Cdc42 regulates microtubule-dependent Golgi positioning.
The molecular mechanisms underlying cytoskeleton-dependent Golgi positioning are poorly understood. In mammalian cells, the Golgi apparatus is localized near the juxtanuclear centrosome via dynein-mediated motility along microtubules. Previous studies implicate Cdc42 in regulating dynein-dependent motility. Here we show that reduced expression of the Cdc42-specific GTPase-activating protein, ARHGAP21, inhibits the ability of dispersed Golgi membranes to reposition at the centrosome following nocodazole treatment and washout. Cdc42 regulation of Golgi positioning appears to involve ARF1 and a binding interaction with the vesicle-coat protein coatomer. We tested whether Cdc42 directly affects motility, as opposed to the formation of a trafficking intermediate, using a Golgi capture and motility assay in permeabilized cells. Disrupting Cdc42 activation or the coatomer/Cdc42 binding interaction stimulated Golgi motility. The coatomer/Cdc42-sensitive motility was blocked by the addition of an inhibitory dynein antibody. Together, our results reveal that dynein and microtubule-dependent Golgi positioning is regulated by ARF1-, coatomer-, and ARHGAP21-dependent Cdc42 signaling.
Hehnly
Heidi
H
Department of Molecular Physiology & Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
Xu
Weidong
W
Chen
Ji-Long
JL
Stamnes
Mark
M
D020823:ADP-Ribosylation Factor 1 / Q000235:genetics / Q000378:metabolism; D000818:Animals; D020126:Brefeldin A / Q000378:metabolism; D002522:Chlorocebus aethiops; D020756:Coatomer Protein / Q000235:genetics / Q000378:metabolism; D015638:Cytochalasin D / Q000378:metabolism; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism*; D004398:Dyneins / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D006367:HeLa Cells; D006801:Humans; D008870:Microtubules / Q000378:metabolism*; D015739:Nocodazole / Q000494:pharmacology; D019384:Nucleic Acid Synthesis Inhibitors / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D051381:Rats; D050257:Tubulin Modulators / Q000494:pharmacology; D014709:Vero Cells; D020764:cdc42 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism
C459590:ARHGAP21 protein, human; D020756:Coatomer Protein; D020690:GTPase-Activating Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D011500:Protein Synthesis Inhibitors; D034741:RNA, Small Interfering; D050257:Tubulin Modulators; D020126:Brefeldin A; D015638:Cytochalasin D; D004398:Dyneins; D020823:ADP-Ribosylation Factor 1; D020764:cdc42 GTP-Binding Protein; D020741:rho GTP-Binding Proteins; D015739:Nocodazole