SHP-1 protein tyrosine phosphatase associates with the adaptor protein CrkL

SHP-1, encoded by the PTPN6 gene, is a protein tyrosine phosphatase with two src-homology-2 (SH2) domains that is implicated as providing suppression of hematopoietic malignancies. A number of reports have shown protein-protein interactions between SHP-1 SH2 domains and tyrosine-phosphorylated proteins. However, despite its having three proline-rich, potential SH3-binding motifs, no reports of protein-protein interactions through src-homology-3 (SH3)-binding domains with SHP-1 have been described. Herein we show that the SH3 domain-containing CT10 regulator of kinase-like (CrkL) adaptor protein associates with SHP-1. We also provide results that suggest this association is due to CrkL binding to PxxP domains located at amino acid residues 158-161 within the SHP-1 C-terminal SH2 domain, and amino acid residues 363-366 within its phosphatase domain. This study is the first to identify and define an interaction between SHP-1 and an SH3 domain-containing protein. Our findings provide an alternative way that SHP-1 can be linked to potential substrates.