title: Golgi vesicle proteins are linked to the assembly of an actin complex defined by mAbp1.
abstract: Recent studies indicate that regulation of the actin cytoskeleton is important for protein trafficking, but its precise role is unclear. We have characterized the ARF1-dependent assembly of actin on the Golgi apparatus. Actin recruitment involves Cdc42/Rac and requires the activation of the Arp2/3 complex. Although the actin-binding proteins mAbp1 (SH3p7) and drebrin share sequence homology, they are differentially segregated into two distinct ARF-dependent actin complexes. The binding of Cdc42 and mAbp1, which localize to the Golgi apparatus, but not drebrin, is blocked by occupation of the p23 cargo-protein-binding site on coatomer. Exogenously expressed mAbp1 is mislocalized and inhibits Golgi transport in whole cells. The ability of ARF, vesicle-coat proteins, and cargo to direct the assembly of cytoskeletal structures helps explain how only a handful of vesicle types can mediate the numerous trafficking steps in the cell.
authors.affiliation: Department of Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
authors.forename: Raymond V
authors.initials: RV
authors.lastname: Fucini
authors.forename: Ji-Long
authors.initials: JL
authors.lastname: Chen
authors.forename: Catherine
authors.initials: C
authors.lastname: Sharma
authors.forename: Michael M
authors.initials: MM
authors.lastname: Kessels
authors.forename: Mark
authors.initials: M
authors.lastname: Stamnes
mesh_terms: D020823:ADP-Ribosylation Factor 1 / Q000502:physiology; D000199:Actins / Q000502:physiology*; D000818:Animals; D002417:Cattle; D003599:Cytoskeleton / Q000502:physiology; D006056:Golgi Apparatus / Q000502:physiology*; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000502:physiology*; D008840:Microfilament Proteins / Q000502:physiology*; D051381:Rats; D022142:Secretory Vesicles / Q000502:physiology; D020764:cdc42 GTP-Binding Protein / Q000502:physiology; D020741:rho GTP-Binding Proteins / Q000502:physiology; D018909:src Homology Domains
chemical_list: D000199:Actins; C485513:Dbnl protein, rat; D046911:Macromolecular Substances; D008565:Membrane Proteins; D008840:Microfilament Proteins; D020823:ADP-Ribosylation Factor 1; D020764:cdc42 GTP-Binding Protein; D020741:rho GTP-Binding Proteins