Hiraoka K, Kaibuchi K, Ando S, Musha T, Takaishi K, Mizuno T, Asada M, Ménard L, Tomhave E, Didsbury J
Department of Biochemistry, Kobe University School of Medicine, Japan.
Biochem Biophys Res Commun. 1992 Jan 31;182(2):921-30. doi: 10.1016/0006-291x(92)91820-g.
Six peaks of small GTP-binding proteins (G proteins) were separated by column chromatographies from the cytosol fraction of the differentiated HL-60 cells: two peaks of rho p21, one peak of smg/rap1 p21, two peaks of rac1 p21, and one peak of an unidentified small G protein with a Mr of about 20,000 (20 KG). smg GDS, previously thought to be a stimulatory GDP/GTP exchange protein for smg p21, Ki-ras p21, and rho p21, but not for Ha-ras p21 or smg p25A, was also active on rac1 p21. rho GDI, previously thought to be an inhibitory GDP/GTP exchange protein specific for rho p21, was also active on rac1 p21. These results indicate that both smg GDS and rho GDI are active on multiple small G proteins.
