GTP-Binding Proteins: Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.Guanosine Triphosphate: Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.Heterotrimeric GTP-Binding Proteins: GTP-BINDING PROTEINS that contain three non-identical subunits. They are found associated with members of the seven transmembrane domain superfamily of G-PROTEIN-COUPLED RECEPTORS. Upon activation the GTP-BINDING PROTEIN ALPHA SUBUNIT of the complex dissociates leaving a dimer of a GTP-BINDING PROTEIN BETA SUBUNIT bound to a GTP-BINDING PROTEIN GAMMA SUBUNIT.GTP Phosphohydrolases: Enzymes that hydrolyze GTP to GDP. EC 3.6.1.-.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.Guanosine Diphosphate: A guanine nucleotide containing two phosphate groups esterified to the sugar moiety.Guanosine 5'-O-(3-Thiotriphosphate): Guanosine 5'-(trihydrogen diphosphate), monoanhydride with phosphorothioic acid. A stable GTP analog which enjoys a variety of physiological actions such as stimulation of guanine nucleotide-binding proteins, phosphoinositide hydrolysis, cyclic AMP accumulation, and activation of specific proto-oncogenes.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.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 3.6.1.47Pertussis Toxin: One of the virulence factors produced by BORDETELLA PERTUSSIS. It is a multimeric protein composed of five subunits S1 - S5. S1 contains mono ADPribose transferase activity.rab GTP-Binding Proteins: A large family of MONOMERIC GTP-BINDING PROTEINS that play a key role in cellular secretory and endocytic pathways. EC 3.6.1.-.Virulence Factors, Bordetella: A set of BACTERIAL ADHESINS and TOXINS, BIOLOGICAL produced by BORDETELLA organisms that determine the pathogenesis of BORDETELLA INFECTIONS, such as WHOOPING COUGH. They include filamentous hemagglutinin; FIMBRIAE PROTEINS; pertactin; PERTUSSIS TOXIN; ADENYLATE CYCLASE TOXIN; dermonecrotic toxin; tracheal cytotoxin; Bordetella LIPOPOLYSACCHARIDES; and tracheal colonization factor.GTP-Binding Protein alpha Subunits: The GTPase-containing subunits of heterotrimeric GTP-binding proteins. When dissociated from the heterotrimeric complex these subunits interact with a variety of second messenger systems. Hydrolysis of GTP by the inherent GTPase activity of the subunit causes it to revert to its inactive (heterotrimeric) form. The GTP-Binding protein alpha subunits are grouped into families according to the type of action they have on second messenger systems.ADP-Ribosylation Factors: MONOMERIC GTP-BINDING PROTEINS that were initially recognized as allosteric activators of the MONO(ADP-RIBOSE) TRANSFERASE of the CHOLERA TOXIN catalytic subunit. They are involved in vesicle trafficking and activation of PHOSPHOLIPASE D. This enzyme was formerly listed as EC 3.6.1.47Protein 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.Adenosine Diphosphate Ribose: An ester formed between the aldehydic carbon of RIBOSE and the terminal phosphate of ADENOSINE DIPHOSPHATE. It is produced by the hydrolysis of nicotinamide-adenine dinucleotide (NAD) by a variety of enzymes, some of which transfer an ADP-ribosyl group to target proteins.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.rho GTP-Binding Proteins: A large family of MONOMERIC GTP-BINDING PROTEINS that are involved in regulation of actin organization, gene expression and cell cycle progression. This enzyme was formerly listed as EC 3.6.1.47.ADP Ribose Transferases: Enzymes that transfer the ADP-RIBOSE group of NAD or NADP to proteins or other small molecules. Transfer of ADP-ribose to water (i.e., hydrolysis) is catalyzed by the NADASES. The mono(ADP-ribose)transferases transfer a single ADP-ribose. POLY(ADP-RIBOSE) POLYMERASES transfer multiple units of ADP-ribose to protein targets, building POLY ADENOSINE DIPHOSPHATE RIBOSE in linear or branched chains.Botulinum Toxins: Toxic proteins produced from the species CLOSTRIDIUM BOTULINUM. The toxins are synthesized as a single peptide chain which is processed into a mature protein consisting of a heavy chain and light chain joined via a disulfide bond. The botulinum toxin light chain is a zinc-dependent protease which is released from the heavy chain upon ENDOCYTOSIS into PRESYNAPTIC NERVE ENDINGS. Once inside the cell the botulinum toxin light chain cleaves specific SNARE proteins which are essential for secretion of ACETYLCHOLINE by SYNAPTIC VESICLES. This inhibition of acetylcholine release results in muscular PARALYSIS.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.Guanine Nucleotide Exchange Factors: Protein factors that promote the exchange of GTP for GDP bound to GTP-BINDING PROTEINS.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Thionucleotides: Nucleotides in which the base moiety is substituted with one or more sulfur atoms.GTPase-Activating Proteins: Proteins that activate the GTPase of specific GTP-BINDING PROTEINS.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.ras Proteins: Small, monomeric GTP-binding proteins encoded by ras genes (GENES, RAS). The protooncogene-derived protein, PROTO-ONCOGENE PROTEIN P21(RAS), plays a role in normal cellular growth, differentiation and development. The oncogene-derived protein (ONCOGENE PROTEIN P21(RAS)) can play a role in aberrant cellular regulation during neoplastic cell transformation (CELL TRANSFORMATION, NEOPLASTIC). This enzyme was formerly listed as EC 3.6.1.47.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.rhoA GTP-Binding Protein: A RHO GTP-BINDING PROTEIN involved in regulating signal transduction pathways that control assembly of focal adhesions and actin stress fibers. This enzyme was formerly listed as EC 3.6.1.47.GTP-Binding Protein beta Subunits: Heterotrimeric GTP-binding protein subunits that tightly associate with GTP-BINDING PROTEIN GAMMA SUBUNITS. A dimer of beta and gamma subunits is formed when the GTP-BINDING PROTEIN ALPHA SUBUNIT dissociates from the GTP-binding protein heterotrimeric complex. The beta-gamma dimer can play an important role in signal transduction by interacting with a variety of second messengers.GTP-Binding Protein alpha Subunits, Gi-Go: A family of heterotrimeric GTP-binding protein alpha subunits that were originally identified by their ability to inhibit ADENYLYL CYCLASES. Members of this family can couple to beta and gamma G-protein subunits that activate POTASSIUM CHANNELS. The Gi-Go part of the name is also spelled Gi/Go.Kinetics: The rate dynamics in chemical or physical systems.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Poly(A)-Binding Proteins: Proteins that bind to the 3' polyadenylated region of MRNA. When complexed with RNA the proteins serve an array of functions such as stabilizing the 3' end of RNA, promoting poly(A) synthesis and stimulating mRNA translation.GTP-Binding Protein gamma Subunits: Heterotrimeric GTP-binding protein subunits that tightly associate with GTP-BINDING PROTEIN BETA SUBUNITS. A dimer of beta and gamma subunits is formed when the GTP-BINDING PROTEIN ALPHA SUBUNIT dissociates from the GTP-binding protein heterotrimeric complex. The beta-gamma dimer can play an important role in signal transduction by interacting with a variety of second messengers.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.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.RGS Proteins: A large family of evolutionarily conserved proteins that function as negative regulators of HETEROTRIMERIC GTP-BINDING PROTEINS. RGS PROTEINS act by increasing the GTPase activity of the G alpha subunit of a heterotrimeric GTP-binding protein, causing it to revert to its inactive (GDP-bound) form.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.GTP-Binding Protein alpha Subunits, G12-G13: A ubiquitously expressed family of heterotrimeric GTP-binding protein alpha subunits that signal through interactions with a variety of second messengers as GTPASE-ACTIVATING PROTEINS; GUANINE NUCLEOTIDE EXCHANGE FACTORS; and HEAT SHOCK PROTEINS. The G12-G13 part of the name is also spelled G12/G13.GTP-Binding Protein alpha Subunit, Gi2: A PERTUSSIS TOXIN-sensitive GTP-binding protein alpha subunit. It couples with a variety of CELL SURFACE RECEPTORS, has been implicated in INTERLEUKIN-12 production, and may play a role in INFLAMMATORY BOWEL DISEASES.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.GTP-Binding Protein alpha Subunits, Gs: A family of heterotrimeric GTP-binding protein alpha subunits that activate ADENYLYL CYCLASES.Transducin: A heterotrimeric GTP-binding protein that mediates the light activation signal from photolyzed rhodopsin to cyclic GMP phosphodiesterase and is pivotal in the visual excitation process. Activation of rhodopsin on the outer membrane of rod and cone cells causes GTP to bind to transducin followed by dissociation of the alpha subunit-GTP complex from the beta/gamma subunits of transducin. The alpha subunit-GTP complex activates the cyclic GMP phosphodiesterase which catalyzes the hydrolysis of cyclic GMP to 5'-GMP. This leads to closure of the sodium and calcium channels and therefore hyperpolarization of the rod cells. EC 3.6.1.-.GTP Cyclohydrolase: (GTP cyclohydrolase I) or GTP 7,8-8,9-dihydrolase (pyrophosphate-forming) (GTP cyclohydrolase II). An enzyme group that hydrolyzes the imidazole ring of GTP, releasing carbon-8 as formate. Two C-N bonds are hydrolyzed and the pentase unit is isomerized. This is the first step in the synthesis of folic acid from GTP. EC 3.5.4.16 (GTP cyclohydrolase I) and EC 3.5.4.25 (GTP cyclohydrolase II).GTP-Binding Protein alpha Subunits, Gq-G11: A family of heterotrimeric GTP-binding protein alpha subunits that activate TYPE C PHOSPHOLIPASES dependent signaling pathways. The Gq-G11 part of the name is also spelled Gq/G11.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Guanine NucleotidesCell Line: Established cell cultures that have the potential to propagate indefinitely.Hydrolysis: The process of cleaving a chemical compound by the addition of a molecule of water.Aluminum Compounds: Inorganic compounds that contain aluminum as an integral part of the molecule.DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Tacrolimus Binding Proteins: A family of immunophilin proteins that bind to the immunosuppressive drugs TACROLIMUS (also known as FK506) and SIROLIMUS. EC 5.2.1.-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.Guanylyl Imidodiphosphate: A non-hydrolyzable analog of GTP, in which the oxygen atom bridging the beta to the gamma phosphate is replaced by a nitrogen atom. It binds tightly to G-protein in the presence of Mg2+. The nucleotide is a potent stimulator of ADENYLYL CYCLASES.Poly(A)-Binding Protein I: A poly(A) binding protein that has a variety of functions such as mRNA stabilization and protection of RNA from nuclease activity. Although poly(A) binding protein I is considered a major cytoplasmic RNA-binding protein it is also found in the CELL NUCLEUS and may be involved in transport of mRNP particles.Enzyme Activation: Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.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.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).Insulin-Like Growth Factor Binding Proteins: A family of soluble proteins that bind insulin-like growth factors and modulate their biological actions at the cellular level. (Int J Gynaecol Obstet 1992;39(1):3-9)Wasp Venoms: Venoms produced by the wasp (Vespid) family of stinging insects, including hornets; the venoms contain enzymes, biogenic amines, histamine releasing factors, kinins, toxic polypeptides, etc., and are similar to bee venoms.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Two-Hybrid System Techniques: Screening techniques first developed in yeast to identify genes encoding interacting proteins. Variations are used to evaluate interplay between proteins and other molecules. Two-hybrid techniques refer to analysis for protein-protein interactions, one-hybrid for DNA-protein interactions, three-hybrid interactions for RNA-protein interactions or ligand-based interactions. Reverse n-hybrid techniques refer to analysis for mutations or other small molecules that dissociate known interactions.Macromolecular Substances: Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.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.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.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.Receptors, G-Protein-Coupled: The largest family of cell surface receptors involved in SIGNAL TRANSDUCTION. They share a common structure and signal through HETEROTRIMERIC G-PROTEINS.Mutagenesis, Site-Directed: Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Nuclear Proteins: Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.RNA-Binding Proteins: Proteins that bind to RNA molecules. Included here are RIBONUCLEOPROTEINS and other proteins whose function is to bind specifically to RNA.Protein Subunits: Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly.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.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).)Adenylate Cyclase: An enzyme of the lyase class that catalyzes the formation of CYCLIC AMP and pyrophosphate from ATP. EC 4.6.1.1.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.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.Fluorides: Inorganic salts of hydrofluoric acid, HF, in which the fluorine atom is in the -1 oxidation state. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed) Sodium and stannous salts are commonly used in dentifrices.Fatty Acid-Binding Proteins: Intracellular proteins that reversibly bind hydrophobic ligands including: saturated and unsaturated FATTY ACIDS; EICOSANOIDS; and RETINOIDS. They are considered a highly conserved and ubiquitously expressed family of proteins that may play a role in the metabolism of LIPIDS.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Dimerization: The process by which two molecules of the same chemical composition form a condensation product or polymer.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.ADP-Ribosylation Factor 1: ADP-RIBOSYLATION FACTOR 1 is involved in regulating intracellular transport by modulating the interaction of coat proteins with organelle membranes in the early secretory pathway. It is a component of COAT PROTEIN COMPLEX I. This enzyme was formerly listed as EC 3.6.1.47.Bacterial Proteins: Proteins found in any species of bacterium.Cyclic AMP: An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.Proto-Oncogene Proteins p21(ras): Cellular proteins encoded by the H-ras, K-ras and N-ras genes. The proteins have GTPase activity and are involved in signal transduction as monomeric GTP-binding proteins. Elevated levels of p21 c-ras have been associated with neoplasia. This enzyme was formerly listed as EC 3.6.1.47.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.DNA 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.Type C Phospholipases: A subclass of phospholipases that hydrolyze the phosphoester bond found in the third position of GLYCEROPHOSPHOLIPIDS. Although the singular term phospholipase C specifically refers to an enzyme that catalyzes the hydrolysis of PHOSPHATIDYLCHOLINE (EC 3.1.4.3), it is commonly used in the literature to refer to broad variety of enzymes that specifically catalyze the hydrolysis of PHOSPHATIDYLINOSITOLS.GTP-Binding Protein Regulators: Proteins that regulate the signaling activity of GTP-BINDING PROTEINS. They are divided into three categories depending upon whether they stimulate GTPase activity (GTPASE-ACTIVATING PROTEINS), inhibit release of GDP; (GUANINE NUCLEOTIDE DISSOCIATION INHIBITORS); or exchange GTP for GDP; (GUANINE NUCLEOTIDE EXCHANGE FACTORS).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.Guanosine Monophosphate: A guanine nucleotide containing one phosphate group esterified to the sugar moiety and found widely in nature.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.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.Peptide Elongation Factor Tu: A protein found in bacteria and eukaryotic mitochondria which delivers aminoacyl-tRNA's to the A site of the ribosome. The aminoacyl-tRNA is first bound to a complex of elongation factor Tu containing a molecule of bound GTP. The resulting complex is then bound to the 70S initiation complex. Simultaneously the GTP is hydrolyzed and a Tu-GDP complex is released from the 70S ribosome. The Tu-GTP complex is regenerated from the Tu-GDP complex by the Ts elongation factor and GTP.Molecular Weight: The sum of the weight of all the atoms in a molecule.Transglutaminases: Transglutaminases catalyze cross-linking of proteins at a GLUTAMINE in one chain with LYSINE in another chain. They include keratinocyte transglutaminase (TGM1 or TGK), tissue transglutaminase (TGM2 or TGC), plasma transglutaminase involved with coagulation (FACTOR XIII and FACTOR XIIIa), hair follicle transglutaminase, and prostate transglutaminase. Although structures differ, they share an active site (YGQCW) and strict CALCIUM dependence.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.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.Fungal Proteins: Proteins found in any species of fungus.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.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.Poly(A)-Binding Protein II: A poly(A) binding protein that is involved in promoting the extension of the poly A tails of MRNA. The protein requires a minimum of ten ADENOSINE nucleotides in order for binding to mRNA. Once bound it works in conjunction with CLEAVAGE AND POLYADENYLATION SPECIFICITY FACTOR to stimulate the rate of poly A synthesis by POLY A POLYMERASE. Once poly-A tails reach around 250 nucleotides in length poly(A) binding protein II no longer stimulates POLYADENYLATION. Mutations within a GCG repeat region in the gene for poly(A) binding protein II have been shown to cause the disease MUSCULAR DYSTROPHY, OCULOPHARYNGEAL.Peptide Elongation Factor G: Peptide Elongation Factor G catalyzes the translocation of peptidyl-tRNA from the A to the P site of bacterial ribosomes by a process linked to hydrolysis of GTP to GDP.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.Cholera Toxin: An ENTEROTOXIN from VIBRIO CHOLERAE. It consists of two major protomers, the heavy (H) or A subunit and the B protomer which consists of 5 light (L) or B subunits. The catalytic A subunit is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE. The B protomer binds cholera toxin to intestinal epithelial cells, and facilitates the uptake of the A1 fragment. The A1 catalyzed transfer of ADP-RIBOSE to the alpha subunits of heterotrimeric G PROTEINS activates the production of CYCLIC AMP. Increased levels of cyclic AMP are thought to modulate release of fluid and electrolytes from intestinal crypt cells.Phospholipase C beta: A phosphoinositide phospholipase C subtype that is primarily regulated by its association with HETEROTRIMERIC G-PROTEINS. It is structurally related to PHOSPHOLIPASE C DELTA with the addition of C-terminal extension of 400 residues.GTP Phosphohydrolase-Linked Elongation Factors: Factors that utilize energy from the hydrolysis of GTP to GDP for peptide chain elongation. EC 3.6.1.-.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Protein Prenylation: A post-translational modification of proteins by the attachment of an isoprenoid to the C-terminal cysteine residue. The isoprenoids used, farnesyl diphosphate or geranylgeranyl diphosphate, are derived from the same biochemical pathway that produces cholesterol.3T3 Cells: Cell lines whose original growing procedure consisted being transferred (T) every 3 days and plated at 300,000 cells per plate (J Cell Biol 17:299-313, 1963). Lines have been developed using several different strains of mice. Tissues are usually fibroblasts derived from mouse embryos but other types and sources have been developed as well. The 3T3 lines are valuable in vitro host systems for oncogenic virus transformation studies, since 3T3 cells possess a high sensitivity to CONTACT INHIBITION.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Binding, Competitive: The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.Protein Structure, Secondary: The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.Dynamins: A family of high molecular weight GTP phosphohydrolases that play a direct role in vesicle transport. They associate with microtubule bundles (MICROTUBULES) and are believed to produce mechanical force via a process linked to GTP hydrolysis. This enzyme was formerly listed as EC 3.6.1.50.Insulin-Like Growth Factor Binding Protein 3: One of the six homologous soluble proteins that bind insulin-like growth factors (SOMATOMEDINS) and modulate their mitogenic and metabolic actions at the cellular level.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Periplasmic Binding Proteins: Periplasmic proteins that scavenge or sense diverse nutrients. In the bacterial environment they usually couple to transporters or chemotaxis receptors on the inner bacterial membrane.PhosphoproteinsReceptors, Cell Surface: Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.Rho Guanine Nucleotide Exchange Factors: Signaling proteins which function as master molecular switches by activating Rho GTPases through conversion of guanine nucleotides. Rho GTPases in turn control many aspects of cell behavior through the regulation of multiple downstream signal transduction pathways.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Adenylosuccinate Synthase: A carbon-nitrogen ligase. During purine ribonucleotide biosynthesis, this enzyme catalyzes the synthesis of adenylosuccinate from GTP; IMP; and aspartate with the formation of orthophosphate and GDP. EC 6.3.4.4.Structure-Activity Relationship: The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.Cytosol: Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.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.cdc42 GTP-Binding Protein: A member of the Rho family of MONOMERIC GTP-BINDING PROTEINS. It is associated with a diverse array of cellular functions including cytoskeletal changes, filopodia formation and transport through the GOLGI APPARATUS. This enzyme was formerly listed as EC 3.6.1.47.Conserved Sequence: A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences.Peptide Elongation Factors: Protein factors uniquely required during the elongation phase of protein synthesis.Promoter Regions, Genetic: DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.Protein-Serine-Threonine Kinases: A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.Cross-Linking Reagents: Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.Tacrolimus Binding Protein 1A: A 12-KDa tacrolimus binding protein that is found associated with and may modulate the function of calcium release channels. It is a peptidyl-prolyl cis/trans isomerase which is inhibited by both tacrolimus (commonly called FK506) and SIROLIMUS.Tubulin: A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from SPERM FLAGELLUM; CILIA; and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120,000 and a sedimentation coefficient of 5.8S. It binds to COLCHICINE; VINCRISTINE; and VINBLASTINE.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.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.Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Latent TGF-beta Binding Proteins: A family of secreted multidomain proteins that were originally identified by their association with the latent form of TRANSFORMING GROWTH FACTORS. They interact with a variety of EXTRACELLULAR MATRIX PROTEINS and may play a role in the regulation of TGB-beta bioavailability.Ribosomes: Multicomponent ribonucleoprotein structures found in the CYTOPLASM of all cells, and in MITOCHONDRIA, and PLASTIDS. They function in PROTEIN BIOSYNTHESIS via GENETIC TRANSLATION.rab5 GTP-Binding Proteins: A genetically related subfamily of RAB GTP-BINDING PROTEINS involved in transport from the cell membrane to early endosomes. This enzyme was formerly listed as EC 3.6.1.47.rab2 GTP-Binding Protein: A protein involved in transport between the ENDOPLASMIC RETICULUM and the GOLGI APPARATUS. This enzyme was formerly listed as EC 3.6.1.47.Amino Acid Substitution: The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.Oncogene Protein p21(ras): Transforming protein encoded by ras oncogenes. Point mutations in the cellular ras gene (c-ras) can also result in a mutant p21 protein that can transform mammalian cells. Oncogene protein p21(ras) has been directly implicated in human neoplasms, perhaps accounting for as much as 15-20% of all human tumors. This enzyme was formerly listed as EC 3.6.1.47.Receptors, Muscarinic: One of the two major classes of cholinergic receptors. Muscarinic receptors were originally defined by their preference for MUSCARINE over NICOTINE. There are several subtypes (usually M1, M2, M3....) that are characterized by their cellular actions, pharmacology, and molecular biology.Affinity Labels: Analogs of those substrates or compounds which bind naturally at the active sites of proteins, enzymes, antibodies, steroids, or physiological receptors. These analogs form a stable covalent bond at the binding site, thereby acting as inhibitors of the proteins or steroids.Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Mutagenesis: Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.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.Insulin-Like Growth Factor Binding Protein 2: One of the six homologous soluble proteins that bind insulin-like growth factors (SOMATOMEDINS) and modulate their mitogenic and metabolic actions at the cellular level.Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Point Mutation: A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.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.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.CCAAT-Enhancer-Binding Proteins: A class of proteins that were originally identified by their ability to bind the DNA sequence CCAAT. The typical CCAAT-enhancer binding protein forms dimers and consists of an activation domain, a DNA-binding basic region, and a leucine-rich dimerization domain (LEUCINE ZIPPERS). CCAAT-BINDING FACTOR is structurally distinct type of CCAAT-enhancer binding protein consisting of a trimer of three different subunits.Arabidopsis Proteins: Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.Septins: A family of GTP-binding proteins that were initially identified in YEASTS where they were shown to initiate the process of septation and bud formation. Septins form into hetero-oligomeric complexes that are comprised of several distinct septin subunits. These complexes can act as cytoskeletal elements that play important roles in CYTOKINESIS, cytoskeletal reorganization, BIOLOGICAL TRANSPORT, and membrane dynamics.Chromatography, Gel: Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.rac GTP-Binding Proteins: A sub-family of RHO GTP-BINDING PROTEINS that is involved in regulating the organization of cytoskeletal filaments. This enzyme was formerly listed as EC 3.6.1.47.TATA-Box Binding Protein: A general transcription factor that plays a major role in the activation of eukaryotic genes transcribed by RNA POLYMERASES. It binds specifically to the TATA BOX promoter element, which lies close to the position of transcription initiation in RNA transcribed by RNA POLYMERASE II. Although considered a principal component of TRANSCRIPTION FACTOR TFIID it also takes part in general transcription factor complexes involved in RNA POLYMERASE I and RNA POLYMERASE III transcription.Rhodopsin: A purplish-red, light-sensitive pigment found in RETINAL ROD CELLS of most vertebrates. It is a complex consisting of a molecule of ROD OPSIN and a molecule of 11-cis retinal (RETINALDEHYDE). Rhodopsin exhibits peak absorption wavelength at about 500 nm.Actins: Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.Magnesium: A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.Protein Structure, Quaternary: The characteristic 3-dimensional shape and arrangement of multimeric proteins (aggregates of more than one polypeptide chain).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)Insulin-Like Growth Factor Binding Protein 1: One of the six homologous proteins that specifically bind insulin-like growth factors (SOMATOMEDINS) and modulate their mitogenic and metabolic actions. The function of this protein is not completely defined. However, several studies demonstrate that it inhibits IGF binding to cell surface receptors and thereby inhibits IGF-mediated mitogenic and cell metabolic actions. (Proc Soc Exp Biol Med 1993;204(1):4-29)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.Cyclic AMP Response Element-Binding Protein: A protein that has been shown to function as a calcium-regulated transcription factor as well as a substrate for depolarization-activated CALCIUM-CALMODULIN-DEPENDENT PROTEIN KINASES. This protein functions to integrate both calcium and cAMP signals.Tumor Cells, Cultured: Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.rab3 GTP-Binding Proteins: A genetically related subfamily of RAB GTP-BINDING PROTEINS involved in calcium-dependent EXOCYTOSIS. This enzyme was formerly listed as EC 3.6.1.47.Replication Protein A: A single-stranded DNA-binding protein that is found in EUKARYOTIC CELLS. It is required for DNA REPLICATION; DNA REPAIR; and GENETIC RECOMBINATION.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.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)Retinol-Binding Proteins: Proteins which bind with RETINOL. The retinol-binding protein found in plasma has an alpha-1 mobility on electrophoresis and a molecular weight of about 21 kDa. The retinol-protein complex (MW=80-90 kDa) circulates in plasma in the form of a protein-protein complex with prealbumin. The retinol-binding protein found in tissue has a molecular weight of 14 kDa and carries retinol as a non-covalently-bound ligand.Nucleotides: The monomeric units from which DNA or RNA polymers are constructed. They consist of a purine or pyrimidine base, a pentose sugar, and a phosphate group. (From King & Stansfield, A Dictionary of Genetics, 4th ed)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.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)Chromatography, Affinity: A chromatographic technique that utilizes the ability of biological molecules to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th 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.Protein Multimerization: The assembly of the QUATERNARY PROTEIN STRUCTURE of multimeric proteins (MULTIPROTEIN COMPLEXES) from their composite PROTEIN SUBUNITS.Nerve Tissue ProteinsRabbits: 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.Cyclic AMP-Dependent Protein Kinases: A group of enzymes that are dependent on CYCLIC AMP and catalyze the phosphorylation of SERINE or THREONINE residues on proteins. Included under this category are two cyclic-AMP-dependent protein kinase subtypes, each of which is defined by its subunit composition.S100 Calcium Binding Protein G: A calbindin protein found in many mammalian tissues, including the UTERUS, PLACENTA, BONE, PITUITARY GLAND, and KIDNEYS. In intestinal ENTEROCYTES it mediates intracellular calcium transport from apical to basolateral membranes via calcium binding at two EF-HAND MOTIFS. Expression is regulated in some tissues by VITAMIN D.Arabidopsis: A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.CREB-Binding Protein: A member of the p300-CBP transcription factor family that was initially identified as a binding partner for CAMP RESPONSE ELEMENT-BINDING PROTEIN. Mutations in CREB-binding protein are associated with RUBINSTEIN-TAYBI SYNDROME.Multiprotein Complexes: Macromolecular complexes formed from the association of defined protein subunits.Cytoskeletal Proteins: Major constituent of the cytoskeleton found in the cytoplasm of eukaryotic cells. They form a flexible framework for the cell, provide attachment points for organelles and formed bodies, and make communication between parts of the cell possible.Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.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.Protein Phosphatase 2: A phosphoprotein phosphatase subtype that is comprised of a catalytic subunit and two different regulatory subunits. At least two genes encode isoforms of the protein phosphatase catalytic subunit, while several isoforms of regulatory subunits exist due to the presence of multiple genes and the alternative splicing of their mRNAs. Protein phosphatase 2 acts on a broad variety of cellular proteins and may play a role as a regulator of intracellular signaling processes.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.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.Peptide Termination Factors: Proteins that are involved in the peptide chain termination reaction (PEPTIDE CHAIN TERMINATION, TRANSLATIONAL) on RIBOSOMES. They include codon-specific class-I release factors, which recognize stop signals (TERMINATOR CODON) in the MESSENGER RNA; and codon-nonspecific class-II release factors.Cell Fractionation: Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.Vitamin D-Binding Protein: An alpha-globulin found in the plasma of man and other vertebrates. It is apparently synthesized in the liver and carries vitamin D and its metabolites through the circulation and mediates the response of tissue. It is also known as group-specific component (Gc). Gc subtypes are used to determine specific phenotypes and gene frequencies. These data are employed in the classification of population groups, paternity investigations, and in forensic medicine.Ligands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)Protein Isoforms: Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.

*G protein

... they also bind GTP and GDP and are involved in signal transduction. Different types of heterotrimeric G proteins share a common ... Heterotrimeric G proteins, sometimes referred to as the "large" G proteins, are activated by G protein-coupled receptors and ... "Regulator of G protein signalling"). Receptors stimulate GTP binding (turning the G protein on). RGS proteins stimulate GTP ... They are small (20-kDa to 25-kDa) proteins that bind to guanosine triphosphate (GTP). This family of proteins is homologous to ...

*Opioid receptor

... a GTP molecule binds to the free nucleotide-binding pocket, and the G protein becomes active. A Gα(GTP) complex is formed, ... it phosphorylates the CREB protein (adds a high energy phosphate group) and activates it. The CREB protein binds to cAMP ... The gamma and beta sub-units are permanently bound together, producing a single Gβγ sub-unit. Heterotrimeric G proteins act as ... G proteins are specialised proteins wherby the nucleotides Guanosine diphosphate (GDP), and Guanosine triphosphate (GTP) bind ...

*Neuromedin B

When NMB binds to its 7-TMR, the heterotrimeric G protein that is attached to the receptor is activated. The G-protein is ... In the activated NMBR/G-protein complex, there occurs an exchange of GTP for GDP bound to G-α subunit. The G-α subunit, in turn ... PKA enters the nucleus and activates the cAMP response element-binding protein. The activated CREB binds along with CREB ... cAMP activates of the enzyme Protein Kinase A (PKA). ... binding protein, co-activator to the CRE region of the DNA in ...

*GNAO1

Wu HC, Lin CT (1994). "Association of heterotrimeric GTP binding regulatory protein (Go) with mitosis". Lab. Invest. 71 (2): ... "Entrez Gene: GNAO1 guanine nucleotide binding protein (G protein), alpha activating activity polypeptide O". Nakamura K, Kodera ... 1994). "Identification of GTP-binding proteins in human glomeruli". Nippon Jinzo Gakkai shi. 36 (1): 9-12. PMID 8107314. ... 1991). "Structure of the human gene and two rat cDNAs encoding the alpha chain of GTP-binding regulatory protein Go: two ...

*PREX1

It has been shown to bind to and activate RAC1 by exchanging bound GDP for free GTP. The encoded protein, which is found mainly ... 5-trisphosphate and the beta-gamma subunits of heterotrimeric G proteins. The protein has been implicated in the spread of ... The protein encoded by this gene acts as a guanine nucleotide exchange factor for the RHO family of small GTP-binding proteins ... Phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchanger 1 protein is a protein that in humans is encoded by the PREX1 ...

*Small GTPase

A typical G-protein is active when bound to GTP and inactive when bound to GDP (i.e. when the GTP is hydrolyzed to GDP). The ... Therefore, a G-protein can be switched on and off. GTP hydrolysis is accelerated by GTPase activating proteins (GAPs), while ... GTP). They are a type of G-protein found in the cytosol that are homologous to the alpha subunit of heterotrimeric G-proteins, ... GTP-binding protein regulators Wennerberg K, Rossman KL, Der CJ (March 2005). "The Ras superfamily at a glance". J. Cell Sci. ...

*GoLoco motif

GTPase activating proteins (GAPs), which enhance GTP hydrolysis (see PDOC50132), and guanine dissociation inhibitors (GDIs), ... When the ligand is associated to the receptor, GDP is displaced from G-alpha and GTP is bound. The GTP/G-alpha complex ... GoLoco motif is a protein structural motif. In heterotrimeric G-protein signalling, cell surface receptors (GPCRs) are coupled ... Ponting CP (1999). "Raf-like Ras/Rap-binding domains in RGS12- and still-life-like signalling proteins". J. Mol. Med. 77 (10): ...

*Glucagon (medication)

The conformation change in the receptor activates G proteins, a heterotrimeric protein with α, β, and γ subunits. When the G ... a conformational change that results in the replacement of the GDP molecule that was bound to the α subunit with a GTP molecule ... which activates protein kinase A (cAMP-dependent protein kinase). This enzyme, in turn, activates phosphorylase kinase, which ... Glucagon binds to the glucagon receptor, a G protein-coupled receptor, located in the plasma membrane. ...

*SNX13

The RGS family members are regulatory molecules that act as GTPase activating proteins for G alpha subunits of heterotrimeric G ... The RGS domain of this protein interacts with G alpha(s), accelerates its GTP hydrolysis, and attenuates G alpha(s)-mediated ... family and the regulator of G protein signaling (RGS) family. The PHOX domain is a phosphoinositide binding domain, and the SNX ... Because of its bifunctional role, this protein may link heterotrimeric G protein signaling and vesicular trafficking. GRCm38: ...

*G protein-coupled receptor

The GPCR can then activate an associated G protein by exchanging the GDP bound to the G protein for a GTP. The G protein's α ... It is known that in the inactive state, the GPCR is bound to a heterotrimeric G protein complex. Binding of an agonist to the ... binding of G proteins to receptors affects the receptor's affinity for ligands. Activated G proteins are bound to GTP. Further ... in this case the G protein Gs. Adenylate cyclase activity is activated when it binds to a subunit of the activated G protein. ...

*Transducin

... seems to be about 100-fold smaller than for GTP-bound Tα. The mechanism by which GDP-boundactivates PDE remains unknown ... It is a type of heterotrimeric G-protein with different α subunits in rod and cone photoreceptors. Light leads to ... Interaction with photolyzed rhodopsin opens up the GTP-binding site to allow for rapid exchange of GDP for GTP. The binding ... opening the GTP-binding site. Once GTP has been exchanged for GDP, the GTP-Tα complex undergoes two major changes: dissociation ...

*GNA13

"Expression of GTP-binding protein alpha subunits in human thymocytes". Molecular and Cellular Biochemistry. 144 (1): 45-51. doi ... "Interaction of heterotrimeric G13 protein with an A-kinase-anchoring protein 110 (AKAP110) mediates cAMP-independent PKA ... "G proteins of the G12 family are activated via thromboxane A2 and thrombin receptors in human platelets". Proceedings of the ... Guanine nucleotide-binding protein subunit alpha-13 is a protein that in humans is encoded by the GNA13 gene. GNA13 has been ...

*GNAQ

G-alpha-q is the alpha subunit of one of the heterotrimeric GTP-binding proteins that mediates stimulation of phospholipase C- ... functionally couples to the G proteins Gq and G11 in vivo and is activated by the isoprostane 8-epi prostaglandin F2 alpha". J ... Guanine nucleotide-binding proteins are a family of heterotrimeric proteins that couple cell surface, 7-transmembrane domain ... "Regulation of GTP-binding protein alpha q (Galpha q) signaling by the ezrin-radixin-moesin-binding phosphoprotein-50 (EBP50)". ...

*G alpha subunit

The activated receptor promotes the exchange of bound GDP for GTP on the G protein alpha subunit. GTP binding changes the ... Guanine nucleotide binding proteins (G proteins) are membrane-associated, heterotrimeric proteins composed of three subunits: ... The alpha subunit consists of two domains: a GTP-binding domain and a helical insertion domain (INTERPRO). The GTP-binding ... The length of the G protein signal is controlled by the duration of the GTP-bound alpha subunit, which can be regulated by RGS ...

*Heterotrimeric G protein

For example, the Gβγ complex, when bound to histamine receptors, can activate phospholipase A2. Gβγ complexes bound to ... and the GTP form of the α subunit of the stimulatory G protein (Gs) activates hormone-sensitive adenylate cyclase. Gα subunits ... "G protein" usually refers to the membrane-associated heterotrimeric G proteins, sometimes referred to as the "large" G proteins ... These proteins are activated by G protein-coupled receptors and are made up of alpha (α), beta (β) and gamma (γ) subunits, the ...

*Protein kinase A

In protein synthesis, PKA first directly activates CREB, which binds the cAMP response element, altering the transcription and ... The Gs alpha subunit of the stimulated G protein complex exchanges GDP for GTP and is released from the complex. The activated ... change is induced in the receptor that is transmitted to an attached intracellular heterotrimeric G protein complex by protein ... activating the proteins. As protein expression varies from cell type to cell type, the proteins that are available for ...

*Ras subfamily

Since the GDP-bound form is "off" or "inactive" for signaling, GTPase Activating Protein inactivates Ras by activating its ... This GTP-bound state of Ras is the "on" state, and the GDP-bound state is the "off" state. Ras also binds a magnesium ion which ... which is related in structure to the Gα subunit of heterotrimeric G proteins (large GTPases). G proteins function as binary ... they may also bind to the rest of the protein surface. Other proteins exist may change the activity of Ras family proteins. One ...

*Regulator of G protein signaling

... active GTP-bound alpha subunit and beta-gamma dimer, both of which activate downstream effectors. The response is terminated ... Regulators of G protein signaling (or RGS) are protein structural domains that activate GTPases for heterotrimeric G-protein ... Whereas receptors stimulate GTP binding, RGS proteins stimulate GTP hydrolysis. RGS proteins have been conserved in evolution. ... RGS proteins markedly reduce the lifespan of GTP-bound alpha subunits by stabilising the G protein transition state. ...

*CAMP-dependent pathway

... and the effector protein. In humans, cAMP works by activating protein kinase A (PKA, cAMP-dependent protein kinase), one of the ... In a cAMP-dependent pathway, the activated Gs alpha subunit binds to and activates an enzyme called adenylyl cyclase, which, in ... The Gs alpha subunit of the stimulated G protein complex exchanges GDP for GTP and is released from the complex. ... a conformational change is induced in the receptor that is transmitted to an attached intracellular heterotrimeric G protein ...

*GNAI1

"GTP-binding proteins in human platelet membranes serving as the specific substrate of islet-activating protein, pertussis toxin ... Tall GG, Krumins AM, Gilman AG (Mar 2003). "Mammalian Ric-8A (synembryn) is a heterotrimeric Galpha protein guanine nucleotide ... Guanine nucleotide-binding protein G(i), alpha-1 subunit is a protein that in humans is encoded by the GNAI1 gene. Click on ... "Entrez Gene: GNAI1 Guanine nucleotide binding protein (G protein), alpha inhibiting activity polypeptide 1". Schiaffino MV, ...

*GTPase-activating protein

The activity of G proteins comes from their ability to bind guanosine triphosphate (GTP). Binding of GTP inherently changes the ... Most GAPs that act on alpha subunits of heterotrimeric G proteins belong to a distinct family, the RGS protein family. While ... GTPase-activating proteins or GTPase-accelerating proteins (GAPs) are a family of regulatory proteins whose members can bind to ... EIF5 is a GTPase-activating protein. Furthermore, YopE is a protein domain that is a Rho GTPase-activating protein (GAP), which ...

*CDC42

... which promote the exchange of bound GDP for free GTP, GTPase activating proteins (GAPs) which increase GTP hydrolysis activity ... "Analysis of RhoA-binding proteins reveals an interaction domain conserved in heterotrimeric G protein beta subunits and the ... a transcriptionally inducible adapter protein that binds GTP-Cdc42 and activates SAPK/JNK. A potential marker transcript for ... "The Ras GTPase-activating-protein-related human protein IQGAP2 harbors a potential actin binding domain and interacts with ...

*Pertussis toxin

PT has also become widely used as a biochemical tool to ADP-ribosylate GTP-binding proteins in the study of signal transduction ... PT catalyzes the ADP-ribosylation of the αi subunits of the heterotrimeric G protein. This prevents the G proteins from ... At some point during this transport, the A subunit (or protomer) becomes activated, perhaps through the action of glutathione ... Once in the cytosol, it can bind to NAD and form a stable, folded protein again. Being thermally unstable is also the Achilles ...

*RGS19

"GTPase-activating proteins for heterotrimeric G proteins: regulators of G protein signaling (RGS) and RGS-like proteins". ... 1997). "GAIP is membrane-anchored by palmitoylation and interacts with the activated (GTP-bound) form of G alpha i subunits". ... 1998). "RGS-GAIP, a GTPase-activating protein for Galphai heterotrimeric G proteins, is located on clathrin-coated vesicles". ... family and specifically interacts with G protein, GAI3. This protein is a guanosine triphosphatase-activating protein that ...

*List of MeSH codes (D12.644)

... heterotrimeric gtp-binding proteins MeSH D12.644.360.375.100 --- gtp-binding protein alpha subunits MeSH D12.644.360.375. ... mitogen-activated protein kinase 14 MeSH D12.644.360.525 --- monomeric gtp-binding proteins MeSH D12.644.360.525.100 --- adp- ... rab5 gtp-binding proteins MeSH D12.644.360.525.450 --- ral gtp-binding proteins MeSH D12.644.360.525.462 --- ran gtp-binding ... rab gtp-binding proteins MeSH D12.644.360.525.400.025 --- rab1 gtp-binding proteins MeSH D12.644.360.525.400.050 --- rab2 gtp- ...
Looking for online definition of ras-related GTP-binding protein 4b in the Medical Dictionary? ras-related GTP-binding protein 4b explanation free. What is ras-related GTP-binding protein 4b? Meaning of ras-related GTP-binding protein 4b medical term. What does ras-related GTP-binding protein 4b mean?
Looking for online definition of guanine nucleotide binding protein (G protein), beta polypeptide 4 in the Medical Dictionary? guanine nucleotide binding protein (G protein), beta polypeptide 4 explanation free. What is guanine nucleotide binding protein (G protein), beta polypeptide 4? Meaning of guanine nucleotide binding protein (G protein), beta polypeptide 4 medical term. What does guanine nucleotide binding protein (G protein), beta polypeptide 4 mean?
TY - JOUR. T1 - Signal transduction by guanine nucleotide binding proteins. AU - Spiegel, Allen M.. PY - 1987/1. Y1 - 1987/1. N2 - High affinity binding of guanine nucleotides and the ability to hydrolyze bound GTP to GDP are characteristics of an extended family of intracellular proteins. Subsets of this family include cytosolic initiation and elongation factors involved in protein synthesis, and cytoskeletal proteins such as tubulin (Hughes S.M. (1981) FEBS Lett. 164, 1-8). A distinct subset of guanine nucleotide binding proteins is membrane-associated; members of this subset include the ras gene products (Ellis R.W. et al. (1981) Nature 292, 506-511) and the heterotrimeric G-proteins (also termed N-proteins) (Gilman A.G. ...
Author: Praefcke, G. J. K. et al.; Genre: Other; Published in Print: 2000; Title: Identification of regions in human guanylate binding protein 1 (hGBP1) responsible for oligomerization and GTPase activity
Ras-homologous GTPases constitute a large family of signal transducers that alternate between an activated, GTP-binding state and an inactivated, GDP-binding state. These proteins represent cellular switches that are operated by GTP-exchange factors and factors that stimulate their intrinsic GTPase activity. All GTPases of the Ras superfamily have in common the presence of six conserved motifs involved in GTP/GDP binding, three of which are phosphate-/magnesium-binding sites (PM1-PM3) and three of which are guanine nucleotide-binding sites (G1-G3). Transcript variants encoding distinct isoforms have been identified. [provided by RefSeq, Jul 2008 ...
Itsui, Y., Sakamoto, N., Kakinuma, S., Nakagawa, M., Sekine-Osajima, Y., Tasaka-Fujita, M., Nishimura-Sakurai, Y., Suda, G., Karakama, Y., Mishima, K., Yamamoto, M., Watanabe, T., Ueyama, M., Funaoka, Y., Azuma, S. and Watanabe, M. (2009), Antiviral effects of the interferon-induced protein guanylate binding protein 1 and its interaction with the hepatitis C virus NS5B protein. Hepatology, 50: 1727-1737. doi: 10.1002/hep.23195 ...
LOW-molecular-weight GTP-binding proteins are strong candidates for regulators of membrane traffic1-3. In yeast, mutations in the sec4 or ypt1 genes encoding small GTP-binding proteins inhibit constitutive membrane flow at the plasma membrane or Golgi complex, respectively4-6. It has been suggested that membrane fusion-fission events are regulated by cycling of small GTP-binding proteins between a membrane-bound and free state7, but although most of these small proteins are found in both soluble and tightly membrane-bound forms, there is no direct evidence to support such cycling. In rat brain a small GTP-binding protein, rab3A, is exclusively associated with synaptic vesicles, the secretory organelles of nerve terminals8,9. Here we use ...
The Rac proteins, Rac1 and Rac2, are essential components of the NADPH oxidase system of phagocytes and regulate the actin assembly associated with membrane ruffling. These functions are controlled by the GTP-bound form of Rac. The biochemical interaction between Rac and its only known GDP-dissociation stimulator (termed smgGDS) was characterized. SmgGDS was able to stimulate the incorporation of guanosine 5′-[gamma-thio]-triphosphate GTP[gamma S] into the RhoA, Rac2, Rac1, Rap1A and CDC42Hs GTP-binding proteins, but the activity was greatest toward RhoA and Rac2. Isoprenoid modification of these proteins was not absolutely required for the interaction with smgGDS. Interestingly, the activity of smgGDS toward Rac1 could not be observed in a [3H]GDP/GTP exchange assay under conditions where it stimulated incorporation of ...
In the yeast Saccharomyces cerevisiae, the G protein beta gamma subunits are essential for pheromone signaling. The Galpha subunit Gpa1 can also promote signaling, but the effectors in this pathway are not well characterized. To identify candidate Gpa1 effectors, we expressed the constitutively active Gpa1(Q323L) mutant in each of nearly 5000 gene-deletion strains and measured mating-specific responses. Our analysis reveals a requirement for both the catalytic (Vps34) and regulatory (Vps15) subunits of the sole phosphatidylinositol 3-kinase in yeast. We demonstrate that Gpa1 is present at endosomes, where it interacts directly with both Vps34 and Vps15 and stimulates increased production of phosphatidylinositol 3-phosphate. Notably, Vps15 binds to GDP-bound Gpa1 and is predicted to have a seven-WD repeat structure similar to that of known G protein beta subunits. These findings reveal two new components of the pheromone signaling pathway. More remarkably, these proteins ...
This gene encodes a member of the guanylate-binding protein (GBP) family. GBPs specifically bind guanine nucleotides (GMP, GDP, and GTP) and contain two of the three consensus motifs found in typical GTP-binding proteins. The encoded protein interacts with a member of the germinal center kinase family. Multiple transcript variants encoding different isoforms have been been found for this gene. [provided by RefSeq, Jan 2016 ...
Looking for online definition of guanine nucleotide-binding protein G(I)/G(S)/G(T) beta subunit 1 in the Medical Dictionary? guanine nucleotide-binding protein G(I)/G(S)/G(T) beta subunit 1 explanation free. What is guanine nucleotide-binding protein G(I)/G(S)/G(T) beta subunit 1? Meaning of guanine nucleotide-binding protein G(I)/G(S)/G(T) beta subunit 1 medical term. What does guanine nucleotide-binding protein G(I)/G(S)/G(T) beta subunit 1 mean?
Small GTP-binding proteins (G proteins) are monomeric G proteins with a low molecular weight of 20 to 40 kDa. A small G protein acts as a molecular switch that cycles between inactive GDP-bound and active GTP-bound forms. Thus far, ,100 small G proteins have been identified in eukaryotes from yeast to humans. The small G proteins in this superfamily are structurally classified into ≥5 families: the Ras, Rho, Rab, Sar/Arf, and Ran families. In general, the Ras family mainly regulates gene expression, the Rho family regulates both cytoskeletal reorganization and gene expression, the Rab and Sar1/Arf families regulate intracellular vesicle trafficking, and the Ran family regulates nucleocytoplasmic transport and microtubule organization during the cell cycle.1. Multiple downstream effectors of ...
Agonist binding to guanine nucleotide-binding protein (G protein)-coupled receptors in membranes of myeloid differentiated human leukemia (HL-60) cells is inhibited by guanine nucleotides, most potently by the GTP analog guanosine 5-(gamma-thio)triphosphate (GTP gamma S). In order to study whether GTP gamma S formed locally from adenosine 5-(gamma-thio)triphosphate (ATP gamma S) and GDP by nucleoside diphosphokinase has any advantage over exogenously added GTP gamma S in binding to and activating G proteins, regulation of complement component 5a (C5a) binding to its receptors, as well as formation of GTP gamma S, was studied in membranes of HL-60 cells. GTP gamma S added to HL-60 membranes potently inhibited binding of 125I-C5a (IC50 about 3 nM), an effect not influenced by addition of ...
Many microbes create and maintain pathogen-containing vacuoles (PVs) as an intracellular niche permissive for microbial growth and survival. The destruction of PVs by IFNγ-inducible guanylate binding protein (GBP) and immunity-related GTPase (IRG) host proteins is central to a successful immune response directed against numerous PV-resident pathogens. However, the mechanism by which IRGs and GBPs cooperatively detect and destroy PVs is unclear. We find that host cell priming with IFNγ prompts IRG-dependent association of Toxoplasma- and Chlamydia-containing vacuoles with ubiquitin through regulated translocation of the E3 ubiquitin ligase tumor necrosis factor (TNF) receptor associated factor 6 (TRAF6). This initial ubiquitin labeling elicits p62-mediated escort and deposition of GBPs to PVs, thereby conferring cell-autonomous immunity. Hypervirulent strains of Toxoplasma gondii evade this process via specific rhoptry protein kinases that ...
Signaling by kinases and phosphatases that act on serine, threonine, and tyrosine residues of proteins is among the most extensively studied regulatory mechanisms in mammalian cells, and research focused in this area is ongoing. We are just beginning to appreciate that such signaling mechanisms are extended and enriched by the reversible phosphorylation of histidine residues. The most exciting developments in this field to date come from studies on the β subunit of heterotrimeric guanosine triphosphate-binding proteins (G proteins), the enzyme adenosine 5′-triphosphate-citrate lyase, and now the Ca2+-activated K+ channel KCa3.1, all of which are targeted by nucleoside diphosphate kinase (which phosphorylates histidines) and protein histidine phosphatase (which dephosphorylates phosphorylated histidines).. ...
TY - JOUR. T1 - Inhibiting ras signaling in the therapy of breast cancer. AU - Li, Tianhong. AU - Sparano, Joseph A.. PY - 2003/2. Y1 - 2003/2. N2 - Ras is a small guanosine triphosphate-binding protein that plays an important role in signal transduction pathways that influence cellular proliferation, apoptosis, cytoskeletal organization, and other important biological processes. Prenylation of Ras proteins by the enzyme farnesyltransferase renders the protein hydrophobic, causing localization to the inner surface of the cell membrane, where it exerts its biological effects. Ras mutations that result in constitutive activation of the Ras pathway are common in certain human cancers, and transfection of cell lines with mutant Ras renders them tumorigenic. Farnesyltransferase inhibitors (FTIs) were initially developed to inhibit growth of cancers harboring Ras mutations, but preclinical data suggests that they also have antiproliferative effects in cell lines ...
Caspase-11 directly detects LPS within the host cell cytosol (6). To explain how LPS gains access to the host cell cytosol, four distinct LPS delivery pathways were proposed: (i) some intracellular Gram-negative bacteria escape vacuoles to enter the host cell cytosol, where they release LPS (30); (ii) host GBPs execute membranolytic activities to extrude intracellular Gram-negative bacteria from PVs and extract LPS through bacteriolysis (10, 19-21); (iii) endocytosed bacterial OMVs release LPS into the host cell cytosol potentially through fusion with or transport across endosomal membranes (15, 31); and (iv) circulating free LPS (in the form of aggregates or bound to LPS-binding proteins) is consumed in vivo by an undefined cell population able to present LPS for caspase-11-mediated recognition (4, 5). Here, we present evidence that GBPs play previously unknown roles in the latter two pathways.. GBPs assist caspase-11 activation in response to infections ...
G protein-coupled receptors (GPCRs) which are also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptor, and G protein-linked receptors (GPLR), constitute a large protein family of receptors that detect molecules outside the cell and activate internal signal transduction pathways and, ultimately, cellular responses. Coupling with G proteins, they are called seven-transmembrane receptors because they pass through the cell membrane seven times. G protein-coupled receptors are found only in eukaryotes, including yeast, choanoflagellates, and animals. The ligands that bind and activate these receptors include light-sensitive compounds, odors, pheromones, hormones, and neurotransmitters, and vary in size from small molecules to peptides to large proteins. G protein-coupled receptors are involved in many diseases, and are also the target of approximately ...
Nuclear envelope assembly is promoted by phosphoinositide- specific phospholipase C with selective recruitment of phosphatidylinositol-enriched membranes Nuclear envelope (NE) formation in a cell-free egg extract proceeds by precursor membrane vesicle binding to chromatin in an ATP-dependent manner, followed by a GTP-induced NE assembly step. The requirement for GTP in the latter step of this process can be mimicked by addition of bacterial PI-PLC [phosphoinositide (PtdIns)-specific phospholipase C]. The NE assembly process is here dissected in relation to the requirement for endogenous phosphoinositide metabolism, employing recombinant eukaryotic PI-PLC, inhibitors and direct phospholipid analysis using ESI-MS (electrospray ionization mass spectrometry). PtdIns (phosphatidylinositol) species analysis by ESI-MS indicates that the chromatin-bound NE precursor vesicles are enriched for specific PtdIns species. Moreover, during GTP-induced ...
MAP4K component of the MAPK pathway required for the mating pheromone response, haploid invasive growth and diploid pseudohyphal development. Links the pheromone response G-protein beta gamma subunits to downstream signaling components. Needed for mating in haploid cells, induction of a mating-specific gene FUS1, induction of mating-specific morphologies, and pheromone-induced proliferation arrest. Required for the regulation of the actin polarization and bud emergence during cell cycle in G1. Involved in the high osmolarity glycerol (HOG) response. Phosphorylates Thr-307 and Ser-302 or Ser-306 of STE11 and Ser-357 of MYO3. Phosphorylates histone H2B to form H2BS10ph during meiosis and H(2)O(2)-induced apoptosis. Its interaction with CDC42 is required for both invasive growth and the formation of pseudohyphae. Its interaction with STE4 is required for the pheromone signaling.
Brefeldin A-inhibited guanine nucleotide-exchange protein 3 (BIG3) has been identified recently as a novel regulator of estrogen signalling in breast cancer cells. Despite being a potential target for new breast cancer treatment, its amino acid sequence suggests no association with any well-characterized protein family and provides little clues as to its molecular function. In this paper, we predicted the structure, function and interactions of BIG3 using a range of bioinformatic tools. Homology search results showed that BIG3 had distinct features from its paralogues, BIG1 and BIG2, with a unique region between the two shared domains, Sec7 and DUF1981. Although BIG3 contains Sec7 domain, the lack of the conserved motif and the critical glutamate residue suggested no potential guaninyl-exchange factor (GEF) activity. Fold recognition tools predicted BIG3 to adopt an α-helical repeat structure similar to that of the armadillo (ARM) family. Using state-of-the-art methods, we predicted interaction sites
The quantitative determination of pertussis-toxin-sensitive guanine-nucleotide-binding proteins (G-proteins) in cell membranes is still a problem. Pertussis-toxin-catalysed [32P]ADP-ribosylation strongly relies on the substrate quality of the alpha-subunits and is influenced by the concentration of nucleotides, beta gamma-subunits, the physicochemical properties of the membranes influencing the availability of Gi alpha for pertussis toxin, and covalent modification of Gi alpha. Quantification of immunoreactive material on Western blots can be only imprecisely performed by two-dimensional densitometry. In order to generate a method for quantification of pertussis-toxin-sensitive G-proteins in membranes we have developed a fast and sensitive radioimmunoassay. The C-terminal decapeptide of retinal transducin alpha (KENLKDCGLF) was 125I-labelled and used as tracer. Polyclonal antiserum (DS 4) ...
387554453 - EP 1118621 A4 2003-06-25 - NOVEL G PROTEIN-COUPLED RECEPTOR PROTEIN AND DNA THEREOF - [origin: WO0020456A1] A human-origin G protein-coupled receptor protein or its peptide fragment or its salt, a nucleic acid encoding this receptor protein and its derivative, etc. The human hippocampus-origin G protein-coupled receptor protein or the nucleic acid encoding the same and its derivative are usable in determining a ligand (an agonist) to the G protein-coupled receptor protein, as preventives and/or remedies for diseases in association with dysfunction of the G protein-coupled receptor protein, as gene diagnostics, in a method for screening a compound capable of varying the expression dose of the G protein-coupled receptor protein or its peptide fragment, etc.[origin: WO0020456A1] A human-origin G protein-coupled receptor protein or its peptide fragment or its salt, a nucleic acid encoding this receptor protein and its derivative, etc. The human hippocampus-origin G protein-coupled receptor
In this study, we have shown that basal MOR activity is detectable in mouse brain tissue and that it is up-regulated by morphine treatment. A role for basal MOR signaling in narcotic dependence is buttressed by the finding that changes in basal MOR activity persist for prolonged time periods, consistent with prolonged signs of antagonist-induced withdrawal after exposure to morphine.. The basal signaling activity of MOR was detected with the use of inverse agonists, β-CNA and BNTX (Wang et al., 2001b). Since basal MOR signaling spontaneously increases receptor/G protein coupling, inverse agonists are expected to decreased basal receptor/G protein coupling. We used two assays to test basal MOR activity, [35S]GTPγS binding and adenylyl cyclase activity assays. [35S]GTPγS binding measures direct receptor/G protein coupling, whereas adenylyl cyclase activity is an immediate downstream event, capable of amplifying the signal, and therefore, a ...
PST receptors were purified and characterized in the liver, hepatoma membranes, as well as the signal transduction (55, 62, 63). This receptor appears to mediate the dual signaling mechanism in liver (57). PST stimulation activates pertussis toxin-insensitive G protein (Gαq/11), leading to the activation of phospholipase C b3 isoform (PLC-b3) (69), and therefore mediates the glycogenolytic effect in the liver by increasing cytoplasmic free calcium and stimulating PKC, while the pertussis toxin-sensitive G protein (Gai1,2) leads to the activation of guanylatecyclase (51). In the signaling pathway, hydrolysis of phosphatidylinositol 4,5-bisphosphate by Ca2+-mobilizing hormones leads to the formation of two second messengers i.e., inositol-1,4,5-triphosphate (InsP3) and diacylglycerol (DAG). The primary function of InsP3 is to mobilize Ca2+ from intracellular stores (60), whereas DAG stimulates PKC (58).. Active PST receptors were solubilized from rat liver membranes, and these results support ...
rho GTP-Binding Proteins: A large family of MONOMERIC GTP-BINDING PROTEINS that are involved in regulation of actin organization, gene expression and cell cycle progression. This enzyme was formerly listed as EC 3.6.1.47.
The guanosine triphosphate (GTP)-binding proteins include signal-transducing heterotrimeric G proteins (for example, Gs, Gi), smaller GTP-binding proteins that function in protein sorting, and the oncogenic protein p21ras. The T cell receptor complexes CD4-p56lck and CD8-p56lck were found to include a 32- to 33-kilodalton phosphoprotein (p32) that was recognized by an antiserum to a consensus GTP-binding region in G proteins. Immunoprecipitated CD4 and CD8 complexes bound GTP and hydrolyzed it to guanosine diphosphate (GDP). The p32 protein was covalently linked to [alpha-32P]GTP by ultraviolet photoaffinity labeling. These results demonstrate an interaction between T cell receptor complexes and an intracellular ...
A wide range of extracellular signals are transduced by G protein-coupled receptors (GPCRs). When activated by ligands, GPCRs can activate associated heterotrimeric guanine nucleotide-binding proteins (G proteins), which in turn act on various effectors. Increasing evidence indicates that GPCRs also signal independently of heterotrimeric G proteins. Several GPCRs directly interact with Src-family kinases. Here, we discuss the evidence for direct interaction and activation of Src-family kinases by GPCRs and data that suggest that agonist dosage provides a mechanism by which GPCRs can switch between G protein-dependent and G protein-independent signaling.. ...
The lipoglycoproteins of the WNT family act on seven transmembrane-spanning Class Frizzled receptors. Here, we show that WNT-5A evokes a proliferative response in a mouse microglia-like cell line (N13), which is sensitive to pertussis toxin, thus implicating the involvement of heterotrimeric G proteins of the G(i/o) family. We continue to show that WNT-5A stimulation of N13 membranes and permeabilized cells evokes the exchange of GDP for GTP of pertussis toxin-sensitive G proteins employing [gamma-(35)S]GTP assay and activity state-specific antibodies to GTP-bound G(i) proteins. Our functional analysis of the PTX-sensitivity of WNT-induced G protein activation and PCR analysis of G protein and FZD expression patterns suggest that WNT-5A stimulation leads to the activation of G(i2/3) ...
Previous studies on immortalized B lymphoblasts from patients with EH and enhanced Na+-H+ exchanger activity have revealed an enhanced activation of PTX-sensitive G proteins.7 This conclusion was mainly based on two findings. First, HT lymphoblasts displayed enhanced [Ca2+]i signals upon stimulation with platelet-activating factor and somatostatin. Pretreatment with PTX strongly reduced these agonist-evoked Ca2+ signals, and the residual Ca2+ responses were no longer different between NT and HT cell lines. Second, both receptor-mediated stimulation and direct (by mastoparan-7) stimulation of GTPγS binding to PTX-sensitive G proteins were significantly increased in HT lymphoblasts.7 Unfortunately, B lymphoblasts apparently do not express functional receptors that are selectively coupled to PTX-insensitive G proteins, eg, Gq or Gs. Therefore, our proposal of a selective ...
Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-3 is a protein that in humans is encoded by the GNB3 gene. Heterotrimeric guanine nucleotide-binding proteins ( G proteins), which integrate signals between receptors and effector proteins, are composed of an alpha, a beta, and a gamma subunit. These subunits are encoded by families of related genes. This gene encodes a beta subunit. Beta subunits are important regulators of alpha subunits, as well as of certain signal transduction receptors and effectors. A single-nucleotide polymorphism (C825T) in this gene is associated with essential hypertension and obesity. This polymorphism is also associated with the occurrence of the splice variant GNB3-s, which appears to have increased activity. GNB3-s is an example of alternative splicing caused by a nucleotide change outside of the splice donor and ...
We studied the effects of various beta-adrenoceptor (beta AR) antagonists and local anesthetics (LAs), i.e. substances possessing one basic and one lipophilic domain each, on activation of regulatory heterotrimeric guanine nucleotide-binding proteins (G-proteins). In membranes of differentiated HL-60 cells, propranolol activated high-affinity GTP hydrolysis with a half-maximal effect at 0.19 mM and a maximum at 1 mM. There was a close correlation between the log Q values (logarithm of the octanol: water partition coefficient) of beta AR antagonists and the logarithm of their effectiveness at activating GTPase (EC 3.6.1.-) in HL-60 membranes. The lipophilic LA, tetracaine, was also an effective activator of GTPase in HL-60 membranes, whereas more hydrophilic LAs were less stimulatory (bupivacaine and lidocaine) or even inhibitory (procaine). ...
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Several studies have demonstrated that AngII infusion leads to the formation of AAAs in mice.12,13,50 AngII exerts its diverse bioactive effects primarily by activating the AT1a receptor in mice, which plays a critical role in AngII-induced AAA development.17 In addition to mediating traditional G-protein-dependent signaling, the AT1a receptor is involved in G-protein-independent signaling by forming a complex with the multifunctional scaffolding protein βarr2.19,24 In the present study, we investigated a role for βarr2 in AngII-induced AAA formation and found that βarr2 deficiency significantly attenuates AAA formation in mice both on a hyperlipidemic apoE background and on a normolipidemic C57BL/6 background (Figure 1). These studies suggest that G-protein-independent, βarr2-dependent signaling for the AT1a receptor plays a major role in AngII-induced AAA formation.. Although our present studies showed that βarr2 deficiency attenuated AngII-induced AAA formation in mice on the ...
The Escherichia coli guanosine triphosphate (GTP)-binding proteins Ffh and FtsY have been proposed to catalyze the cotranslational targeting of proteins to the bacterial plasma membrane. A mutation was introduced into the GTP-binding domain of FtsY that altered its nucleotide specificity from GTP to xanthosine triphosphate (XTP). The mutant FtsY protein stimulated GTP hydrolysis by a ribonucleoprotein consisting of Ffh and 4.5S RNA in a reaction that required XTP, and it hydrolyzed XTP in a reaction that required both the Ffh-4.5S ribonucleoprotein and GTP. Thus, nucleotide triphosphate hydrolysis by Ffh and FtsY is likely to occur in reciprocally coupled reactions in which the two interacting guanosine triphosphatases act as regulatory proteins for each other. ...
beta Karyopherins: Nucleocytoplasmic transport molecules that bind to ALPHA KARYOPHERINS in the CYTOSOL and are involved in transport of molecules through the NUCLEAR PORE COMPLEX. Once inside the CELL NUCLEUS beta karyopherins interact with RAN GTP-BINDING PROTEIN and dissociate from alpha karyopherins. Beta karyopherins bound to RAN GTP-BINDING PROTEIN are then re-transported to the cytoplasm where hydrolysis of the GTP of RAN GTP-BINDING PROTEIN causes release of karyopherin beta.
Inositol phosphate accumulation and adenylate cyclase activity were investigated in the cortex of young and aged ethanol-treated rats. Three months of ethanol treatment of young rats decreased maximal stimulation of inositol phosphate accumulation by carbachol by 26%, from 494 ± 76% of basal turnover in control animals to 396 ± 54% in ethanol-treated animals (mean ± SD). In aged rats ethanol-related changes were no longer observed but age-related changes were evident. EC50 was significantly higher than in young animals and maximal stimulation was significantly lower. Basal adenylate cyclase activity in cortical membranes of all groups of animals was not different. Forskolin-stimulated adenylate cyclase activity was not affected by ethanol treatment, but was higher in aged animals. The activity of forskolin-stimulated adenylate cyclase in the presence of carbachol was higher in both young and aged ethanol-treated animals, when compared to young controls. These results suggest that both ethanol ...
Breast cancer is the most common malignancy in women worldwide. Although the endocrine therapy that targets estrogen receptor α (ERα) signaling has been well established as an effective adjuvant treatment for patients with ERα-positive breast cancers, long-term exposure may eventually lead to the development of acquired resistance to the anti-estrogen drugs, such as fulvestrant and tamoxifen. A better understanding of the mechanisms underlying antiestrogen resistance and identification of the key molecules involved may help in overcoming antiestrogen resistance in breast cancer. The whole-genome gene expression and DNA methylation profilings were performed using fulvestrant-resistant cell line 182R-6 and tamoxifen-resistant cell line TAMR-1 as a model system. In addition, qRT-PCR and Western blot analysis were performed to determine the levels of mRNA and protein molecules. MTT, apoptosis and cell cycle analyses were performed to examine the effect of either guanine nucleotide-binding ...
In vivo administration of pertussis toxin is often used to study the involvement of guanine nucleotide binding proteins in signal transduction. Especially when it is administered in the brain the effect is often poor. This could be due to the fact that pertussis toxin does not reach the area of interest. To evaluate the extent to which pertussis toxin is distributed in rat brain after intraventricular injection, different techniques were used. Immunohistochemical studies with an antibody against pertussis toxin showed that immunoreactivity was limited to periventricular brain structures less than 0.5 mm from the lumen. The highest immunoreactivity was seen 16-24 h after injection. After 96 h the labeling was very weak. The proportion of guanine nucleotide binding proteins that were ADP-ribosylated by in vivo injection of pertussis toxin into the ventricles as assessed by in vitro [32P]-back-ADP-ribosylation ...
The ability of morphine to alleviate pain is mediated through a heterotrimeric guanine nucleotide binding protein (G protein)-coupled heptahelical receptor (GPCR), the mu opioid receptor (muOR). The efficiency of GPCR signaling is tightly regulated and ultimately limited by the coordinated phosphorylation of the receptors by specific GPCR kinases and the subsequent interaction of the phosphorylated receptors with beta-arrestin 1 and beta-arrestin 2. Functional deletion of the beta-arrestin 2 gene in mice resulted in remarkable potentiation and prolongation of the analgesic effect of morphine, suggesting that muOR desensitization was impaired. These results provide evidence in vivo for the physiological importance of beta-arrestin 2 in regulating the function of a specific GPCR, the muOR. Moreover, they suggest that inhibition of beta-arrestin 2 function might lead to enhanced analgesic effectiveness of morphine and provide potential new avenues for the study and treatment of ...
The guanosine triphosphate (GTP)-loaded form of the guanosine triphosphatase (GTPase) Ras initiates multiple signaling pathways by binding to various effectors, such as the kinase Raf and phosphatidylinositol 3-kinase (PI3K). Ras activity is increased by guanine nucleotide exchange factors that stimulate guanosine diphosphate release and GTP loading and is inhibited by GTPase-activating proteins that stimulate GTP hydrolysis. KRAS is the most frequently mutated RAS gene in cancer. Here, we report that monoubiquitination of lysine-147 in the guanine nucleotide-binding motif of wild-type K-Ras could lead to enhanced GTP loading. Furthermore, ubiquitination increased the binding of the oncogenic Gly12Val mutant of K-Ras to the downstream effectors PI3K and Raf. Thus, monoubiquitination could enhance GTP loading ...
Previously we used mass spectrometry to show that the yeast G protein alpha subunit Gpa1 is ubiquitinated at Lys-165, located within a subdomain not present in other G alpha proteins (Marotti, L. A., Jr., Newitt, R., Wang, Y., Aebersold, R., and Dohlman, H. G. (2002) Biochemistry 41, 5067-5074). Here we describe the functional role of Gpa1 ubiquitination. We find that Gpa1 expression is elevated in mutants deficient in either proteasomal or vacuolar protease function. Vacuolar protease pep4 mutants accumulate monoubiquitinated Gpa1, and much of the protein is localized within the vacuolar compartment. In contrast, proteasome-defective rpt6/cim3 mutants accumulate polyubiquitinated Gpa1, and in this case the protein exhibits cytoplasmic localization. Cells that lack Ubp12 ubiquitin-processing protease activity accumulate both mono- and polyubiquitinated forms of Gpa1. In this case, Gpa1 accumulates in both the cytoplasm and vacuole. Finally, a Gpa1 mutant that lacks the ...
The signal recognition particle (SRP) consists of one RNA and six protein subunits. The N-terminal domain of the 54K subunit contains a putative GTP-binding site, whereas the C-terminal domain binds signal sequences and SRP RNA. Binding of SRP to the signal sequence as it emerges from the ribosome creates a cytosolic targeting complex containing the nascent polypeptide chain, the translating ribosome, and SRP. This complex is directed to the endoplasmic reticulum membrane as a result of its interaction with the SRP receptor, a membrane protein composed of two subunits, SR alpha and SR beta, each of which also contains a GTP-binding domain. In the presence of GTP, SRP receptor binding to SRP causes the latter to dissociate from both the signal sequence and the ribosome. GTP is then hydrolysed so that SRP can be released from the SRP receptor and returned to the cytosol. Here ...
We have demonstrated previously the potent activation of PLD by the chemokine IL-8 in T lymphocytes (18). We have now extended our findings to include the C-C chemokine RANTES in demonstrating that in the Jurkat T cell line, the activation of this enzyme occurs at subnanomolar concentrations and is dependent on the activation of small GTP-binding protein cofactors. RANTES-induced PLD activation is consistently maximal at 1 nM, a concentration corresponding to the optimal chemotaxis-inducing dose in normal T lymphocytes. Interestingly, PLD activation in T lymphocytes and Jurkat T cells appears to be an important biologic consequence of chemokine action and more readily measurable (at nanomolar concentrations) than readouts of receptor activation such as calcium flux. It was also apparent that RANTES is the only chemokine tested to date (RANTES, MIP-1α, MIP-1β, MCP-1, MCP-3, lymphotactin) that induces as robust a response as seen in this study, although the others listed were ...
We recently identified dynamin as a third nucleotide-sensitive microtubule-associated protein in brain tissue, in addition to kinesin and cytoplasmic dynein. Molecular cloning analysis has revealed that dynamin contains the three consensus elements characteristic of GTP-binding proteins, and biochemical results support a role for GTP in dynamin function. Dynamin is also homologous to the Mx proteins, involved in interferon-induced viral resistance, and the product of the yeast VPS1 gene, involved in vacuolar protein sorting. These results identify a novel class of GTP-utilizing proteins, with apparently diverse functions. ...
1. Guanosine 5′-[gamma-thio]triphosphate (GTP[S]), if added before GTP, blocks both Ca2+ efflux promoted by GTP and the effect of GTP on enhancement of inositol 1,4,5-triphosphate (IP3)-promoted Ca2+ release from preloaded microsomal vesicles. If, however, GTP[S] is added after GTP, it does not reverse the Ca2+ efflux promoted by GTP, nor does it inhibit IP3-promoted Ca2+ release. 2. The effect of GTP in enhancing IP3-promoted Ca2+ release is maintained after washing the microsomal vesicles free of added GTP. After this treatment, enhancement of IP3-promoted Ca2+ efflux can be observed in the absence of poly(ethylene glycol). 3. Electron microscopy shows that during GTP treatment of microsomal vesicles there is rapid production of very large vesicular structures, apparently produced by fusion of smaller vesicles. 4. Light-scattering changes ...
Metabotropic glutamate receptors (mGluRs) are coupled to effector systems through GTP-binding proteins (G-proteins) and appear to mediate slow synaptic responses in the CNS. Although mGluR-mediated increases in phosphoinositide hydrolysis have been well characterized, other mechanisms for signal transduction employed by mGluRs are poorly understood. We recently reported that the selective mGluR agonist 1- aminocyclopentane-1 S,3R-dicarboxylic acid (1S,3R-ACPD) increases cAMP accumulation in rat hippocampal slices. We have now investigated the mechanisms involved in this response. A number of G-protein-linked receptors that are not directly coupled to adenylate cyclase increase cAMP accumulation by potentiating cAMP responses to other agonists. Furthermore, previous studies suggest that glutamate increases cAMP accumulation by a mechanism that is dependent upon the presence of endogenous adenosine. Therefore, ...
Sphingosine 1-phosphate (S1P) is one of several bioactive phospholipids that exert profound mitogenic and morphogenic actions. Originally characterized as a second messenger, S1P is now recognized to achieve many of its effects through cell surface, G protein-coupled receptors. We used a subunit-selective [35S]GTPγS binding assay to investigate whether the variety of actions exerted through Edg-1, a recently identified receptor for S1P, might be achieved through multiple G proteins. We found, employing both Sf9 and HEK293 cells, that Edg-1 activates only members of the Gi family, and not Gs, Gq, G12, or G13. We additionally established that Edg-1 activates Gi in response not only to S1P but also sphingosylphosphorylcholine; no effects of lysophosphatidic acid through Edg-1 were evident. Our assays further revealed a receptor(s) for S1P endogenous to HEK293 cells that mediates activation of G13 as well as Gi. ...
GUANOSINE TRIPHOSPHATE | C10H16N5O14P3 | CID 6830 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.
As shown above, the morphology of the mitotic figure of arsenic-treated cells had features found with both Taxol and Colcemid. These observations correlate with recent findings on the three-dimensional structure of tubulin (18) that show that when the GTP binding site is unoccupied, two cysteine residues, Cys-12 and Cys-213, are in close proximity in the three-dimensional structure, separating after GTP binding occurs. Reaction of trivalent arsenic with these vicinal cysteine residues would inactivate the GTP binding site. This is further supported by an earlier finding that two cysteines in tubulin can be cross-linked after the removal of GTP (19) . These features provide a biochemical basis for the action of arsenic as a noncompetitive inhibitor of GTP binding to tubulin. Confirmation of this mechanism is provided by the preventive effect ...
Guanine is one of the five main nucleobases found in the nucleic acids DNA and RNA. Guanine is a derivative of purine, consisting of a fused pyrimidine-imidazole ring system with conjugated double bonds. Being unsaturated, the bicyclic molecule is planar. The guanine nucleoside is called guanosine. The first isolation of guanine was reported in 1844 from the excreta of sea birds, known as guano, which was used as a source of fertilizer. High affinity binding of guanine nucleotides and the ability to hydrolyze bound GTP to GDP are characteristics of an extended family of intracellular proteins. Guanine nucleotide-binding regulatory proteins may be involved in the activation of phospholipases C and A2 by hormones and other ligands. The binding of hormones to receptors that activate phospholipase C is decreased by guanine nucleotides and these hormones also ...
Vasopressin is the key regulator of water homeostasis in vertebrates. Central to its antidiuretic action in mammals is the redistribution of the water channel aquaporin 2 (AQP2) from intracellular vesicles to the apical membrane of kidney epithelial cells, an event initiated by an increase in cAMP and activation of protein kinase A. The subsequent steps of the signaling cascade are not known. To identify proteins involved in the AQP2 shuttle we exploited a recently developed cell line (CD8) derived from the rabbit cortical collecting duct and stably transfected with rat AQP2 cDNA. Treatment of CD8 cells with pertussis toxin (PTX) inhibited both the vasopressin-induced increase in water permeability and the redistribution of AQP2 from an intracellular compartment to the apical membrane. ADP-ribosylation studies revealed the presence of at least two major PTX substrates. Correspondingly, two alpha subunits of PTX-sensitive G proteins, Galphai2 ...
The researchers compared the results of prior single-particle electron microscopy analysis of the β2AR-Gs complex to the structure predicted by their model and found good agreement. They also used continuous wave electron paramagnetic resonance spectroscopy (CW-EPR) and peptide amide hydrogen-deuterium exchange mass spectrometry data to calculate changes in the solvent accessibility of key residues in the free versus receptor-bound Gα subunit. The results of these calculations agreed well with predictions based on the model. To further test the models validity, they selected an amino acid in the GTPase domain and another in the helical domain of Gi. They expressed a Gi protein bearing mutations in both of these amino acids to cysteine and then attached a sulfur-accessible nitroxide probe to each cysteine. The altered protein allowed them to use DEER to assess the changes in the distance between the GTPase and helical domains upon interaction of Gα with the ...
Guanyl nucleotide binding-proteins, or G-proteins, are ubiquitous molecules that are involved in cellular signal transduction mechanisms. Because a role has been established for cAMP in meiosis and G-proteins participate in cAMP-generating systems by stimulating or inhibiting adenylate cyclase, the present study was conducted to examine the possible involvement of G-proteins in the resumption of meiotic maturation. Cumulus cell-free mouse oocytes (denuded oocytes) were maintained in meiotic arrest in a transient and dose-dependent manner when microinjected with the nonhydrolyzable GTP analog, GTP gamma S. This effect was specific for GTP gamma S, because GppNHp, GTP, and ATP gamma S were without effect. Three compounds, known to interact with ...
βarrestin (βarr)-1 and -2 (βarrs) (or Arrestin-2 and -3, respectively) are universal G protein-coupled receptor (GPCR) adapter proteins expressed abundantly in extra-retinal tissues, including the myocardium. Both were discovered in the lab of the 2012 Nobel Prize in Chemistry co-laureate Robert Lefkowitz, initially as terminators of signaling from the β-adrenergic receptor (βAR), a process known as functional desensitization. They are now known to switch GPCR signaling from G protein-dependent to G protein-independent, which, in the case of βARs and angiotensin II type 1 receptor (AT1R), might be beneficial, e.g., anti-apoptotic, for the heart. However, the specific role(s) of each βarr isoform in cardiac GPCR signaling and function (or dysfunction in disease), remain unknown. The current consensus is that, whereas both βarr isoforms can desensitize and internalize cardiac GPCRs, they play quite different (even opposing in certain instances) roles in the G ...
FUNCTION: Guanine nucleotide-exchange factor (GEF) required for the formation or budding of transport vesicles from the ER. This function involves the cytoplasmic domain of the protein, which is thought to interact with the small GTP-binding protein SAR1. Required for autophagy. MISCELLANEOUS: In the process of transport, SEC12 itself may migrate to the Golgi apparatus and function in subsequent transport events. MISCELLANEOUS: Present with 6160 molecules/cell in log phase SD medium ...
The bacterial homologues of the signal recognition particle (SRP) and its receptor, the Ffh*4.5S RNA ribonucleoprotein complex and the FtsY protein, respectively, form a unique complex in which both Ffh and FtsY act as GTPase activating proteins for one another, resulting in the mutual stimulation of GTP hydrolysis by both proteins. Previous work showed that 4.5S RNA enhances the GTPase activity in the presence of both Ffh and FtsY, but it was not clear how this was accomplished. In this work, kinetic and thermodynamic analyses of the GTPase reactions of Ffh and FtsY have provided insights into the role of 4.5S RNA in the GTPase cycles of Ffh and FtsY. We found that 4.5S RNA accelerates the association between Ffh and FtsY 400-fold in their GTP-bound form, analogous to its 200-fold catalytic effect on Ffh*FtsY association previously observed ...
Regulator of G protein signaling (RGS) proteins accelerate GTP hydrolysis by Gα subunits and thus facilitate termination of signaling initiated by G protein-coupled receptors (GPCRs). RGS proteins hold great promise as disease intervention points, given their signature role as negative regulators of GPCRs-receptors to which the largest fraction of approved medications are currently directed. RGS proteins share a hallmark RGS domain that interacts most avidly with Gα when in its transition state for GTP hydrolysis; by binding and stabilizing switch regions I and II of Gα, RGS domain binding consequently accelerates Gα-mediated GTP hydrolysis. The human genome encodes more than three dozen RGS domain-containing proteins with varied Gα substrate specificities. To facilitate their exploitation ...
Summary is not available for the mouse gene. This summary is for the human ortholog.] Regulator of G protein signaling (RGS) family members are regulatory molecules that act as GTPase activating proteins (GAPs) for G alpha subunits of heterotrimeric G proteins. RGS proteins are able to deactivate G protein subunits of the Gi alpha, Go alpha and Gq alpha subtypes. They drive G proteins into their inactive GDP-bound forms. Regulator of G protein signaling 4 belongs to this family. All RGS proteins share a conserved 120-amino acid sequence termed the RGS domain. Regulator of G protein signaling 4 protein is 37% identical to RGS1 and 97% identical to rat Rgs4. This protein negatively regulate signaling upstream or at the level of the heterotrimeric G protein and is localized in ...
TY - JOUR. T1 - ADP ribosylation factor 6 regulates neuronal migration in the developing cerebral cortex through FIP3/arfophilin-1-dependent endosomal trafficking of N-cadherin. AU - Hara, Yoshinobu. AU - Fukaya, Masahiro. AU - Hayashi, Kanehiro. AU - Kawauchi, Takeshi. AU - Nakajima, Kazunori. AU - Sakagami, Hiroyuki. PY - 2016. Y1 - 2016. N2 - During neural development, endosomal trafficking controls cell shape and motility through the polarized transport of membrane proteins related to cellcell and cellextracellular matrix interactions. ADP ribosylation factor 6 (Arf6) is a critical small GTPase that regulates membrane trafficking between the plasma membrane and endosomes. We herein demonstrated that the knockdown of endogenous Arf6 in mouse cerebral cortices led to impaired neuronal migration in the intermediate zone and cytoplasmic retention of N-cadherin and syntaxin12 in migrating neurons. Rescue experiments with separation-of-function Arf6 mutants ...
The beta-adrenergic receptor kinase (beta ARK) phosphorylates the agonist-occupied beta-adrenergic receptor to promote rapid receptor uncoupling from Gs, thereby attenuating adenylyl cyclase activity. Beta ARK-mediated receptor desensitization may reflect a general molecular mechanism operative on many G-protein-coupled receptor systems and, particularly, synaptic neurotransmitter receptors. Two distinct cDNAs encoding beta ARK isozymes were isolated from rat brain and sequenced. The regional and cellular distributions of these two gene products, termed beta ARK1 and beta ARK2, were determined in brain by in situ hybridization and by immunohistochemistry at the light and electron microscopic levels. The beta ARK isozymes were found to be expressed primarily in neurons distributed throughout the CNS. Ultrastructurally, beta ARK1 and beta ARK2 immunoreactivities were present both in association with postsynaptic densities and, presynaptically, with axon terminals. The beta ARK isozymes have a ...
Functional selectivity, which highlights the ability of ligands to differentially activate the signalling pathways linked to G protein-couple receptors (GPCRs) has provided an avenue for developing ligands with greater safety profiles. Pilocarpine (Pilo), a non-selective muscarinic acetylcholine receptor (mAChR) agonist has been shown to differentially activate G protein subtypes linked to the M3 mAChR. In this study the pharmacology of Pilo was further investigated using a number of readouts. When compared to methacholine (MCh), a reference agonist, Pilo appeared to preferentially stimulate inositol phosphates production than global receptor phosphorylation. The ligand also appeared to preferentially promote phosphorylation of Ser412 at the third intracellular loop of the receptor than Ser577 at the C-terminal tail. This differential phosphorylation may be linked to the fact that these residues are phosphorylated by distinct protein kinases. However, such preferential ...
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Video created by Icahn School of Medicine at Mount Sinai for the course Introduction to Systems Biology. Module description goes here. 2000+ courses from schools like Stanford and Yale - no application required. Build career skills in data ...
In biology, small GTPases are small (20-25 kDa) proteins that bind to guanosine triphosphate (GTP). This family of proteins is homologous to Ras GTPases and also called the Ras superfamily GTPases. Together with heterotrimeric G-proteins they constitute the G-proteins. They are all GTPases and share common features, but small GTPases have slightly different structures and mechanisms of action. A typical G-protein is active when bound to GTP and inactive when bound to GDP (i.e. when the GTP is hydrolyzed to GDP). The GDP can be then replaced by free GTP. Therefore, a G-protein can be switched on and off. GTP hydrolysis is accelerated by GTPase accelating ...
Ver más] The small GTP-binding protein ADP-ribosylation factor 1 (ARF1) is an essential component of the molecular machinery that catalyzes the formation of membranebound transport intermediates. By using an in vitro assay that reproduces recruitment of cytosolic proteins onto purified, high salt-washed Golgi membranes, we have analyzed the role of cAMP-dependent protein kinase A (PKA) on ARF1 incorporation. Addition to this assay of either pure catalytic subunits of PKA (C-PKA) or cAMP increased ARF1 binding. By contrast, ARF1 association was inhibited following C-PKA inactivation with either PKA inhibitory peptide or RIIa as well as after cytosol depletion of C-PKA. C-PKA also stimulated recruitment and activation of a recombinant form of human ARF1 in the absence of additional cytosolic components. The binding step could be dissociated from the activation reaction and found to be independent of guanine ...
Addresses: Bilgin N, Univ Uppsala, Ctr Biomed, Dept Biochem, Box 576, S-75123 Uppsala, Sweden. Uppsala Univ, Ctr Biomed, Dept Biol Mol, S-75124 Uppsala, Sweden. Inst Biol Struct, F-38027 Grenoble 1, France. DESY, European Mol Biol Lab, D-22603 Hamburg, GeAvailable from: 2008-10-17 Created: 2008-10-17 Last updated: 2011-01-14 ...
The time course of cAMP production by S49 cell membranes in the presence of forskolin and a nonhydrolyzable GTP analog can yield information about the regulation of adenylate cyclase by both the inhibitory and stimulatory GTP-binding proteins (Gi and Gs). The time courses are complex and interpretation in terms of the activities of G1 and Gs requires a quantitative hypothesis. We present a general quantitative hypothesis that defines adenylate cyclase as existing in a distribution of two states, active and inactive. Gi and Gs, in their active states, alter the equilibrium of this distribution. Two distinct models are derived based on this hypothesis to accommodate two different proposed mechanisms for the action of Gi to inhibit adenylate cyclase: 1) a direct interaction between Gi and the catalytic subunit of adenylate cyclase and 2) a direct interaction between Gi and Gs. Perturbations of the regulation of adenylate ...
It has been debated whether the potassium channel of the atrium is activated by the alpha subunit or by the beta gamma subunits of guanine nucleotide binding (G) proteins, which dissociate on activation with guanosine triphosphate (GTP). Therefore, the channel-activating effectiveness of these subunits on isolated guinea pig atrial cells was tested. The activated alpha K subunit from human erythrocytes activated the channel in subpicomolar concentrations. The beta gamma dimer from bovine brain activated the channel in nanomolar concentrations. These results support the view that, physiologically, the alpha subunit activates the channel. ...
Ahnert-Hilger, G.; Wegenhorst, U.; Stecher, B.; Spicher, K.; Rosenthal, W. und Gratzl, Manfred (1992): Exocytosis from permeabilized bovine adrenal chromaffin cells is differently modulated by guanosine 5-[gamma-thio]triphosphate and guanosine 5-[beta gamma-imido]triphosphate. Evidence for the involvement of various guanine nucleotide-binding proteins. In: Biochemical Journal, Vol. 284: S. 321-326 [PDF, 3MB] ...
G protein-coupled receptors (GPCRs) relay diverse extracellular signals into cells by catalyzing nucleotide release from heterotrimeric G proteins, but the mechanism underlying this quintessential molecular signaling event has remained unclear. Here we use atomic-level simulations to elucidate the nucleotide-release mechanism. We find that the G protein α subunit Ras and helical domains-previously observed to separate widely upon receptor binding to expose the nucleotide-binding site-separate spontaneously and frequently even in the absence of a receptor. Domain separation is necessary but not sufficient for rapid nucleotide release. Rather, receptors catalyze nucleotide release by favoring an internal structural rearrangement of the Ras domain that weakens its nucleotide affinity. We use double electron-electron resonance spectroscopy and protein engineering to confirm predictions of our computationally determined ...
Title:Application of BRET for Studying G Protein-Coupled Receptors. VOLUME: 14 ISSUE: 5. Author(s):Agnieszka A. Kaczor, Magdalena Makarska-Bialokoz, Jana Selent, Rocio A. de la Fuente, Maria Marti-Solano and Marian Castro. Affiliation:Department of Synthesis and Chemical Technology of Pharmaceutical Substances with Computer Modeling Lab, Faculty of Pharmacy with Division of Medical Analytics, Medical University of Lublin, 4A Chodzki St., PL-20093 Lublin, Poland.. Keywords:BRET, G protein-coupled receptors, G protein-coupled receptor dimers.. Abstract:G protein-coupled receptors (GPCRs) constitute one of the largest classes of cell surface receptors. GPCR biology has been a subject of widespread interest owing to the functional relevance of these receptors and their potential importance in the development of new drugs. At present, over 30% of all launched drugs target these receptors. GPCRs have been considered for a long time to function as monomeric entities and the idea of GPCR dimerization ...
Regulation of neuronal voltage-activated Ca2+ channels by neurotransmitters and intracellular signaling pathways is an important step in the control of neurotransmitter release, synaptic transmission, and neuronal plasticity. In the present study, we have determined the effect of a novel anti-dementia drug FK960 on voltage-activated Ca2+ channels in isolated rat hippocampal neurons. Our results demonstrate for the first time that FK960 modulates the G protein-mediated inhibitory effect of somatostatin on Ca2+ channels and, furthermore, enhances the basal Ca2+ currents in hippocampal neurons.. It has been suggested that somatostatin receptors inhibit N-type Ca2+ channels via PTX-sensitive G proteins through a direct membrane-delimited model (Shapiro and Hille, 1993; Hille et al., 1995; Zhang et al., 1996). Somatostatin-induced inhibition of Ca2+ currents in these isolated hippocampal neurons is mediated by activation of G ...
gs99, invoking micro-intelligence isnt needed to explain the arrival of activated nucleotides during replication. The Polymerase doesnt send out for the right nucleotide triphosphate; instead, random nucleotide triphosphates bump into the template nucleotide. If the nucleotide triphosphate hydrogen bonds correctly with the template nucleotide, the new phosphodiester linkage forms. If the nucleotide triphosphate is the wrong one then usually it will not slip into the correct orientation to form the new bond, so it is quickly displaced and another random activated nucleotide slips into position at the polymerase active site and bumps against the template nucleotide. Eventually (in a tiny fraction of a second) a correct nucleotide is fitted and reacted and the polymerase advances. If a mistake is made (and this sometimes happens), it is almost always caught by the proofreading function of the polymerase and corrected. If not, a mutation has occurred (a rare event). The process ...
1. General Function. Rab1 is a small GTP binding protein that is expressed in virtually all mammalian cells, fish, worms and flies and is homologous to the yeast protein Ypt1 (3). It is essential for ER to Golgi transport and has also been implicated in intra Golgi transport (22, 30). There are two isoforms Rab1a (205 aa) and Rab1b (201aa) which are 92% identical at the amino acid level with most differences in the carboxyl terminus (28). These two isoforms are generally localized in the same cellular regions and have similar biochemical properties and functions. Rab1a may also play a role in transcytosis (14). In addition to localization by immunoflourescence in tissue culture cells, Rab1a has been localized by immunogold labeling to vesicles between the ER and Golgi region and over Golgi stacks in NRK cells (23).. The vesicular transport activity of Rab1 is dependent on its GTPase activity as a GDP bound mutant form, Rab1aS25N and the nucleotide free ...
Controls Rho proteins homeostasis. Regulates the GDP/GTP exchange reaction of the Rho proteins by inhibiting the dissociation of GDP from them, and the subsequent binding of GTP to them. Retains Rho proteins such as CDC42, RAC1 and RHOA in an inactive cytosolic pool, regulating their stability and protecting them from degradation. Actively involved in the recycling and distribution of activated Rho GTPases in the cell, mediates extraction from membranes of both inactive and activated molecules due its exceptionally high affinity for prenylated forms. Through the modulation of Rho proteins, may play a role in cell motility regulation. In glioma cells, inhibits cell migration and invasion by mediating the signals of SEMA5A and PLXNB3 that lead to inactivation of RAC1.
Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems.
TY - JOUR. T1 - Modulation of forskolin binding to rat brain membranes. AU - Seamon, K. B.. AU - Vaillancourt, Richard. AU - Daly, J. W.. PY - 1985. Y1 - 1985. N2 - High affinity binding sites for [3H]forskolin have been identified in rat brain membranes. These sites have a K(d) of 15 nM and a B(max) of about 200 fmol/mg protein. The binding of [3H]forskolin to those high affinity sites in rat brain membranes is increased about two-fold by addition of MgCl2 or MnCl2. Smaller increases are observed in the presence of calcium, sodium, or potassium. The binding of [3H]forskolin is also increased in the presence of NaF or GppNHp, agents that are known to activate adenylate cyclase through the stimulatory guanine nucleotide regulatory protein (N(s)). The increase in [3H]forskolin binding in the presence of NaF or GppNHp is due to an increase in the number of binding sites with no change in the ...
Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems.
Guanine nucleotides regulate binding of opiate agonists to membrane receptors by increasing agonist dissociation rates. The current study demonstrates that the ability of guanosine 5-triphosphate (GTP) and its nonhydrolyzable analogue guanylyl-5-imidodiphosphate (Gpp(NH)p) to inhibit opiate agonist binding to rat brain membranes can be altered by two methods: by preincubating with EDTA, and by preincubating at pH 4.5. EDTA pretreatment increased the potency of Gpp(NH)p in inhibiting [3H]morphine binding by 4-fold, with little apparent change in the maximum effect of Gpp(NH)p or on levels of binding itself. The effect of EDTA pretreatment was blocked by prior incubation of membranes with excess calcium or manganese but could not be reversed by any divalent cation if the EDTA incubation was longer than 10 min. EDTA pretreatment increased the effects of GTP on dissociation rates of agonists. Pretreatment of ...
Research Summary. Research in my laboratory is centered around signalling events, particularly those that involve intracellular Ca2+ and the major Ca2+ -binding regulatory protein calmodulin. Two systems we are investigating are the regulation of protein synthesis and the control of endocytosis by Ca2+, both of which involve (different) calmodulin-regulated events. We are also interested in the mechanism of action of neurotrophic factors like nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) as they relate to the effects of these proteins on CNS neurons. Part of the action of these factors also involves Ca2+. Current projects. Neurotrophic factors and CNS neurons We have shown that primary cultures of rat embryonic hippocampal neurons can be used for biochemical investigations of the signal transduction pathways activated by BDNF and neurotrophin-3. These cells homogeneously express the receptors for these neurotrophins ...
B pertussis produces numerous virulence factors, including toxins and attachment agents, many of which are antigenic and included in the acellular vaccine. The link of each virulence factor to clinical illness has been difficult to elucidate due to lack of an animal model for experimentation. However, a recently developed model in infant baboons has the potential to address unanswered questions. The bacteria attach to ciliated epithelial cells of the respiratory tract, induce ciliary paralysis and local inflammation, and thicken and decrease clearance of secretions. B pertussis is not invasive. Pertussis toxin, necessary but not sufficient to cause clinical pertussis, is secreted by the bacteria and affects G-protein function, which prevents migration of lymphocytes to the area of infection, and inhibits the function of neutrophils, macrophages, monocytes, and lymphocytes. Adenylate cyclase toxin invades phagocytes and induces high levels of cyclic adenosine monophosphate (AMP), which impairs ...
Arginine adenosine-5′-diphosphoribosylation (ADP-ribosylation) is an enzyme-catalyzed potentially reversible posttranslational changes where the ADP-ribose moiety is transferred from NAD+ towards the guanidino CHR2797 moiety of arginine. proteins with binding companions e.g. toxin-catalyzed ADP-ribosylation of actin at R177 blocks actin polymerization sterically. In case there is the nucleotide-gated P2X7 ion route ADP-ribosylation at R125 near the ligand-binding site causes route Rabbit Polyclonal to SF3B3. gating. Arginine-specific ADP-ribosyltransferases (ARTs) bring a quality R-S-EXE theme that distinguishes these enzymes from structurally related enzymes which catalyze ADP-ribosylation of additional amino acid part chains DNA or little substances. Arginine-specific ADP-ribosylation could be inhibited by little molecule arginine analogues such as for example CHR2797 agmatine or meta-iodobenzylguanidine (MIBG) which themselves can serve ...
Guanine nucleotide-binding proteins (G-proteins) are known to act as important modulators of insulin release from the islets of Langerhans. We have recently found that the deoxynojirimycin-derivative emiglitate, a recognized inhibitor of intestinal α-glucosidehydrolase activity, is a powerful inhibitor of glucose-induced insulin release. With the use of isolated mouse islets the present investigation was performed in a primary attempt to elucidate whether this inhibitory mechanism in some way was linked to the β-cell G-protein system. Treatment of freshly isolated islets with pertussis toxin (PTX), which is known to inactivate the Gi-proteins, abolished the inhibitory effect of the α2-adrenoceptor agonist clonidine on insulin release stimulated by the phosphodiesterase inhibitor IBMX in the presence of the protein kinase C activator TPA and even changed it into an increase. ...
GDP-dissociation inhibitors (GDIs) play a primary role in modulating the activity of GTPases. We recently reported the identification of a new GDI for the Rho-related GTPases named RhoGDIgamma. This gene is now designated ARHGDIG by HUGO. Here, in a detailed analysis of tissue expression of ARHGDIG, we observe high levels in the entire brain, with regional variations. The mRNA is also present at high levels in kidney and pancreas and at moderate levels in spinal cord, stomach, and pituitary gland. In other tissues examined, the mRNA levels are very low (lung, trachea, small intestine, colon, placenta) or undetectable. RT-PCR analysis of total RNA isolated from exocrine pancreas and islets shows that the gene is expressed in both tissues. We also report the genomic structure of ARHGDIG. The gene spans over 4 kb and is organized into six exons and five introns. The upstream region lacks a canonical TATA box and contains several putative binding sites for ...
Rhodopsin is a member of an ancient class of receptors that transduce signals through their interaction with guanine nucleotide-binding proteins (G proteins). We have mapped the sites of interaction of rhodopsin with its G protein, which by analogy suggests how other members of this class of receptors may interact with their G proteins. Three regions of rhodopsins cytoplasmic surface interact with the rod cell G protein transducin (Gt). These are (i) the second cytoplasmic loop, which connects rhodopsin helices III and IV, (ii) the third cytoplasmic loop, which connects rhodopsin helices V and VI, and (iii) a putative fourth cytoplasmic loop formed by amino acids 310-321, as the carboxyl-terminal sequence emerges from helix VII and anchors to the lipid bilayer via palmitoylcysteines 322 and 323. Evidence for these regions of interaction of rhodopsin and Gt comes from the ability of synthetic ...
The NADPH oxidase generates microbicidal superoxide in phagocytes, and when defective it leads to chronic granulomatous disease (CGD). Oxidase specific proteins in the cytosol, p47phox and p67phox, as well as the small GTP binding protein p21rac are important for activation of superoxide production. Because the activity of this oxidase is normally tightly restricted to the phagocytic vacuole, and its temporal and spatial organisation might be regulated by cytoskeletal proteins, we examined the cytosolic phox proteins for interactions with cytoskeletal elements. p67phox copurified with a 57 kDa protein, identified as coronin, an actin binding protein that is important for movement and phagocytosis in Dictyostelium. Binding studies revealed that coronin attaches to the C-terminal half of p40phox, a binding partner of p67phox. ...
The nonselective alpha-adrenergic agonist oxymetazoline inhibits parathyroid hormone (PTH)-stimulated cAMP production in intact OK cells, an epithelial cell line derived from an American opossum kidney. This inhibition, however, is not blocked by alpha 2-adrenergic receptor antagonists. After excluding several alternate hypotheses to explain this anomalous activity of oxymetazoline, we hypothesized that oxymetazoline activates a receptor in OK cells that is negatively coupled to adenylate cyclase but distinct from the alpha 2-adrenergic receptor. Prior exposure of OK cells to pertussis toxin blocks the inhibitory response to oxymetazoline, suggesting involvement of a guanine nucleotide-binding regulatory protein. Screening various compounds for attenuation of PTH-stimulated adenylate cyclase showed that serotonin (5HT) is a potent and fully efficacious agonist. Desensitization of alpha 2-receptor-mediated inhibition of cAMP production by epinephrine did not alter the ...
Myc-DDK-tagged ORF clone of Homo sapiens GDP dissociation inhibitor 2 (GDI2), transcript variant 2 as transfection-ready DNA - 10 µg - OriGene - cdna clones
Recent clinical studies have revealed that increased serum triglyceride (TG) levels are closely related to atherosclerosis, independently of serum levels of high-density lipoproteins (HDL) and low-density lipoproteins (LDL). Among triglyceride-rich lipoproteins (TRLs), remnant lipoproteins (RLPs) are considered to be atherogenic and an independent coronary risk factor. We previously reported that monocytes cultured in the presence of RLPs increased their adhesion to vascular endothelial cells. The underlying mechanism involved activation of RhoA, a member of small GTP binding proteins, resulting in activation of focal adhesion kinase (FAK) and s1-integrin. It is also known that RLPs enter vessel walls. In another study, we reported that RLPs induced smooth muscle cell (SMC) proliferation, independently of ...
By using MT1 homodimers and MT1/MT2 heterodimers as model GPCRs, we are extending here two emerging concepts: the pre‐assembly of GPCR‐interacting complexes and the asymmetric function and organization of GPCR dimers. In addition, we are providing a new functional justification for GPCR dimerization that applies to homo‐ and heterodimers, namely the possibility of simultaneous and direct binding of GPCR‐interacting proteins (GIPs) to the same GPCR dimer composed of two asymmetric protomers. Heterotrimeric G proteins are central, although not exclusive signal transducers of GPCRs. An increasing number of reports suggests the formation of pre‐assembled receptor-G‐protein complexes, which rearrange upon agonist activation of the receptor (Bunemann et al, 2003; Galés et al, 2006; Audet et al, 2008). This central complex is surrounded by a number of other GIPs that might either compete with the G protein for ...
Proteins that hydrolyze guanine triphosphate to yield guanine diphosphate. This is a class of proteins that belongs to a family of high energy phosphate hydrolases. Members of this family play major roles in biological signal transduction pathways.
Guanosine triphosphate, labeled on the alpha phosphate group with 32P, is typically used in reactions involving enzymes that will incorporate the ribonucleoside monophosphate (base, sugar, and alpha-labeled phosphate) into a chain of RNA. Common applications include:. ...
Guanine nucleotide-binding proteins (G proteins) ares involved as modulators or transducers in various transmembranes signaling ...
2. Ans. is other than B & E. IN the presence of GTP & all the process has -deltaG & the original AA to Prot reaction has been combined with the GTP hydrolysis as its individual deltaG is positive. MOre than that for deltaG to be positive u cant have -deltaH along with +deltaS. Im seeing for more info ...
泰国公共债务管理办事处负责人朱拉乐女士日前表示,今年7月分公债总额为5兆2111亿9401万铢,在国内生产总值(GDP)占比约44.11%,与今年6月相比,公债规模减少127亿1700万铢。

The G Protein-Coupled Receptor Gpr1 Is a Nutrient Sensor That Regulates Pseudohyphal Differentiation in Saccharomyces...The G Protein-Coupled Receptor Gpr1 Is a Nutrient Sensor That Regulates Pseudohyphal Differentiation in Saccharomyces...

... and the Gpa2-GTP complex then binds to and activates cAMP production by adenylyl cyclase (see Figure 9). More complex models in ... Heterotrimeric G proteins are regulated by seven transmembrane domain receptors of the β-adrenergic receptor family. Signaling ... 1992 Constitutive mutants of the protein kinase STE11 activate the pheromone response pathway in the absence of the G protein. ... 1998 Sex and crime: heterotrimeric G proteins in mating and pathogenesis. Fungal Genet. Biol. 25: 143-156. ...
more infohttp://www.genetics.org/content/154/2/609

SMART: Secondary literature for PLDc domainSMART: Secondary literature for PLDc domain

Compound 48/80 activates mast cell phospholipase D via heterotrimeric GTP-binding proteins. ... Those molecules include heterotrimeric GTP binding proteins, members of the protein kinase C family, and members of the Rho ... presumably promoting the release of bound GDP and the binding of GTP to activate the G-protein which controls phospholipase C ... receptor-coupled G proteins, small GTP binding proteins, ceramide metabolisms, and protein kinase C. We have investigated a ...
more infohttp://smart.embl-heidelberg.de/smart/show_secondary.cgi?domain=PLDc

gq g11 gtp binding protein alpha subunitsgq g11 gtp binding protein alpha subunits

Research Grants about gq g11 gtp binding protein alpha subunits ... heterotrimeric GTP-binding protein alpha subunits that activate ... heterotrimeric gtp binding proteins , gtp binding protein alpha subunits , gq g11 gtp binding protein alpha subunits ... heterotrimeric gtp binding proteins*gi go gtp binding protein alpha subunits*phospholipase c*g protein coupled receptors* ... protein kinase c*gtp binding proteins*enzyme activation*muscarinic receptors*signal transduction*gs gtp binding protein alpha ...
more infohttps://www.labome.org/topics/chemicals/and/peptides/intracellular/heterotrimeric/gtp/gq-g11-gtp-binding-protein-alpha-subunits-12352.html

Frontiers | Ghrelin and eating behavior: evidence and insights from genetically-modified mouse models | NeuroscienceFrontiers | Ghrelin and eating behavior: evidence and insights from genetically-modified mouse models | Neuroscience

GHSR is a 7 transmembrane protein coupled to the Gq subfamily of heterotrimeric GTP-binding proteins that activates ... Using in vitro methods, these mutations result in loss of endogenous constitutive activity of GHSR, altered binding of ghrelin ... 2012). High constitutive activity is an intrinsic feature of Ghrelin receptor protein: a study with a functional monomeric GHS- ... 2009). A mouse model of ghrelinoma exhibited activated growth hormone-insulin-like growth factor I axis and glucose intolerance ...
more infohttps://www.frontiersin.org/articles/10.3389/fnins.2013.00121/full

Frontiers | Neurobehavioral phenotyping of Gαq knockout mice reveals impairments in motor functions and spatial working memory...Frontiers | Neurobehavioral phenotyping of Gαq knockout mice reveals impairments in motor functions and spatial working memory...

... stimuli elicit their cellular responses through the targeted activation of receptors coupled to Gq family heterotrimeric G ... proteins. Nevertheless, we still understand little about the consequences of loss of this signaling activity on brain function ... stimuli elicit their cellular responses through the targeted activation of receptors coupled to Gq family heterotrimeric G ... proteins. Nevertheless, we still understand little about the consequences of loss of this signaling activity on brain function ...
more infohttps://www.frontiersin.org/articles/10.3389/fnbeh.2012.00029/full

Regulation of MAPK Function by Direct Interaction with the Mating-Specific Gα in Yeast | ScienceRegulation of MAPK Function by Direct Interaction with the Mating-Specific Gα in Yeast | Science

... mating response of the budding yeast Saccharomyces cerevisiae is mediated by a prototypical heterotrimeric GTP-binding protein ... G protein) and mitogen-activated protein kinase (MAPK) cascade. Although signal transmission by such pathways has been modeled ... The pheromone-responsive G protein α subunit (Gα) of yeast down-regulates the mating signal, but its targets are unknown. We ... have found that Gα binds directly to the mating-specific MAPK in yeast cells responding to pheromone. This interaction ...
more infohttp://science.sciencemag.org/content/296/5572/1483

The heterotrimeric G protein subunits Gαq and Gβ1 have lysophospholipase D activity | Biochemical JournalThe heterotrimeric G protein subunits Gαq and Gβ1 have lysophospholipase D activity | Biochemical Journal

... heterotrimeric G protein α subunit q; GAP, GTPase-activating protein; Gβ1, heterotrimeric GTP-binding protein β subunit 1; GPC ... 1999) Rapid GTP binding and hydrolysis by Gq promoted by receptor and GTPase-activating proteins. Proc. Natl. Acad. Sci. U.S.A. ... The onset and termination of G protein signalling is determined by the length of time spent in the active GTP-bound state. GTP ... Agonist-activated GPCRs enhance GDP/GTP exchange on the G protein α subunit, thereby generating an active GTPbound Gα subunit, ...
more infohttp://www.biochemj.org/content/440/2/241

This Week in Science | ScienceThis Week in Science | Science

... couples to a heterotrimeric GTP-binding protein (G protein), and eventually activates a mitogen-activated protein kinase (MAPK ... A single swap of the connections between promoter and DNA binding protein could dramatically change the behavior of the network ... The protein is a receptor kinase with a single transmembrane domain and features leucine-rich repeats in the extracellular ... Prior administration of proteins that inhibit myostatin activity, such as follistatin, slowed weight loss in the mice. These ...
more infohttp://science.sciencemag.org/content/296/5572/twis

Involvement of heterotrimeric GTP-binding protein and rho protein, but not protein kinase C, in agonist-induced Ca2+...Involvement of heterotrimeric GTP-binding protein and rho protein, but not protein kinase C, in agonist-induced Ca2+...

... and GTP (GTP gamma S)-induced Ca2+ sensitization. AIF4-, which activates heterotrimeric G-, but not small G-protein also ... Involvement of heterotrimeric GTP-binding protein and rho protein, but not protein kinase C, in agonist-induced Ca2+ ... Involvement of heterotrimeric GTP-binding protein and rho protein, but not protein kinase C, in agonist-induced Ca2+ ... Involvement of heterotrimeric GTP-binding protein and rho protein, but not protein kinase C, in agonist-induced Ca2+ ...
more infohttp://jpet.aspetjournals.org/content/274/1/555

NAVER Academic > Search...NAVER Academic > Search...

GTPase-Activating Proteins, metabolism, Heterotrimeric GTP-Binding Proteins, Humans, Mitogen-Activated Protein Kinases,... ... Pregnancy-associated plasma protein-A (PAPP-A) cleaves insulin-like growth factor binding protein (IGFBP)-5 independent of IGF ... Pregnancy-associated plasma protein-A (PAPP-A) cleaves insulin-like growth factor binding protein (IGFBP)-5 independent of IGF ... An internal segment (residues **-***) of the hepatitis B virus X protein is sufficient to activate MAP kinase pathways in mouse ...
more infohttps://academic.naver.com/search.naver?field=3&query=FEBS+LETTERS+504%EA%B6%8C+1-2%ED%98%B8

Activation of the cloned muscarinic potassium channel by G protein beta gamma subunits.  - PubMed - NCBIActivation of the cloned muscarinic potassium channel by G protein beta gamma subunits. - PubMed - NCBI

... activation of these muscarinic potassium channels is mediated by a pertussis toxin-sensitive heterotrimeric GTP-binding protein ... Moreover, application of recombinant G beta gamma, but not G alpha i-GTP-gamma S, activates GIRK1 channels. Thus G beta gamma ... Using a heterologous expression system, we have tested the ability of different G protein subunits to activate the cloned ... G protein). It has not been resolved whether exogenously applied G alpha or G beta gamma, or both, activate the channel. ...
more infohttps://www.ncbi.nlm.nih.gov/pubmed/8022483?dopt=Abstract

Potentiation of Fcε Receptor I-activated Ca2+ Current (ICRAC) by Cholera Toxin: Possible Mediation by ADP Ribosylation Factor |...Potentiation of Fcε Receptor I-activated Ca2+ Current (ICRAC) by Cholera Toxin: Possible Mediation by ADP Ribosylation Factor |...

Role of heterotrimeric GTP binding proteins in vesicular protein transport: indications for both classical and alternative G ... The protein cofactor necessary for ADP-ribosylation of Gs by cholera toxin is itself a GTP binding protein. J. Biol. Chem. 261: ... In their GTP-bound state, ARF proteins activate phospholipase D (Brown et al., 1993; Cockcroft et al., 1994) and promote the ... The guanine nucleotide-binding protein Gs activates a novel calcium transporter in Xenopus oocytes. J. Biol. Chem. 267:883-888. ...
more infohttp://jcb.rupress.org/content/148/1/137

A β-Arrestin-Biased Agonist of the Parathyroid Hormone Receptor (PTH1R) Promotes Bone Formation Independent of G Protein...A β-Arrestin-Biased Agonist of the Parathyroid Hormone Receptor (PTH1R) Promotes Bone Formation Independent of G Protein...

... one through heterotrimeric GTP-binding proteins (G proteins) and one through β-arrestins; so-called biased agonists can ... PTH-related protein receptor (PTH1R), (d-Trp12,Tyr34)-PTH(7-34) (PTH-βarr), which activates β-arrestin but not classic G ... A biased agonist binds to the seven-transmembrane parathyroid hormone receptor to trigger certain downstream effects but not ... A biased agonist binds to the seven-transmembrane parathyroid hormone receptor to trigger certain downstream effects but not ...
more infohttps://stm.sciencemag.org/content/1/1/1ra1

The effects of norepinephrine on the activity of the Na+/H+ exchanger in acutely dissociated adult rat hippocampal CA1 neurons ...The effects of norepinephrine on the activity of the Na+/H+ exchanger in acutely dissociated adult rat hippocampal CA1 neurons ...

... that is a direct interaction between the receptor-activated heterotrimeric GTP-binding protein (G protein) subunit and pHj ... Thalmann, R. H. (1988). Evidence that guanosine triphosphate (GTP)-binding proteins control a synaptic response in brain: ... Cholera toxin acts by catalyzing the ADP-ribosylation of the GTP-binding protein, G s a , and uncouples it from both the B- ... such as the phospholipase C/protein kinase C system or the Ca2+-activated, calmodulin-dependent protein kinase II system (see ...
more infohttps://open.library.ubc.ca/cIRcle/collections/ubctheses/831/items/1.0087578

Table of Contents - June 24, 2008, 1 (25) | Science SignalingTable of Contents - June 24, 2008, 1 (25) | Science Signaling

GTP)-binding proteins (G proteins) may function as activated heterotrimers. This is in addition to the well-characterized ... The image shows the structure of a heterotrimeric G protein, which consists of α (blue), β (purple), and γ (green) subunits and ... G proteins may function as activated heterotrimers, as well as dissociated subunits. ... Mitosis begins in mammalian cells when a protein accumulates between cell divisions and interacts with a second protein to ...
more infohttp://stke.sciencemag.org/content/1/25

Gebhard Schertler | BIO | Paul Scherrer Institut (PSI)Gebhard Schertler | BIO | Paul Scherrer Institut (PSI)

... transduce extracellular signals across the cell membrane by activating cytoplasmic-bound heterotrimeric GTP binding proteins (G ... Stabilized G protein binding site in the structure of constitutively active metarhodopsin-II. Proceedings of the National ... The role of water molecules in phototransduction of retinal proteins and G protein-coupled receptors. Faraday Discussions. 2018 ... Conformational selection in a protein-protein interaction revealed by dynamic pathway analysis. Cell Reports. 2016; 14(1): 32- ...
more infohttps://www.psi.ch/en/bio/people/gebhard-schertler

New G Protein Interactions | Science SignalingNew G Protein Interactions | Science Signaling

GTP)-binding proteins (G proteins). Ligand binding to G protein-coupled receptors (GPCRs) activates G proteins by catalyzing ... A RACK1 fusion protein bound to both Gβ1γ1 and the heterotrimeric Gαtβ1γ1 transducin heterotrimer but not to Gαt alone; Gαtβ1γ1 ... NG-GPAs stimulation of GTPγS binding, unlike GPCR-stimulated GTPγS binding, was unaffected by treatment with pertussis toxin, ... NG-GPA stimulated guanosine 5-O-thiotriphosphate (GTPγS) binding to purified brain G protein, as well as to recombinant Gαo ...
more infohttp://stke.sciencemag.org/content/2003/164/TW6

Orphanin FQ: a neuropeptide that activates an opioidlike G protein-coupled receptor. - Semantic ScholarOrphanin FQ: a neuropeptide that activates an opioidlike G protein-coupled receptor. - Semantic Scholar

Orphanin FQ bound to its receptor in a saturable manner and with high affinity. When injected intracerebroventricularly into ... This inhibitory activity was not affected by the addition of opioid ligands, nor did the peptide activate opioid receptors. ... G protein)-coupled receptor (LC132) that is similar in sequence to opioid receptors. This peptide, orphanin FQ, has a primary ... A heptadecapeptide was identified and purified from porcine brain tissue as a ligand for an orphan heterotrimeric GTP-binding ...
more infohttps://www.semanticscholar.org/paper/Orphanin-FQ%3A-a-neuropeptide-that-activates-an-G-Reinscheid-Nothacker/3f13aac64d3620658c9d3f905530df49fd5437d9

G protein, inhibitory gi Dictionary Definition and More from Dictionary.netG protein, inhibitory gi Dictionary Definition and More from Dictionary.net

Definitions of G Protein, Inhibitory Gi. * A heterotrimeric GTP- binding protein that inhibits adenylate cyclase and activates ... previousG protein signaling regulators next G protein, stimulatory gs G protein, inhibitory gi. ...
more infohttp://www.dictionary.net/g%20protein%2C%20inhibitory%20gi

Mechanical stimulation activates Galphaq signaling pathways and 5-hydroxytryptamine release from human carcinoid BON cells.  -...Mechanical stimulation activates Galphaq signaling pathways and 5-hydroxytryptamine release from human carcinoid BON cells. -...

GTP-Binding Protein alpha Subunits, Gq-G11. *GTP-Binding Proteins/metabolism. *Heterotrimeric GTP-Binding Proteins/metabolism* ... GTP-Binding Proteins. *GTP-Binding Protein alpha Subunits, Gq-G11. *Heterotrimeric GTP-Binding Proteins ... Selective suppression of Gαq protein with antisense oligonucleotide. (a) BON cells were untreated (C) or treated with 1 μM of ... Mechanical stimulation activates Galphaq signaling pathways and 5-hydroxytryptamine release from human carcinoid BON cells.. ...
more infohttps://www.ncbi.nlm.nih.gov/pubmed/11581306?dopt=Abstract

Gs GTP-Binding Protein alpha Subunits
      - G(s)alpha
     Summary Report | CureHunterGs GTP-Binding Protein alpha Subunits - G(s)alpha Summary Report | CureHunter

A family of heterotrimeric GTP-binding protein alpha subunits that activate ADENYLATE CYCLASE. ... GTP-Binding Proteins: 5070*Heterotrimeric GTP-Binding Proteins: 88*GTP-Binding Protein alpha Subunits: 49*Gs GTP-Binding ... Proteins: 90489*Carrier Proteins: 11456*GTP-Binding Proteins: 5070*Heterotrimeric GTP-Binding Proteins: 88*GTP-Binding Protein ... Membrane Proteins: 5300*Heterotrimeric GTP-Binding Proteins: 88*GTP-Binding Protein alpha Subunits: 49*Gs GTP-Binding Protein ...
more infohttp://www.curehunter.com/public/keywordSummaryD019205-G-s-alpha.do

5-Lipoxygenase-Activating Proteins | Harvard Catalyst Profiles | Harvard Catalyst5-Lipoxygenase-Activating Proteins | Harvard Catalyst Profiles | Harvard Catalyst

Heterotrimeric GTP-Binding Proteins. *LDL-Receptor Related Protein-Associated Protein. *Lipid-Linked Proteins ... "5-Lipoxygenase-Activating Proteins" by people in Harvard Catalyst Profiles by year, and whether "5-Lipoxygenase-Activating ... "5-Lipoxygenase-Activating Proteins" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH ... Below are the most recent publications written about "5-Lipoxygenase-Activating Proteins" by people in Profiles. ...
more infohttps://connects.catalyst.harvard.edu/Profiles/display/Concept/5-Lipoxygenase-Activating%20Proteins

Phospholipase C - A new family of covalent inhibitors block nucleotide bindingPhospholipase C - A new family of covalent inhibitors block nucleotide binding

... usually less clear but involves the activity of heterotrimeric GTP-binding proteins and potentially mitogen-activated protein ... a trimeric fusion proteins F with type I viral fusion proteins features and a receptor binding proteins variously called HN H ... Rho-GTP binding towards the GTPase binding domains of Dia relieves autoinhibition. The formin homology 1 (FH1) and Father ... receptor binding protein (HN H or G) and fusion protein (F) around the viral surface. However despite numerous biochemical and ...
more infohttp://bio-aromatica.com/category/phospholipase-c/

Activation of Endogenous Thrombin Receptors Causes Clustering and Sensitization of Epidermal Growth Factor Receptors of Swiss...Activation of Endogenous Thrombin Receptors Causes Clustering and Sensitization of Epidermal Growth Factor Receptors of Swiss...

Such receptors include those that couple to heterotrimeric GTP-binding proteins and those with intrinsic tyrosine kinase ... Pleiotropic coupling of G protein-coupled receptors to the mitogen-activated protein kinase cascade. Role of focal adhesions ... Pleiotropic coupling of G protein-coupled receptors to the mitogen-activated protein kinase cascade. Role of focal adhesions ... The G-protein Gi regulates mitosis but not DNA synthesis in growth factor-activated fibroblastsa role for the nuclear ...
more infohttps://rupress.org/jcb/article/152/2/263/47889/Activation-of-Endogenous-Thrombin-Receptors-Causes

Most recent papers with the keyword Alpha helix mimetic | Read by QxMDMost recent papers with the keyword Alpha helix mimetic | Read by QxMD

... each of which has a different coupling selectivity for heterotrimeric GTP-binding proteins (G-proteins). m4 mAChR specifically ... These peptides activate a two-component system in gram-negative bacteria, binding to and activating a histidine kinase receptor ... Protein-protein interactions encompass large surface areas, but often a handful of key residues dominate the binding energy ... Computational analysis of protein-protein interfaces involving an alpha helix: insights for terphenyl-like molecules binding. ...
more infohttps://www.readbyqxmd.com/keyword/74922
  • Another class of regulatory proteins, the Guanosine nucleotide dissociation inhibitors (GDIs), bind to the GDP-bound form of Rho and Rab small GTPases and not only prevent exchange (maintaining the small GTPase in an off-state), but also prevent the small GTPase from localizing at the membrane, which is their place of action. (wikipedia.org)
  • An antisense phosphorothioated oligonucleotide targeted to a unique sequence of Galphaq abolished mechanically evoked 5-HT release and reduced Galphaq protein levels without affecting the expression of Galpha(11). (nih.gov)
  • There is evidence suggesting that PLD acts downstream from G-proteins, but a direct interaction of specific members has not been shown. (embl-heidelberg.de)
  • Indeed, all known Gβγ effectors bind to the Gα-interacting region, suggesting a novel mechanism for RACK1-G protein interaction. (sciencemag.org)
  • The interaction appears to require at least two separated amino-acid sequences present specifically in the beta isoform of p110 and the GTP-bound form of Rab5. (embl-heidelberg.de)
  • According to this scheme, conceived by James Putney to account for inositol trisphosphate (InsP 3 )-induced Ca 2+ influx in exocrine cells, depletion of lumenal Ca 2+ from the ER activates a Ca 2+ entry pathway in the plasma membrane ( Putney, 1986 , 1990 ). (rupress.org)
  • G proteins were discovered when Alfred G. Gilman and Martin Rodbell investigated stimulation of cells by adrenaline. (wikipedia.org)
  • In the present paper, a PLD cDNA clone was isolated from tobacco, expressed as a GST fusion in bacteria, and the recombinant protein was purified by glutathione affinity. (embl-heidelberg.de)
  • Moreover, application of recombinant G beta gamma, but not G alpha i-GTP-gamma S, activates GIRK1 channels. (nih.gov)
  • NG-GPA stimulated guanosine 5'- O -thiotriphosphate (GTPγS) binding to purified brain G protein, as well as to recombinant Gα o and Gα i , and inhibited adenylyl cyclase activity in DDT 1 -MF-2 cell membranes. (sciencemag.org)
  • A biased agonist binds to the seven-transmembrane parathyroid hormone receptor to trigger certain downstream effects but not others, potentially avoiding undesirable side effects. (sciencemag.org)
  • 5-Lipoxygenase-Activating Proteins" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (harvard.edu)
  • 10 microM) and GTP gamma S, a non-hydrolyzable GTP analogue, also induced Ca2+ sensitization. (aspetjournals.org)
  • It has not been resolved whether exogenously applied G alpha or G beta gamma, or both, activate the channel. (nih.gov)
  • We report here that coexpression of GIRK1 with G beta gamma but not G alpha beta gamma in Xenopus oocytes results in channel activity that persists in the absence of cytoplasmic GTP. (nih.gov)
  • Together with the absence of immunochemical cross-reactivity, these enzymatic properties demonstrate that the membrane-bound enzyme is distinct from the extracellular enzyme recently characterized and cloned from the same bacterial strain [C. Ogino et al. (embl-heidelberg.de)
  • Antigen-evoked influx of extracellular Ca 2+ into mast cells may occur via store-operated Ca 2+ channels called calcium release-activated calcium (CRAC) channels. (rupress.org)
  • Changes in pH can alter the structure and activity of proteins and may be used by the cell to control molecular function. (readbyqxmd.com)
  • used a yeast two-hybrid screen to identify new Gβγ effectors and isolated three proteins containing WD40 motifs (which Gβγ also contains) that bound to Gβγ. (sciencemag.org)
  • Caruso later purified the detergent-extracted component of rat brain membrane that eluted with the specifically bound 3H-chlornaltrexamine. (wikipedia.org)
  • The mechanism that links Ca 2+ store depletion to Ca 2+ influx via calcium release-activated calcium (CRAC) channels has yet to be determined, and we do not address this issue here. (rupress.org)
  • In mice, PTH-βarr induces anabolic bone formation, as does the nonselective agonist PTH(1-34), which activates both mechanisms. (sciencemag.org)
  • A single swap of the connections between promoter and DNA binding protein could dramatically change the behavior of the network. (sciencemag.org)
  • Cholera toxin dramatically amplified (two- to fourfold) the Ca 2+ release-activated Ca 2+ current (I CRAC ) elicited by suboptimal concentrations of antigen, without itself inducing I CRAC , and this enhancement was not mimicked by cAMP elevation. (rupress.org)
  • We have previously shown that the α-helicity and helix-helix interactions of the TM2 α-helix of the proteolipid protein (PLP) are sensitive to the local hydrophobicity at its C-terminus. (readbyqxmd.com)