The CAP10 domain is found in glycosyltransferases from animals, plants and fungi. Rumi is a Drosophila protein with a CAP10 domain that functions as a protein O-glucosyltransferase. In human and mouse, three potential homologues exist: one with a high degree of identity to Drosophila Rumi (52%), and two others with lower degrees of identity but including a CAP10 domain (KDELC1 and KDELC2) [ expand

The CAP10 domain is found in glycosyltransferases from animals, plants and fungi. Rumi is a Drosophila protein with a CAP10 domain that functions as a protein O-glucosyltransferase. In human and mouse, three potential homologues exist: one with a high degree of identity to Drosophila Rumi (52%), and two others with lower degrees of identity but including a CAP10 domain (KDELC1 and KDELC2) [ PUBMED:21949356 ]. Rumi catalyzes the transfer of glucose and/or xylose from UDP-glucose and UDP-xylose, respectively, to a serine within the consensus Cys-Xaa-Ser-Xaa-Pro-Cys) in epidermal growth factor repeats, such as those found in coagulation factors F7, F9 and NOTCH proteins. Notch signaling is regulated by Notch glucosylation and glucosylation is required for the correct folding and cleavage of Notch [ PUBMED:18243100 PUBMED:21490058 ].

CAP10 from Cryptococcus neoformans encodes a xylosyltransferase [ PUBMED:24751576 ]. This pathogenic fungus, which most commonly affects the central nervous system and causes fatal meningoencephalitis primarily in patients with AIDS, produces a thick extracellular polysaccharide capsule which is well recognised as a virulence factor. The CAP10 domain is required for capsule formation and virulence [ PUBMED:10482503 ]. The capsule is primarily made of two xylose-containing polysaccharides, glucuronoxylomannan and galactoxylomannan, and the glycosyltransferase transfers xylose to alpha-1,3-dimannoside in a beta-1,2-linkage [ PUBMED:17430900 ].