A multifunctional protein that is found primarily within membrane-bound organelles. In the ENDOPLASMIC RETICULUM it binds to specific N-linked oligosaccharides found on newly-synthesized proteins and functions as a MOLECULAR CHAPERONE that may play a role in PROTEIN FOLDING or retention and degradation of misfolded proteins. In addition calreticulin is a major storage form for CALCIUM and functions as a calcium-signaling molecule that can regulate intracellular calcium HOMEOSTASIS.
A lectin found in ENDOPLASMIC RETICULUM membranes that binds to specific N-linked OLIGOSACCHARIDES found on newly synthesized proteins. It may play role in PROTEIN FOLDING or retention and degradation of misfolded proteins in the endoplasmic reticulum.
Complexes of RNA-binding proteins with ribonucleic acids (RNA).
Proteins to which calcium ions are bound. They can act as transport proteins, regulator proteins, or activator proteins. They typically contain EF HAND MOTIFS.
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)
A family of cellular proteins that mediate the correct assembly or disassembly of polypeptides and their associated ligands. Although they take part in the assembly process, molecular chaperones are not components of the final structures.
Acidic protein found in SARCOPLASMIC RETICULUM that binds calcium to the extent of 700-900 nmoles/mg. It plays the role of sequestering calcium transported to the interior of the intracellular vesicle.
Sulfur-sulfur bond isomerases that catalyze the rearrangement of disulfide bonds within proteins during folding. Specific protein disulfide-isomerase isoenzymes also occur as subunits of PROCOLLAGEN-PROLINE DIOXYGENASE.
Indolizines are organic compounds that consist of a condensed pyridine and pyrrole ring structure, which can be found in certain natural and synthetic substances, and have been studied for their potential biological activities.
A class of enzymes that catalyze geometric or structural changes within a molecule to form a single product. The reactions do not involve a net change in the concentrations of compounds other than the substrate and the product.(from Dorland, 28th ed) EC 5.
Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.
Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.
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.
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.
A calbindin protein that is differentially expressed in distinct populations of NEURONS throughout the vertebrate and invertebrate NERVOUS SYSTEM, and modulates intrinsic neuronal excitability and influences LONG-TERM POTENTIATION. It is also found in LUNG, TESTIS, OVARY, KIDNEY, and BREAST, and is expressed in many tumor types found in these tissues. It is often used as an immunohistochemical marker for MESOTHELIOMA.
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.
A de novo myeloproliferation arising from an abnormal stem cell. It is characterized by the replacement of bone marrow by fibrous tissue, a process that is mediated by CYTOKINES arising from the abnormal clone.
Conditions which cause proliferation of hemopoietically active tissue or of tissue which has embryonic hemopoietic potential. They all involve dysregulation of multipotent MYELOID PROGENITOR CELLS, most often caused by a mutation in the JAK2 PROTEIN TYROSINE KINASE.
A Janus kinase subtype that is involved in signaling from GROWTH HORMONE RECEPTORS; PROLACTIN RECEPTORS; and a variety of CYTOKINE RECEPTORS such as ERYTHROPOIETIN RECEPTORS and INTERLEUKIN RECEPTORS. Dysregulation of Janus kinase 2 due to GENETIC TRANSLOCATIONS have been associated with a variety of MYELOPROLIFERATIVE DISORDERS.
A clinical syndrome characterized by repeated spontaneous hemorrhages and a remarkable increase in the number of circulating platelets.
A myeloproliferative disorder of unknown etiology, characterized by abnormal proliferation of all hematopoietic bone marrow elements and an absolute increase in red cell mass and total blood volume, associated frequently with splenomegaly, leukocytosis, and thrombocythemia. Hematopoiesis is also reactive in extramedullary sites (liver and spleen). In time myelofibrosis occurs.
Enlargement of the spleen.
Increased numbers of platelets in the peripheral blood. (Dorland, 27th ed)

Calreticulin, a peptide-binding chaperone of the endoplasmic reticulum, elicits tumor- and peptide-specific immunity. (1/690)

Calreticulin (CRT), a peptide-binding heat shock protein (HSP) of the endoplasmic reticulum (ER), has been shown previously to associate with peptides transported into the ER by transporter associated with antigen processing (Spee, P., and J. Neefjes. 1997. Eur. J. Immunol. 27: 2441-2449). Our studies show that CRT preparations purified from tumors elicit specific immunity to the tumor used as the source of CRT but not to an antigenically distinct tumor. The immunogenicity is attributed to the peptides associated with the CRT molecule and not to the CRT molecule per se. It is further shown that CRT molecules can be complexed in vitro to unglycosylated peptides and used to elicit peptide-specific CD8(+) T cell response in spite of exogenous administration. These characteristics of CRT closely resemble those of HSPs gp96, hsp90, and hsp70, although CRT has no apparent structural homologies to them.  (+info)

Peptide-bound major histocompatibility complex class I molecules associate with tapasin before dissociation from transporter associated with antigen processing. (2/690)

Major histocompatibility complex (MHC) class I molecules present antigenic peptides to CD8 T cells. The peptides are generated in the cytosol, then translocated across the membrane of the endoplasmic reticulum by the transporter associated with antigen processing (TAP). TAP is a trimeric complex consisting of TAP1, TAP2, and tapasin (TAP-A) as indicated for human cells by reciprocal coprecipitation with anti-TAP1/2 and anti-tapasin antibodies, respectively. TAP1 and TAP2 are required for the peptide transport. Tapasin is involved in the association of class I with TAP and in the assembly of class I with peptide. The mechanisms of tapasin function are still unknown. Moreover, there has been no evidence for a murine tapasin analogue, which has led to the suggestion that murine MHC class I binds directly to TAP1/2. In this study, we have cloned the mouse analogue of tapasin. The predicted amino acid sequence showed 78% identity to human tapasin with identical consensus sequences of signal peptide, N-linked glycosylation site, transmembrane domain and double lysine motif. However, there was less homology (47%) found at the predicted cytosolic domain, and in addition, mouse tapasin is 14 amino acids longer than the human analogue at the C terminus. This part of the molecule may determine the species specificity for interaction with MHC class I or TAP1/2. Like human tapasin, mouse tapasin binds both to TAP1/2 and MHC class I. In TAP2-mutated RMA-S cells, both TAP1 and MHC class I were coprecipitated by anti-tapasin antiserum indicative of association of tapasin with TAP1 but not TAP2. With crosslinker-modified peptides and purified microsomes, anti-tapasin coprecipitated both peptide-bound MHC class I and TAP1/2. In contrast, anti-calreticulin only coprecipitated peptide-free MHC class I molecules. This difference in association with peptide-loaded class I suggests that tapasin functions later than calreticulin during MHC class I assembly, and controls peptide loading onto MHC class I molecules in the endoplasmic reticulum.  (+info)

Calreticulin is essential for cardiac development. (3/690)

Calreticulin is a ubiquitous Ca2+ binding protein, located in the endoplasmic reticulum lumen, which has been implicated in many diverse functions including: regulation of intracellular Ca2+ homeostasis, chaperone activity, steroid-mediated gene regulation, and cell adhesion. To understand the physiological function of calreticulin we used gene targeting to create a knockout mouse for calreticulin. Mice homozygous for the calreticulin gene disruption developed omphalocele (failure of absorption of the umbilical hernia) and showed a marked decrease in ventricular wall thickness and deep intertrabecular recesses in the ventricular walls. Transgenic mice expressing a green fluorescent protein reporter gene under the control of the calreticulin promoter were used to show that the calreticulin gene is highly activated in the cardiovascular system during the early stages of cardiac development. Calreticulin protein is also highly expressed in the developing heart, but it is only a minor component of the mature heart. Bradykinin-induced Ca2+ release by the InsP3-dependent pathway was inhibited in crt-/- cells, suggesting that calreticulin plays a role in Ca2+ homeostasis. Calreticulin-deficient cells also exhibited impaired nuclear import of nuclear factor of activated T cell (NF-AT3) transcription factor indicating that calreticulin plays a role in cardiac development as a component of the Ca2+/calcineurin/NF-AT/GATA-4 transcription pathway.  (+info)

Antibody levels to recombinant tick calreticulin increase in humans after exposure to Ixodes scapularis (Say) and are correlated with tick engorgement indices. (4/690)

The antibody responses of subjects who presented with a definite Ixodes scapularis (Say) tick bite were measured to determine the utility of the antibody response against recombinant tick calreticulin (rTC) as a biologic marker of tick exposure. Subjects bitten by I. scapularis evidenced an increase in anti-rTC antibody levels between visit 1 and visit 2 from 24.3 to 27.1 ng/microl serum (n = 88, p = 0.003), and levels remained elevated at visit 3 (p = 0.005). These anti-rTC antibody levels during visits 2 and 3 were significantly higher than those in four non-exposed controls. Tick engorgement indices, measured on the biting ticks, were found to be correlated with anti-rTC antibody levels (e.g., for visit 3: Pearson's r = 0.357, p = 0.001). Tick engorgement index (TEI), ratio of body length to scutal width, was identified to be the only independent predictor of anti-rTC antibody levels in linear regression models. Logistic regression revealed that a bite from an I. scapularis tick that became engorged (TEI >3.4) was a risk factor for anti-rTC antibody seropositivity (adjusted odds ratio for age and bite location = 7.4 (95% confidence interval 2.1-26.4)). The anti-rTC antibody test had a sensitivity of 0.50 and a specificity of 0.86 for a bite from I. scapularis that became engorged. Immunoblotting revealed that subjects made a specific anti-rTC antibody response.  (+info)

Calreticulin expression is associated with androgen regulation of the sensitivity to calcium ionophore-induced apoptosis in LNCaP prostate cancer cells. (5/690)

Calreticulin has been identified previously as one of the androgen-response genes in the prostate. The role of calreticulin in androgen action was studied using androgen-sensitive LNCaP and androgen-insensitive PC-3 human prostate cancer cell lines. Calreticulin appears to be a primary androgen-response gene in cultured LNCaP cells because androgen induction of calreticulin mRNA resists protein synthesis inhibition. Calreticulin is a high capacity intracellular Ca2+ binding protein, suggesting that calreticulin expression is likely to be associated with the intracellular Ca2+ buffering capacity that could regulate the sensitivity to cytotoxic intracellular Ca2+ overload. As expected, androgen protects androgen-sensitive LNCaP but not androgen-insensitive PC-3 cells from cytotoxic intracellular Ca2+ overload induced by Ca2+ ionophore A23187. To provide evidence for the role of calreticulin in reducing cytotoxic effect of Ca2+ influx in prostatic cells, we have shown that calreticulin antisense oligonucleotide down-regulates calreticulin protein level and significantly increases the sensitivity to A23187-induced apoptosis in both LNCaP and PC-3 cells. Furthermore, calreticulin antisense oligonucleotide reverses the androgen-induced resistance to A23187 in LNCaP cells. The above observations collectively suggest that calreticulin mediates androgen regulation of the sensitivity to Ca2+ ionophore-induced apoptosis in LNCaP cells.  (+info)

Ligand-specific, transient interaction between integrins and calreticulin during cell adhesion to extracellular matrix proteins is dependent upon phosphorylation/dephosphorylation events. (6/690)

As transmembrane heterodimers, integrins bind to both extracellular ligands and intracellular proteins. We are currently investigating the interaction between integrins and the intracellular protein calreticulin. A prostatic carcinoma cell line (PC-3) was used to demonstrate that calreticulin can be found in the alpha3 immunoprecipitates of cells plated on collagen type IV, but not when plated on vitronectin. Conversely, alphav immunoprecipitates contained calreticulin only when cells were plated on vitronectin, i. e. not when plated on collagen IV. The interactions between these integrins and calreticulin were independent of actin cytoskeleton assembly and were transient, being maximal approx. 10-30 min after the cells came into contact with the substrates prior to complete cell spreading and formation of firm adhesive contacts. We demonstrate that okadaic acid, an inhibitor of intracellular serine/threonine protein phosphatases, inhibited the alpha3beta1-mediated adhesion of PC-3 cells to collagen IV and the alpha2beta1-mediated attachment of Jurkat cells to collagen I. This inhibition by okadaic acid was accompanied by inhibition of the ligand-specific interaction of calreticulin with the respective integrins in the two cell types. Additionally, we found that pharmacological inhibition of mitogen-activated protein kinase kinase (MEK) resulted in prolongation of the calreticulin-integrin interaction, and enhancement of PC-3 cell attachment to collagen IV. We conclude that calreticulin interacts transiently with integrins during cell attachment and spreading. This interaction depends on receptor occupation, is ligand-specific, and can be modulated by protein phosphatase and MEK activity.  (+info)

Trypanosoma cruzi calreticulin is a lectin that binds monoglucosylated oligosaccharides but not protein moieties of glycoproteins. (7/690)

Trypanosoma cruzi is a protozoan parasite that belongs to an early branch in evolution. Although it lacks several features of the pathway of protein N-glycosylation and oligosaccharide processing present in the endoplasmic reticulum of higher eukaryotes, it displays UDP-Glc:glycoprotein glucosyltransferase and glucosidase II activities. It is herewith reported that this protozoan also expresses a calreticulin-like molecule, the third component of the quality control of glycoprotein folding. No calnexin-encoding gene was detected. Recombinant T. cruzi calreticulin specifically recognized free monoglucosylated high-mannose-type oligosaccharides. Addition of anti-calreticulin serum to extracts obtained from cells pulse-chased with [35S]Met plus [35S]Cys immunoprecipitated two proteins that were identified as calreticulin and the lysosomal proteinase cruzipain (a major soluble glycoprotein). The latter but not the former protein disappeared from immunoprecipitates upon chasing cells. Contrary to what happens in mammalian cells, addition of the glucosidase II inhibitor 1-deoxynojirimycin promoted calreticulin-cruzipain interaction. This result is consistent with the known pathway of protein N-glycosylation and oligosaccharide processing occurring in T. cruzi. A treatment of the calreticulin-cruzipain complexes with endo-beta-N-acetylglucosaminidase H either before or after addition of anti-calreticulin serum completely disrupted calreticulin-cruzipain interaction. In addition, mature monoglucosylated but not unglucosylated cruzipain isolated from lysosomes was found to interact with recombinant calreticulin. It was concluded that the quality control of glycoprotein folding appeared early in evolution, and that T. cruzi calreticulin binds monoglucosylated oligosaccharides but not the protein moiety of cruzipain. Furthermore, evidence is presented indicating that glucosyltransferase glucosylated cruzipain at its last folding stages.  (+info)

Calreticulin affects focal contact-dependent but not close contact-dependent cell-substratum adhesion. (8/690)

We used two cell lines expressing fast (RPEfast) and slow (RPEslow) attachment kinetics to investigate mechanisms of cell-substratum adhesion. We show that the abundance of a cytoskeletal protein, vinculin, is dramatically decreased in RPEfast cells. This coincides with the diminished expression level of an endoplasmic reticulum chaperone, calreticulin. Both protein and mRNA levels for calreticulin and vinculin were decreased in RPEfast cells. After RPEfast cells were transfected with cDNA encoding calreticulin, both the expression of endoplasmic reticulum-resident calreticulin and cytoplasmic vinculin increased. The abundance of other adhesion-related proteins was not affected. RPEfast cells underexpressing calreticulin displayed a dramatic increase in the abundance of total cellular phosphotyrosine suggesting that the effects of calreticulin on cell adhesiveness may involve modulation of the activities of protein tyrosine kinases or phosphatases which may affect the stability of focal contacts. The calreticulin and vinculin underexpressing RPEfast cells lacked extensive focal contacts and adhered weakly but attached fast to the substratum. In contrast, the RPEslow cells that expressed calreticulin and vinculin abundantly developed numerous and prominent focal contacts slowly, but adhered strongly. Thus, while the calreticulin overexpressing RPEslow cells "grip" the substratum with focal contacts, calreticulin underexpressing RPEfast cells use close contacts to "stick" to it.  (+info)

Calreticulin is a multifunctional protein found in the endoplasmic reticulum (ER) of eukaryotic cells. Its primary function is as a calcium-binding chaperone, helping to ensure proper folding and quality control of newly synthesized glycoproteins in the ER. Calreticulin also plays roles in ER-to-Golgi transport, regulation of ER calcium homeostasis, and acts as a sensor for ER stress. Additionally, it has been implicated in various cellular processes such as adhesion, migration, phagocytosis, and immune response. Defects in calreticulin have been linked to several diseases, including neurodegenerative disorders and cancer.

Calnexin is a type I transmembrane protein found in the endoplasmic reticulum (ER) of eukaryotic cells. It is a chaperone protein involved in the folding and quality control of newly synthesized glycoproteins. Calnexin binds to monoglucosylated oligosaccharides on unfolded or misfolded proteins, facilitating their correct folding and preventing their aggregation. Once the protein is correctly folded, calnexin dissociates from it and it can proceed through the ER for further processing and transport to its final destination in the cell. Calnexin also plays a role in the degradation of misfolded proteins by targeting them for ER-associated degradation (ERAD).

Ribonucleoproteins (RNPs) are complexes composed of ribonucleic acid (RNA) and proteins. They play crucial roles in various cellular processes, including gene expression, RNA processing, transport, stability, and degradation. Different types of RNPs exist, such as ribosomes, spliceosomes, and signal recognition particles, each having specific functions in the cell.

Ribosomes are large RNP complexes responsible for protein synthesis, where messenger RNA (mRNA) is translated into proteins. They consist of two subunits: a smaller subunit containing ribosomal RNA (rRNA) and proteins that recognize the start codon on mRNA, and a larger subunit with rRNA and proteins that facilitate peptide bond formation during translation.

Spliceosomes are dynamic RNP complexes involved in pre-messenger RNA (pre-mRNA) splicing, where introns (non-coding sequences) are removed, and exons (coding sequences) are joined together to form mature mRNA. Spliceosomes consist of five small nuclear ribonucleoproteins (snRNPs), each containing a specific small nuclear RNA (snRNA) and several proteins, as well as numerous additional proteins.

Other RNP complexes include signal recognition particles (SRPs), which are responsible for targeting secretory and membrane proteins to the endoplasmic reticulum during translation, and telomerase, an enzyme that maintains the length of telomeres (the protective ends of chromosomes) by adding repetitive DNA sequences using its built-in RNA component.

In summary, ribonucleoproteins are essential complexes in the cell that participate in various aspects of RNA metabolism and protein synthesis.

Calcium-binding proteins (CaBPs) are a diverse group of proteins that have the ability to bind calcium ions (Ca^2+^) with high affinity and specificity. They play crucial roles in various cellular processes, including signal transduction, muscle contraction, neurotransmitter release, and protection against oxidative stress.

The binding of calcium ions to these proteins induces conformational changes that can either activate or inhibit their functions. Some well-known CaBPs include calmodulin, troponin C, S100 proteins, and parvalbumins. These proteins are essential for maintaining calcium homeostasis within cells and for mediating the effects of calcium as a second messenger in various cellular signaling pathways.

The endoplasmic reticulum (ER) is a network of interconnected tubules and sacs that are present in the cytoplasm of eukaryotic cells. It is a continuous membranous organelle that plays a crucial role in the synthesis, folding, modification, and transport of proteins and lipids.

The ER has two main types: rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER). RER is covered with ribosomes, which give it a rough appearance, and is responsible for protein synthesis. On the other hand, SER lacks ribosomes and is involved in lipid synthesis, drug detoxification, calcium homeostasis, and steroid hormone production.

In summary, the endoplasmic reticulum is a vital organelle that functions in various cellular processes, including protein and lipid metabolism, calcium regulation, and detoxification.

Molecular chaperones are a group of proteins that assist in the proper folding and assembly of other protein molecules, helping them achieve their native conformation. They play a crucial role in preventing protein misfolding and aggregation, which can lead to the formation of toxic species associated with various neurodegenerative diseases. Molecular chaperones are also involved in protein transport across membranes, degradation of misfolded proteins, and protection of cells under stress conditions. Their function is generally non-catalytic and ATP-dependent, and they often interact with their client proteins in a transient manner.

Calsequestrin is a protein found primarily in the sarcoplasmic reticulum of muscle cells, including both cardiac and skeletal muscles. It plays a crucial role in muscle function by binding calcium ions (Ca²+) and regulating calcium release during muscle contraction and relaxation cycles.

There are two main types of calsequestrin:

1. Calsequestrin 1 (CSQ1): This form is predominantly found in the sarcoplasmic reticulum of fast-twitch skeletal muscle fibers, which have a higher contraction speed and fatigability. CSQ1 has a high capacity for calcium binding but a lower affinity compared to calsequestrin 2.
2. Calsequestrin 2 (CSQ2): This form is primarily found in the sarcoplasmic reticulum of cardiac and slow-twitch skeletal muscle fibers, which have a lower contraction speed and fatigability. CSQ2 has a lower capacity for calcium binding but a higher affinity compared to calsequestrin 1.

Calsequestrin's ability to bind large amounts of calcium ions helps maintain low cytoplasmic calcium concentrations during muscle relaxation, while also serving as a reservoir for rapid calcium release during muscle contraction. Dysregulation of calsequestrin function has been implicated in several muscle disorders, including certain forms of cardiomyopathy and neuromuscular diseases.

Protein Disulfide-Isomerases (PDIs) are a family of enzymes found in the endoplasmic reticulum (ER) of eukaryotic cells. They play a crucial role in the folding and maturation of proteins by catalyzing the formation, breakage, and rearrangement of disulfide bonds between cysteine residues in proteins. This process helps to stabilize the three-dimensional structure of proteins and is essential for their proper function. PDIs also have chaperone activity, helping to prevent protein aggregation and assisting in the correct folding of nascent polypeptides. Dysregulation of PDI function has been implicated in various diseases, including cancer, neurodegenerative disorders, and diabetes.

I'm sorry for any confusion, but "Indolizines" is not a medical term. It is a chemical term that refers to a class of heterocyclic organic compounds which contain a seven-membered ring with two nitrogen atoms and a carbon-carbon double bond. They are used in the synthesis of various pharmaceuticals and natural products, but they are not a medical condition or diagnosis.

Isomerases are a class of enzymes that catalyze the interconversion of isomers of a single molecule. They do this by rearranging atoms within a molecule to form a new structural arrangement or isomer. Isomerases can act on various types of chemical bonds, including carbon-carbon and carbon-oxygen bonds.

There are several subclasses of isomerases, including:

1. Racemases and epimerases: These enzymes interconvert stereoisomers, which are molecules that have the same molecular formula but different spatial arrangements of their atoms in three-dimensional space.
2. Cis-trans isomerases: These enzymes interconvert cis and trans isomers, which differ in the arrangement of groups on opposite sides of a double bond.
3. Intramolecular oxidoreductases: These enzymes catalyze the transfer of electrons within a single molecule, resulting in the formation of different isomers.
4. Mutases: These enzymes catalyze the transfer of functional groups within a molecule, resulting in the formation of different isomers.
5. Tautomeres: These enzymes catalyze the interconversion of tautomers, which are isomeric forms of a molecule that differ in the location of a movable hydrogen atom and a double bond.

Isomerases play important roles in various biological processes, including metabolism, signaling, and regulation.

Protein folding is the process by which a protein molecule naturally folds into its three-dimensional structure, following the synthesis of its amino acid chain. This complex process is determined by the sequence and properties of the amino acids, as well as various environmental factors such as temperature, pH, and the presence of molecular chaperones. The final folded conformation of a protein is crucial for its proper function, as it enables the formation of specific interactions between different parts of the molecule, which in turn define its biological activity. Protein misfolding can lead to various diseases, including neurodegenerative disorders such as Alzheimer's and Parkinson's disease.

Lectins are a type of proteins that bind specifically to carbohydrates and have been found in various plant and animal sources. They play important roles in biological recognition events, such as cell-cell adhesion, and can also be involved in the immune response. Some lectins can agglutinate certain types of cells or precipitate glycoproteins, while others may have a more direct effect on cellular processes. In some cases, lectins from plants can cause adverse effects in humans if ingested, such as digestive discomfort or allergic reactions.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Calbindin 2 is a calcium-binding protein that belongs to the calbindin family and is found in various tissues, including the brain and intestines. It has a molecular weight of approximately 28 kDa and plays a crucial role in regulating intracellular calcium levels, neurotransmitter release, and protecting neurons from excitotoxicity. Calbindin 2 is also known as calbindin D-28k or calbindin-D9k, depending on the species and its molecular weight. It has multiple isoforms generated by alternative splicing and is involved in various physiological processes, including muscle contraction, hormone secretion, and cell proliferation. In the nervous system, calbindin 2 is expressed in specific populations of neurons and glial cells, where it functions as a neuroprotective agent and modulates synaptic plasticity.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

Primary myelofibrosis (PMF) is a rare, chronic bone marrow disorder characterized by the replacement of normal bone marrow tissue with fibrous scar tissue, leading to impaired production of blood cells. This results in cytopenias (anemia, leukopenia, thrombocytopenia), which can cause fatigue, infection susceptibility, and bleeding tendencies. Additionally, PMF is often accompanied by the proliferation of abnormal megakaryocytes (large, atypical bone marrow cells that produce platelets) and extramedullary hematopoiesis (blood cell formation outside the bone marrow, typically in the spleen and liver).

PMF is a type of myeloproliferative neoplasm (MPN), which is a group of clonal stem cell disorders characterized by excessive proliferation of one or more types of blood cells. PMF can present with various symptoms such as fatigue, weight loss, night sweats, abdominal discomfort due to splenomegaly (enlarged spleen), and bone pain. In some cases, PMF may progress to acute myeloid leukemia (AML).

The exact cause of PMF remains unclear; however, genetic mutations are known to play a significant role in its development. The Janus kinase 2 (JAK2), calreticulin (CALR), and MPL genes have been identified as commonly mutated in PMF patients. These genetic alterations contribute to the dysregulated production of blood cells and the activation of signaling pathways that promote fibrosis.

Diagnosis of PMF typically involves a combination of clinical evaluation, complete blood count (CBC), bone marrow aspiration and biopsy, cytogenetic analysis, and molecular testing to identify genetic mutations. Treatment options depend on the individual patient's symptoms, risk stratification, and disease progression. They may include observation, supportive care, medications to manage symptoms and control the disease (such as JAK inhibitors), and stem cell transplantation for eligible patients.

Myeloproliferative disorders (MPDs) are a group of rare, chronic blood cancers that originate from the abnormal proliferation or growth of one or more types of blood-forming cells in the bone marrow. These disorders result in an overproduction of mature but dysfunctional blood cells, which can lead to serious complications such as blood clots, bleeding, and organ damage.

There are several subtypes of MPDs, including:

1. Chronic Myeloid Leukemia (CML): A disorder characterized by the overproduction of mature granulocytes (a type of white blood cell) in the bone marrow, leading to an increased number of these cells in the blood. CML is caused by a genetic mutation that results in the formation of the BCR-ABL fusion protein, which drives uncontrolled cell growth and division.
2. Polycythemia Vera (PV): A disorder characterized by the overproduction of all three types of blood cells - red blood cells, white blood cells, and platelets - in the bone marrow. This can lead to an increased risk of blood clots, bleeding, and enlargement of the spleen.
3. Essential Thrombocythemia (ET): A disorder characterized by the overproduction of platelets in the bone marrow, leading to an increased risk of blood clots and bleeding.
4. Primary Myelofibrosis (PMF): A disorder characterized by the replacement of normal bone marrow tissue with scar tissue, leading to impaired blood cell production and anemia, enlargement of the spleen, and increased risk of infections and bleeding.
5. Chronic Neutrophilic Leukemia (CNL): A rare disorder characterized by the overproduction of neutrophils (a type of white blood cell) in the bone marrow, leading to an increased number of these cells in the blood. CNL can lead to an increased risk of infections and organ damage.

MPDs are typically treated with a combination of therapies, including chemotherapy, targeted therapy, immunotherapy, and stem cell transplantation. The choice of treatment depends on several factors, including the subtype of MPD, the patient's age and overall health, and the presence of any comorbidities.

Janus Kinase 2 (JAK2) is a tyrosine kinase enzyme that plays a crucial role in intracellular signal transduction. It is named after the Roman god Janus, who is depicted with two faces, as JAK2 has two similar phosphate-transferring domains. JAK2 is involved in various cytokine receptor-mediated signaling pathways and contributes to hematopoiesis, immune function, and cell growth.

Mutations in the JAK2 gene have been associated with several myeloproliferative neoplasms (MPNs), including polycythemia vera, essential thrombocythemia, and primary myelofibrosis. The most common mutation is JAK2 V617F, which results in a constitutively active enzyme that promotes uncontrolled cell proliferation and survival, contributing to the development of these MPNs.

Essential thrombocythemia (ET) is a myeloproliferative neoplasm (MPN), a type of blood cancer characterized by the overproduction of platelets (thrombocytosis) in the bone marrow. In ET, there is an excessive proliferation of megakaryocytes, the precursor cells that produce platelets. This leads to increased platelet counts in the peripheral blood, which can increase the risk of blood clots (thrombosis) and bleeding episodes (hemorrhage).

The term "essential" is used to indicate that the cause of this condition is not known or idiopathic. ET is primarily a disease of older adults, but it can also occur in younger individuals. The diagnosis of essential thrombocythemia requires careful evaluation and exclusion of secondary causes of thrombocytosis, such as reactive conditions, inflammation, or other myeloproliferative neoplasms.

The clinical presentation of ET can vary widely among patients. Some individuals may be asymptomatic and discovered only during routine blood tests, while others may experience symptoms related to thrombosis or bleeding. Common symptoms include headaches, visual disturbances, dizziness, weakness, numbness, or tingling in the extremities, if there are complications due to blood clots in the brain or other parts of the body. Excessive bruising, nosebleeds, or blood in the stool can indicate bleeding complications.

Treatment for essential thrombocythemia is aimed at reducing the risk of thrombosis and managing symptoms. Hydroxyurea is a commonly used medication to lower platelet counts, while aspirin may be prescribed to decrease the risk of blood clots. In some cases, interferon-alpha or ruxolitinib might be considered as treatment options. Regular follow-up with a hematologist and monitoring of blood counts are essential for managing this condition and detecting potential complications early.

Polycythemia Vera is a type of myeloproliferative neoplasm, a group of rare blood cancers. In Polycythemia Vera, the body produces too many red blood cells, leading to an increased risk of blood clots and thickening of the blood, which can cause various symptoms such as fatigue, headache, dizziness, and itching. It can also lead to enlargement of the spleen. The exact cause of Polycythemia Vera is not known, but it is associated with genetic mutations in the JAK2 gene in most cases. It is a progressive disease that can lead to complications such as bleeding, thrombosis, and transformation into acute leukemia if left untreated.

Splenomegaly is a medical term that refers to an enlargement or expansion of the spleen beyond its normal size. The spleen is a vital organ located in the upper left quadrant of the abdomen, behind the stomach and below the diaphragm. It plays a crucial role in filtering the blood, fighting infections, and storing red and white blood cells and platelets.

Splenomegaly can occur due to various underlying medical conditions, including infections, liver diseases, blood disorders, cancer, and inflammatory diseases. The enlarged spleen may put pressure on surrounding organs, causing discomfort or pain in the abdomen, and it may also lead to a decrease in red and white blood cells and platelets, increasing the risk of anemia, infections, and bleeding.

The diagnosis of splenomegaly typically involves a physical examination, medical history, and imaging tests such as ultrasound, CT scan, or MRI. Treatment depends on the underlying cause and may include medications, surgery, or other interventions to manage the underlying condition.

Thrombocytosis is a medical condition characterized by an abnormally high platelet count (also known as thrombocytes) in the blood. Platelets are small cell fragments that play a crucial role in blood clotting. A normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. Thrombocytosis is typically defined as a platelet count exceeding 450,000-500,000 platelets/µL.

Thrombocytosis can be classified into two types: reactive (or secondary) thrombocytosis and primary (or essential) thrombocytosis. Reactive thrombocytosis is more common and occurs as a response to an underlying condition, such as infection, inflammation, surgery, or certain types of cancer. Primary thrombocytosis, on the other hand, is caused by intrinsic abnormalities in the bone marrow cells responsible for platelet production (megakaryocytes), and it is often associated with myeloproliferative neoplasms like essential thrombocythemia.

While mild thrombocytosis may not cause any symptoms, higher platelet counts can increase the risk of blood clots (thrombosis) and bleeding disorders due to excessive platelet aggregation. Symptoms of thrombocytosis may include headaches, dizziness, visual disturbances, or chest pain if a blood clot forms in the brain or heart. Bleeding symptoms can manifest as easy bruising, nosebleeds, or gastrointestinal bleeding.

Treatment for thrombocytosis depends on the underlying cause and the severity of the condition. In cases of reactive thrombocytosis, treating the underlying disorder often resolves the high platelet count. For primary thrombocytosis, medications like aspirin or cytoreductive therapy (such as hydroxyurea) may be used to reduce the risk of blood clots and control platelet production. Regular monitoring of platelet counts is essential for managing this condition and preventing potential complications.

... is also found in the nucleus, suggesting that it may have a role in transcription regulation. Calreticulin binds ... The term "Mobilferrin" is considered to be the same as calreticulin by some sources. Calreticulin binds to misfolded proteins ... Systemic lupus erythematosus is associated with increased autoantibody titers against calreticulin, but calreticulin is not a ... "Entrez Gene: CALR calreticulin". Nangalia J, Massie CE, Baxter EJ, Nice FL, Gundem G, Wedge DC, Avezov E, Li J, Kollmann K, ...
This family includes Calreticulin, Calnexin and Camlegin. Michalak M, Milner RE, Burns K, Opas M (August 1992). "Calreticulin ... In molecular biology, the calreticulin protein family is a family of calcium-binding proteins. ...
"Protein acyltransferase function of purified calreticulin. Part 1: Characterization of propionylation of protein utilizing ...
In 2013, two groups detected calreticulin mutations in a majority of JAK2-negative/MPL-negative patients with essential ... "Somatic mutations of calreticulin in myeloproliferative neoplasms". The New England Journal of Medicine. 369 (25): 2379-90. doi ...
July 1998). "Interaction between a Ca2+-binding protein calreticulin and perforin, a component of the cytotoxic T-cell granules ... 1998). "Interaction between a Ca2+-binding protein calreticulin and perforin, a component of the cytotoxic T-cell granules". ... Perforin has been shown to interact with calreticulin. Granzymes Defensin Complement membrane attack complex GRCh38: Ensembl ... perforin molecules translocate to the target cell with the help of calreticulin, which works as a chaperone protein to prevent ...
Another externalized molecule marking apoptotic cells is calreticulin. Generally, the ability of apoptotic cells to change ... interacts with calreticulin which is a known C1q receptor), or complement receptors (CR3 and CR4). There is a variety of ... altered surface sugars on apoptotic cell and enable easier uptake by phagocytes which recognize their complex with calreticulin ...
He elucidated the molecular features of substrate recognition by endoplasmic reticulum chaperones calreticulin and calnexin. He ... "Interactions of substrate with calreticulin, an endoplasmic reticulum chaperone". Journal of Biological Chemistry. 278 (8): ... "Isothermal titration calorimetric study defines the substrate binding residues of calreticulin". Biochemical and Biophysical ...
"Calreticulin exposure dictates the immunogenicity of cancer cell death". Nature Medicine. 13 (1): 54-61. doi:10.1038/nm1523. ...
Cahu X, Constantinescu SN (December 2015). "Oncogenic Drivers in Myeloproliferative Neoplasms: From JAK2 to Calreticulin ...
... VIII and calreticulin as molecular determinants of sink strength?". Plant Physiology. 126 (1): 39-46. doi:10.1104/pp. ...
After the β2-microglobulin binds to the MHC class I peptide-loading complex (PLC), calreticulin and ERp57 take over the job of ... Oliver JD, Hresko RC, Mueckler M, High S (Jun 1996). "The glut 1 glucose transporter interacts with calnexin and calreticulin ... Del Bem LE (Feb 2011). "The evolutionary history of calreticulin and calnexin genes in green plants". Genetica. 139 (2): 225-9 ... Otteken A, Moss B (Jan 1996). "Calreticulin interacts with newly synthesized human immunodeficiency virus type 1 envelope ...
"Modulation of gene expression by calreticulin binding to the glucocorticoid receptor". Nature. 367 (6462): 476-480. doi:10.1038 ...
Carpio MA, Decca MB, Lopez Sambrooks C, Durand ES, Montich GG, Hallak ME (July 2013). "Calreticulin-dimerization induced by ... López Sambrooks C, Carpio MA, Hallak ME (June 2012). "Arginylated calreticulin at plasma membrane increases susceptibility of ... Another protein which benefits from arginylation is calreticulin because when modified, its role during endoplasmic reticulum ...
... has been shown to interact with calreticulin and PAX8. GRCh38: Ensembl release 89: ENSG00000136352 - Ensembl, ... Perrone L, Tell G, Di Lauro R (February 1999). "Calreticulin enhances the transcriptional activity of thyroid transcription ... Perrone L, Tell G, Di Lauro R (February 1999). "Calreticulin enhances the transcriptional activity of thyroid transcription ...
... cell surface calreticulin)". Immunopharmacology. 38 (1-2): 73-80. doi:10.1016/S0162-3109(97)00076-3. PMID 9476117. Karinch AM, ...
"Calreticulin is released from activated neutrophils and binds to C1q and mannan-binding protein". Clinical Immunology and ... cell surface calreticulin)". Immunopharmacology. 38 (1-2): 73-80. doi:10.1016/S0162-3109(97)00076-3. PMID 9476117. Nepomuceno ...
"Adiponectin modulates inflammatory reactions via calreticulin receptor-dependent clearance of early apoptotic bodies". J Clin ...
... and calreticulin". Immunity. 14 (3): 303-13. doi:10.1016/s1074-7613(01)00111-x. PMID 11290339. Williams SE, Inoue I, Tran H, ... "Low density lipoprotein receptor-related protein is a calreticulin coreceptor that signals focal adhesion disassembly". The ...
This protein of the endoplasmic reticulum interacts with lectin chaperones such as calreticulin and CNX in order to modulate ... This protein localizes to the endoplasmic reticulum (ER) and interacts with lectin chaperones calreticulin and calnexin (CNX) ... and polypeptide binding sites of calnexin and calreticulin". The Journal of Biological Chemistry. 277 (33): 29686-97. doi: ...
"Post-translational arginylation of calreticulin: a new isospecies of calreticulin component of stress granules". The Journal of ...
The peptide-loading complex consists of TAP, tapasin, MHC class I, calreticulin, and ERp57. Tapasin recruits MHC class I ... Sadasivan B, Lehner PJ, Ortmann B, Spies T, Cresswell P (August 1996). "Roles for calreticulin and a novel glycoprotein, ... Sadasivan B, Lehner PJ, Ortmann B, Spies T, Cresswell P (August 1996). "Roles for calreticulin and a novel glycoprotein, ...
Lectin chaperones: calnexin and calreticulin Non-classical molecular chaperones: HSP47 and ERp29 Folding chaperones: Protein ... "TROSY-NMR reveals interaction between ERp57 and the tip of the calreticulin P-domain". Proceedings of the National Academy of ...
Calreticulin: Evidence has indicated the presence of the protein, calreticulin, within the cortical granule. Researchers have ... On the other hand, different research has shown that calreticulin may be released from vesicles other than cortical granules. ... Furthermore, upon exocytosis, this calreticulin interacts with the oocyte's cytoskeleton, thereby allowing the transmission of ... Additionally contributing to polyspermy prevention, calreticulin may also inhibit certain glycoproteins, which promote ...
The network of endoplasmic reticulum-resident chaperones (ERp72, GRP94, calreticulin, and BiP) interacts with apolipoprotein b ... calreticulin, and cyclophilin B". The Journal of Biological Chemistry. 278 (9): 7459-68. doi:10.1074/jbc.M207976200. PMID ... "C1q and mannose binding lectin engagement of cell surface calreticulin and CD91 initiates macropinocytosis and uptake of ... "Low density lipoprotein receptor-related protein is a calreticulin coreceptor that signals focal adhesion disassembly". The ...
Examples include: calmodulin calnexin calreticulin gelsolin Ghoshdastider U, Popp D, Burtnick LD, Robinson RC (2013). "The ...
... may refer to: Calreticulin, a protein that in humans is encoded by the CALR gene. Chief Albert Luthuli Regiment, an ...
In the ER, PPIB interacts with proteins such as P3H1, CRTAP, BiP, GRP94, PDI, and calreticulin to form foldase and chaperone ... PPIB has been shown to interact with: Apolipoprotein B. P3H1, CRTAP, BiP, GRP94, PDI, and calreticulin. GRCh38: Ensembl release ... calreticulin, and cyclophilin B". J. Biol. Chem. 278 (9): 7459-68. doi:10.1074/jbc.M207976200. PMID 12397072. Rasmussen HH, van ... is retained intracellularly via a unique COOH-terminal sequence and colocalizes with the calcium storage protein calreticulin ...
At the same time, calreticulin prevents any misfolded Gn/Gc from being exported to the Golgi. Sixth, The correctly folded Gn/Gc ...
High levels of CD47 allows cancer cells to avoid phagocytosis despite having a higher level of calreticulin - the dominant pro- ... "Calreticulin is the dominant pro-phagocytic signal on multiple human cancers and is counterbalanced by CD47". Sci Transl Med. 2 ...
Calreticulin is crucial and is highly dependant in the assembly and maturation of MHC-I in the PLC. The globular lectin domain ... MHC-I heavy chains may work as chaperones with the aid of the calnexin-calreticulin complex in the ER. In addition to this, β2- ... When MHC-I chains are empty, they are recruited by calreticulin and form a transient PLC. Tapasin regularly plays a role in the ... In general, preliminary MHC-I heavy chains are chaperoned by the calnexin-calreticulin system in the ER. Together with β2- ...
Calreticulin is also found in the nucleus, suggesting that it may have a role in transcription regulation. Calreticulin binds ... The term "Mobilferrin" is considered to be the same as calreticulin by some sources. Calreticulin binds to misfolded proteins ... Systemic lupus erythematosus is associated with increased autoantibody titers against calreticulin, but calreticulin is not a ... "Entrez Gene: CALR calreticulin". Nangalia J, Massie CE, Baxter EJ, Nice FL, Gundem G, Wedge DC, Avezov E, Li J, Kollmann K, ...
... Christensen, Anna Umeå universitet, Teknisk- ... Background: Calreticulin (CRT) is a ubiquitous ER protein involved in multiple cellular processes in animals, such as protein ...
Calreticulin (CALR) is a chaperone protein that localizes primarily to the endoplasmic reticulum (ER) lumen where it is ... Calreticulin (CALR) is a chaperone protein that localizes primarily to the endoplasmic reticulum (ER) lumen where it is ... Calreticulin affects hematopoietic stem/progenitor cell fate by impacting erythroid and megakaryocytic differentiation. Salati ... Calreticulin affects hematopoietic stem/progenitor cell fate by impacting erythroid and megakaryocytic differentiation / Salati ...
Rat CRT(Calreticulin) ELISA Kit Synonyms:Calreticulin, calregulin,CRP55,CaBP3,calsequestrin-like protein, endoplasmic reticulum ... Rat CRT(Calreticulin) ELISA Kit Trade Information. * Supply Ability. 500 Kit Per Day ... Rat CRT(Calreticulin) ELISA Kit Price And Quantity. * Price. 18500 INR/Kit ... Calreticulin) ELISA Kit based in Delhi, India ... Get a price quote for Rat CRT(Calreticulin) ELISA Kit. Email Id ...
The CALR gene provides instructions for making a multi-functional protein called calreticulin. Learn about this gene and ... Calreticulin: non-endoplasmic reticulum functions in physiology and disease. FASEB J. 2010 Mar;24(3):665-83. doi: 10.1096/fj.09 ... It is not clear how the alteration in calreticulin affects the proteins function or leads to the signs and symptoms of ... The CALR gene provides instructions for making a multi-functional protein called calreticulin. This protein is found in several ...
Calreticulin Expression in Human Carcinomas: A Systematic Review and Meta-Analysis. Calreticulin Expression in Human Carcinomas ... Calreticulin (CRT) is a multifunctional protein in the endoplasmic reticulum that can play distinct roles in different cancers ... The present study performed a systematic review and meta-analysis of observational studies on whether calreticulin levels could ...
COX IV, histone H3, GAPDH, and calreticulin were used as mitochondrial, nuclear, cytosolic, and membrane markers, respectively ... Antibodies for histone H3 and calreticulin were from Cell Signaling. The GAPDH antibody was from Millipore. ...
Somatic mutations of calreticulin in myeloproliferative neoplasms. N Engl J Med. 2013 Dec 19. 369(25):2379-90. [QxMD MEDLINE ... In two separate studies, Klampfl et al and Nangalia et al found that mutations in the gene encoding calreticulin (CALR) were ...
Inhibited calreticulin expression reduced the phosphorylation of EGFR, and ERK and the expression of NF-κB in nuclear ... and calreticulin were identified. Furthermore, intracellular signal pathway analysis shows that EGFR and NF-κB are the main ...
Pinto, J. P., Ramos, P., de Almeida, S. F., Oliveira, S., et al. (2008). Protective role of calreticulin in HFE hemochromatosis ...
In macrophages exposed to DM-albumin a higher expression of PDI and calreticulin was observed together with a trend of enhanced ... calreticulin and ubiquitin was determined by immunoblot and ABCA-1 protein level, by flow cytometry and imunocytochemistry. ...
... calreticulin, a Ca2+ -binding chaperon indispensable for cardiac development; and (5) colligin-1/2. All but tubulin-alpha have ...
... namely calreticulin-deficient fetal liver chimeras (FLC), which develop severe blepharitis and alopecia due to T cell hyper ...
View News titled, Breaking mAb: a Novel Monoclonal Antibody Takes Aim at Mutant Calreticulin ...
Except where otherwise noted, this work is subject to a Creative Commons Attribution-NonCommercial License. Please contact us to use this work in a way not covered by the license.. ...
An AND search displays only data that satisfy all conditions, while an OR search displays all data that satisfy one of the conditions. Filtering conditions are reflected even if the column is hidden. ...
Prognostic role of the innate immune signature CD163 and "eat me" signal calreticulin in clear cell renal cell carcinoma. Anno ...
Calreticulin (CALR) Background. Calreticulin (CALR) mutations have been found to be present in 67-88% of JAK2 and the ...
Human gene-engineered calreticulin mutant stem cells recapitulate MPN hallmarks and identify targetable vulnerabilities. ...
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Mutations of the thrombopoietin receptor gene (MPL) or the calreticulin (CALR) gene also may be the cause of primary ...
Somatic mutations of calreticulin in myeloproliferative neoplasms. N Engl J Med. 2013 Dec 19. 369(25):2379-90. [QxMD MEDLINE ... In two separate studies, Klampfl et al and Nangalia et al found that mutations in the gene encoding calreticulin (CALR) were ...
The chaperone proteins, calnexin and calreticulin, enhance both FVIII secretion and degradation. ...
Role of calreticulin mutations in the aetiological diagnosis of splanchnic vein thrombosis. Journal of hepatology 2015 Jan 62 ( ...
Basu, Binder, Ramalingam, Srivastava, CD91 is a common receptor for heat shock proteins gp96, hsp90, hsp70, and calreticulin, ... Berwin, Scavenger receptor-A mediates gp96/GRP94 and calreticulin internalization by antigen-presenting cells, EMBO J ...
The presence with the myeloproliferative leukemia virus proto-oncogene (MPL) along with the calreticulin mutation werent ...
Gateway to HIV and AIDS Research. ...
Two humans of ATMs was that sluggish thousands along have a download in a condition launched calreticulin( CALR). CALR cells ...
... and now we are at the advent of potentially having immunotherapies with antibodies in the market called calreticulin, which is ...
  • In 2013, two groups detected calreticulin mutations in a majority of JAK2-negative/MPL-negative patients with essential thrombocythemia and primary myelofibrosis, which makes CALR mutations the second most common in myeloproliferative neoplasms. (wikipedia.org)
  • Mutations of the thrombopoietin receptor gene ( MPL ) or the calreticulin ( CALR ) gene also may be the cause of primary myelofibrosis. (msdmanuals.com)
  • Role of calreticulin mutations in the aetiological diagnosis of splanchnic vein thrombosis. (cdc.gov)
  • Calreticulin also known as calregulin, CRP55, CaBP3, calsequestrin-like protein, and endoplasmic reticulum resident protein 60 (ERp60) is a protein that in humans is encoded by the CALR gene. (wikipedia.org)
  • The CALR gene provides instructions for making a multi-functional protein called calreticulin. (medlineplus.gov)
  • Calreticulin is a multifunctional soluble protein that binds Ca2+ ions (a second messenger in signal transduction), rendering it inactive. (wikipedia.org)
  • Calreticulin (CRT) is a multifunctional protein in the endoplasmic reticulum that can play distinct roles in different cancers . (bvsalud.org)
  • Calreticulin is a multifunctional protein that acts as a major Ca(2+)-binding (storage) protein in the lumen of the endoplasmic reticulum. (promab.com)
  • Calreticulin is located in storage compartments associated with the endoplasmic reticulum and is considered an ER resident protein. (wikipedia.org)
  • Calreticulin binds to misfolded proteins and prevents them from being exported from the endoplasmic reticulum to the Golgi apparatus. (wikipedia.org)
  • Calreticulin: non-endoplasmic reticulum functions in physiology and disease. (medlineplus.gov)
  • A similar quality-control molecular chaperone, calnexin, performs the same service for soluble proteins as does calreticulin, however it is a membrane-bound protein. (wikipedia.org)
  • Calreticulin and Calnexin's ability to bind carbohydrates associates them with the lectin protein family. (wikipedia.org)
  • After the β2-microglobulin binds to the peptide-loading complex (PLC), calreticulin (along with ERp57) takes over the job of chaperoning the MHC class I protein while the tapasin links the complex to the transporter associated with antigen processing (TAP) complex. (wikipedia.org)
  • The ER is involved in protein processing and transport, and within this structure, calreticulin plays a role in ensuring the proper folding of newly formed proteins. (medlineplus.gov)
  • These genetic changes lead to production of an altered calreticulin protein with a different sequence of building blocks (amino acids) at one end. (medlineplus.gov)
  • The effect of the genetic changes on calreticulin function is unknown, and researchers are working to determine how the altered protein is involved in primary myelofibrosis. (medlineplus.gov)
  • Systemic lupus erythematosus is associated with increased autoantibody titers against calreticulin, but calreticulin is not a Ro/SS-A antigen. (wikipedia.org)
  • Earlier papers referred to calreticulin as an Ro/SS-A antigen, but this was later disproven. (wikipedia.org)
  • Studies on transgenic mice reveal that calreticulin is a cardiac embryonic gene that is essential during development. (wikipedia.org)
  • Thus, calreticulin can act as an important modulator of the regulation of gene transcription by nuclear hormone receptors. (wikipedia.org)
  • Through calcium regulation and other mechanisms, calreticulin is thought to play a role in the control of gene activity, cell growth and division (proliferation) and movement (migration), the attachment of cells to one another (adhesion), and regulation of programmed cell death (apoptosis). (medlineplus.gov)
  • Calreticulin binds to the synthetic peptide KLGFFKR, which is almost identical to an amino acid sequence in the DNA-binding domain of the superfamily of nuclear receptors. (wikipedia.org)
  • The amino terminus of calreticulin interacts with the DNA-binding domain of the glucocorticoid receptor and prevents the receptor from binding to its specific glucocorticoid response element. (wikipedia.org)
  • Calreticulin can inhibit the binding of androgen receptor to its hormone-responsive DNA element and can inhibit androgen receptor and retinoic acid receptor transcriptional activities in vivo, as well as retinoic acid-induced neuronal differentiation. (wikipedia.org)
  • Calreticulin is also found in the nucleus, suggesting that it may have a role in transcription regulation. (wikipedia.org)
  • Calreticulin (CRT) is expressed in many cancer cells and plays a role to promote macrophages to engulf hazardous cancerous cells. (wikipedia.org)
  • Both proteins, calnexin and calreticulin, have the function of binding to oligosaccharides containing terminal glucose residues, thereby targeting them for degradation. (wikipedia.org)
  • It is not clear how the alteration in calreticulin affects the protein's function or leads to the signs and symptoms of essential thrombocythemia. (medlineplus.gov)
  • We studied B cell homeostasis in two murine models of T cell mediated chronic inflammation, namely calreticulin-deficient fetal liver chimeras (FLC), which develop severe blepharitis and alopecia due to T cell hyper responsiveness, and inflammatory bowel disease (IBD) caused by injection of CD4+ naïve T cells. (rero.ch)
  • Increased autoantibody titer against human calreticulin is found in infants with complete congenital heart block of both the IgG and IgM classes. (wikipedia.org)
  • The ER is also a storage location for charged calcium atoms (calcium ions), and calreticulin is involved in maintaining the correct levels of calcium ions in this structure. (medlineplus.gov)
  • The present study performed a systematic review and meta-analysis of observational studies on whether calreticulin levels could represent a prognostic factor in carcinoma patients . (bvsalud.org)
  • Calreticulin and calnexin are also integral in the production of MHC class I proteins. (wikipedia.org)
  • Calreticulin mutations and long-term survival in essential thrombocythemia. (cdc.gov)
  • 1. Calreticulin exposure correlates with robust adaptive antitumor immunity and favorable prognosis in ovarian carcinoma patients. (nih.gov)
  • Through calcium regulation and other mechanisms, calreticulin is thought to play a role in the control of gene activity, cell growth and division (proliferation) and movement (migration), the attachment of cells to one another (adhesion), and regulation of programmed cell death (apoptosis). (medlineplus.gov)
  • Antibody levels to recombinant tick calreticulin increase in humans after exposure to Ixodes scapularis (Say) and are correlated with tick engorgement indices. (nih.gov)
  • The antibody responses of subjects who presented with a definite Ixodes scapularis (Say) tick bite were measured to determine the utility of the antibody response against recombinant tick calreticulin (rTC) as a biologic marker of tick exposure. (nih.gov)
  • 6. Side-by-side comparison of flow cytometry and immunohistochemistry for detection of calreticulin exposure in the course of immunogenic cell death. (nih.gov)
  • The effect of the genetic changes on calreticulin function is unknown, and researchers are working to determine how the altered protein is involved in primary myelofibrosis. (medlineplus.gov)
  • It is not clear how the alteration in calreticulin affects the protein's function or leads to the signs and symptoms of essential thrombocythemia. (medlineplus.gov)
  • The detection of autoantibodies to calreticulin isoforms may have utility for the early diagnosis of pancreatic cancer. (nih.gov)
  • The ER is also a storage location for charged calcium atoms (calcium ions), and calreticulin is involved in maintaining the correct levels of calcium ions in this structure. (medlineplus.gov)
  • In addition calreticulin is a major storage form for CALCIUM and functions as a calcium-signaling molecule that can regulate intracellular calcium HOMEOSTASIS . (bvsalud.org)
  • Immunohistochemical analysis of calreticulin in pancreatic/ampullary tumor tissue arrays using an isoform nonspecific antibody revealed diffuse and consistent cytoplasmic staining in the neoplastic epithelial cells of the pancreatic and ampullary adenocarcinomas. (nih.gov)