title: Changes in cytoskeletal proteins of polymorphonuclear leukocytes induced by chemotactic peptides.
abstract: Changes in the state of polymerization of actin and phosphorylation of myosin have been observed in polymorphonuclear leukocytes (PMNs) soon after the addition of the chemotactic peptide N-formylnorleucylleucylphenylalanine. At a time when the cells are observed to extend many ruffles or lamellipodia from their surface, the fraction of the cellular actin present in a monomeric form is decreased by about 25% as assayed by the ability of the G-actin to inhibit DNAase. These changes are temporally correlated with an increase in the staining by nitrobenzooxadiazole (NBD)-phallacidin, a probe that binds F-actin selectively. The NBD-phallacidin staining is observed in the surface ruffles. When the peptide concentration is decreased by addition of a tenfold excess of buffer, cells withdraw their surface ruffles and form blebs. These changes correlate with an increase in the G-actin levels detected with the DNAase inhibition assay. An increase in phosphorylation of the 20,000-dalton light chain of myosin is also observed in leukocytes stimulated by addition of chemotactic peptide. These observations of changes in cytoskeletal proteins of PMNs provide a beginning for further studies on the regulation of cell motility by chemotactic factors.
mesh_terms: D000199:Actins / Q000097:blood*; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D002630:Chemotactic Factors / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008970:Molecular Weight; D009218:Myosins / Q000097:blood*; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D009842:Oligopeptides / Q000494:pharmacology*; D010766:Phosphorylation; D011108:Polymers; D011817:Rabbits
chemical_list: D000199:Actins; D002630:Chemotactic Factors; D009842:Oligopeptides; D011108:Polymers; C024998:N-formylnorleucyl-leucyl-4-phenylalanine; D009218:Myosins