Presence and some characterization of GDP dissociation inhibitors for a low Mr GTP-binding protein, ram p25, in rat spleen cytosol.
Two proteinous factors, designated here as ram p25 GDP dissociation inhibitor (I) and (II) (ram-GDI (I) and (II)), were detected in the cytosolic fraction of rat spleen, which inhibited the initial dissociation of GDP from ram p25 produced by E. coli by causing characteristic lag. They had very weak effects on the rate of dissociation of GDP after the lag, and did not affect the mode of the dissociation of 5'-(3-O-thio)triphosphate (GTP gamma S) from ram p25. By gel filtration, the molecular masses of ram-GDI (I) and (II) were calculated to be 90 KDa and 40 KDa, respectively. These ram-GDIs did not affect the GDP-dissociation of Ha-ras protein produced in E. coli.
Nagata
K
K
Department of Biochemistry, Gifu University School of Medicine, Japan.
Suzuki
T
T
Okano
Y
Y
Nozawa
Y
Y
D000818:Animals; D003600:Cytosol / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D051381:Rats; D013154:Spleen / Q000378:metabolism*; D020691:rab GTP-Binding Proteins; D000075745:rab27 GTP-Binding Proteins
D000075745:rab27 GTP-Binding Proteins; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins; C512961:Rab27a protein, rat; D020691:rab GTP-Binding Proteins