A novel arachidonic acid-selective cytosolic PLA sub(2) contains a Ca super(2+)-dependent translocation domain with homology to PKC and GAP

We report the cloning and expression of a cDNA encoding a high molecular weight (85.2 kd) cytosolic phospholipase A sub(2) (cPLA sub(2)) that has no detectable sequence homology with the secreted forms of PLA sub(2). We show that cPLA sub(2) selectively cleaves arachidonic acid from natural membrane vesicles and demonstrate that cPLA sub(2) translocates to membrane vesicles in response to physiologically relevant changes in free calcium. We demonstrate that an amino-terminal 140 amino acid fragment of cPLA sub(2) translocates to natural membrane vesicles in a Ca super(2+)-dependent fashion. We note that this 140 amino acid domain of cPLA sub(2) contains a 45 amino acid region with homology to PKC, p65, GAP, and PLC.