Fig. 4.

Tyrosine phosphorylation at Y¹⁹⁴ modulates the binding affinities of Lyn SH2 domain and pY-containing proteins. A Mv4–11 cells untreated (Lane 1) or treated with pervanadate (Lane 2) were lysed and incubated with SA beads alone (Lanes 3, 6), SH2 (Lanes 4, 7), or pSH2 (Lanes 5, 8) to allow binding. The bound proteins (Lanes 3–5) and the flow-through (Lanes 6–8) were analyzed by anti-pY Western blotting. The two lanes in the lower panel were blotted with streptavidin-horseradish peroxidase showing equivalent loading of SA-immobilized biotin-labeled SH2 (left) and pSH2 (right) preparations. B A volcano plot showing Student's t test p value (y axis), calculated from six replicates versus protein quantification fold changes (x axis). A statistical significance p value cut-off is indicated. C Schematic representation of proteins bound differentially (twofold or higher) to Lyn SH2 (shades of blue/purple) or pSH2 (shades of green). Proteins predicted to bind directly are connected to Lyn SH2 by a line. Known Lyn interacting proteins are highlighted with red boarders. Asterisks denote Student's t test p values: *p < .05; **p < .01; ***p < .001.