Cloning, expression and partial characterization of a novel rat phospholipase A2.

We report the cloning of a novel rat cDNA encoding a Ca(2+)-dependent, low molecular weight phospholipase A2 (PLA2). A rat RNA blot hybridized with the cDNA exhibited a putative 2.4 kb transcript in heart. When the cDNA was expressed in human 293s cells, PLA2 activity accumulated in the culture medium. This conditioned medium optimally hydrolyzed the phospholipids of [1-14C]oleate-labeled Escherichia coli at neutral to alkaline pH with 10 mM or greater Ca2+. When single substrates were tested, L-alpha-palmitoyl-2-oleoyl phosphatidylcholine was more efficiently hydrolyzed than L-alpha-1-palmitoyl-2-arachidonyl phosphatidylcholine, L-alpha-1-palmitoyl-2-arachidonyl phosphatidylethanolamine or L-alpha-1-stearoyl-2-arachidonyl phosphatidylinositol.