p130Cas, a Substrate Associated with v-Src and v-Crk, Localizes to Focal Adhesions and Binds to Focal Adhesion Kinase

doi:10.1074/jbc.271.23.13649

p130^Cas, a Substrate Associated with v-Src and v-Crk, Localizes to Focal Adhesions and Binds to Focal Adhesion Kinase*

From the Department of Microbiology and Cancer Center, University of Virginia, Health Sciences Center, Charlottesville, Virginia 22908

^‡ To whom correspondence should be addressed:
Dept. of Microbiology, Box 441, Health Sciences Center, University of Virginia, Charlottesville, VA 22908.
Tel.: 804-924-5395; Fax: 804-982-1071; E-mail: jtp{at}virginia.edu

Abstract

p130^Cas (rk ssociated ubstrate) has the structural characteristics of an adapter protein, containing multiple consensus SH2 binding sites, an SH3 domain, and a proline-rich domain. The structure of p130^Cas suggests that it may act to provide a framework for protein-protein interactions; however, as yet, its functional role in cells is unknown. In this report we show that p130^Cas is localized to focal adhesions. We demonstrate that p130^Cas associates both in vitro and in vivo with pp125^FAK (ocal dhesion inase), a kinase implicated in signaling by the integrin family of cell adhesion receptors. p130^Cas also associates with pp41/43^FRNK (pp125^FAK-related, non-kinase), an autonomously expressed form of pp125^FAK composed of only the C-terminal noncatalytic domain. We show that the association of p130^Cas with pp125^Fak and pp41/43^FRNK is direct, and is mediated by the binding of the SH3 domain of p130^Cas to a proline-rich sequence present in both the C terminus of pp125^FAK and in pp41/43^FRNK. In agreement with recent studies we show that p130^Cas is tyrosine-phosphorylated upon integrin mediated cell adhesion. The association of p130^Cas with pp125^FAK, a kinase which is activated upon cell adhesion, is likely to be functionally important in integrin mediated signal transduction.

Footnotes

↵* This work was supported in part by National Institutes of Health, DHSS Grants CA 40042 and CA 29243 (to J. T. P.), and National Science Foundation Grant MCB-9210188 and Jeffress Memorial Trust Grant J-261 (to A. H. B.). The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¹ The abbreviations used are:

pp125^FAK or FAK

focal adhesion kinase

p130^Cas or Cas

Crk associated substrate

EFS

embryonal Fyn-associated substrate

pp41/43^FRNK or FRNK

FAK-related nonkinase

GRAF

GTPase regulator associated with FAK

SH2

Src homology 2

SH3

Src homology 3

GST

glutathione S-transferase

CE

chicken embryo

REF

rat embryo fibroblasts

PAGE

polyacrylamide gel electrophoresis.
↵² A. Richardson and J. T. Parsons, unpublished results.
↵³ M. T. Harte and J. T. Parsons, unpublished results.
- Received February 14, 1996.
- Revision received April 1, 1996.