Role of bound GDP in the stability of the rho A-rho GDI complex purified from neutrophil cytosol.
The rho A-rho GDI complex purified from bovine neutrophil cytosol was found to contain GDP as the only bound nucleotide at a ratio of 1 mol of GDP per mol of complex. The rho GDI component of the complex (pI 4.8-5.0, apparent molecular mass 28-29 kDa) and the rho A component (pI scattered between 5.0-6.2, apparent molecular mass 24 kDa) were resolved by 2D gel electrophoresis. Upon dephosphorylation of bound GDP by apyrase, the rho A component of the complex was prone to proteolytic cleavage. The integrity of rho A in the presence of apyrase was preserved by addition of excess GTP. These data suggest that rho A liganded by GDP in the rho A-rho GDI complex is maintained in a conformation that escapes action of proteases.
Bourmeyster
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N
Laboratoire de Biochimie (URA 1130/CNRS), Département de Biologie Moléculaire et Structurale, CEA/Centre d'Etudes Nucléaires de Grenoble, France.
Boquet
P
P
Vignais
P V
PV
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D003600:Cytosol / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D020730:Guanine Nucleotide Dissociation Inhibitors; D006153:Guanosine Diphosphate / Q000378:metabolism*; D006868:Hydrolysis; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000378:metabolism*; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors; D020742:rhoA GTP-Binding Protein
D020730:Guanine Nucleotide Dissociation Inhibitors; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors; D006153:Guanosine Diphosphate; D019204:GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein