Molecular cloning of rat phosphatidylinositol synthase cDNA by functional complementation of the yeast <i>Saccharomyces cerevisiae pis</i> mutation

Abstract

Phosphatidylinositol synthase (CDP-1,2-diacyl-sn-glycerol: 3-phosphatidyltransferase, EC 2.7.8.11) catalyzes the formation of phosphatidylinositol and CMP from CDP-diacylglycerol and myo-inositol. We have cloned a phosphatidylinositol synthase cDNA from rat brain by functional complementation of the yeast pis mutation, which is defective in phosphatidylinositol synthase. The deduced protein comprised 213 amino acids with a calculated molecular mass of 23,613 Da. The predicted protein sequence is highly homologous to the previously determined yeast phosphatidylinositol synthase sequence. The cDNA hybridized to a 1.7-kb mRNA that was abundantly expressed in rat brain and kidney.