Identification of the human platelet GTPase activating protein for the CDC42Hs protein.

摘要: The CDC42Hs protein appears to be an isoform of the ras-related GTP-binding G25K and is apparent human homolog Saccharomyces cerevisiae cell-division-cycle protein, CDC42Sc. In this study, we report identification a GTPase-activating (GAP) for from platelets (designated here on as CDC42Hs-GAP). CDC42Hs-GAP activity was solubilized platelet membranes, recovered through successive chromatography steps (the final step being Mono-Q chromatography), purified approximately 3500-fold. appeared correspond polypeptide with Mr 25,000. GTPase activities CDC42Hs, Escherichia coli-recombinant Spodoptera frugiperda-recombinant proteins are all stimulated by identical extents, which indicates that recombinant effective native in coupling GAP. However, mutant form E. contains valine residue at position 12 (CDC42HsVal-12) has significantly reduced intrinsic (relative wild type CDC42HsGly-12) not CDC42Hs-GAP. also does stimulate ras or rap proteins; however, it capable weak stimulation mammalian rho. Based similarities molecular size CDC42Hs- rho-GAPs (i.e. 25-30 kDa), cross-reactivity rho CDC42Hs-GAP, seems likely will constitute specific subclass GAP superfamily.