FIG. 2.

Ectopic expression of wild-type, but not K430E mutant, Btk leads to enhanced tyrosine phosphorylation of TFII-I. (A) TFII-I and either wild-type or K430E mutant Btk was coexpressed in COS cells, and TFII-I was pulled down by GST-agarose beads and probed with anti-P-Tyr (α-P-Tyr) antibody 4G10 in a Western blot analysis. The blot was stripped and reprobed with anti-TFII-I (α-TFII-I) antibody. The lysates were also tested for the expression of wild-type and K430E Btks. (B) For quantitation, these experiments were performed three times and the results are represented as graphs with error bars.