Roles of Rac and p38 kinase in the activation of cytosolic phospholipase A2 in response to PMA.

Phosphorylation of cytosolic phospholipase A2 and the release of arachidonic acid in human neutrophils.

Kinases mediating phosphorylation and activation of cytosolic phospholipase A2 (cPLA2) in intact cells remain to be fully characterized. Platelet-activating factor stimulation of human neutrophils increases cPLA2 phosphorylation. This increase is inhibited by PD 98059, a mitogen-activated protein (MAP)/extracellular signal-regulating kinase (erk) 1 inhibitor, but not by SB 203580, a p38 MAP kin...

Urokinase induces matrix metalloproteinase-9/gelatinase B expression in THP-1 monocytes via ERK1/2 and cytosolic phospholipase A2 activation and eicosanoid production.

OBJECTIVE Urokinase-type plasminogen activator (uPA) regulates cell migration and invasion by pericellular proteolysis and signal transduction events. We characterized the mechanisms by which uPA regulates matrix metalloproteinase-9 (MMP9) function in THP-1 monocytes. METHODS AND RESULTS In THP-1 monocytes, MMP9 production induced by urokinase was completely inhibited by the ERK1/2 inhibitor,...

Calcium Dependency of Prostaglandin E2 Production

Calcium has been implicated as an important factor in prostaglandin production. Phospholipase A2, the enzyme believed to be rate limiting for prostaglandin synthesis, is stimulated by Ca2+; however, the levels of Ca2' necessary to stimulate phospholipase A2 in cell-free systems are higher than levels achieved in intact cells in response to agonists that stimulate prostaglandin synthesis. We exa...

Regulation of cytosolic phospholipase A2 by hsp90 and a p54 kinase in okadaic acid-stimulated macrophages

In resident mouse peritoneal macrophages, group IVA cytosolic phospholipase A2 (cPLA2 ) mediates arachidonic acid (AA) release and eicosanoid production in response to diverse agonists such as A23187, phorbol myristate acetate, zymosan, and the enterotoxin, okadaic acid (OA). cPLA2 is regulated by phosphorylation and by calcium that binds to the C2 domain and induces translocation from the cyto...

Rac and Protein Kinase C- Regulate ERKs and Cytosolic Phospholipase A2 in Fc RI Signaling to Cysteinyl Leukotriene Synthesis in Mast Cells