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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; OMA:B3GAT1 - orthologs
Gene location (Human)
Chr.	Chromosome 11 (human)
End	134,412,242 bp
Gene location (Mouse)
Chr.	Chromosome 9 (mouse)
End	26,674,397 bp
RNA expression pattern
	Top expressed in
	C1 segment; ; right frontal lobe; ; Amygdala; ; anterior cingulate cortex; ; prefrontal cortex; ; Brodmann area 9; ; hippocampus proper; ; putamen; ; nucleus accumbens; ; Region I of hippocampus proper;
	Top expressed in
	habenula; ; visual cortex; ; primary visual cortex; ; piriform cortex; ; superior frontal gyrus; ; subiculum; ; dentate gyrus; ; dentate gyrus of hippocampal formation granule cell; ; lateral septal nucleus; ; superior colliculus;
	More reference expression data
	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
	27087
	76898
	ENSG00000109956
	ENSMUSG00000045994
	Q9P2W7
	Q9CW73
	NM_018644; NM_054025; NM_001367973
	NM_029792; NM_001310766
	NP_061114; NP_473366; NP_001354902
	NP_001297695; NP_084068
	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

^ ^a ^b ^c GRCh38: Ensembl release 89: ENSG00000109956 – Ensembl, May 2017
^ ^a ^b ^c GRCm38: Ensembl release 89: ENSMUSG00000045994 – Ensembl, May 2017
^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^ ^a ^b "Entrez Gene: B3GAT1 beta-1,3-glucuronyltransferase 1 (glucuronosyltransferase P)".
^ Mitsumoto Y, Oka S, Sakuma H, Inazawa J, Kawasaki T (April 2000). "Cloning and chromosomal mapping of human glucuronyltransferase involved in biosynthesis of the HNK-1 carbohydrate epitope". Genomics. 65 (2): 166–173. doi:10.1006/geno.2000.6152. PMID 10783264.
^ Wick MR (2010). "Chapter 11 – Immunohistology of the Mediastinum". In Dabbs DJ (ed.). Diagnostic immunohistochemistry: theranostic and genomic applications (3rd ed.). Philadelphia, PA: Saunders/Elsevier. pp. 345–6. doi:10.1016/B978-1-4160-5766-6.00015-7. ISBN 978-1-4160-5766-6.
^ ^a ^b ^c Leong AS, Cooper K, Leong FJ (2003). Manual of Diagnostic Antibodies for Immunohistology (2nd ed.). London: Greenwich Medical Media. pp. 131–134. ISBN 978-1-84110-100-2.
^ Bottomley MJ, Harden PN, Wood KJ (May 2016). "CD8+ Immunosenescence Predicts Post-Transplant Cutaneous Squamous Cell Carcinoma in High-Risk Patients". Journal of the American Society of Nephrology. 27 (5): 1505–1515. doi:10.1681/ASN.2015030250. PMC 4849821. PMID 26563386.