Identification of Regions of the Wiskott-Aldrich Syndrome Protein Responsible for Association with Selected Src Homology 3 Domains

doi:10.1074/jbc.271.42.26291

Identification of Regions of the Wiskott-Aldrich Syndrome Protein Responsible for Association with Selected Src Homology 3 Domains*

From the ^‡ Yamanouchi Research Institute, Littlemore Hospital, Oxford OX4 4XN, United Kingdom, the
^¶ Metabolism Branch, NCI, National Institutes of Health, Bethesda, Maryland 20892, the
^∥ Ludwig Institute for Cancer Research, University College London, London W1P 8BT, United Kingdom, and the
^″ Department of Biochemistry and Molecular Biology, University College, London W1E 6BT, United Kingdom

^‴ To whom correspondence should be addressed. Tel.: 44-1865-747100; Fax: 44-1865-748974; E-mail: skellie{at}yam-res.co.uk

↵^§ Current address: Protein Phosphorylation Laboratory, Imperial Cancer Research Fund Laboratories, P. O. Box 123, 34-43 Lincoln's Inn Fields, London WC2A 3PX, United Kingdom.

Abstract

Src homology 3 (SH3) domains have been shown to mediate selected interactions between signaling molecules and are essential for the activation of a number of receptor-driven pathways. The Wiskott-Aldrich syndrome protein was identified as a protein that associated selectively with the SH3 domains derived from c-Src, p85α, phospholipase Cγ1, and c-Fgr. Significantly reduced association was detected to the N-terminal SH3 domain and the tandem SH3 domains of p47^phox, and no binding was detected to the SH3 domain of n-Src, the C-terminal SH3 domain of p47^phox, or either of the SH3 domains of p67^phox. Three peptides corresponding to potential Wiskott-Aldrich syndrome protein SH3 domain binding motifs were found to inhibit its association with c-Src, Fgr, and phospholipase Cγ1 SH3 domains, but not the p85α SH3 domain. These peptides have the sequences MRRQEPLPPPPPPSRG, TGRSGPLPPPPPGA, and KGRSGPLPPVPLGI and show homology with other SH3 domain binding motifs. It is possible that the intracellular association of Wiskott-Aldrich syndrome protein with other signaling proteins is mediated by its SH3 domain-binding regions, and this may play a role in its putative function as a regulatory molecule in immune cells.

Footnotes

↵* 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:

SH2

Src homology 2

SH3

Src homology 3

PLCγ1

phospholipase Cγ1

GST

glutathione S-transferase

WASP

Wiskott-Aldrich syndrome protein

PAGE

polyacrylamide gel electrophoresis

HPLC

high performance liquid chromatography.
↵² C. Soames and L. Wilson manuscript in preparation.
- Received May 6, 1996.
- Revision received July 11, 1996.