Figure 3: Expression and function of p67phox in K562 cells. K562 cells containing all NADPH oxidase components except p67phox were transfected with cDNA encoding p67phoxAla202Val (p67A202), p67phoxVal204Ala with a myc-tag (p67V204myc) or p67phoxAla202 (p67wt). A representative Western blot in Figure 3A shows that all proteins were expressed in similar amounts in the cells. Figure 3B shows that upon activation with PMA, the mutated proteins did not support the oxidase activity in K562 cells, in contrast to the wild-type protein.