TY - JOUR
T1 - Stoichiometric interaction of smg p21 with its GDP GTP exchange protein and its novel action to regulate the translocation of smg p21 between membrane and cytoplasm
AU - Kawamura, Shiro
AU - Kaibuchi, Kozo
AU - Hiroyoshi, Motoki
AU - Hata, Yutaka
AU - Takai, Yoshimi
N1 - Funding Information:
1This investigation was supported by grants-in-aid Scientific Research and Cancer Research from the Ministry Education, Science, and Culture, Japan (199(l), a grant-in-aid for Abnormalities in Hormone Receptor Mechanisms from the Ministry of Health and Welfare, Japan (1990), and by grants from the Human Frontier Science Program (1990), the Yamanouchi Foundation for Research on Metabolic Disease (1990), and the Research Program on Cell Calcium Signal in the Cardiovascular System (1990). 2To whom correspondence should be addressed. The abbreviations used are: G protein, GTP-binding protein; GAP, GTPase activatinq protein; GDS, GDP dissociation stimulator; GTPyS, guanosine 5'-(3L0-thio)triphosphate; DTT, dithiothreitol; SDS-PAGE, sodium dodecylsulfate-polyacrylamide gel electrophoresis; GDI, GDP dissociation inhibitor.
PY - 1991/2/14
Y1 - 1991/2/14
N2 - We have previously purified a GDP GTP exchange protein for smg p21A and -B, members of a ras p21 ras p21-like small GTP-binding protein superfamily. This regulatory protein, named smg p21 GDP dissociation stimulator (GDS), stimulates the dissociation of both GDP and GTP from and the subsequent binding of both GDP and GTP to smg p21s. We show here that smg p21 GDS forms a complex with both the GDP- and GTP-bound forms of smg p21B at a molar ratio of about 1:1. Both the GDP- and GTP-bound forms of smg p21B bound to membranes. smg p21 GDS inhibited this binding and moreover induced the dissociation of the prebound smg p21B from the membranes. These results indicate that smg p21 GDS stoichiometrically interacts with smg p21B and thereby regulates its GDP GTP exchange reaction and its translocation between membranes and cytoplasm.
AB - We have previously purified a GDP GTP exchange protein for smg p21A and -B, members of a ras p21 ras p21-like small GTP-binding protein superfamily. This regulatory protein, named smg p21 GDP dissociation stimulator (GDS), stimulates the dissociation of both GDP and GTP from and the subsequent binding of both GDP and GTP to smg p21s. We show here that smg p21 GDS forms a complex with both the GDP- and GTP-bound forms of smg p21B at a molar ratio of about 1:1. Both the GDP- and GTP-bound forms of smg p21B bound to membranes. smg p21 GDS inhibited this binding and moreover induced the dissociation of the prebound smg p21B from the membranes. These results indicate that smg p21 GDS stoichiometrically interacts with smg p21B and thereby regulates its GDP GTP exchange reaction and its translocation between membranes and cytoplasm.
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U2 - 10.1016/0006-291X(91)91533-I
DO - 10.1016/0006-291X(91)91533-I
M3 - Article
C2 - 1900001
AN - SCOPUS:0026026295
SN - 0006-291X
VL - 174
SP - 1095
EP - 1102
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 3
ER -