ST6GALNAC1
Function
Protein sialyltransferase specifically expressed in goblet cells that plays a key role in intestinal host-commensal homeostasis (PubMed:35303419). Conjugates sialic acid with an alpha-2-6 linkage to N-acetylgalactosamine (GalNAc) glycan chains linked to serine or threonine in glycoproteins (PubMed:16319059, PubMed:35303419). Catalyzes the formation of the sialyl-Tn (S-Tn) antigen, an antigen found in intestinal goblet cells, as well as ulcerative colitis (UC) and various cancers (PubMed:16319059, PubMed:35303419). Protein sialylation in globlet cells is essential for mucus integrity and is required to protect the intestinal mucus against excessive bacterial proteolytic degradation (PubMed:35303419).
Involvement in disease
Inflammatory bowel disease (PubMed:35303419). A chronic, relapsing inflammation of the gastrointestinal tract with a complex etiology (PubMed:35303419). It is subdivided into Crohn disease and ulcerative colitis phenotypes (PubMed:35303419). Crohn disease may affect any part of the gastrointestinal tract from the mouth to the anus, but most frequently it involves the terminal ileum and colon (PubMed:35303419). Bowel inflammation is transmural and discontinuous; it may contain granulomas or be associated with intestinal or perianal fistulas (PubMed:35303419). In contrast, in ulcerative colitis, the inflammation is continuous and limited to rectal and colonic mucosal layers; fistulas and granulomas are not observed (PubMed:35303419). Both diseases include extraintestinal inflammation of the skin, eyes, or joints (PubMed:35303419). Disease susceptibility is associated with variants affecting the gene represented in this entry (PubMed:35303419).
Pathway
Protein modification; protein glycosylation.
Post-translational modifications
Glycosylated; autosialylated.
Sequence Similarities
Belongs to the glycosyltransferase 29 family.
Tissue Specificity
Expression is restricted to the gastrointestinal tract (PubMed:16319059). Highly expressed in goblet cells (PubMed:35303419). Also expressed in various tumor cells (PubMed:16319059).
Cellular localization
- Golgi apparatus membrane
- Single-pass type II membrane protein
Alternative names
SIAT7A, UNQ543/PRO848, ST6GALNAC1, ST6GalNAc I, Sialyltransferase 7A, ST6GalNAc-I, ST6GalNAcI, hST6GalNAc-I, SIAT7-A