Regulation of the Golgi structure by the alpha subunits of heterotrimeric G proteins

Disassembly of the Golgi apparatus is elicited by the action of nordihydrog uaiaretic acid (NDGA) and this disassembly is prevented by the activation o f heterotrimeric G proteins. In the present study we showed that overexpres sion of G(alpha z) or G(alpha i2) significantly suppresses the disassembly of the Golgi apparatus induced by NDCA. Overexpression of G beta(1)gamma(2) , on the other hand, had no effect on NDGA-induced Golgi disassembly, G(alp ha z), neither blocked Golgi disassembly induced by brefeldin A or nocodazo le, nor interfered with protein transport, suggesting its specificity on th e action of NDGA, Our results suggest that the cc subunits of heterotrimeri c G proteins are responsible for the maintenance of the Golgi structure. (C ) 2000 Federation of European Biochemical Societies.