Effect of Val204Ala p67^phox mutation on NADPH oxidase activation in whole cells.

(A) COS-7 cells stably expressing gp91^phox, p22^phox, and p47^phox, but not p67^phox, were transiently transfected with expression vectors encoding either wild-type p67^phox or p67^phox containing a Val204Ala point mutation. Control cells were mock transfected. At 21 hours after transfection, cells were harvested and stimulated with 0.4 μg/mL PMA plus 60 μM AA, and superoxide production was measured by the ferricytochrome creduction assay. Data are expressed as mean ± SD; n = 3. *P = .01, Student t test. (B) COS-phox cells stably expressing gp91^phox, p22^phox, p47^phox, and p67^phox were transiently transfected and tested as described above. Data are expressed as mean ± SD; n = 5. *P < .01, Student t test.