B3GAT1

B3GAT1
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1V82, 1V83, 1V84
Identifiers
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
Gene location (Human) Chr. Chromosome 11 (human)[1] Band 11q25 Start 134,378,504 bp[1] End 134,412,242 bp[1]
Gene location (Mouse) Chr. Chromosome 9 (mouse)[2] Band 9|9 A4 Start 26,645,024 bp[2] End 26,674,397 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in amygdala prefrontal cortex Brodmann area 9 hippocampus proper putamen nucleus accumbens Region I of hippocampus proper caudate nucleus endothelial cell substantia nigra Top expressed in habenula visual cortex piriform cortex superior frontal gyrus subiculum dentate gyrus superior colliculus Region I of hippocampus proper primary motor cortex medial dorsal nucleus More reference expression data BioGPS More reference expression data
Gene ontology Molecular function transferase activity metal ion binding galactosylgalactosylxylosylprotein 3-beta-glucuronosyltransferase activity UDP-galactose:beta-N-acetylglucosamine beta-1,3-galactosyltransferase activity Cellular component integral component of membrane Golgi apparatus membrane extracellular region endoplasmic reticulum endoplasmic reticulum membrane intracellular membrane-bounded organelle Golgi membrane Biological process glycosaminoglycan metabolic process protein glycosylation chondroitin sulfate proteoglycan biosynthetic process chondroitin sulfate metabolic process carbohydrate metabolic process cellular response to hypoxia Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 27087 76898 Ensembl ENSG00000109956 ENSMUSG00000045994 UniProt Q9P2W7 Q9CW73 RefSeq (mRNA) NM_018644 NM_054025 NM_001367973 NM_029792 NM_001310766 RefSeq (protein) NP_061114 NP_473366 NP_001354902 NP_001297695 NP_084068 Location (UCSC) Chr 11: 134.38 – 134.41 Mb Chr 9: 26.65 – 26.67 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

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]

Function

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]

Immunohistochemistry

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]

References

Further reading

External links

• CD57+Antigen at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
• Human B3GAT1 genome location and B3GAT1 gene details page in the UCSC Genome Browser.