TYROSINE PHOSPHORYLATION AND SUBCELLULAR REDISTRIBUTION OF P125 RAS GUANOSINE TRIPHOSPHATASE-ACTIVATING PROTEIN IN HUMAN NEUTROPHILS STIMULATED WITH FMLP

In this paper, we show that the p125 ras guanosine triphosphatase-acti vating protein (p125 GAP) is present in the cytosol of human neutrophi ls and is transiently tyrosine phosphorylated and translocated to the membranes upon cell activation with formyl-methionyl-leucyl-phenylalan ine (FMLP). When concanavalin A (ConA) or phorbol 12-myristate 13-acet ate (PMA), which both induced a long-lasting respiratory burst, were u sed as stimuli, tyrosine phosphorylation and translocation of p125 GAP did not occur.