Regulation of protein transport from the Golgi complex to the endoplasmic reticulum by CDC42 and N-WASP.
Actin is involved in the organization of the Golgi complex and Golgi-to-ER protein transport in mammalian cells. Little, however, is known about the regulation of the Golgi-associated actin cytoskeleton. We provide evidence that Cdc42, a small GTPase that regulates actin dynamics, controls Golgi-to-ER protein transport. We located GFP-Cdc42 in the lateral portions of Golgi cisternae and in COPI-coated and non-coated Golgi-associated transport intermediates. Overexpression of Cdc42 and its activated form Cdc42V12 inhibited the retrograde transport of Shiga toxin from the Golgi complex to the ER, the redistribution of the KDEL receptor, and the ER accumulation of Golgi-resident proteins induced by the active GTP-bound mutant of Sar1 (Sar1[H79G]). Coexpression of wild-type or activated Cdc42 and N-WASP also inhibited Golgi-to-ER transport, but this was not the case in cells expressing Cdc42V12 and N-WASP(Delta WA), a mutant form of N-WASP that lacks Arp2/3 binding. Furthermore, Cdc42V12 recruited GFP-N-WASP to the Golgi complex. We therefore conclude that Cdc42 regulates Golgi-to-ER protein transport in an N-WASP-dependent manner.
Luna
Ana
A
Departament de Biologia Cel.lular i Anatomia Patològica, Facultat de Medicina, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, E-08036 Barcelona, Spain.
Matas
Olga B
OB
Martínez-Menárguez
José Angel
JA
Mato
Eugenia
E
Durán
Juan M
JM
Ballesta
José
J
Way
Michael
M
Egea
Gustavo
G
D000818:Animals; D002460:Cell Line; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism; D008845:Microinjections; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology*; D051381:Rats; D018000:Receptors, Peptide / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D022603:Shiga Toxins / Q000378:metabolism; D022161:Transport Vesicles / Q000737:chemistry / Q000378:metabolism; D014759:Viral Envelope Proteins / Q000378:metabolism; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism*
C028391:G protein, vesicular stomatitis virus; C064459:KDEL receptor; D008164:Luminescent Proteins; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D018000:Receptors, Peptide; D011993:Recombinant Fusion Proteins; D022603:Shiga Toxins; D014759:Viral Envelope Proteins; C495771:WASL protein, human; C495770:Wasl protein, rat; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D049452:Green Fluorescent Proteins; D020764:cdc42 GTP-Binding Protein