome Database
ENCODES a protein that exhibits enzyme binding (ortholog); ubiquitin conjugating enzyme binding (ortholog); ubiquitin protein ligase activity (ortholog); INVOLVED IN proteasomal protein catabolic process (ortholog); proteasome-mediated ubiquitin-dependent protein catabolic process (ortholog); protein K48-linked ubiquitination (ortholog); PARTICIPATES IN Endoplasmic Reticulum-associated degradation pathway; ASSOCIATED WITH familial adult myoclonic epilepsy 3 (ortholog); FOUND IN endoplasmic reticulum (ortholog); integral component of endoplasmic reticulum membrane (ortholog); integral component of membrane (ortholog); INTERACTS WITH bis(2-ethylhexyl) phthalate; chromium(6+); ethanol
FBXO2 - F-box only protein 2 - Homo sapiens (Human) - FBXO2 gene & protein
Substrate recognition component of a SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complex that mediates the ubiquitination and subsequent proteasomal degradation of target proteins. Involved in the endoplasmic reticulum-associated degradation pathway (ERAD) for misfolded lumenal proteins by recognizing and binding sugar chains on unfolded glycoproteins that are retrotranslocated into the cytosol and promoting their ubiquitination and subsequent degradation. Prevents formation of cytosolic aggregates of unfolded glycoproteins that have been retrotranslocated into the cytosol. Able to recognize and bind denatured glycoproteins, preferentially those of the high-mannose type (By similarity).
Endoplasmic Reticulum Stress As a Therapeutic Target in Cardiovascular Disease Biology of Endoplasmic Reticulum Stress in the...
Cardiovascular disease constitutes a major and increasing health burden in developed countries. Although treatments have progressed, the development of novel treatments for patients with cardiovascular diseases remains a major research goal. The endoplasmic reticulum (ER) is the cellular organelle in which protein folding, calcium homeostasis, and lipid biosynthesis occur. Stimuli such as oxidative stress, ischemic insult, disturbances in calcium homeostasis, and enhanced expression of normal and/or folding-defective proteins lead to the accumulation of unfolded proteins, a condition referred to as ER stress. ER stress triggers the unfolded protein response (UPR) to maintain ER homeostasis. The UPR involves a group of signal transduction pathways that ameliorate the accumulation of unfolded protein by increasing ER-resident chaperones, inhibiting protein translation and accelerating the degradation of unfolded proteins. The UPR is initially an adaptive response but, if unresolved, can lead to apoptotic
A pathway distinct from the mammalian unfolded protein response regulates expression of endoplasmic reticulum chaperones in non...
The biogenesis of nascent proteins translocated into the calcium‐rich, oxidizing milieu of the endoplasmic reticulum (ER) lumen is assisted by a group of resident ER proteins that include molecular chaperones and folding enzymes. These specialized ER proteins are constitutively expressed in all cells, where they play a role in monitoring and assisting the maturation of normal proteins (Gething and Sambrook, 1992; Hendrick and Hartl, 1993) and are essential for proper steady‐state operations of the eukaryotic secretory pathway. Expression of mutant secretory pathway proteins or exposure of cells to agents that adversely affect ER protein folding and maturation all result in the accumulation of unfolded proteins in the ER, thereby activating an inter‐organelle signaling pathway linking the ER and nucleus. This response, termed the unfolded protein response (UPR), includes the coordinate transcriptional up‐regulation of ER chaperones and folding enzymes (Lee, 1992).. In yeast, an ER ...
Structural Biochemistry/Cell Organelles/Animal Cell/Membrane Contact Site - Wikibooks, open books for an open world
There are many contact sites of ER-PM in different cell types. The function of ER-plasma membrane contact sites is similar to that of the mitochondria-ER junctions, since Ca2+ homeostasis and lipid synthesis and trafficking take place there. As mentioned above, Ca2+ regulation is crucial as it is also responsible for protein synthesis, folding, and signaling. In excitable cells, the global calcium signal is generated by the coupling of PM depolarization and ER calcium release. In non-excitable cells, calcium influx is controlled by detecting luminal ER Ca2+ levels. Research has showed that the PM-ER contact site is involved in non-vesicular lipid trafficking. We know that lipids are insoluble in water. So to transfer lipid from its synthesis sites to its desired work place, one must shield the lipid. In fact, couple families of lipid transfer protein (LTPs) that can perform this task have been found on the contact sites. One of them is oxysterol-binding protein (OSBP) related proteins(ORPS). The ...
Frontiers | Endoplasmic reticulum stress-induced PCD and caspase-like activities involved | Plant Science
Plant cells, like cells from other kingdoms, have the ability to self-destruct in a genetically controlled manner. This process is defined as Programmed Cell Death (PCD). PCD can be triggered by various stimuli in plants including by endoplasmic reticulum (ER) stress. Research in the past two decades discovered that disruption of protein homeostasis in the endoplasmic reticulum (ER) could cause ER stress, which when prolonged/unresolved leads cells into PCD. ER stress-induced PCD is part of several plant processes, for instance, drought and heat stress have been found to elicit ER stress-induced PCD. Despite the importance of ER stress-induced PCD in plants, its regulation remains largely unknown, when compared with its counterpart in animal cells. In mammalian cells, several pro-apoptotic proteases called caspases were found to play a crucial role in ER stress-induced PCD. Over the past decade, several key proteases with caspase-like enzymatic activity have been discovered in plants and implicated in
The endoplasmic reticulum and junctional membrane communication during calcium signaling - Department of Pharmacology
The endoplasmic reticulum is a major organelle in all eukaryotic cells which performs multiple functions including protein and lipid synthesis and sorting, drug metabolism, and Ca 2+ storage and release. The endoplasmic reticulum, and its specialized muscle counterpart the sarcoplasmic reticulum, is the largest and most extensive of Ca 2+ storage organelle in eukaryotic cells, often occupying in excess of 10% of the cell volume. There are three major components of Ca 2+ storage organelles which mediate their major functions: Ca 2+ uptake, mediated by pumps and exchangers; storage enhanced by luminal Ca 2+ binding proteins, and Ca 2+ mobilization mediated by specific ion channels. Ca 2+ mobilization from the endoplasmic reticulum plays a central role in Ca 2+ signaling. Through Ca 2+ release channels in its membrane, the pervading and plastic structure of the endoplasmic reticulum allows Ca 2+ release to be rapidly targeted to specific cytoplasmic sites across the whole cell. That several
Lipids at membrane contact sites: cell signaling and ion transport | EMBO Reports
Communication between organelles is essential to coordinate cellular functions and the cells response to physiological and pathological stimuli. Organellar communication occurs at membrane contact sites (MCSs), where the endoplasmic reticulum (ER) membrane is tethered to cellular organelle membranes by specific tether proteins and where lipid transfer proteins and cell signaling proteins are located. MCSs have many cellular functions and are the sites of lipid and ion transfer between organelles and generation of second messengers. This review discusses several aspects of MCSs in the context of lipid transfer, formation of lipid domains, generation of Ca2+ and cAMP second messengers, and regulation of ion transporters by lipids. ...
The Hrd1p ligase complex forms a linchpin between ER-lumenal substrate selection and Cdc48p recruitment - MDC Repository
Misfolded proteins of the endoplasmic reticulum (ER) are targeted to the cytoplasm for proteasomal degradation. Key components of this process are ER membrane-bound ubiquitin ligases. These ligases associate with the cytoplasmic AAA-ATPase Cdc48p/p97, which is thought to support the release of malfolded proteins from the ER. Here, we characterize a yeast protein complex containing the ubiquitin ligase Hrd1p and the ER membrane proteins Hrd3p and Der1p. Hrd3p binds malfolded proteins in the ER lumen enabling their delivery to downstream components. Therefore, we propose that Hrd3p acts as a substrate recruitment factor for the Hrd1p ligase complex. Hrd3p function is also required for the association of Cdc48p with Hrd1p. Moreover, our data demonstrate that recruitment of Cdc48p depends on substrate processing by the Hrd1p ligase complex. Thus, the Hrd1p ligase complex unites substrate selection in the ER lumen and polyubiquitination in the cytoplasm and links these processes to the release of ER ...
Resveratrol reduces liver endoplasmic reticulum stress and improves insulin sensitivity in vivo and in vitro.
A summary of the article is shown below:. Purpose: The aim of the study was to examine the effects of resveratrol upon hepatic endoplasmic reticulum stress (ERS) and insulin sensitivity in vivo and in vitro. Material and methods: C57BL/6J mice were fed a high-fat diet (HFD) for 8 weeks, and insulin resistance was evaluated by the intraperitoneal glucose tolerance test (IPGTT). Mice were then treated with resveratrol for 12 weeks and blood and liver samples collected. Blood biochemical indicators were determined by kits, liver protein expression was determined by western blot, and morphological changes were observed by histological staining. Palmitic acid (PA)-induced insulin-resistant HepG2 cells were established. Cells were exposed to 100, 50 or 20 μM resveratrol for 24 hrs, and proliferation/cytotoxicity was determined. Cells were divided into five groups: control, PA, PA + Rev (100 μM), PA + Rev (50 μM) and PA + Rev (20 μM) groups. After 24 hrs of treatment, cellular proteins were ...
Caspase cleavage product of BAP31 induces mitochondrial fission through endoplasmic reticulum calcium signals, enhancing...
Engagement of the TNF receptor family of death receptors, including TNF-R1, Fas, Trail-R1, and Trail-R2, with their cognate ligands leads to the recruitment and autoactivation of initiator procaspase-8 (Krammer, 2000). Recent studies implicate that caspase-8 substrates located at distinct cellular loci play key roles in mediating death receptor-induced apoptosis. For example, caspase-8 cleavage of the BH3-only molecule BID promotes mitochondrial release of cyt.c and Smac/Diablo (Yin et al., 1999; Li et al., 2002); cleavage of RIP prevents the activation of NF-κB survival responses (Lin et al., 1999); and cleavage of the cytolinker plectin is important for disassembly of microfilaments (Stegh et al., 2000). In this work, we investigated the consequence of caspase-8 cleavage of BAP31 at the ER by expressing the pro-apoptotic p20 cleavage fragment in cells using an adenovirus vector. This approach allowed us to isolate and delineate a predicted branch of the death receptor signaling cascade. ...
Chemical chaperones reduce ionizing radiation-induced endoplasmic reticulum stress and cell death in IEC-6 cells<...
TY - JOUR. T1 - Chemical chaperones reduce ionizing radiation-induced endoplasmic reticulum stress and cell death in IEC-6 cells. AU - Lee, Eun Sang. AU - Lee, Hae June. AU - Lee, Yoon Jin. AU - Jeong, Jae Hoon. AU - Kang, Seong Man. AU - Lim, Young Bin. PY - 2014/7/25. Y1 - 2014/7/25. N2 - Radiotherapy, which is one of the most effective approaches to the treatment of various cancers, plays an important role in malignant cell eradication in the pelvic area and abdomen. However, it also generates some degree of intestinal injury. Apoptosis in the intestinal epithelium is the primary pathological factor that initiates radiation-induced intestinal injury, but the mechanism by which ionizing radiation (IR) induces apoptosis in the intestinal epithelium is not clearly understood. Recently, IR has been shown to induce endoplasmic reticulum (ER) stress, thereby activating the unfolded protein response (UPR) signaling pathway in intestinal epithelial cells. However, the consequences of the IR-induced ...
Trimeric Intracellular Cation Channels and Sarcoplasmic/Endoplasmic Reticulum Calcium Homeostasis | Circulation Research
Ca2+ ions are important second messengers in many cellular signal transduction pathways. Compromised Ca2+ homeostasis and signaling have been linked to many human diseases, including muscle dysfunction and heart failure.1-5 Two principal sources provide Ca2+ to the cell: channels in the plasma membrane (PM) that allow external Ca2+ to enter the cell and internal stores sequestered in the endoplasmic reticulum (ER) or sarcoplasmic reticulum (SR) that release Ca2+. Junctional membrane complexes between PM and ER/SR are present in all excitable cells, providing effective mechanisms for cross-talk between Ca2+ channels/transporters in the PM and Ca2+ release channels in intracellular membranes.6-10 A central focus in cardiovascular research is to understand the basic mechanisms that underlie the control of Ca2+ signaling in the heart and to search for ways to correct the defective Ca2+ signaling process associated with arrhythmogenesis and heart failure.. In the heart, entry of extracellular Ca2+ ...
The 70 carboxyl-terminal amino acids of nascent secretory proteins are protected from proteolysis by the ribosome and the...
We have used proteolysis to examine the environment through which nascent secretory proteins are translocated across the membrane of the endoplasmic reticulum. After solubilization of rough microsomes with detergent, fragments comprised of the approximately 70 carboxyl-terminal amino acids of translocating nascent chains initiated and targeted in vivo were protected from digestion by added proteases. About 40 amino acids of nascent chains were protected from proteolysis by the ribosome; thus, membrane-derived components protect an additional 30 amino acids. Under conditions in which those 30 additional amino acids are protected, only a small set of integral membrane proteins remained associated with the ribosome. These proteins include the Sec61 complex previously identified as the core component of the membrane-bound protein translocation apparatus. These results support the concept of a translocation pore that makes intimate contact with the ribosome and thereby protects nascent chains from ...
KEGG PATHWAY: Protein processing in endoplasmic reticulum - Homo sapiens (human)
The endoplasmic reticulum (ER) is a subcellular organelle where proteins are folded with the help of lumenal chaperones. Newly synthesized peptides enter the ER via the sec61 pore and are glycosylated. Correctly folded proteins are packaged into transport vesicles that shuttle them to the Golgi complex. Misfolded proteins are retained within the ER lumen in complex with molecular chaperones. Proteins that are terminally misfolded bind to BiP and are directed toward degradation through the proteasome in a process called ER-associated degradation (ERAD). Accumulation of misfolded proteins in the ER causes ER stress and activates a signaling pathway called the unfolded protein response (UPR). In certain severe situations, however, the protective mechanisms activated by the UPR are not sufficient to restore normal ER function and cells die by apoptosis ...
Prof. Sima Lev | Lipid Transfer Proteins and Membrane Contact Sites in Human Cancer
ATF6, a membrane-anchored transcription factor from the endoplasmic reticulum (ER) that - Aurora Kinases as Druggable Targets...
ATF6, a membrane-anchored transcription factor from the endoplasmic reticulum (ER) that modulates the cellular response to stress as an effector of the unfolded-protein response (UPR), is a key player in the development of tumors of different origin. reticulum (ER) can be particularly affected by the presence of mutations in secretory proteins or by dynamic changes in the cellular microenvironment, events which are often encountered in cancers. In the ER, these events are sensed by specific sensors, which in turn trigger select Rabbit Polyclonal to CPB2 signaling pathways, collectively named the unfolded-protein response (UPR) (1). The UPR is an adaptive response that allows the cells to either overcome the stress or promote cell death in the case of overwhelming burden (1). Three ER-resident proteins, namely, the protein kinase PKR-like ER kinase (PERK), the inositol-requiring protein 1 alpha (IRE1), and the activating transcription factor 6 alpha (ATF6), have been identified as the major ...
Endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) in plants - Semantic Scholar
Being a major factory for protein synthesis, assembly, and export, the endoplasmic reticulum (ER) has a precise and robust ER quality control (ERQC) system monitoring its product line. However, when organisms are subjected to environmental stress, whether biotic or abiotic, the levels of misfolded proteins may overwhelm the ERQC system, tilting the balance between the capacity of and demand for ER quality control and resulting in a scenario termed ER stress. Intense or prolonged ER stress may cause damage to the ER as well as to other organelles, or even lead to cell death in extreme cases. To avoid such serious consequences, cells activate self-rescue programs to restore protein homeostasis in the ER, either through the enhancement of protein-folding and degradation competence or by alleviating the demands for such reactions. These are collectively called the unfolded protein response (UPR). Long investigated in mammalian cells and yeasts, the UPR is also of great interest to plant scientists. Among
LHS1 and SIL1 provide a lumenal function that is essential for protein translocation into the endoplasmic reticulum<...
TY - JOUR. T1 - LHS1 and SIL1 provide a lumenal function that is essential for protein translocation into the endoplasmic reticulum. AU - Tyson, John R. AU - Stirling, Colin J. PY - 2000. Y1 - 2000. N2 - Lhs1p is an Hsp70-related chaperone localized in the endoplasmic reticulum (ER) lumen. Δlhs1 mutant cells are viable but are constitutively induced for the unfolded protein response (UPR). Here, we demonstrate a severe growth defect in Δire1Δlhs1 double mutant cells in which the UPR can no longer be induced. In addition, we have identified a UPR- regulated gene, SIL1, whose overexpression is sufficient to suppress the Δire1Δlhs1 growth defect. SIL1 encodes an ER-localized protein that interacts directly with the ATPase domain of Kar2p (BiP), suggesting some role in modulating the activity of this vital chaperone. SIL1 is a non-essential gene but the Δlhs1Δsil1 double mutation is lethal and correlates with a complete block of protein translocation into the ER. We conclude that the ...
Increased sensitivity to apoptosis upon endoplasmic reticulum stress-induced activation of the unfolded protein response in...
Standard treatment for advanced malignant pleural mesothelioma (MPM) is a cisplatin/pemetrexed (MTA) regimen; however, this is confronted by drug resistance. Proteotoxic stress in the endoplasmic reticulum (ER) is a hallmark of cancer and some rely on this stress signalling in response to cytotoxic chemotherapeutics. We hypothesise that ER stress and the adaptive unfolded protein response (UPR) play a role in chemotherapy resistance of MPM. In vitro three-dimensional (3D) and ex vivo organotypic culture were used to enrich a chemotherapy-resistant population and recapitulate an in vivo MPM microenvironment, respectively. Markers of ER stress, the UPR and apoptosis were assessed at mRNA and protein levels. Cell viability was determined based on acid phosphatase activity. MPM cells with de novo and/or acquired chemotherapy resistance displayed low ER stress, which rendered the cells hypersensitive to agents that induce ER stress and alter the UPR. Bortezomib, an FDA-approved proteasome inhibitor,
The role of endoplasmic reticulum protein GRP78 in normal hematopoeises and PTEN-null leukemogenesis :: University of Southern...
The endoplasmic reticulum (ER) is an intracellular organelle for protein folding, lipid synthesis and Ca²⁺ storage. It is also responsible for the transportation for most of the secretory and transmembrane proteins. When the protein load exceeds the ER folding capacity, the ER undergoes stress and activates a set of signaling cascades that is termed the unfolded protein response (UPR). The multifunctional GRP78 is the major ER molecular chaperone with protein folding abilities and the master regulator of the UPR, and recently has been shown that a subfraction of it is localized on the cell surface acting as a co-receptor for various signaling pathway activation. ❧ Traditionally GRP78 is regarded as protective against hypoxia and nutrient starvation prevalent in the microenvironment of solid tumors, thus, its role in the development of hematologic malignancies remains to be determined. In this thesis, elevated GRP78 expression was detected in leukemic blasts of adult patients, leukemia cell ...
Heme Oxygenase (HO)-1 Induction Prevents Endoplasmic Reticulum Stress-Mediated Endothelial Cell Death and Dysfunction |...
Diabetes is intimately associated with cardiovascular complications. Much evidence highlighted the complex interplay between Endoplasmic Reticulum (ER) stress and oxidative stress in the pathogenesis of diabetes. Hemeoxygenase-1 (HO-1) induction was shown to protect against oxidative stress in diabetes; however the underlying molecular mechanisms have not yet been fully elucidated. We aim in this project to test the hypothesis that HO-1 induction will protect against high glucose-mediated ER stress and oxidative stress in endothelial cells and will enhance cell survival. Endothelial cells were cultured in physiological or high concentrations of glucose in the presence of cobalt protoporphyrin 1X (CoPP, HO-1 inducer), 4-phenylbutyrate (PBA, chemical chaperone to inhibit ER stress) or vehicle. Then, ER stress response was assessed (PCR, western blot). The productions of ROS (flow cytometer) and NO (Griess assay) were analysed. Also, apoptosis and caspase 3/7 activity were assessed. High glucose treatment
References - GRP78 | GRP78
1.Radons,J. The human HSP70 family of chaperones: where do we stand? Cell Stress Chaperones 21, 379-404 (2016).[PubMed]. 2.Zuiderweg,E.R., Hightower,L.E., & Gestwicki,J.E. The remarkable multivalency of the Hsp70 chaperones. Cell Stress Chaperones 22, 173-189 (2017).[PubMed]. 3.Braakman,I. & Bulleid,N.J. Protein folding and modification in the mammalian endoplasmic reticulum. Annu. Rev. Biochem. 80, 71-99 (2011).[PubMed]. 4.Genereux,J.C. et al. Unfolded protein response-induced ERdj3 secretion links ER stress to extracellular proteostasis. EMBO J. 34, 4-19 (2015). [PubMed]. 5.Cook,K.L. et al. Endoplasmic reticulum stress protein GRP78 modulates lipid metabolism to control drug sensitivity and antitumor immunity in breast cancer. Cancer Res. 76, 5657-5670 (2016).[PubMed]. 6.Gonzales,P.A. et al. Large-scale proteomics and phosphoproteomics of urinary exosomes. J. Am. Soc. Nephrol. 20, 363-379 (2009).[PubMed]. 7.Prunotto,M. et al. Proteomic analysis of podocyte exosome-enriched fraction from normal ...
SGTA antagonizes BAG6-mediated protein triage | PNAS
Protein targeting to the endoplasmic reticulum can be either co- or posttranslational and involves the binding of a hydrophobic signal sequence by delivery factors such as signal recognition particle or components of the TRC/GET pathway, respectively (1). Inefficient recognition and/or delivery of precursor proteins destined for the endoplasmic reticulum can lead to their cytosolic accumulation, resulting in toxicity such as that observed in neurodegenerative disorders such as prionopathies (2, 3). The disposal of such mislocalized proteins in mammalian cells has recently been shown to depend on the BAG6 complex comprised of the BAG6 protein together with TRC35 and UBL4A. The BAG6 complex recognizes mislocalized proteins, recruits the E2 conjugating enzyme, UbcH5, and an unidentified E3 ligase(s), and thereby selectively promotes the rapid ubiquitination and proteasomal degradation of these substrates (4). This role for the BAG6 complex in cytosolic quality control extends other studies showing ...
Unresolved endoplasmic reticulum stress engenders immune-resistant, latent pancreatic cancer metastases - CSHL Scientific...
The majority of patients with pancreatic ductal adenocarcinoma (PDA) develop metastatic disease after resection of their primary tumor. We found that livers from patients and mice with PDA harbor single, disseminated cancer cells (DCCs) lacking expression of cytokeratin-19 (CK19) and major histocompatibility complex class I (MHCI). We created a mouse model to determine how these DCCs develop. Intra-portal injection of immunogenic PDA cells into pre-immunized mice seeded livers only with single, non-replicating DCCs that were CK19(-) and MHCI(-) The DCCs exhibited an endoplasmic reticulum (ER) stress response but, paradoxically lacked both inositol-requiring enzyme 1alpha activation and expression of the spliced form of transcription factor XBP1 (XBP1s). Inducible expression of XBP1s in DCCs, in combination with T cell-depletion, stimulated the outgrowth of macro-metastatic lesions that expressed CK19 and MHCI. Thus, unresolved ER stress enables DCCs to escape immunity and establish latent ...
Insertion and folding pathways of single membrane proteins guided by translocases and insertases | Science Advances
The biogenesis of most membrane proteins is governed by specific interactions between the newly synthetized nascent polypeptide chain and the evolutionary conserved and essential insertases and translocases (1-3). Insertases and translocases recognize their substrate and lower the free-energy barrier for inserting and folding the polypeptide into cellular membranes (3, 4). This insertion and folding can occur cotranslationally as the polypeptide exits the ribosome or posttranslationally after the polypeptide has been released by the ribosome. The bacterial translocase SecYEG has a eukaryotic homolog, Sec61, in the endoplasmatic reticulum (1), whereas the bacterial insertase YidC has Oxa1 and Oxa2 homologs in mitochondria, Get1 in endoplasmatic reticulum, and Alb3 in chloroplasts (5-7). In Gram-negative bacteria, SecYEG folds α-helical membrane proteins into the inner membrane and translocates precursors of soluble periplasmic and β-barrel outer membrane proteins to the periplasm (1, 8). ...
The role of endoplasmic reticulum proteins GRP78 and IP3R1 in regulation of glucose homeostasis and acute pancreatitis ::...
The endoplasmic reticulum (ER) is an intracellular organelle for protein folding, lipid synthesis and Ca2+ storage. It also is responsible for transporting most secreted and transmembrane proteins to their proper cellular locations. ER undergoes stress when the protein load exceeds its folding capacity, and cellular signaling cascades are activated as unfolded protein response (UPR). GRP78 is a major chaperone assisting protein folding, as well as a master regulator of UPR signaling. In this thesis, we discovered that heterozygosity of Grp78 enhances energy expenditure through upregulation of mitochondria activity, and alleviate high fat diet (HFD)-induced obesity and type 2 diabetes in mouse. The latter is also achieved through increase in insulin sensitivity in the white adipose tissue (WAT) of HFD-fed Grp78+/- mice, with adaptive UPR improving ER folding capacity and quality control. This mechanism is validated through overexpression of the active form of ATF6, a transcription factor known to ...
ERO1α is a novel endogenous marker of hypoxia in human cancer cell lines | BMC Cancer | Full Text
Hypoxia is an important factor that contributes to tumour aggressiveness and correlates with poor prognosis and resistance to conventional therapy. Therefore, identifying hypoxic environments within tumours is extremely useful for understanding cancer biology and developing novel therapeutic strategies. Several studies have suggested that carbonic anhydrase 9 (CA9) is a reliable biomarker of hypoxia and a potential therapeutic target, while pimonidazole has been identified as an exogenous hypoxia marker. However, other studies have suggested that CA9 expression is not directly induced by hypoxia and it is not expressed in all types of tumours. Thus, in this study, we focused on endoplasmic reticulum disulphide oxidase 1α (ERO1α), a protein that localises in the endoplasmic reticulum and is involved in the formation of disulphide bonds in proteins, to determine whether it could serve as a potential tumour-hypoxia biomarker. Using quantitative real-time polymerase chain reaction, we analysed the mRNA
Chen Y~Koong AC, 2005 / Papers / YeastPhenome.org
Hypoxia activates all components of the unfolded protein response (UPR), a stress response initiated by the accumulation of unfolded proteins within the endoplasmic reticulum (ER). Our group and others have shown previously that the UPR, a hypoxia-inducible factor-independent signaling pathway, mediates cell survival during hypoxia and is required for tumor growth. Identifying new genes and pathways that are important for survival during ER stress may lead to the discovery of new targets in cancer therapy. Using the set of 4,728 homozygous diploid deletion mutants in budding yeast, Saccharomyces cerevisiae, we did a functional screen for genes that conferred resistance to ER stress-inducing agents. Deletion mutants in 56 genes showed increased sensitivity under ER stress conditions. Besides the classic UPR pathway and genes related to calcium homeostasis, we report that two additional pathways, including the SLT2 mitogen-activated protein kinase (MAPK) pathway and the osmosensing MAPK pathway, ...
RePub, Erasmus University Repository: Mitochondrial Dysfunction Underlies Cardiomyocyte Remodeling in Experimental and...
Atrial fibrillation (AF), the most common progressive tachyarrhythmia, results in structural remodeling which impairs electrical activation of the atria, rendering them increasingly permissive to the arrhythmia. Previously, we reported on endoplasmic reticulum stress and NAD+ depletion in AF, suggesting a role for mitochondrial dysfunction in AF progression. Here, we examined mitochondrial function in experimental model systems for AF (tachypaced HL-1 atrial cardiomyocytes and Drosophila melanogaster) and validated findings in clinical AF. Tachypacing of HL-1 cardiomyocytes progressively induces mitochondrial dysfunction, evidenced by impairment of mitochondrial Ca2+-handling, upregulation of mitochondrial stress chaperones and a decrease in the mitochondrial membrane potential, respiration and ATP production. Atrial biopsies from AF patients display mitochondrial dysfunction, evidenced by aberrant ATP levels, upregulation of a mitochondrial stress chaperone and fragmentation of the ...
What Additional Protective Layer Of Protein Surrounds Some Viruses - gabrieldroberts.com
What Additional Protective Layer Of Protein Surrounds Some Viruses - The capsid and envelope play many roles in viral contamination, inclusive of virus attachment to cells, entry into cells, release of the capsid contents into the cells, and packaging of newly fashioned viral debris. The capsid and envelope are also answerable for transfer of the viral genetic material from one mobile to another. these systems also decide the stableness traits of the virus particle, which includes resistance to chemical or bodily inactivation.. The primary role of capsid is to bundle the viral genome. There are strategies related to this feature: the recruitment of the viral RNA all through assembly and the discharge of the genome at some stage in infection. even though particle assembly takes vicinity on endoplasmic reticulum membranes, capsid localizes in nucleoli and lipid droplets.. Because the capsid is outermost, most agents of inactivation must act on the capsid before they can reach the viral RNA, and in ...
RCSB PDB for 1DL2
Calcium Homeostasis Endoplasmic Reticulum Protein | definition of Calcium Homeostasis Endoplasmic Reticulum Protein by Medical...
Looking for online definition of Calcium Homeostasis Endoplasmic Reticulum Protein in the Medical Dictionary? Calcium Homeostasis Endoplasmic Reticulum Protein explanation free. What is Calcium Homeostasis Endoplasmic Reticulum Protein? Meaning of Calcium Homeostasis Endoplasmic Reticulum Protein medical term. What does Calcium Homeostasis Endoplasmic Reticulum Protein mean?
Ssz1 Restores Endoplasmic Reticulum-Associated Protein Degradation in Cells Expressing Defective Cdc48-Ufd1-Npl4 Complex by...
Our genetic screen for suppressors that restore defective ERAD in cdc48-10 cells identified Ssz1p. Being a member of the Hsp70 family, we considered the possibility that Ssz1p acted as a cytosolic chaperone that functions in ERAD by either activating or replacing the defective Cdc48p. The ability of Ssz1p to partially restore the impaired 6myc-Hmg2 degradation in ufd1-2 and npl4-1 mutants could have suggested that Ssz1p replaced the entire Cdc48p-Ufd1p-Npl4p complex in its role in ERAD. However, Ssz1p was not an essential ERAD factor and we could not detect any interaction of Ssz1p with the ERAD-M substrate 6myc-Hmg2. Moreover, Ssz1p is an unusual chaperone (Gautschi et al. 2001; Gautschi et al. 2002; Hundley et al. 2002; Shaner and Morano 2007), and therefore, we attributed its ability to correct ERAD to other functions of this Hsp70 member.. On the basis of the RAC-independent participation of Ssz1p in the PDR network, we examined whether other PDR members might be linked to ERAD. Indeed, ...
The cell. 5. Vesicular trafficking. From the reticulum to the Golgi. Atlas of plant and animal histology.
Transition zones are associated with the Golgi stacks. They are close to each other. This makes sense because the communication is more efficient. Vesicles dont need to travel long distances and the existence of the Golgi apparatus itself depends on a continuous process of vesicle incoming. It has been observed that a new transition zone led quickly to the nearby formation of a new Golgi stack. On the contrary, if a transition zone disappears, the associated Golgi cisternae are also lost. Transition zones can fuse with others and one transition zone can be split in two. Their associated Golgi stacks match this behavior. Vesicles budding from the transition zones are COPII coated vesicles ( COPII: coat protein II; Figure 1). Several proteins are involved in the formation of this COPII molecular framework: Sec16, Sar1 GTPases, Sec23/24 and Sec13/31. In this order, they are assembled at the cytosolic surface of the transition zone membranes. Transition zones are the more suitable environments for ...
Frontiers | Acetic Acid Causes Endoplasmic Reticulum Stress and Induces the Unfolded Protein Response in Saccharomyces...
Since acetic acid inhibits the growth and fermentation ability of Saccharomyces cerevisiae, it is one of the practical hindrances to the efficient production of bioethanol from a lignocellulosic biomass. Although extensive information is available on yeast response to acetic acid stress, the involvement of endoplasmic reticulum (ER) and unfolded protein response (UPR) has not been addressed. We herein demonstrated that acetic acid causes ER stress and induces the UPR. The accumulation of misfolded proteins in the ER and activation of Ire1p and Hac1p, an ER-stress sensor and ER stress-responsive transcription factor, respectively, were induced by a treatment with acetic acid stress (| 0.2% v/v). Other monocarboxylic acids such as propionic acid and sorbic acid, but not lactic acid, also induced the UPR. Additionally, ire1∆ and hac1∆ cells were more sensitive to acetic acid than wild-type cells, indicating that activation of the Ire1p-Hac1p pathway is required for maximum tolerance to acetic acid.
An endoplasmic reticulum protein, Nogo-B, facilitates alcoholic liver disease through regulation of kupffer cell polarization<...
TY - JOUR. T1 - An endoplasmic reticulum protein, Nogo-B, facilitates alcoholic liver disease through regulation of kupffer cell polarization. AU - Park, Jin Kyu. AU - Shao, Mingjie. AU - Kim, Moonyoung. AU - Baik, Soonkoo. AU - Cho, Meeyon. AU - Utsumi, Teruo. AU - Satoh, Ayano. AU - Ouyang, Xinsho. AU - Chung, Chuhan. AU - Iwakiri, Yasuko. PY - 2017/5/1. Y1 - 2017/5/1. N2 - Nogo-B (Reticulon 4B) is an endoplasmic reticulum (ER) resident protein that regulates ER structure and function. Because ER stress is known to induce M2 macrophage polarization, we examined whether Nogo-B regulates M1/M2 polarization of Kupffer cells and alters the pathogenesis of alcoholic liver disease (ALD). M1 and M2 phenotypes were assessed in relation to Nogo-B expression and disease severity in liver specimens from ALD patients (NCT01875211). Liver specimens from wild-type (WT) and Nogo-B knockout (KO) mice fed a control or Lieber-DeCarli ethanol liquid diet (5% ethanol) for 6 weeks were analyzed for liver injury ...
JAIRO | Tight repression of yeast endoplasmic reticulum stress sensor Ire1 by its N-terminal intrinsically disordered subdomain
Human ERP44 ELISA Kit | biobool.com
Human ER protein 44 ELISA Kit;Human ERp44 ELISA Kit;Human thioredoxin domain-containing protein 4 ELISA Kit;Human KIAA0573 ELISA Kit;Human TXNDC4 ELISA Kit;Human PDIA10 ELISA Kit;Human endoplasmic reticulum protein 44 ELISA Kit;Human endoplasmic reticulum resident protein 44 ELISA Kit;Human endoplasmic reticulum resident protein 44 kDa ELISA Kit;Human protein disulfide isomerase family A, member 10 ELISA Kit;Human thioredoxin domain containing 4 (endoplasmic reticulum) ELISA Kit ...
Chromatolysis: Do Injured Axons Regenerate Poorly when Ribonucleases Fragment or Degranulate Rough Endoplasmic Reticulum,...
After axonal injury, chromatolysis (fragmentation of Nissl substance) occurs in both intrinsic neurons (whose processes are within the CNS) and extrinsic neurons (whose axons extend outside the CNS). Electron microscopy shows that chromatolysis involves fission of the rough endoplasmic reticulum. In intrinsic neurons (which do not regenerate axons) or in extrinsic neurons denied axon regeneration, chromatolysis is often accompanied by degranulation (loss of ribosomes from rough endoplasmic reticulum), disaggregation of polyribosomes and degradation of monoribosomes into dust-like particles. Ribosomes and rough endoplasmic reticulum may also be degraded in autophagic vacuoles by Ribophagy and Reticulophagy, respectively. In other words, chromatolysis is disruption of parts of the protein synthesis infrastructure. Whereas some neurons may show transient or no chromatolysis, severely injured neurons can remain chromatolytic and never again synthesise normal levels of protein; some may atrophy or die. What
The Endoplasmic Reticulum and the Golgi Structures in Maize Root Cells | JCB
Maize root tips were fixed in potassium permanganate, embedded in epoxy resin, sectioned to show silver interference color, and studied with the electron microscope. All the cells were seen to contain an endoplasmic reticulum and apparently independent Golgi structures.. The endoplasmic reticulum is demonstrated as a membrane-bounded, vesicular structure comparable in many aspects to that of several types of animal cells. With the treatment used here the membranes appear smooth surfaced. The endoplasmic reticulum is continuous with the nuclear envelope and, by contact at least, with structures passing through the cell wall. The nuclear envelope is characterized by discontinuities, as previously reported for animal cells. The reticula of adjacent cells seem to be in contact at or through the plasmodesmata. Because of these contacts the endoplasmic reticulum of a given cell appears to be part of an intercellular system.. The Golgi structures appear as stacks of platelet-vesicles which apparently ...
"Endoplasmic reticulum chaperone GRP78 regulates macrophage function an" by Jong Hun Kim, Eunjung Lee et al.
Obesity-mediated inflammation is a major cause of insulin resistance, and macrophages play an important role in this process. The 78-kDa glucose-regulated protein (GRP78) is a major endoplasmic reticulum chaperone that modulates unfolded protein response (UPR), and mice with GRP78 heterozygosity were resistant to diet-induced obesity. Here, we show that mice with macrophage-selective ablation of GRP78 (Lyz- GRP78(-/-)) are protected from skeletal muscle insulin resistance without changes in obesity compared with wild-type mice after 9 wk of high-fat diet. GRP78-deficient macrophages demonstrated adapted UPR with up-regulation of activating transcription factor (ATF)-4 and M2-polarization markers. Diet-induced adipose tissue inflammation was reduced, and bone marrow-derived macrophages from Lyz- GRP78(-/-) mice demonstrated a selective increase in IL-6 expression. Serum IL-13 levels were elevated by | 4-fold in Lyz- GRP78(-/-) mice, and IL-6 stimulated the myocyte expression of IL-13 and IL-13 receptor.
Ethanol extract of Brazilian red propolis induces apoptosis in human breast cancer MCF-7 cells through endoplasmic reticulum...
Propolis, a natural product collected from plants by honey bees, is commonly used in folk medicines. Endoplasmic reticulum (ER) stress is known to induce apoptosis through the induction of CCAAT/enhancer-binding protein homologous protein (CHOP). Here, we investigated whether ethanol extracts of pro …
Structural Basis of Molecular Recognition of the Leishmania Small Hydrophilic Endoplasmic Reticulum-associated Protein (SHERP)...
PubMed Central Canada (PMC Canada) provides free access to a stable and permanent online digital archive of full-text, peer-reviewed health and life sciences research publications. It builds on PubMed Central (PMC), the U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature and is a member of the broader PMC International (PMCI) network of e-repositories.
Dynamics and inheritance of the endoplasmic reticulum | Journal of Cell Science
Fig. 1. Models of ER segregation in proliferating animal cells. In interphase (left panel), the peripheral ER forms an interconnected network that is contiguous with the outer membrane of the nuclear envelope. The outer nuclear membrane is biochemically similar to the peripheral ER membrane. By contrast, some integral membrane proteins are localized specifically to the inner nuclear membrane (yellow ovals) or to nuclear pores where the outer and inner nuclear membranes meet (red ovals). In one model of ER segregation (model a), the peripheral ER and the nuclear envelope undergo progressive vesiculation. By metaphase, the cell contains vesicles derived from the peripheral ER or outer nuclear membrane, and from the inner nuclear membrane or nuclear pore domains. Diffusion of these vesicles during metaphase and anaphase ensures the equal partition of ER elements. Another model (model b) predicts that the peripheral ER retains its integrity during mitosis. The nuclear envelope is absorbed into the ...
The critical role of membralin in postnatal motor neuron survival and disease | eLife
Subcellular distribution of GABAB receptor homo- and hetero-dimers | Biochemical Journal
GBRs (GABAB receptors; where GABA stands for γ-aminobutyric acid) are G-protein-coupled receptors that mediate slow synaptic inhibition in the brain and spinal cord. In vitro assays have previously demonstrated that these receptors are heterodimers assembled from two homologous subunits, GBR1 and GBR2, neither of which is capable of producing functional GBR on their own. We have used co-immunoprecipitation in combination with bioluminescence and fluorescence resonance energy transfer approaches in living cells to assess directly the interaction between GBR subunits and determine their subcellular localization. The results show that, in addition to forming heterodimers, GBR1 and GBR2 can associate as stable homodimers. Confocal microscopy indicates that, while GBR1/GBR1 homodimers are retained in the endoplasmic reticulum and endoplasmic reticulum-Golgi intermediate compartment, both GBR2/GBR2 homodimers and GBR1/GBR2 heterodimers are present at the plasma membrane. Although these observations ...
Reducing endoplasmic reticulum stress through a macrophage lipid chaperone alleviates atherosclerosis | Nature Medicine
Gökhan Hotamisligil and his colleagues report that reducing endoplasmic reticulum stress in macrophages by targeting the lipid chaperone aP2 ameliorates atherosclerosis in a mouse model, paving the way for a possible new clinical therapy. Macrophages show endoplasmic reticulum (ER) stress when exposed to lipotoxic signals associated with atherosclerosis, although the pathophysiological importance and the underlying mechanisms of this phenomenon remain unknown. Here we show that mitigation of ER stress with a chemical chaperone results in marked protection against lipotoxic death in macrophages and prevents macrophage fatty acid-binding protein-4 (aP2) expression. Using genetic and chemical models, we show that aP2 is the predominant regulator of lipid-induced macrophage ER stress. The absence of lipid chaperones incites an increase in the production of phospholipids rich in monounsaturated fatty acids and bioactive lipids that render macrophages resistant to lipid-induced ER stress. Furthermore, the
UDP-glucose:glycoprotein glucosyltransferase (UGGT1) promotes substrate solubility in the endoplasmic reticulum
Protein folding in the endoplasmic reticulum (ER) is error prone, and ER quality control (ERQC) processes ensure that only correctly folded proteins are exported from the ER. Glycoproteins can be retained in the ER by ERQC, and this retention contributes to multiple human diseases, termed ER storage diseases. UDP-glucose:glycoprotein glucosyltransferase (UGGT1) acts as a central component of glycoprotein ERQC, monoglucosylating deglucosylated N-glycans of incompletely folded glycoproteins and promoting subsequent reassociation with the lectin-like chaperones calreticulin and calnexin. The extent to which UGGT1 influences glycoprotein folding, however, has only been investigated for a few selected substrates. Using mouse embryonic fibroblasts lacking UGGT1 or those with UGGT1 complementation, we investigated the effect of monoglucosylation on the soluble/insoluble distribution of two misfolded alpha 1-antitrypsin (AAT) variants responsible for AAT deficiency disease: null Hong Kong (NHK) and Z ...
AN ELECTRON MICROSCOPE STUDY OF MATURE AND DIFFERENTIATING PANETH CELLS IN THE RAT, ESPECIALLY OF THEIR ENDOPLASMIC RETICULUM...
In an electron microsope study, the morphology of mature Paneth cells from the small intestine of adult rats is compared with that of differentiating Paneth cells from young rats 2 to 4 weeks old. All mature cells exhibit a marked polarity similar to that of other exocrine gland cells and contain a well developed endoplasmic reticulum, an elaborate Golgi complex, and numerous large secretory granules; they also possess an abundance of lysosomes. The most conspicuous occurrence in the process of differentiation is the development of the endoplasmic reticulum. The most immature Paneth cells possess an endoplasmic reticulum of the vesicular type, which, during maturation, is replaced by the characteristic lamellated ergastoplasm of the mature cell. At a certain stage of differentiation the cavities of the developing cisternae show numerous communications with the perinuclear space, suggesting an outgrowth of the ergastoplasm from the nuclear envelope. Furthermore, the cavities and the perinuclear ...
Bip overexpression, but not CHOP inhibition, attenuates fatty-acid-induced endoplasmic reticulum stress and apoptosis in HepG2...
AIMS: In this study we investigated whether attenuation of endoplasmic reticulum stress (ER stress) could protect HepG2 cells from free fatty acid (FFA)-induced apoptosis. MAIN METHODS: Human liver cell line HepG2 cells were exposed to Sodium Palmitate (Pa) or Sodium Oleate (Ol). Apoptosis and ER stress of HepG2 cells were analyzed with flow cytometry, real-time RT-PCR and Western Blotting. An expression plasmid encoding for the ER chaperone immunoglobulin heavy chain-binding protein (Bip) was transfected into HepG2 cells to attenuate ER stress. Small interfering RNA siCHOP was used to knockdown the expression of C/EBP Homologous Protein (CHOP) in HepG2. KEY FINDINGS: Pa led to cytotoxicity and apoptosis in HepG2 cells in a dose-dependent pattern and also induced ER stress indicated by increased phosphorylation of eIF2alpha, upregulation of IRE1alpha and CHOP. Bip expression levels were slightly down regulated after Pa treatment. The unsaturated fatty acid, Ol, induced neither apoptosis nor ER stress in
Component of splicing factor SF3b plays a key role in translational control of polyribosomes on the endoplasmic reticulum<...
TY - JOUR. T1 - Component of splicing factor SF3b plays a key role in translational control of polyribosomes on the endoplasmic reticulum. AU - Ueno, Tomonori. AU - Taga, Yuki. AU - Yoshimoto, Rei. AU - Mayeda, Akila. AU - Hattori, Shunji. AU - Ogawa-Goto, Kiyoko. PY - 2019/5/7. Y1 - 2019/5/7. N2 - One of the morphological hallmarks of terminally differentiated secretory cells is highly proliferated membrane of the rough endoplasmic reticulum (ER), but the molecular basis for the high rate of protein biosynthesis in these cells remains poorly documented. An important aspect of ER translational control is the molecular mechanism that supports efficient use of targeted mRNAs in polyribosomes. Here, we identify an enhancement system for ER translation promoted by p180, an integral ER membrane protein we previously reported as an essential factor for the assembly of ER polyribosomes. We provide evidence that association of target mRNAs with p180 is critical for efficient translation, and that SF3b4, ...
Comprehensive analysis of the endoplasmic reticulum stress response in the soybean genome: conserved and plant-specific...
Despite the relevance of the eukaryotic endoplasmic reticulum (ER)-stress response as an integrator of multiple stress signals into an adaptive response, knowledge about these ER-mediated cytoprotective pathways in soybean (Glycine max) is lacking. Here, we searched for genes involved in the highly conserved unfolded protein response (UPR) and ER stress-induced plant-specific cell death signaling pathways in the soybean genome. Previously characterized Arabidopsis UPR genes were used as prototypes for the identification of the soybean orthologs and the in silico assembly of the UPR in soybean, using eggNOG v4.0 software. Functional studies were also conducted by analyzing the transcriptional activity of soybean UPR transducers. As a result of this search, we have provided a complete profile of soybean UPR genes with significant predicted protein similarities to A. thaliana UPR-associated proteins. Both arms of the plant UPR were further examined functionally, and evidence is presented that the soybean
Endoplasmic reticulum-associated degradation regulates mitochondrial dynamics in brown adipocytes | Science
Endoplasmic reticulum (ER)-associated degradation (ERAD) is a quality control mechanism that allows for targeted degradation of proteins in the ER. Zhou et al. found that a particular protein complex in ERAD, Sel1L-Hrd1, regulates the dynamics of another organelle, the mitochondrion, by altering ER-mitochondria contacts. Three-dimensional high-resolution imaging in brown adipocytes from cold-challenged mice revealed that defective ERAD led to the formation of enlarged and abnormally shaped mitochondria with perforating ER tubules. The authors explored the consequences of ERAD deficiency on mitochondrial function and thermogenesis, which provides insights into ERADmediated ER-mitochondrial cross-talk and advances our understanding of the physiological importance of interorganelle contact.. Science, this issue p. 54 ...
Ribosome-translocon complex mediates calcium leakage from endoplasmic reticulum stores | Journal of Cell Science
This work shows that the ubiquitous translocon complex in the endoplasmic reticulum membrane may act as a Ca2+ leak channel. The complex is not as tight as previously thought. Heritage and Wonderlin demonstrated that permeability of small polar molecules increased in cells treated with puromycin (Heritage and Wonderlin, 2001). Recently, it has been shown that the permeability of the ER to small polar molecules is coupled to translation (Roy and Wonderlin, 2003). In an initial study, we measured the effect of puromycin on the Ca2+ permeability of the ER membrane in mouse acinar pancreatic cells (Lomax et al., 2002). In the present work, we demonstrate that puromycin acts on the translocon to induce a Ca2+ leak in LNCaP cells and also that a physiological calcium leak through the translocon is possible at the end of termination when the ribosome is still in place. Puromycin is a potent translation inhibitor, specifically blocking the ribosome on the translocon and clearing the nascent peptide ...
Nucleation of COPII Vesicular Coat Complex by Endoplasmic Reticulum to Golgi Vesicle SNAREs | Science
Protein trafficking from the endoplasmic reticulum (ER) to the Golgi apparatus involves specific uptake into coat protein complex II (COPII)-coated vesicles of secretory and of vesicle targeting (v-SNARE) proteins. Here, two ER to Golgi v-SNAREs, Bet1p and Bos1p, were shown to interact specifically with Sar1p, Sec23p, and Sec24p, components of the COPII coat, in a guanine nucleotide-dependent fashion. Other v-SNAREs, Sec22p and Ykt6p, might interact more weakly with the COPII coat or interact indirectly by binding to Bet1p or Bos1p. The data suggest that transmembrane proteins can be taken up into COPII vesicles by direct interactions with the coat proteins and may play a structural role in the assembly of the COPII coat complex. ...
negative regulation of transcription from RNA polymerase II promoter in response to endoplasmic reticulum stress Antibodies |...
Endoplasmic Reticulum Stress in the Heart | Circulation Research
Several studies have correlated ER stress with myocardial damage. For example, the ER stress response is activated in the hearts of transgenic mice that overexpress monocyte chemoattractant protein-1 and develop heart failure,36 suggesting that in this model, the proapoptotic phase of ER stress contributes to the loss of myocardium associated with failure. In further support of a role for ER stress in heart failure is the finding that transgenic overexpression of a mutant KDEL receptor, an ER protein that facilitates ER protein targeting, activates the ER stress response in mouse hearts and causes dilated cardiomyopathy.69 Also, overexpression of the ER stress response gene product p53-upregulated modulator of apoptosis (PUMA) contributes to ER stress-mediated apoptosis in cultured cardiomyocytes70 and targeted deletion of PUMA in mouse hearts attenuates cardiomyocyte death during ex vivo I/R.71. In contrast to the studies cited above, other studies suggest that ER stress might protect the ...
Characterisation of a differentially expressed protein that shows an unusual localisation to intracellular membranes in...
The SHERP genes are found as a tandem pair within the differentially regulated LmcDNA16 locus of Leishmania major. The SHERP gene product (Small Hydrophilic Endoplasmic Reticulum-associated Protein) is unusual in its small size (6.2kDa), its acidic pI (4.6) and its exclusive, high-level expression ( 100000 copies per cell) in infective non-replicative parasite stages. No homologues have been found to date. Secondary-structure predictions suggest that SHERP contains an amphiphilic a-helix that is presumably involved in protein-protein interactions. SHERP has been localized to the endoplasmic reticulum as well as to the outer mitochondrial membrane in both wild-type and over-expressing parasites. Given the absence of an N-terminal signal sequence, transmembrane-spanning domains or detectable post-translational modifications, it is likely that this hydrophilic molecule is a peripheral membrane protein on the cytosolic face of intracellular membranes. This weak membrane association has been ...
Inhibition of the sarco/endoplasmic reticulum (ER) Ca2+-ATPase by thapsigargin analogs induces cell death via ER Ca2+ depletion...
Calcium (Ca2+) is a fundamental regulator of cell signaling and function. Thapsigargin (Tg) blocks the sarco/endoplasmic reticulum (ER) Ca2+-ATPase (SERCA), disrupts Ca2+ homeostasis, and causes cell death. However, the exact mechanisms whereby SERCA-inhibition induces cell death are incompletely understood. Here, we report that low (0.1 μM) concentrations of Tg and Tg analogs with various long-chain substitutions at the O(8) position extensively inhibit SERCA1a-mediated Ca2+ transport. We also found that in both prostate and breast cancer cells, exposure to Tg or Tg analogs for 1 day caused extensive drainage of the ER Ca2+ stores. This Ca2+ depletion was followed by markedly reduced cell proliferation rates and morphological changes that developed over 2-4 days and culminated in cell death. Interestingly, these changes were not accompanied by bulk increases in cytosolic Ca2+ levels. Moreover, knockdown of two key store-operated Ca2+ entry (SOCE) components, Orai1 and STIM1, did not reduce Tg ...
Characterisation of cell death pathways upon activation of the endoplasmic reticulum stress sensor IRE1alpha at Durham...
Category:GO:0034663 ! endoplasmic reticulum chaperone complex - GONUTS
Library System/Howard University
Apoptotic DNA fragmentation may be a cooperative activity between caspase-activated deoxyribonuclease and the poly(ADP-ribose) polymerase-regulated DNAS1L3, an endoplasmic reticulum-localized endonucleasethat translocates to the nucleus during apoptosis. Journal of Biological Chemistry, Vol.288, No.5 (2013): 3460-3468. Errami, Y., Naura, A.S., Kim, H., Ju, J., Suzuki, Y., El-Bahrawy, A.H., Ghonim, M.A., Hemeida, R.A., Mansy, M.S., Zhang, J., Xu, M., Smulson, M.E., Hassan Brim, Boulares, A.H.. ...
Library System/Howard University
Apoptotic DNA fragmentation may be a cooperative activity between caspase-activated deoxyribonuclease and the poly(ADP-ribose) polymerase-regulated DNAS1L3, an endoplasmic reticulum-localized endonucleasethat translocates to the nucleus during apoptosis. Journal of Biological Chemistry, Vol.288, No.5 (2013): 3460-3468. Errami, Y., Naura, A.S., Kim, H., Ju, J., Suzuki, Y., El-Bahrawy, A.H., Ghonim, M.A., Hemeida, R.A., Mansy, M.S., Zhang, J., Xu, M., Smulson, M.E., Hassan Brim, Boulares, A.H.. ...
Endoplasmic reticulum. 1 Nucleus 2 Nuclear pore 3 Rough endoplasmic reticulum (RER) 4 Smooth endoplasmic reticulum (SER) ... Main article: Endoplasmic reticulum. The endoplasmic reticulum (ER) is a membranous synthesis and transport organelle that is ... The rough endoplasmic reticulum is so named because the cytoplasmic surface is covered with ribosomes, giving it a bumpy ... The nuclear membrane contains a lipid bilayer that encompass the contents of the nucleus. The endoplasmic reticulum (ER) is ...
Endoplasmic-reticulum-associated protein degradation
Recognition of misfolded or mutated proteins in the endoplasmic reticulum. The recognition of misfolded or mutated ... Tyler Mateucci (ERAD) designates a cellular pathway which targets misfolded proteins of the endoplasmic reticulum for ... Endoplasmic-reticulum-associated protein degradation is one of several protein degradation pathways in the ER ... endoplasmic reticulum-associated degradation". Nat. Rev. Mol. Cell Biol. 9 (12): 944-57. doi:10.1038/nrm2546. PMC 2654601 . ...
Glossary of biology
For this to occur, an N-terminus "signal sequence" of amino acids directs proteins to the endoplasmic reticulum, which inserts ... Cooper, Geoffrey M. (2000). "The Endoplasmic Reticulum". The Cell: A Molecular Approach. 2nd edition. Sinauer Associates. Xu, ... and only the outer membrane is continuous with the endoplasmic reticulum (ER) membrane. Like the ER, the outer membrane also ...
Endoplasmic reticulum resident protein
ER retention refers to proteins that are retained in the endoplasmic reticulum, or ER, after folding; these are known as ER ... Retrieved from "https://en.wikipedia.org/w/index.php?title=Endoplasmic_reticulum_resident_protein&oldid=864649351" ... and KKXX Retrieval Signals Appended to the Same Reporter Protein Determine Different Trafficking between Endoplasmic Reticulum ...
Along with PPIC, PPIB localizes to the endoplasmic reticulum (ER), where it maintains redox homeostasis. Depletion of these two ... Hasel KW, Glass JR, Godbout M, Sutcliffe JG (1991). "An endoplasmic reticulum-specific cyclophilin". Mol. Cell. Biol. 11 (7): ... Ishikawa Y, Bächinger HP (Nov 2013). "An additional function of the rough endoplasmic reticulum protein complex prolyl 3- ... PPIB localizes to the endoplasmic reticulum (ER) and participates in many biological processes, including mitochondrial ...
"Endoplasmic Reticulum (Rough and Smooth)". British Society for Cell Biology. Retrieved 12 November 2017. "Golgi Apparatus". ... Various tube- and sheet-like extensions of the nuclear membrane form the endoplasmic reticulum, which is involved in protein ... In 1987 and later papers, Thomas Cavalier-Smith proposed instead that the membranes of the nucleus and endoplasmic reticulum ... It includes the rough endoplasmic reticulum where ribosomes are attached to synthesize proteins, which enter the interior space ...
Oh, J., Riek, A.E., Weng, S., Petty, M., Kim, D., Colonna, M., Cella, M., Bernal-Mizrachi, C. (2012). "Endoplasmic reticulum ... Hotamisligil, G.S. (2010). "Endoplasmic reticulum stress and atherosclerosis". Nature Medicine. 16(4): 396-399. PMC 2897068 . ... Free cholesterol is transported to the endoplasmic reticulum where it is re-esterified by ACAT1 (acyl-CoA: cholesterol ...
Signal recognition particle
Gilmore R, Blobel G, Walter P (November 1982). "Protein translocation across the endoplasmic reticulum. I. Detection in the ... Walter P, Ibrahimi I, Blobel G (November 1981). "Translocation of proteins across the endoplasmic reticulum. I. Signal ... Endoplasmic reticulum) membrane. This occurs via the interaction and docking of SRP with its cognate SRP receptor that is ... that recognizes and targets specific proteins to the endoplasmic reticulum in eukaryotes and the plasma membrane in prokaryotes ...
SSCRs promote nuclear mRNA export and the proper localization to the surface of the endoplasmic reticulum. In addition SSCRs ... Walter P, Ibrahimi I, Blobel G (Nov 1981). "Translocation of proteins across the endoplasmic reticulum. I. Signal recognition ... Gilmore R, Blobel G, Walter P (Nov 1982). "Protein translocation across the endoplasmic reticulum. I. Detection in the ... These proteins include those that reside either inside certain organelles (the endoplasmic reticulum, golgi or endosomes), ...
Walter P, Ibrahimi I, Blobel G (November 1981). "Translocation of proteins across the endoplasmic reticulum. I. Signal ... Ron, D.; Walter, P. (2007). "Signal integration in the endoplasmic reticulum unfolded protein response". Nature Reviews ... which is one of three known sensors of the folding capacity within the endoplasmic reticulum lumen responsible for initiating a ... "Signal recognition particle contains a 7S RNA essential for protein translocation across the endoplasmic reticulum". Nature. ...
Very long chain fatty acid
Magnesium in biology
EFR (EF-Tu receptor)
Endoplasmic reticulum protein 29 (ERp29) is a chaperone protein that in humans is encoded by the ERP29 gene. ERp29 is a ... Ferrari DM, Nguyen Van P, Kratzin HD, Söling HD (Aug 1998). "ERp28, a human endoplasmic-reticulum-lumenal protein, is a member ... Shnyder SD, Hubbard MJ (Apr 2002). "ERp29 is a ubiquitous resident of the endoplasmic reticulum with a distinct role in ... Mkrtchian S, Fang C, Hellman U, Ingelman-Sundberg M (Jan 1998). "A stress-inducible rat liver endoplasmic reticulum protein, ...
Signal recognition particle RNA
In eukaryotes, the target is the membrane of the endoplasmic reticulum (ER). In Archaea, SRP delivers proteins to the plasma ... Walter P, Ibrahimi I, Blobel G (Nov 1981). "Translocation of proteins across the endoplasmic reticulum. I. Signal recognition ... which promoted the translocation of secretory proteins across the membrane of the endoplasmic reticulum. It was then discovered ... "Signal recognition particle contains a 7S RNA essential for protein translocation across the endoplasmic reticulum". Nature. ...
LMNA - 维基百科，自由的百科全书
OST is a component of the translocon in the endoplasmic reticulum (ER) membrane. A lipid-linked core-oligosaccharide is ... "Determination of the distance between the oligosaccharyltransferase active site and the endoplasmic reticulum membrane". J. ... assembled at the membrane of the endoplasmic reticulum and transferred to selected asparagine residues of nascent polypeptide ... responsible for cotranslational glycosylation of the nascent polypeptide as it enters the lumen of the endoplasmic reticulum ...
Endoplasmic reticulum - Simple English Wikipedia, the free encyclopedia
1 Nucleus 2 Nuclear pore 3 Rough endoplasmic reticulum (RER) 4 Smooth endoplasmic reticulum (SER) 5 Ribosome on the rough ER 6 ... The endoplasmic reticulum is in cells that have a nucleus: in eukaryote cells but not in prokaryote cells. It takes these forms ... Rough endoplasmic reticulum (RER), so called because it is studded with ribosomes, and secretes proteins into the cytoplasm. ... Smooth endoplasmic reticulum (SER). Among its functions is the production of proteins and steroids, the maintenance of plasma ...
PB28 - Википедија, слободна енциклопедија
endoplasmic reticulum membrane. • Golgi membrane. • integral component of plasma membrane. • smooth endoplasmic reticulum. • ... rough endoplasmic reticulum. • dendritic shaft. • aggresome. • cell surface. • membrane-bounded organelle. • endoplasmic ... endoplasmic reticulum calcium ion homeostasis. • response to oxidative stress. • autophagosome assembly. • positive regulation ... smooth endoplasmic reticulum calcium ion homeostasis. • synaptic vesicle targeting. • Cajal-Retzius cell differentiation. • ...
Дофаминовый рецептор D1 - Википедия
原生質絲 - 维基百科，自由的百科全书
කොලෙස්ටරෝල් - විකිපීඩියා, නිදහස් විශ්වකෝෂය
... s can be derived from the endoplasmic reticulum and replicate by fission. Peroxisome matrix proteins are ... "Contribution of the endoplasmic reticulum to peroxisome formation". Cell. 122 (1): 85-95. doi:10.1016/j.cell.2005.04.025. PMID ... proteome found homologies between the peroxisomal import machinery and the ERAD pathway in the endoplasmic reticulum, ...
Estatocito, a enciclopedia libre
Brain-derived neurotrophic factor
The N-linked glycosylation process occurs in eukaryotes in the lumen of the endoplasmic reticulum and widely in archaea, but ... Secondly, N-linked glycans mediate a critical quality control check point in glycoprotein folding in the endoplasmic reticulum. ... The majority of proteins synthesized in the rough endoplasmic reticulum undergo glycosylation. It is an enzyme-directed site- ... endoplasmic reticulum, cisternae in Golgi apparatus). Therefore, glycosylation is a site-specific modification. ...
ಕೋಶ ವಿಭಜನೆ - ವಿಕಿಪೀಡಿಯ
Kawano M, Kumagai K, Nishijima M, Hanada K (2006). "Efficient trafficking of ceramide from the endoplasmic reticulum to the ... interacts with the oxysterol-binding protein to modify export from the endoplasmic reticulum". J. Biol. Chem. United States. ... interacts with the oxysterol-binding protein to modify export from the endoplasmic reticulum". J. Biol. Chem. 277 (33): 29908- ...
The Endoplasmic Reticulum and Golgi Body: What's the Difference?
... and Endoplasmic reticulum (ER) are both organelles found in the majority of eukaryotic cells. They are very closely associated ... The Endoplasmic Reticulum and Golgi Body: Whats the Difference?. *Download PDF Copy ... Endoplasmic reticulum is a continuous membrane, which is present in both plant cells, animal cells and absent in prokaryotic. ... The Golgi body (or Golgi complex, apparatus), and Endoplasmic reticulum (ER) are both organelles found in the majority of ...
Involvement of endoplasmic reticulum stress-associated apoptosis ...: Ingenta Connect
Endoplasmic reticulum resident protein - Wikipedia
ER retention refers to proteins that are retained in the endoplasmic reticulum, or ER, after folding; these are known as ER ... Retrieved from "https://en.wikipedia.org/w/index.php?title=Endoplasmic_reticulum_resident_protein&oldid=864649351" ... and KKXX Retrieval Signals Appended to the Same Reporter Protein Determine Different Trafficking between Endoplasmic Reticulum ...
JCI - Endoplasmic reticulum stress in the pathogenesis of fibrotic disease
Mechanisms of Alcohol-Induced Endoplasmic Reticulum Stress and Organ Injuries
Excessive alcohol consumption induces numerous pathological stress responses, part of which is endoplasmic reticulum (ER) ... Mechanisms of Alcohol-Induced Endoplasmic Reticulum Stress and Organ Injuries. Cheng Ji. 1. 1Southern California Research ... H. Bommiasamy, S. H. Back, P. Fagone et al., "ATF6α induces XBP1-independent expansion of the endoplasmic reticulum," Journal ... H. Malhi and R. J. Kaufman, "Endoplasmic reticulum stress in liver disease," Journal of Hepatology, vol. 54, no. 4, pp. 795-809 ...
Methods for Monitoring Endoplasmic Reticulum Stress and the Unfolded Protein Response
Physiological or pathological processes that disturb protein folding in the endoplasmic reticulum cause ER stress and activate ... The endoplasmic reticulum (ER) is the site of folding of membrane and secreted proteins in the cell. ... The endoplasmic reticulum (ER) is the cellular site for storage and for synthesis, folding, and maturation of most secreted and ... Methods for Monitoring Endoplasmic Reticulum Stress and the Unfolded Protein Response. Afshin Samali. ,1 Una FitzGerald. ,2 ...
KEGG PATHWAY: Protein processing in endoplasmic reticulum - Homo sapiens (human)
1 Nucleus 2 Nuclear pore 3 Rough endoplasmic reticulum (RER) 4 Smooth endoplasmic reticulum (SER) 5 Ribosome on the rough ER 6 ... Wikimedia Commons has media related to Endoplasmic reticulum.. *Lipid and protein composition of Endoplasmic reticulum in OPM ... The rough endoplasmic reticulum is especially prominent in cells such as hepatocytes. The smooth endoplasmic reticulum lacks ... The surface of the rough endoplasmic reticulum (often abbreviated RER or Rough ER) (also called granular endoplasmic reticulum ...
Endoplasmic Reticulum | Encyclopedia.com
The ER comes in two different morphological forms: smooth endoplasmic reticulum (sER) and rough endoplasmic reticulum (rER). ... Endoplasmic Reticulum The endoplasmic reticulum (ER) is a series of interconnected membranes or flattened sacs adjacent and ... There are two types of endoplasmic reticulum: rough endoplasmic reticulum and smooth endoplasmic reticulum. Rough endoplasmic ... Endoplasmic Reticulum Biology COPYRIGHT 2002 The Gale Group Inc.. Endoplasmic Reticulum. The endoplasmic reticulum (ER) is a ...
Sarcoplasmic/Endoplasmic Reticulum Calcium ATPase 1 | SpringerLink
Calcium-transporting ATPase sarcoplasmic reticulum type, fast-twitch skeletal muscle isoform; Endoplasmic... ... Calcium-transporting ATPase sarcoplasmic reticulum type, fast-twitch skeletal muscle isoform; Endoplasmic reticulum class 1/2 ... Sahoo SK, Shaikh SA, Sopariwala DH, Bal NC, Periasamy M. Sarcolipin protein interaction with sarco(endo)plasmic reticulum Ca2+ ... Zádor E, Kósa M. The neonatal sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA1b): a neglected pump in scope. Pflugers ...
Protein Folding in the Endoplasmic Reticulum | SpringerLink
The endoplasmic reticulum(ER) is the first and usually the largest compartment of the secretory pathway. It is a highly ... Structure and assembly of the endoplasmic reticulum: the synthesis of three major endoplasmic reticulum proteins during ... The endoplasmic reticulum (ER) is the first and usually the largest compartment of the secretory pathway. It is a highly ... Endoplasmic Reticulum Disulfide Bond Protein Disulfide Isomerase Vesicular Stomatitis Virus Disulfide Bond Formation These ...
Endoplasmic-reticulum-associated protein degradation - Wikipedia
Endoplasmic-reticulum-associated protein degradation (ERAD) designates a cellular pathway which targets misfolded proteins of ... Vembar SS, Brodsky JL (December 2008). "One step at a time: endoplasmic reticulum-associated degradation". Nat. Rev. Mol. Cell ... VCP/p97 transports substrates from the endoplasmic reticulum to the cytoplasm with its ATPase activity. The ubiquitination of ... Endoplasmic reticulum JUNQ and IPOD Oxidative folding Proteasome Protein folding Ubiquitination Multilayered Mechanism of CD4 ...
Endoplasmic reticulum | Define Endoplasmic reticulum at Dictionary.com
... smooth endoplasmic reticulum) or studded with ribosomes (rough endoplasmic reticulum), involved in the transport of materials. ... Endoplasmic reticulum definition, a network of tubular membranes within the cytoplasm of the cell, occurring either with a ... endoplasmic reticulum. in Medicine. endoplasmic reticulum. n.. *The membrane network in cytoplasm that is composed of tubules ... The smooth endoplasmic reticulum also transports the products of the rough endoplasmic reticulum to other cell parts, notably ...
Mitofusin 2 tethers endoplasmic reticulum to mitochondria
Juxtaposition between endoplasmic reticulum (ER) and mitochondria is a common structural feature, providing the physical basis ... Mitofusin 2 tethers endoplasmic reticulum to mitochondria Nature. 2008 Dec 4;456(7222):605-10. doi: 10.1038/nature07534. ... Juxtaposition between endoplasmic reticulum (ER) and mitochondria is a common structural feature, providing the physical basis ...
Who Discovered the Endoplasmic Reticulum? | Reference.com
The endoplasmic reticulum is separated into two categories. The parts of the organelle... ... The endoplasmic reticulum was discovered in 1945 by researchers Ernest Fullman, Keith Porter and Albert Claude. ... the endoplasmic reticulum allows ribosomes to translate mRNA from the nucleus into proteins. The endoplasmic reticulum is ... The endoplasmic reticulum was discovered in 1945 by researchers Ernest Fullman, Keith Porter and Albert Claude. The endoplasmic ...
Lct endoplasmic reticulum gene ontology
Metabolic activity induces membrane phase separation in endoplasmic reticulum | PNAS
The endoplasmic reticulum (ER) is the largest membrane system inside cells and also harbors the richest metabolic activity ... The endoplasmic reticulum (ER) is the largest cellular membrane system and also the most metabolically active organelle ... 1967) Turnover of constituents of the endoplasmic reticulum membranes of rat hepatocytes. J Biol Chem 242:2389-2396. ... 2006) Disruption of endoplasmic reticulum structure and integrity in lipotoxic cell death. J Lipid Res 47:2726-2737. ...
Induction of endoplasmic reticulum stress... & related info | Mendeley
cortical endoplasmic reticulum | SGD
Endoplasmic reticulum stress-mediated apoptosis in pancreatic beta-cells. - PubMed - NCBI
ERO1A endoplasmic reticulum oxidoreductase 1 alpha [Homo sapiens (human)] - Gene - NCBI
ERO1A endoplasmic reticulum oxidoreductase 1 alpha [Homo sapiens] ERO1A endoplasmic reticulum oxidoreductase 1 alpha [Homo ... endoplasmic oxidoreductin-1-like protein. endoplasmic reticulum oxidoreductase alpha. oxidoreductin-1-L-alpha. NP_055399.1. *EC ... endoplasmic reticulum oxidoreductase 1 alphaprovided by HGNC. Primary source. HGNC:HGNC:13280 See related. Ensembl: ... Mechanistic Connections between Endoplasmic Reticulum (ER) Redox Control and Mitochondrial Metabolism. Fan Y, et al. Cells, ...
What does the smooth endoplasmic reticulum do? | Reference.com
The smooth endoplasmic reticulum, or smooth ER, performs functions in several metabolic processes, including synthesis of ... What is the difference between smooth and rough endoplasmic reticulum?. A: Smooth endoplasmic reticulum is primarily involved ... The smooth endoplasmic reticulum, or smooth ER, performs functions in several metabolic processes, including synthesis of ... A: The smooth endoplasmic reticulum is the organelle responsible for the production of lipids in the cell. This particular ...
Wanted: Endoplasmic Reticulum | Smore Newsletters
Endoplasmic Reticulum by Gwyn Reece , This newsletter was created with Smore, an online tool for creating beautiful newsletters ... What are endoplasmic reticulums and what do they do? Endoplasmic reticulums can be rough or smooth. Rough endoplasmic ... Smooth endoplasmic reticulums manufacture and store lipids and steroids. Endoplasmic reticulums are important because your body ... Endoplasmic reticulums are like roads. When lipids, steroids, or proteins are produced, they travel inside smooth or rough ...
Tyrosine phosphorylation of p97 regulates transitional endoplasmic reticulum assembly in vitro | PNAS
endoplasmic reticulum;. tER,. transitional endoplasmic reticulum;. LDM,. low-density microsomes;. PTPase,. protein-tyrosine ... RER, rough endoplasmic reticulum; SER, smooth endoplasmic reticulum. (F) Amount of tER assembly per total membrane ... E) Morphometric studies of the amount of rough endoplasmic reticulum and smooth endoplasmic reticulum membranes in tER networks ... Tyrosine phosphorylation of p97 regulates transitional endoplasmic reticulum assembly in vitro. Christine Lavoie, Eric Chevet, ...
The Endoplasmic Reticulum
Nonvesicular Lipid Transfer from the Endoplasmic Reticulum. Sima Lev. Sphingolipid Homeostasis in the Endoplasmic Reticulum and ... Disulfide Bond Formation in the Mammalian Endoplasmic Reticulum. Neil J. Bulleid. Endoplasmic Reticulum Structure and ... Lipid Transport between the Endoplasmic Reticulum and Mitochondria. Vid V. Flis and Günther Daum. The Role of the Endoplasmic ... The Endoplasmic Reticulum. Subject Area(s): Developmental Biology; Cell Biology; Proteins and Proteomics; Molecular Biology. ...
Endoplasmic reticulum - Simple English Wikipedia, the free encyclopedia
1 Nucleus 2 Nuclear pore 3 Rough endoplasmic reticulum (RER) 4 Smooth endoplasmic reticulum (SER) 5 Ribosome on the rough ER 6 ... The endoplasmic reticulum is in cells that have a nucleus: in eukaryote cells but not in prokaryote cells. It takes these forms ... Rough endoplasmic reticulum (RER), so called because it is studded with ribosomes, and secretes proteins into the cytoplasm. ... Smooth endoplasmic reticulum (SER). Among its functions is the production of proteins and steroids, the maintenance of plasma ...
New ALS Genes Implicate Protein Degradation, Endoplasmic Reticulum | ALZFORUM
signal recognition particle, endoplasmic reticulum targeting | SGD
Gene Ontology Term: signal recognition particle, endoplasmic reticulum targeting. GO ID. GO:0005786 Aspect. Cellular Component ... This binds both to the N-terminal signal peptide for proteins destined for the endoplasmic reticulum as they emerge from the ... The SRP-ribosome complex then diffuses to the endoplasmic reticulum where it is bound to the signal recognition particle ...
Membrane scaffolds of the endoplasmic reticulum and golgi apparatus | Project | FP3 | CORDIS | European Commission
Endoplasmic Reticulum Stress in the β-Cell Pathogenesis of Type 2 Diabetes
... Sung Hoon Back,1 Sang-Wook Kang,2 Jaeseok Han,3 and ... R. S. Hegde and H. L. Ploegh, "Quality and quantity control at the endoplasmic reticulum," Current Opinion in Cell Biology, vol ... A. Helenius and M. Aebi, "Roles of N-linked glycans in the endoplasmic reticulum," Annual Review of Biochemistry, vol. 73, pp. ... L. Ellgaard and A. Helenius, "Quality control in the endoplasmic reticulum," Nature Reviews Molecular Cell Biology, vol. 4, no ...
Regulation of sarco(endo)plasmic reticulum Ca2+-ATPase and calseq...: Ingenta Connect
Endoplasmic reticulum - wikidoc
... smooth endoplasmic reticulum, and sarcoplasmic reticulum. Rough endoplasmic reticulum. The surface of the rough endoplasmic ... 1 Nucleus 2 Nuclear pore 3 Rough endoplasmic reticulum (rER) 4 Smooth endoplasmic reticulum (sER) 5 Ribosome on the rough ER 6 ... The majority of endoplasmic reticulum resident proteins are retained in the endoplasmic reticulum through a retention motif. ... Smooth endoplasmic reticulum. The smooth endoplasmic reticulum has functions in several metabolic processes, including ...
Endoplasmic reticulum stress in liver disease
... is activated upon the accumulation of misfolded proteins in the endoplasmic reticulum (ER) that are sensed by the binding ... Endoplasmic reticulum stress in liver disease J Hepatol. 2011 Apr;54(4):795-809. doi: 10.1016/j.jhep.2010.11.005. Epub 2010 Nov ... The unfolded protein response (UPR) is activated upon the accumulation of misfolded proteins in the endoplasmic reticulum (ER) ...
Endoplasmic Reticulum: An Interface Between the Immune System and Metabolism | Diabetes
Role of endoplasmic reticulum stress in metabolic disease and other disorders. Annu Rev Med 2012;63:317-328pmid:22248326. ... Endoplasmic reticulum stress links obesity, insulin action, and type 2 diabetes. Science 2004;306:457-461pmid:15486293. ... Endoplasmic Reticulum: An Interface Between the Immune System and Metabolism Message Subject (Your Name) has forwarded a page ... Endoplasmic reticulum stress and the inflammatory basis of metabolic disease. Cell 2010;140:900-917pmid:20303879. ...
P3H4 - Endoplasmic reticulum protein SC65 - Homo sapiens (Human) - P3H4 gene & protein
Endoplasmic reticulum protein SC65. Endoplasmic reticulum protein SC65 (Leprecan-like protein 4) (Nucleolar autoantigen No55) ( ... Endoplasmic reticulum protein SC65Imported. ,p>Information which has been imported from another database using automatic ... tr,K7ERA3,K7ERA3_HUMAN Endoplasmic reticulum protein SC65 (Fragment) OS=Homo sapiens OX=9606 GN=P3H4 PE=1 SV=1 ...
GolgiOxidativeApoptosisLumenHomeostasisMechanismsSignaling pathwaysMitochondrialTranslocationDysfunctionEpithelial cellsOrganellePathogenesisImproves insulinCellInducesVitroSarcoplasmic reticulumRibosomesProteins in the endoplasmic reticulumLipidMembranesSmooth and rough endoplasmRole of Endoplasmic Reticulum StressCalciumRough endoplasmic reticFunction of the endoplasmic reticulumFunctions of the endoplasmic reticulumShape the endoplasmic reticulumLipidsDegradationEukaryoticGolgi BodyStress-mediated apoptosisInduces endoplasmic reticulumRegulates endoplasmic reticulumPeripheral endoplasmic reticulumInduceEndomembrane systemIntracellularBeta-cell apoptosisNucleusMetabolicApoptosis in beta-cellsAgranularCellsElectron1945NuclearBiologyATPaseProtein quality controlSecretoryLuminal
- Alcohol-induced perturbations of homeostasis in the endoplasmic reticulum (ER) have evolved as an important factor contributing to fatty liver disease, which has been reviewed by a few comprehensive reviews [ 19 - 22 ]. (hindawi.com)
- TALK-1 channels control β cell endoplasmic reticulum Ca(2+) homeostasis. (vanderbilt.edu)
- The endoplasmic reticulum (ER) is the main organelle for the correct folding procedure, which maintains the homeostasis of the organism. (marmara.edu.tr)
- Resveratrol reduces liver endoplasmic reticulum stress and improves insulin sensitivity in vivo and in vitro. (moleculardepot.com)
- The sarcoplasmic reticulum is a specialized type of smooth ER that regulates the calcium ion concentration in the cytoplasm of striated muscle cells. (britannica.com)
- The Ca2+ is released from the sarcoplasmic reticulum by ryanodine receptor and taken back to the SR by SERCA pumps. (springer.com)
- Adult forms of the Ca2+ATPase of sarcoplasmic reticulum. (springer.com)
- Purification and properties of an adenosine triphosphatase from sarcoplasmic reticulum. (springer.com)
- Amino-acid sequence of a Ca2+ + Mg2+-dependent ATPase from rabbit muscle sarcoplasmic reticulum, deduced from its complementary DNA sequence. (springer.com)
- Mutations in the gene-encoding SERCA1, the fast-twitch skeletal muscle sarcoplasmic reticulum Ca2+ ATPase, are associated with Brody disease. (springer.com)
- Crystal structure of sarcoplasmic reticulum Ca2+-ATPase (SERCA) from bovine muscle. (springer.com)
- Toyoshima C. How Ca2+-ATPase pumps ions across the sarcoplasmic reticulum membrane. (springer.com)
- Toyoshima C, Nakasako M, Nomura H, Ogawa H. Crystal structure of the calcium pump of sarcoplasmic reticulum at 2.6 A resolution. (springer.com)
- Similar to the ER is the sarcoplasmic reticulum ( SR ) found only in muscle cells. (wikipedia.org)
- The sarcoplasmic reticulum (SR) plays a key role controlling calcium concentration in the cytosol. (ingentaconnect.com)
- The three varieties are called rough endoplasmic reticulum , smooth endoplasmic reticulum , and sarcoplasmic reticulum . (wikidoc.org)
- sarcoplasmic reticulum a form of agranular reticulum in the sarcoplasm of striated muscle, comprising a system of smooth-surfaced tubules surrounding each myofibril. (thefreedictionary.com)
- Key regulator of striated muscle performance by acting as the major Ca(2+) ATPase responsible for the reuptake of cytosolic Ca(2+) into the sarcoplasmic reticulum. (rcsb.org)
- Catalyzes the hydrolysis of ATP coupled with the translocation of calcium from the cytosol to the sarcoplasmic reticulum lumen (By similarity). (rcsb.org)
- A specialized form of SER (called sarcoplasmic reticulum ) occurs in muscle cells where calcium ions are stored. (biology-online.org)
- In muscle cells, the smooth endoplasmic reticulum is called sarcoplasmic reticulum . (biology-online.org)
- The outer ( cytosolic ) face of the rough endoplasmic reticulum is studded with ribosomes that are the sites of protein synthesis . (wikipedia.org)
- The smooth endoplasmic reticulum lacks ribosomes and functions in lipid manufacture and metabolism, the production of steroid hormones , and detoxification . (wikipedia.org)
- The surface of the rough endoplasmic reticulum (often abbreviated RER or Rough ER) (also called granular endoplasmic reticulum ) is studded with protein-manufacturing ribosomes giving it a "rough" appearance (hence its name). (wikipedia.org)
- a network of tubular membranes within the cytoplasm of the cell, occurring either with a smooth surface (smooth endoplasmic reticulum) or studded with ribosomes (rough endoplasmic reticulum) , involved in the transport of materials. (dictionary.com)
- The rough endoplasmic reticulum is a series of connected flattened sacs that have many ribosomes on their outer surface. (dictionary.com)
- Due to its close proximity to the nuclear envelope, the endoplasmic reticulum allows ribosomes to translate mRNA from the nucleus into proteins. (reference.com)
- Rough endoplasmic reticulums look rough because there are ribosomes attached to them. (smore.com)
- The ribosomes manufacture proteins and store them in the rough endoplasmic reticulums. (smore.com)
- Rough endoplasmic reticulum ( RER ), so called because it is studded with ribosomes , and secretes proteins into the cytoplasm. (wikipedia.org)
- So, the rough endoplasmic reticulum, as we mentioned, has ribosomes, which means it's the site of protein synthesis. (khanacademy.org)
- But, we know that there are also ribosomes that are in the cytoplasm, so, what's the difference between those proteins that are translated in the cytoplasm, and those that are translated in the rough endoplasmic reticulum? (khanacademy.org)
- So, let's take a look at a protein that was synthesized in the rough endoplasmic reticulum, let's say that this part had a couple of ribosomes and there was a protein made. (khanacademy.org)
- The surface of the rough endoplasmic reticulum is studded with protein-manufacturing ribosomes giving it a "rough" appearance (hence its name). (wikidoc.org)
- But it should be noted that these ribosomes are not resident of the endoplasmic reticulum initially. (wikidoc.org)
- endoplasmic reticulum an ultramicroscopic organelle of nearly all higher plant and animal cells, consisting of a system of membrane-bound cavities in the cytoplasm, occurring in two types: granular or rough-surfaced, bearing large numbers of ribosomes on its outer surface, and agranular or smooth-surfaced. (thefreedictionary.com)
- Ribosomes, the endoplasmic reticulum, and the Golgi apparatus are all organelles. (enotes.com)
- How do the functions of ribosomes, the Golgi body, and the endoplasmic reticulum relate to one. (enotes.com)
- In large part, the misfolding of proteins takes place during synthesis on free ribosomes in the cytoplasm or on endoplasmic reticulum ribosomes. (ahajournals.org)
- All protein synthesis occurs in the ribosomes, some of which are on the endoplasmic reticulum (rough ER), and some are floating in the cytoplasm. (varsitytutors.com)
- Protein synthesis requires the action of ribosomes, which can be found in the cytosol or embedded in the membrane of the rough endoplasmic reticulum. (varsitytutors.com)
- This means that organelle A has more proteins than organelle B. Remember that rough endoplasmic reticulum (rough ER) is termed 'rough' because it contains ribosomes on its surface. (varsitytutors.com)
Proteins in the endoplasmic reticulum2
- Hypoxia induced endoplasmic reticulum stress causes accumulation of unfolded proteins in the endoplasmic reticulum and activates the unfolded protein response, resulting in apoptosis through CCAAT-enhancer-binding protein homologous protein (CHOP) activation. (mdpi.com)
- Accumulation of unfolded/misfolded proteins in the endoplasmic reticulum (ER) activates the unfolded protein response (UPR). (go.jp)
- With electron microscopy , the lacy membranes of the endoplasmic reticulum were first seen in 1945 by Keith R. Porter , Albert Claude , Brody Meskers and Ernest F. Fullam. (wikipedia.org)
- Later, the word " reticulum ", which means "network", was applied by Porter in 1953 to describe this fabric of membranes. (wikipedia.org)
- The general structure of the endoplasmic reticulum is a network of membranes called cisternae . (wikipedia.org)
- The endoplasmic reticulum (ER) is a series of interconnected membranes or flattened sacs adjacent and connected to the nuclear membrane. (encyclopedia.com)
- The lacy membranes of the endoplasmic reticulum were first seen in 1945 using electron microscopy. (wikipedia.org)
- The lacy membranes of the endoplasmic reticulum were first seen in 1945 by Keith R. Porter, Albert Claude, Brody Meskers and Ernest F. Fullam, using electron microscopy. (wikipedia.org)
- A second method of transport out of the endoplasmic reticulum involves areas called membrane contact sites, where the membranes of the endoplasmic reticulum and other organelles are held closely together, allowing the transfer of lipids and other small molecules. (wikipedia.org)
- The smooth endoplasmic reticulum is tubular in form and is involved in the synthesis of phospholipids, the main lipids in cell membranes. (dictionary.com)
- The endoplasmic reticulum (ER) is an extensive network of membranes that folds, modifies, and transports proteins in eukaryotic cells. (cshlpress.com)
- The lacey membranes of the endoplasmic reticulum were first seen in 1945 by scientists using an electron microscope . (wikipedia.org)
- The lacey membranes of the endoplasmic reticulum were first seen by Keith R. Porter, Albert Claude , and Ernest F. Fullam in 1945. (wikidoc.org)
- The network of folded membranes that comprises the endoplasmic reticulum (ER) in all eukaryotic cells constitutes greater than half of the total membrane content in the average animal cell. (thermofisher.com)
- The Arabidopsis ( Arabidopsis thaliana ) genome encodes homologs of the Guided Entry of Tail (GET)-anchored protein system for the posttranslational insertion of tail-anchored ( TA ) proteins into endoplasmic reticulum (ER) membranes. (plantphysiol.org)
- There are two general systems for targeting proteins to endoplasmic reticulum (ER) membranes: one is cotranslational and the other is posttranslational. (plantphysiol.org)
- One of these structures is the endoplasmic reticulum, which is a network of tubular membranes that runs lengthwise along the axon. (elifesciences.org)
Smooth and rough endoplasm1
Role of Endoplasmic Reticulum Stress1
- SERCA1 truncated proteins unable to pump calcium reduce the endoplasmic reticulum calcium concentration and induce apoptosis. (springer.com)
- Zádor E, Kósa M. The neonatal sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA1b): a neglected pump in scope. (springer.com)
- Smooth endoplasmic reticulum is the site of the breakdown of toxins and carcinogens in the liver, the conversion of cholesterol into steroids in the gonads and adrenal glands, and the release of calcium ions in the muscles, causing muscle contraction. (dictionary.com)
- The smooth endoplasmic reticulum has functions in several metabolic processes, including synthesis of lipids, metabolism of carbohydrates and calcium concentration, drug detoxification, and attachment of receptors on cell membrane proteins. (wikidoc.org)
- The smooth endoplasmic reticulum is known for its storage of calcium ions in muscle cells . (wikidoc.org)
- Another agent, thapsigargin, also induces ER stress via inhibition of the sarcoplasmic/endoplasmic Ca 2+ -ATPase, which disrupts ER calcium homeostasis ( 6 ). (aacrjournals.org)
Rough endoplasmic retic2
Function of the endoplasmic reticulum3
- The function of the endoplasmic reticulum can vary greatly with cell type, and even within the same cell it can have different functions depending on whether it is rough or smooth. (dictionary.com)
- Disruptions in Ca 2+ homeostasis, inhibition of protein glycosylation, and accumulation of misfolded proteins can all challenge the function of the endoplasmic reticulum (ER)-Golgi network, resulting in ER stress ( 4 ). (aacrjournals.org)
- Specifically, Ca2+ is required for the function of the endoplasmic reticulum in which proteins, including immuno. (bioportfolio.com)
Functions of the endoplasmic reticulum2
Shape the endoplasmic reticulum2
- The findings may yield new insights for genetic diseases affecting proteins that help shape the endoplasmic reticulum. (nih.gov)
- It is known that spastic paraplegias are sometimes caused by mutations affecting proteins that help to build and shape the endoplasmic reticulum, for example, the proteins of the reticulon and REEP families. (elifesciences.org)
- endoplasmic reticulum Endoplasmic reticulum, a continuous membrane system in eukaryotic cells that plays an important role in the biosynthesis, processing, and transport of proteins and lipids. (britannica.com)
- The smooth endoplasmic reticulum synthesizes and stores lipids in animal cells. (reference.com)
- Smooth endoplasmic reticulum is primarily involved with the production of lipids and removing drugs or poisons from the body, according to the British Soci. (reference.com)
- When lipids, steroids, or proteins are produced, they travel inside smooth or rough endoplasmic reticulums until they reach the cell membrane so that they can be delivered to other parts of the body. (smore.com)
- Smooth endoplasmic reticulums manufacture and store lipids and steroids. (smore.com)
- Endoplasmic reticulums are important because your body needs protein to build tissue and lipids to store energy. (smore.com)
- The smooth endoplasmic reticulum synthesizes lipids. (khanacademy.org)
- In addition to synthesizing lipids, the smooth endoplasmic reticulum plays an important role in detoxification of chemicals. (varsitytutors.com)
- The endoplasmic reticulum occurs in most types of eukaryotic cells, but is absent from red blood cells and spermatozoa . (wikipedia.org)
- All eukaryotic cells contain an endoplasmic reticulum (ER). (britannica.com)
- The Golgi body (or Golgi complex, apparatus), and Endoplasmic reticulum (ER) are both organelles found in the majority of eukaryotic cells. (news-medical.net)
Induces endoplasmic reticulum2
- We have shown previously that bortezomib has activity in pancreatic cancer models and that the drug induces endoplasmic reticulum (ER) stress but also suppresses the unfolded protein response (UPR). (aacrjournals.org)
- Porcine circovirus type 2 ORF5 protein induces endoplasmic reticulum stress and unfolded protein response in porcine alveolar macrophages. (bioportfolio.com)
Regulates endoplasmic reticulum1
Peripheral endoplasmic reticulum1
- Advanced imaging techniques revealed a more accurate picture of how the peripheral endoplasmic reticulum is structured. (nih.gov)
- Integral membrane proteins from the endoplasmic reticulum induce the development of tubular structures in vitro by forming oligomers in the plane of the membrane. (sciencemag.org)
- In the tumor microenvironment hypoxia and nutrient deprived states can induce endoplasmic reticulum (ER) stress. (mdpi.com)
- In this study, we incubated bovine aortic endothelial cells (BAECs) with ox-LDL (100 µg/ml) in order to induce endoplasmic reticulum (ER) stress and to investigate the regulation of endothelial nitric oxide synthase (eNOS). (spandidos-publications.com)
- The endoplasmic reticulum is part of the endomembrane system . (wikidoc.org)
- They also revealed very diverse mechanisms of interaction between viruses and the highly dynamic organelles of the endomembrane system, such as the nuclear membrane, endoplasmic reticulum (ER), Golgi apparatus, endosomes, and vesicles. (nature.com)
- The endoplasmic reticulum (ER) plays crucial roles in intracellular Ca 2+ signaling, serving as both a source and sink of Ca 2+ , and regulating a variety of physiological and pathophysiological events in neurons in the brain. (jneurosci.org)
- The membrane around the smooth endoplasmic reticulum can be used to create intracellular vesicles. (varsitytutors.com)
- The quantity of both rough and smooth endoplasmic reticulum in a cell can slowly interchange from one type to the other, depending on the changing metabolic activities of the cell. (wikipedia.org)
- Adipocyte stress: the endoplasmic reticulum and metabolic disease. (nature.com)
- The endoplasmic reticulum is also the site of many other cell metabolic reactions. (thefreedictionary.com)
- Endoplasmic reticulum (ER) stress is emerging recently as a common feature in the pathology of numerous diseases including cancer, neurodegenerative disorders, metabolic syndromes and inflammatory diseases, affecting millions of patients annually worldwide and assuming a huge economic burden for the health sector. (news-medical.net)
Apoptosis in beta-cells1
- The rough endoplasmic reticulum is especially prominent in cells such as hepatocytes . (wikipedia.org)
- In some cells there are dilated areas like the sacs of rough endoplasmic reticulum. (wikidoc.org)
- The high activity of those cells is revealed through the abundant presence of endoplasmic reticulum from the moment the oocyte begins the secondary growth phase. (thefreedictionary.com)
- Our studies support that both endoplasmic reticulum (ER) stress and autophagy were induced in the melanoma cells after the treatment with dabrafenib. (dovepress.com)
- Tseng, S.-H. HDAC Inhibitors and RECK Modulate Endoplasmic Reticulum Stress in Tumor Cells. (mdpi.com)
- Chen Y, Tsai Y-H, Tseng S-H. HDAC Inhibitors and RECK Modulate Endoplasmic Reticulum Stress in Tumor Cells. (mdpi.com)
- 1. It was discovered by Porter (1945) as fine recticulum in endoplasm of cells and named as endoplasmic reticulum (E.R. (generationq.net)
- Previous studies have demonstrated that endoplasmic reticulum (ER) stress induced by ox-LDL in human vascular cells modulates the balance between survival and apoptosis induced by ox-LDL ( 10 - 12 ). (spandidos-publications.com)
- Cells in the liver, called hepatocytes, have particularly large smooth endoplasmic reticulum regions, allowing them to be especially efficient at clearly toxins from the body. (varsitytutors.com)
- Endoplasmic reticulum stress in beta cells: latent mechanism of secondary sulfonylurea failure in type 2 diabetes? (biomedsearch.com)
- The highly convoluted and labyrinthine structure of the ER led to its description in 1945 as a "lace-like reticulum" by cell biologists Keith Porter, Albert Claude , and Ernest Fullman, who produced the first electron micrograph of a cell. (britannica.com)
- Using high-magnification electron microscopy confirmed these findings, and showed that the tubules of the endoplasmic reticulum in mutant axons were larger, but fewer. (elifesciences.org)
- The membrane of the rough endoplasmic reticulum forms large double membrane sheets that are located near, and continuous with, the outer layer of the nuclear envelope . (wikipedia.org)
- Notice that the space in the nuclear envelope is continuous with the lumen, or space, of the endoplasmic reticulum. (khanacademy.org)
- The membrane of the rough endoplasmic reticulum is continuous with the outer layer of the nuclear envelope . (wikidoc.org)
Protein quality control1
- An animation showing how a protein destined for the secretory pathway is synthesized into the rough endoplasmic reticulum (which appears at upper right in animation when approximately half of animation is done). (wikipedia.org)
- The endoplasmic reticulum (ER) is the first and usually the largest compartment of the secretory pathway. (springer.com)
- The endoplasmic reticulum (ER) constitutes the starting point of the secretory pathway where secretory and membrane proteins are synthesized. (biologists.org)
- Secretory proteins enter the secretory pathway by translocation across the membrane of the endoplasmic reticulum (ER) via a channel formed primarily by the Sec61 protein. (biologists.org)
- Endoplasmic reticulum (ER) stress often occurred when load of client protein exceed the folding capacity in secretory cell. (biomedsearch.com)
- Understanding the dynamics and regulatory mechanisms of the endoplasmic reticulum (ER) luminal free Ca 2+ concentration ([Ca 2+ ] ER ) is critical for understanding the function of the ER in neurons. (jneurosci.org)
- Calreticulin is an ER (endoplasmic reticulum) luminal Ca 2+ -buffering chaperone. (biochemj.org)