Regulation of Golgi structure through heterotrimeric G proteins.
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.
Jamora
C
C
Department of Biology, University of California San Diego, La Jolla 92093-0347, USA.
Takizawa
P A
PA
Zaarour
R F
RF
Denesvre
C
C
Faulkner
D J
DJ
Malhotra
V
V
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
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