Hyperphosphorylated p47-phox lost the ability to activate NADPH oxidase in guinea pig neutrophils.

p47-phox is one of the cytosolic activation factors of NADPH oxidase in neutrophils and known to translocate to plasma membranes and function by protein kinase C-phosphorylation. In cytosol fraction, prepared from calyculin A-treated neutrophils, the activity of cytosolic factor to activate NADPH oxidase was more reduced than that from PMA-treated cells. But, p47-phox did not translocate to the membranes, even if p47-phox was hyperphosphorylated in the calyculin A-treated neutrophils. Such hyperphosphorylated p47-phox seemed to lose the activity to constitute NADPH oxidase complex.