Modulation of Phospholipase A2 Activity by Actin and Myosin.
Final rept. 1 Apr 86-1 Apr 87,
ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA
Pagination or Media Count:
Endothelial cell prostacyclin Phosphogluculsomerase production is closely coupled with cell shape. Since shape change implies cytoskeletal modulations, this finding may be an important clue to implicate cytoskeletal constituents in a mechanism regulating eicosanoid metabolism. Endothelial cells with a diffuse F-actin distribution generate more PGI than cells with many discrete F-actin stress fibers. Because actin can modulate enzyme activity, the myofibril protein effects on phopholipase APLA, the rate limiting eicosanoid cascade enzyme, were studied. F-actin stimulated whereas G-actin suppressed enzyme activity. Myosin in the presence of F-actin, the F-action stimulatory effect was significantly reduced. These findings suggest that the correlation of endothelial cell PGI metabolic modulation to cell shape and actin distribution was perhaps due to changes in PLA activity as a direct result of alterations in the polymerized state of actin and the degree of actin-myosin stress fiber formation.
- Anatomy and Physiology