ST8SIA2
Description
The ST8SIA2 (ST8 alpha-N-acetyl-neuraminide alpha-2,8-sialyltransferase 2) is a protein-coding gene located on chromosome 15.
ST8SIA2 encodes a type II membrane protein that catalyzes the transfer of sialic acid from CMP-sialic acid to N-linked oligosaccharides and glycoproteins. It is located in the Golgi apparatus and is involved in the production of polysialic acid, which modifies the adhesive properties of neural cell adhesion molecule (NCAM1). ST8SIA2 belongs to glycosyltransferase family 29.
ST8SIA2 catalyzes the transfer of a sialic acid from a CMP-linked sialic acid donor to a terminal alpha-2,3-, alpha-2,6-, or alpha-2,8-linked sialic acid on an N-linked glycan acceptor, forming alpha-2,8-linkages. This process contributes to polysialic acid synthesis on various sialylated N-acetyllactosaminyl oligosaccharides, including NCAM1, NCAM1 N-glycans, FETUB N-glycans, and to a lesser extent sialylparagloboside (SPG) and AHSG. It does not require the initial addition of an alpha 2,8-sialic acid for AHSG. Importantly, ST8SIA2 does not demonstrate sialic acid-polymerase activity. In the hippocampus, ST8SIA2 catalyzes polysialic acid synthesis on NCAM1, which supports neurite outgrowth. ST8SIA2-mediated polysialylation influences oligodendrocyte differentiation and potentially promotes the integrity of myelin and axons.
ST8SIA2 is also known as HsT19690, SIAT8-B, SIAT8B, ST8SIA-II, ST8SiaII, STX.
