title: Regulation of Golgi structure through heterotrimeric G proteins.
abstract: We have previously shown that ilimaquinone (IQ), a marine sponge metabolite, causes complete vesiculation of the Golgi stacks. By reconstituting the IQ-mediated vesiculation of the Golgi apparatus in permeabilized cells, we now demonstrate that this process does not require ARF and coatomers, which are necessary for the formation of Golgi-derived COPI vesicles. We find that IQ-mediated Golgi vesiculation is inhibited by G alpha(s)-GDP and G alpha(i3)-GDP. Interestingly, adding betagamma subunits in the absence of IQ is sufficient to vesiculate Golgi stacks. Our findings reveal that IQ-mediated Golgi vesiculation occurs through activation of heterotrimeric G proteins and that it is the free betagamma, and not the activated alpha subunit, that triggers Golgi vesiculation.
authors.affiliation: Department of Biology, University of California San Diego, La Jolla 92093-0347, USA.
authors.forename: C
authors.initials: C
authors.lastname: Jamora
authors.forename: P A
authors.initials: PA
authors.lastname: Takizawa
authors.forename: R F
authors.initials: RF
authors.lastname: Zaarour
authors.forename: C
authors.initials: C
authors.lastname: Denesvre
authors.forename: D J
authors.initials: DJ
authors.lastname: Faulkner
authors.forename: V
authors.initials: V
authors.lastname: Malhotra
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003600:Cytosol / Q000737:chemistry / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019205:GTP-Binding Protein alpha Subunits, Gs; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D006056:Golgi Apparatus / Q000737:chemistry / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D007425:Intracellular Membranes / Q000737:chemistry / Q000378:metabolism; D007668:Kidney / Q000166:cytology; D011809:Quinones / Q000494:pharmacology; D051381:Rats; D015398:Signal Transduction / Q000502:physiology
chemical_list: D004791:Enzyme Inhibitors; D011809:Quinones; D006153:Guanosine Diphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); C067346:illimaquinone; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins; D019205:GTP-Binding Protein alpha Subunits, Gs