Figure 6.
D685A and M686A Stat6 are resistant to the Stat6 protease activity. (A) Alanine substitutions of Stat6 (S683A, S684A, D685A, or M686A Stat6) were transfected to COS7 cells. Cell extracts were then incubated with or without Stat6−/− BMMC extract and blotted with anti-Stat6 (M200) antibody. A representative blot from four independent experiments is shown. (B) Relevant aa sequence of the putative cleavage site of Stat6 is shown in comparison with a reported cleavage site of Stat5a and Stat5b (17). (C) Similar to Fig. 5 B, COS7 cells were transfected with D685A, M686A, or WT Stat6 and the luciferase activity of TPU474 was measured in the presence or absence of IL-4. Data are means ± SD for four experiments.