Anti-SIA4A

The protein encoded by this gene is a type II membrane protein that catalyzes the transfer of sialic acid from CMP-sialic acid to galactose-containing substrates. The encoded protein is normally found in the Golgi but can be proteolytically processed to a soluble form. Correct glycosylation of the encoded protein may be critical to its sialyltransferase activity. This protein, which is a member of glycosyltransferase family 29, can use the same acceptor substrates as does sialyltransferase 4B. Two transcript variants encoding the same protein have been found for this gene. Other transcript variants may exist, but have not been fully characterized yet. [provided by RefSeq, Jul 2008], Protein function: A beta-galactoside alpha2-3 sialyltransferase involved in terminal sialylation of glycoproteins and glycolipids (PubMed:31784620, PubMed:8027041). Catalyzes the transfer of sialic acid (N-acetyl- neuraminic acid, Neu5Ac) from the nucleotide sugar donor CMP-Neu5Ac onto acceptor Galbeta-(1->3)-GalNAc-terminated glycoconjugates through an alpha2-3 linkage (PubMed:31784620, PubMed:8027041). Adds sialic acid to the core 1 O-glycan, Galbeta-(1->3)-GalNAc-O-Ser/Thr, which is a major structure of mucin-type O-glycans. As part of a homeostatic mechanism that regulates CD8-positive T cell numbers, sialylates core 1 O-glycans of T cell glycoproteins, SPN/CD43 and PTPRC/CD45. Prevents premature apoptosis of thymic CD8-positive T cells prior to peripheral emigration, whereas in the secondary lymphoid organs controls the survival of CD8-positive memory T cells generated following a successful immune response. Transfers sialic acid to asialofetuin, presumably onto Galbeta-(1->3)-GalNAc-O-Ser. Sialylates GM1a, GA1 and GD1b gangliosides to form GD1a, GM1b and GT1b, respectively (PubMed:8027041). [The UniProt Consortium] Recommended dilutions: WB 1:500-2000,IHC-p 1:50-300, ELISA 2000-20000. Cellular localization: Golgi apparatus, Golgi stack membrane , Single-pass type II membrane protein . Golgi apparatus, trans-Golgi network membrane , Single-pass type II membrane protein . Secreted. Membrane-bound form in medial and trans cisternae of Golgi (PubMed:9182658). Secreted into the body fluid. .