GRASP and IPCEF promote ARF-to-Rac signaling and cell migration by coordinating the association of ARNO/cytohesin 2 with Dock180

David T White; Katie M McShea; Myriam A Attar; Lorraine C Santy

doi:10.1091/mbc.e09-03-0217

GRASP and IPCEF promote ARF-to-Rac signaling and cell migration by coordinating the association of ARNO/cytohesin 2 with Dock180

Mol Biol Cell. 2010 Feb 15;21(4):562-71. doi: 10.1091/mbc.e09-03-0217. Epub 2009 Dec 16.

Authors

David T White¹, Katie M McShea, Myriam A Attar, Lorraine C Santy

Affiliation

¹ Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA.

Abstract

ARFs are small GTPases that regulate vesicular trafficking, cell shape, and movement. ARFs are subject to extensive regulation by a large number of accessory proteins. The many different accessory proteins are likely specialized to regulate ARF signaling during particular processes. ARNO/cytohesin 2 is an ARF-activating protein that promotes cell migration and cell shape changes. We report here that protein-protein interactions mediated by the coiled-coil domain of ARNO are required for ARNO induced motility. ARNO lacking the coiled-coil domain does not promote migration and does not induce ARF-dependent Rac activation. We find that the coiled-coil domain promotes the assembly of a multiprotein complex containing both ARNO and the Rac-activating protein Dock180. Knockdown of either GRASP/Tamalin or IPCEF, two proteins known to bind to the coiled-coil of ARNO, prevents the association of ARNO and Dock180 and prevents ARNO-induced Rac activation. These data suggest that scaffold proteins can regulate ARF dependent processes by biasing ARF signaling toward particular outputs.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

ADP-Ribosylation Factors / genetics
ADP-Ribosylation Factors / metabolism*
Animals
Carrier Proteins / genetics
Carrier Proteins / metabolism*
Cell Adhesion Molecules / genetics
Cell Adhesion Molecules / metabolism*
Cell Line
Cell Movement / physiology*
Dogs
Enzyme Activation
GTPase-Activating Proteins / chemistry
GTPase-Activating Proteins / genetics
GTPase-Activating Proteins / metabolism*
Gene Knockdown Techniques
Humans
Membrane Proteins / genetics
Membrane Proteins / metabolism*
Multiprotein Complexes / chemistry
Multiprotein Complexes / metabolism
Protein Structure, Secondary
RNA, Small Interfering / genetics
RNA, Small Interfering / metabolism
Signal Transduction / physiology*
rac GTP-Binding Proteins / genetics
rac GTP-Binding Proteins / metabolism*

Substances

Carrier Proteins
Cell Adhesion Molecules
DOCK1 protein, human
GTPase-Activating Proteins
IPCEF1 protein, human
Membrane Proteins
Multiprotein Complexes
RNA, Small Interfering
cytohesin-2
tamalin protein, human
ADP-Ribosylation Factors
rac GTP-Binding Proteins