Regulating the actin cytoskeleton during vesicular transport.
Although the actin cytoskeleton is widely believed to play an important role in intracellular protein transport, this role is poorly understood. Recently, progress has been made toward identifying specific actin-binding proteins and signaling molecules involved in regulating actin structures that function in the secretory pathway. Studies on coat protomer I (COPI)-mediated transport at the Golgi apparatus and on clathrin-mediated endocytosis have been particularly informative in identifying such mechanisms. Important similarities between actin regulation at the Golgi and at the plasma membrane have been uncovered. The studies reveal that ADP-ribosylation factor and vesicle coat proteins are able to act through the Rho-family GTP-binding proteins, Cdc42 and Rac, and several specific actin-binding proteins to direct actin assembly through the Arp2/3 complex. Efficient function of the secretory pathway is likely to require precise temporal regulation among transport-vesicle assembly, vesicle scission, and the targeting machinery. It is proposed that numerous actin regulatory mechanisms and the connections between actin signaling and vesicle-coat formation are employed to provide such temporal regulation.
Stamnes
Mark
M
Department of Physiology and Biophysics, University of Iowa, 52242, Iowa City, IA 52242, USA. mark-stamnes@uiowa.edu
D020727:ADP-Ribosylation Factors / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D002966:Clathrin / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D008954:Models, Biological; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000378:metabolism
C061886:ABF1 protein, S cerevisiae; D000199:Actins; D002966:Clathrin; D004268:DNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C097691:cbp1 protein, S pombe; D020727:ADP-Ribosylation Factors; D020764:cdc42 GTP-Binding Protein; D020744:rac GTP-Binding Proteins; D020741:rho GTP-Binding Proteins