The vav proto-oncogene product (p95(vav)) interacts with the Tyk-2 protein tyrosine kinase

The vav proto-oncogene product participates in the signaling pathways activated by various cell-surface receptors, including the type I IPN receptor, During engagement of the type I IFN receptor, p95(vav) is phosphorylated on tyrosine residues, but the kinase regulating its phosphorylation has not been identified to date, Our studies demonstrate that p95(vav) forms a stable complex with the IFN-receptor-associated Tyk-2 kinase in vivo, and strongly suggest that this kinase regulates its phosphorylation on tyrosine, Thus, p95(vav) is engaged in IFN-signaling by a direct interaction with the functional type I TFN receptor complex to transduce downstream signals. (C) 1997 Federation of European Biochemical Societies.