[Coupling of seven transmembrane domains receptors cytosolic PLA2: role of G proteins and protein kinases].
Cytosolic phospholipase A2 is a constitutive and ubiquitous enzyme. Although its role in the early production of lipid mediators is well established, the mechanisms leading to its activation and its place in the signal transduction pathways triggered by G-protein-coupled receptors is still unclear. Two main mechanisms, have been involved in its activation: its translocation by the increase of intracellular calcium allowing access to its phospholipidic substrate, and its phosphorylation by serine/threonine protein kinases such as protein kinase C or MAP kinases. However these two mechanisms do not fully explain the activation of cytosolic phospholipase A2. The irreversible association to membranes observed after receptor stimulation suggests that a still unknown anchoring mechanism might be involved. The elucidation of this anchoring might take place in the overall synthesis of distinct lipid mediators pools able to play an intracellular role of second messengers or an extracellular role of autocrine/paracrine mediators.
Masliah
J
J
URA CNRS 1283, CHU Saint-Antoine, Chaligny, Paris.
Berguerand
M
M
Bereziat
G
G
D016718:Arachidonic Acid / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology*; D029721:Drosophila Proteins; D005136:Eye Proteins / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D066298:In Vitro Techniques; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D011494:Protein Kinases / Q000378:metabolism*; D020794:Receptor Protein-Tyrosine Kinases; D015398:Signal Transduction
D029721:Drosophila Proteins; D005136:Eye Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D016718:Arachidonic Acid; D011494:Protein Kinases; D020794:Receptor Protein-Tyrosine Kinases; C056737:sev protein, Drosophila; D010741:Phospholipases A; D054467:Phospholipases A2; D019204:GTP-Binding Proteins
Couplage des récepteurs à sept segments transmembranaires/PLA2 cytosolique: rôle des protéines G et des proteines kinases.