Purification and Identification of Protein-Tyrosine Kinase-binding Proteins Using Synthetic Phosphopeptides as Affinity Reagents

doi:10.1074/mcp.M400062-MCP200

Purification and Identification of Protein-Tyrosine Kinase-binding Proteins Using Synthetic Phosphopeptides as Affinity Reagents *

From the ^‡Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0601; and ^¶Department of Molecular Genetics and Microbiology, University of Texas at Austin, Austin, TX 78712-1095

‖ To whom correspondence should be addressed: Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0601. Tel.: 858-822-2024; Fax: 858-822-0079; E-mail: geer{at}ucsd.edu.

Abstract

Protein-tyrosine kinases are known regulators of cell division that have been implicated in the onset of a variety of malignancies. They act through cellular signaling proteins that bind to specific autophosphorylation sites. To find out whether these autophosphorylation sites can be used to identify downstream signaling proteins, synthetic peptides based on an autophosphorylation site in the colony-stimulating factor-1 (CSF-1) receptor were linked to agarose beads and incubated with lysates from macrophages. Bound proteins were analyzed by MS, leading to the identification of both known and novel CSF-1 receptor-interacting proteins. The approach presented here can be applied to phosphorylation sites in a wide variety of proteins. It will lead to the identification of novel protein-protein interactions and provide new insights into the mechanics of signal transduction. Novel protein-protein interactions may provide useful targets for the development of drugs that interfere with the activation of signaling cascades used by protein-tyrosine kinases to turn on cell division.

Footnotes

Published, MCP Papers in Press, June 23, 2004, DOI 10.1074/mcp.M400062-MCP200
↵* This work was supported in part by Grant CA78629 from the National Institutes of Health. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵§ K.W. and J.C. contributed equally to this study.
↵1 The abbreviations used are: SH2, Src homology 2; CSF-1, colony-stimulating factor 1; EGF, epidermal growth factor; PTB, phosphotyrosine binding; P.Tyr, phosphotyrosine; SH3, Src homology 3; TKB, tyrosine kinase binding; PLC, phospholipase C.
- Received May 13, 2004.
- Revision received June 9, 2004.