ABSTRACT
270To kill invading microbes, phagocytes must first get to the infected site. N-formylpeptides produced by bacteria can act as chemotactic signals for neutrophils, monocytes and eosinophils by binding to a seven-transmembrane-domain, G protein-coupled receptor on the plasma membrane. In addition to chemotaxis, activation of this receptor induces upregu-lation of adhesion molecules, degranulation, oxidant production, and synthesis and release of proinflammatory mediators. The receptor is highly related to receptors for other important leukocyte chemotactic signals made by the host, such as chemokines and C5a. The major signal transduction pathway defined for the receptor involves pertussis toxin-sensitive, Gi-type G proteins. The major second messengers formed when the N-formylpeptide receptor is activated are derived from membrane phospholipids by activation of phospho-lipases A2, C and D. This chapter will review the structure, function, regulation, signal transduction properties, and molecular evolution of this receptor.
