LAUSR

The T cell‐specific adaptor protein (TSAd) contains several protein interaction domains, and is merging as a modulator of T cell activation. Several interaction partners for the TSAd proline‐rich region and phosphotyrosines have been identified, including the Src and Tec family kinases lymphocyte‐specific protein tyrosine kinase and interleukin 2‐inducible T cell kinase. Via its Src homology 2 (SH2) domain, TSAd may thus function as a link between these enzymes and other signalling molecules. However, few binding partners to the TSAd SH2 domain in T cells are hitherto known. Through the use of in silico ligand prediction, peptide spot arrays, pull‐down and immunoprecipitation experiments, we here report novel interactions between the TSAd SH2 domain and CD6 phosphotyrosine (pTyr)629 and linker of activated T cells (LAT) pTyr171, pTyr191 and pTyr226.