The metabolism of phosphatidic acid (PA) yields diacylglycerol (DAG), a known activator of protein kinase C (PKC). To examine potential direct effects of PA on PKC activation, PKC purified from bovine pulmonary artery endothelial cells (BPAEC) was utilized in an in vitro assay examining γ-[32P]ATP phosphorylation of H1 histone. In the presence of Ca2+ and phosphatidylserine (PS), DAG (80 μM) produced maximal PKC activity (6.4 pmol γ-[32P]ATP incorporated/μg/min). Dioleoyl-PA (80 μM) and l-stearoyl,2-arachidonyl-PA (80 μM) activated PKC in a concentration-dependent manner (maximal activity of 2.01 ± 0.1 pmol/μg/min). Unlike unlabelled phorbol esters or DAG, dioleoyl-PA did not significantly alter the binding of [3H]-phorbol dibutyrate to PKC, suggesting that PA directly activates endothelial cell PKC in a manner distinct from DAG-mediated PKC activation.
|Original language||English (US)|
|Number of pages||8|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Feb 26 1993|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology