Cytosolic oxidase factors in the NADPH-dependent oxidase of human neutrophils

Abstract

The NADPH-dependent superoxide generating system of human PMNs is a complex, multicomponent system. Studies over the past two decades have identified some of the various components both in the membrane and in the cytosol. The cytosolic factors p47 phox and p67 phox are clearly essential components of the oxidase, as evidenced by their absence producing autosomal CGD. Despite this, the specific function of each of these factors in the assembled oxidase remains unknown. In the case of p47 phox, determinants for translocation are multifactorial, depending in part on phosphorylation and in part on the participation of a functional domain at p47 phox(323-332). The importance of SH3 regions and proline-rich domains in intramolecular interactions and associations with the membrane skeleton remain to be defined. In addition, factors which modulate the assembly of this oxidase are largely unknown and their elucidation may provide insights into novel means by which to modify the inflammatory response.