Comparison of kinetic properties between MSS4 and Rab3A GRF GDP/GTP exchange proteins

FEBS Letters

Araki, Keishi¹  Takai, Yoshimi¹  Imazumi, Katsunori¹  Nagano, Fumiko¹  Takahashi, Kazuo¹  Ueno, Nozomi¹  Miyazaki, Akira¹  Sasaki, Takuya¹ 

[1] Department of Biochemistry, Kobe University School of Medicine, Kobe 650, Japan

关键词: Small G protein;    Rab3A;    MSS4;    Rab3A GRF;    Rab GDI;    G. protein;    GTP-binding protein;    GEP;    GDP/GTP exchange protein;    GRF;    guanine nucleotide releasing factor;    GDI;    GDP dissociation inhibitor;    E. coli;    Escharicia coli;    GST;    glutathione-S-transferase;    GTPγS;    guanosine 5′-(3-O-thio)triphosphate;    GDS;    GDP dissociation stimulator;   

DOI  :  10.1016/0014-5793(94)00804-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The kinetic properties of MSS4 are studied in comparison with those of Rab3A GRF. MSS4 stimulates the dissociation of [³H]GDP from the lipid-modified and lipid-unmodified forms of Rab3A to the same extent, although Rab3A GRF is more effective on the lipid-modified form than on the lipid-unmodified form. Both MSS4 and Rab3A GRF are inactive on other Rab/Sec/Ypt family members including at least Rab2, Rab5, and Rab11. Rab GDI inhibits the MSS4 and Rab3A GRF effects on the lipid-modified form of Rab3A, but the doses of Rab GDI necessary for this inhibitory effect on Rab3A GRF are lower than those on MSS4. Moreover, Rab GDI slightly inhibits the Rab3A GRF effect on the lipid-unmodified form of Rab3A, but does not affect the MSS4 effect on the lipid-unmodified form of Rab3A. These results suggest that MSS4 and Rab3A GRF are different GDP/GTP exchange proteins for Rab3A.

【 授权许可】

Unknown