ESSENTIAL ROLE OF RAC GTPASE IN HYDROGEN PEROXIDE-INDUCED ACTIVATION OF C-FOS SERUM RESPONSE ELEMENT

In the present study, we investigated whether hydrogen peroxide activa tes c-fos serum response element (SRE) in Rat-2 fibroblast cells, By t ransient transfection analysis, exogenous H2O2 stimulated SRE-dependen t reporter gene activity in a dose and time-dependent manner, Also, we examined the role of Rac GTPase and phospholipase A(2) (PLA(2)) in th e H2O2-induced SRE activation, Either transfection of a dominant negat ive Rac mutant, RacN17, plasmid or pretreatment of mepacrine, a potent inhibitor of PLA(2), blocked H2O2-induced SRE activation dramatically , Together, these findings suggest a critical role of 'Rac and subsequ ent activation of phospholipase A(2)' in the signaling pathway of H2O2 to SRE. (C) 1997 Federation of European Biochemical Societies.