Reaction: 1-phosphatidyl-1D-myo-inositol + a very-long-chain mannosylinositol phospho-(2'R)-2'-hydroxyphytoceramide = 1,2-diacyl-sn-glycerol + a very-long-chain mannosyl-diphosphoinositol-(2'R)-2'-hydroxyphytoceramide
Glossary: a very-long-chain mannosyl-diphosphoinositol-(2'R)-2'-hydroxyphytoceramide = a very-long-chain mannosyl-diphosphoinositol-α-hydroxyphytoceramide = MIP2C
Other name(s): IPT1 (gene name)
Systematic name: 1-phosphatidyl-1D-myo-inositol:mannosylinositol phospho-(2'R)-2'-hydroxyphytoceramide phosphoinositoltransferase
Comments: This enzyme catalyses the ultimate reaction in the yeast sphingolipid biosynthesis pathway. It transfers a second phosphoinositol group to mannosyl-inositol-phospho-α-hydroxyphytoceramide (MIPC), forming the final and most abundant yeast sphingolipid, mannosyl-diphosphoinositol-ceramide (MIP2C).
1. Dickson, R.C., Nagiec, E.E., Wells, G.B., Nagiec, M.M. and Lester, R.L. Synthesis of mannose-(inositol-P)2-ceramide, the major sphingolipid in Saccharomyces cerevisiae, requires the IPT1 (YDR072c) gene. J. Biol. Chem 272 (1997) 29620-29625. [PMID: 9368028]