Molecular species of phosphatidylinositol-cycle intermediates in the endoplasmic reticulum and plasma membrane.

ABSTRACT: Phosphatidylinositol (PI) turnover is a process requiring both the plasma and ER membranes. We have determined the distribution of phosphatidic acid (PA) and PI and their acyl chain compositions in these two subcellular membranes using mass spectrometry. We assessed the role of PI cycling in determining the molecular species and quantity of these lipids by comparing the compositions of the two membranes isolated from embryonic fibroblasts obtained from diacylglycerol kinase epsilon (DGKepsilon) knockout (KO) and wild-type (WT) mice. In the KO cells, the conversion of arachidonoyl-rich DAG to PA is blocked by the absence of DGKepsilon, resulting in a reduction in the rate of PI cycling. The acyl chain composition is very similar for PI and PA in the endoplasmic reticulum (ER) versus plasma

SUBMITTER: Shulga YV 

PROVIDER: S-EPMC2805767 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature