Chapter 18 The Role of Phosphorylation in Phagocyte Activation

There is active phosphorylation–dephosphorylation when phagocytes are stimulated by a variety of agonists, but the actual assignment of a particular kinase/phosphatase protein substrate pair in the mapping of an activation cascade has not been satisfactorily accomplished. This chapter discusses the rapid progress that has been made in this area of phagocyte cell biology and examines the most compelling evidence for phosphorylation control that has been established in the human neutrophil for the activation of the nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase, the enzymatic activity of the respiratory burst. Of the various soluble and particulate agonists that stimulate oxidase, phorbol ester, phorbol myristate acetate (PMA), is of most relevance, for its receptor, protein kinase C (PKC) represents an important phosphorylating activity that has offered a functional assessment of oxidase activation in intact cells.