Protein Motifs

One Domain: Multiple Partners

Science's STKE  20 Nov 2001:
Vol. 2001, Issue 109, pp. tw432
DOI: 10.1126/stke.2001.109.tw432

The nonreceptor tyrosine kinase Syk is activated by binding either phosphorylated tyrosine residues in the ITAM motifs of immune response receptors or by binding to ligated integrins. Woodside et al. show that Syk interacted specifically with the cytoplasmic domain of the integrin β3 subunit and that binding did not require the kinase domain of Syk. The domain of Syk responsible for binding the integrin subunit was the same as the domain that interacts with the ITAMs of activated immune response receptors. However, phosphorylated ITAM peptides that inhibit the Syk-ITAM interaction do not inhibit the Syk-β3 interaction. Thus, the same domain of Syk can interact with multiple partners in a specific and noncompetitive manner.

D. G. Woodside, A. Obergfell, L. Leng, J. L. Wilsbacher, C. K. Miranti, J. S. Brugge, S. J. Shattil, M. H. Ginsberg, Activation of Syk protein tyrosine kinase through interaction with integrin β cytoplasmic domains. Curr. Biol. 11, 1799-1804 (2001). [Online Journal]