B3GAT1 | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Aliases | B3GAT1 , CD57, GLCATP, GLCUATP, HNK1, LEU7, NK-1, NK1, beta-1,3-glucuronyltransferase 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||
External IDs | OMIM: 151290 MGI: 1924148 HomoloGene: 49551 GeneCards: B3GAT1 | ||||||||||||||||||||||||||||||||||||||||||||||||||
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Wikidata | |||||||||||||||||||||||||||||||||||||||||||||||||||
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3-beta-glucuronosyltransferase 1 (B3GAT1) is an enzyme that in humans is encoded by the B3GAT1 gene, whose enzymatic activity creates the CD57 epitope on other cell surface proteins. [5] In immunology, the CD57 antigen (CD stands for cluster of differentiation) is also known as HNK1 (human natural killer-1) or LEU7. It is expressed as a carbohydrate epitope that contains a sulfoglucuronyl residue in several adhesion molecules of the nervous system. [6]
The protein encoded by this gene is a member of the glucuronyltransferase gene family. These enzymes exhibit strict acceptor specificity, recognizing nonreducing terminal sugars and their anomeric linkages. This gene product functions as the key enzyme in a glucuronyl transfer reaction during the biosynthesis of the carbohydrate epitope HNK-1 (human natural killer-1, also known as CD57 and LEU7). Alternate transcriptional splice variants have been characterized. [5]
In anatomical pathology, CD57 (immunostaining) is similar to CD56 for use in differentiating neuroendocrine tumors from others. [7] Using immunohistochemistry, CD57 molecule can be demonstrated in around 10 to 20% of lymphocytes, as well as in some epithelial, neural, and chromaffin cells. Among lymphocytes, CD57 positive cells are typically either T cells or NK cells, and are most commonly found within the germinal centres of lymph nodes, tonsils, and the spleen. [8]
There is an increase in the number of circulating CD57 positive cells in the blood of patients who have recently undergone organ or tissue transplants, especially of the bone marrow, and in patients with HIV. Increased CD57+ counts have also been reported in rheumatoid arthritis and Felty's syndrome, among other conditions. [8] High levels of CD57 expression amongst circulating CD8+ T cells is associated with other markers of immune ageing (immunosenescence) and may be associated with increased cancer risk in renal transplant recipients. [9]
Neoplastic CD57 positive cells are seen in conditions as varied as large granular lymphocytic leukaemia, small-cell carcinoma, thyroid carcinoma, and neural and carcinoid tumours. Although the antigen is particularly common in carcinoid tumours, it is found in such a wide range of other conditions that it is of less use in distinguishing these tumours from others than more specific markers such as chromogranin and NSE. [8]
Dihydrolipoyl transacetylase is an enzyme component of the multienzyme pyruvate dehydrogenase complex. The pyruvate dehydrogenase complex is responsible for the pyruvate decarboxylation step that links glycolysis to the citric acid cycle. This involves the transformation of pyruvate from glycolysis into acetyl-CoA which is then used in the citric acid cycle to carry out cellular respiration.
Melanoma-associated antigen 1 is a protein that in humans is encoded by the MAGEA1 gene.
In enzymology, a galactosylgalactosylxylosylprotein 3-beta-glucuronosyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a N-acetylgalactosaminyl-proteoglycan 3-beta-glucuronosyltransferase is an enzyme that catalyzes the chemical reaction
UDP-glucuronosyltransferase 1-10 is an enzyme that in humans is encoded by the UGT1A10 gene.
UDP-glucuronosyltransferase 1-4 is an enzyme that in humans is encoded by the UGT1A4 gene.
Tyrosine-protein kinase TXK is an enzyme that in humans is encoded by the TXK gene.
Carbohydrate sulfotransferase 4 is an enzyme that in humans is encoded by the CHST4 gene.
UDP-GalNAc:beta-1,3-N-acetylgalactosaminyltransferase 1 is an enzyme that in humans is encoded by the B3GALNT1 gene.
Beta-1,4-galactosyltransferase 7 also known as galactosyltransferase I is an enzyme that in humans is encoded by the B4GALT7 gene. Galactosyltransferase I catalyzes the synthesis of the glycosaminoglycan-protein linkage in proteoglycans. Proteoglycans in turn are structural components of the extracellular matrix that is found between cells in connective tissues.
Galactosylgalactosylxylosylprotein 3-beta-glucuronosyltransferase 3 is an enzyme that in humans is encoded by the B3GAT3 gene.
Beta-1,4-galactosyltransferase 5 is an enzyme that in humans is encoded by the B4GALT5 gene.
Carbohydrate sulfotransferase 11 is an enzyme that in humans is encoded by the CHST11 gene.
Galactosylgalactosylxylosylprotein 3-beta-glucuronosyltransferase 2 is an enzyme that in humans is encoded by the B3GAT2 gene.
Dermatan-sulfate epimerase is an enzyme that in humans is encoded by the DSE gene.
Carbohydrate sulfotransferase 12 is an enzyme that in humans is encoded by the CHST12 gene.
CD8a, is a human gene.
Carbohydrate sulfotransferase 10 is an enzyme that in humans is encoded by the CHST10 gene.
In biochemistry, carbohydrate sulfotransferases are enzymes within the class of sulfotransferases which catalyze the transfer of the sulfate functional group to carbohydrate groups in glycoproteins and glycolipids. Carbohydrates are used by cells for a wide range of functions from structural purposes to extracellular communication. Carbohydrates are suitable for such a wide variety of functions due to the diversity in structure generated from monosaccharide composition, glycosidic linkage positions, chain branching, and covalent modification. Possible covalent modifications include acetylation, methylation, phosphorylation, and sulfation. Sulfation, performed by carbohydrate sulfotransferases, generates carbohydrate sulfate esters. These sulfate esters are only located extracellularly, whether through excretion into the extracellular matrix (ECM) or by presentation on the cell surface. As extracellular compounds, sulfated carbohydrates are mediators of intercellular communication, cellular adhesion, and ECM maintenance.
D-Man-alpha-(1->3) -D-Glc-beta-(1->4) -D-Glc-alpha-1-diphosphoundecaprenol 2-beta-glucuronyltransferase is an enzyme with the systematic name UDP-glucuronate: D-Man-alpha-(1->3) -D-Glc-beta-(1->4)-D-Glc-alpha-1-diphospho-ditrans,octacis-undecaprenol beta-1,2-glucuronyltransferase. This enzyme catalyses the following chemical reaction: