cdc42 regulates the exit of apical and basolateral proteins from the trans-Golgi network.
It is well established that Rho-GTPases regulate vesicle fusion and fission events at the plasma membrane through their modulatory role on the cortical actin cytoskeleton. In contrast, their effects on intracellular transport processes and actin pools are less clear. It was recently shown that cdc42 associates with the Golgi apparatus in an ARF-dependent manner, similarly to coat proteins involved in vesicle formation and to several actin-binding proteins. We report here that mutants of cdc42 inhibited the exit of basolateral proteins from the trans-Golgi network (TGN), while stimulating the exit of an apical marker, in two different transport assays. This regulation may result from modulation of the actin cytoskeleton, as GTPase-deficient cdc42 depleted a perinuclear actin pool that rapidly exchanges with exogenous fluorescent actin.
Müsch
A
A
Dyson Institute of Vision Research, Departments of Biochemistry and Cell Biology, Joan and Sanford Weill Medical College of Cornell University, New York, NY 10021, USA. amuesch@mail.med.cornell.edu
Cohen
D
D
Kreitzer
G
G
Rodriguez-Boulan
E
E
D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D000199:Actins / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002460:Cell Line; D002463:Cell Membrane Permeability; D022162:Cytoplasmic Vesicles / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D004285:Dogs; D005456:Fluorescent Dyes / Q000737:chemistry; D008164:Luminescent Proteins / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D019006:Neural Cell Adhesion Molecules / Q000235:genetics; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines; D020764:cdc42 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D021601:trans-Golgi Network / Q000378:metabolism*
D000199:Actins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D019006:Neural Cell Adhesion Molecules; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor; D011993:Recombinant Fusion Proteins; D013844:Thiazoles; D053778:Thiazolidines; D020764:cdc42 GTP-Binding Protein; C037068:latrunculin B