The phosphotyrosine peptide binding specificity of Nck1 and Nck2 Src homology 2 domains.

Nck proteins are essential Src homology (SH) 2 and SH3 domain-bearing adapters that modulate actin cytoskeleton dynamics by linking proline-rich effector molecules to tyrosine kinases or phosphorylated signaling intermediates. Two mammalian pathogens, enteropathogenic Escherichia coli and vaccinia virus, exploit Nck as part of their infection strategy. Conflicting data indicate potential differences in the recognition specificities of the SH2 domains of the isoproteins Nck1 (Nckalpha) and Nck2 (Nckbeta and Grb4).