The NADPH oxidase components p47(phox) and p40(phox) bind to moesin through their PX domain

The NADPH oxidase of phagocytes is a membrane-bound heterodimeric flavocyto chrome which catalyses the transfer of electrons from NADPH in the cytoplas m to oxygen in the phagosome. A number of cytosolic proteins are involved i n its activation/deactivation: p47phox, p67phox, p40phox and the small GTP- binding protein, rac. The cytosolic phox proteins interact with the cytoske leton in human neutrophils and, in particular, an interaction with coronin has been reported (Grogan A., Reeves, E., Keep, N. H., Wientjes, F., Totty, N., Burlingame, N. L., Hsuan, J., and Segal, A. W. (1997) J. Cell Sci. 110 , 3071-3081). Here, we report on the interaction of another cytoskeletal pr otein, moesin, with the phox proteins. Moesin belongs to the ezrin-radixin- moesin family of F-actin-binding proteins and we show that it binds to p47p hox and p40phox in a phosphoinositide-dependent manner. Furthermore, we sho w that its N-terminal part binds to the PX domain of p47phox and p40phox. ( C) 2001 Elsevier Science.