Xyloside xylosyltransferase 1 (XXYLT1)

Xyloside xylosyltransferase 1 (XXYLT1) is a type II membrane glycosyltransferase of the glycosyltransferase family 8, primarily residing in the endoplasmic reticulum. It transfers a xylose residue from UDP-xylose to a pre-existing xylose on the glucose-xylose (Xyl-Glc) disaccharide of epidermal growth factor (EGF)-like repeats, notably on the Notch receptor extracellular domain. This post-translational modification is part of the canonical glycosylation of Notch receptors and modulates their signaling function. Mutations or dysregulation of XXYLT1 can influence Notch-dependent cellular processes, with emerging evidence supporting a role in some cancers, particularly where Notch signaling is implicated. The detailed mechanism of catalysis involves direct nucleophilic attack from the acceptor xylose, consistent with an S~N~i-like retaining glycosyltransferase mechanism[1].

Other names

C3orf21PSEC0251FLJ35155UDP-xylose:alpha-xyloside alpha-1,3-xylosyltransferasexyloside xylosyltransferase 1

Catalytic transfer of xylose in an α1–3 linkage to an existing xylose on EGF-like repeats using a retaining glycosyltransferase mechanism; mechanistically, likely uses an S~N~i-like internal return reaction retaining the configuration at the anomeric carbon[1].