FIG. 4.

Tyr-phosphorylation of Y4F and Y6F His-hnRNP K mutants. (Top) Amino acid sequence of hnRNP K with the Tyr residues that are mutated to Phe residues in the His-hnRNP K mutants Y4F and Y6F underlined and numbered; the other 11 Tyr residues are underlined. (Bottom) HeLa cells were transfected with cDNAs coding for wild-type, Y4F, or Y6F His-hnRNP K, together with control plasmid, c-Src, or Src(Y416F). After immunoprecipitation with anti-His antibody, SDS-PAGE, and Western blotting, the levels of hnRNP K were determined with an anti-His antibody (A), the Tyr phosphorylation of hnRNP K was assayed with an antiphosphotyrosine antibody (p-Tyr) (B), and its interaction with Src was detected with an anti-Src antibody (C).