Abstract
rho GDI is an inhibitory GDP/GTP exchange protein for the rho family. Recently, rho GDI has been reported to interact with the GTP-bound form of G25K and rac1 p21 and to inhibit their basal and GTPase-activating protein (GAP)-stimulated GTPase activity. Here, we examined whether rho GDI interacts with the GTP-bound form of rho p21 and rac p21 and inhibits their basal and rho GAP-stimulated GTPase activity. rho GDI interacted with both the GDP- and GTP-bound forms of rhoA p21 and rac1 p21 as estimated by measuring its ability to form a complex with both forms and to inhibit the membrane- binding activity of both forms. The efficiency of rho GDI for interaction with the GTP-bound form was, however, about 10% that for interaction with the GDP-bound form. Moreover, rho GDI inhibited both the basal and rho GAP- stimulated GTPase activity of rhoA p21 and rac1 p21 in a dose-dependent manner. The doses of rho GDI necessary for this action were, however, about 10-fold higher than those necessary for the action to inhibit their GDP/GTP exchange reaction. These results indicate that rho GDI interacts with the GTP-bound form of its substrate small G proteins, as well as with the GDP- bound form, but much less efficiently than with the GDP-bound form.
| Original language | English |
|---|---|
| Pages (from-to) | 23959-23963 |
| Number of pages | 5 |
| Journal | Journal of Biological Chemistry |
| Volume | 268 |
| Issue number | 32 |
| Publication status | Published - 1993 |
| Externally published | Yes |
Fingerprint
All Science Journal Classification (ASJC) codes
- Biochemistry
Cite this
Consequences of weak interaction of rho GDI with the GTP-bound forms of rho p21 and rac p21. / Sasaki, T.; Kato, Masaki; Takai, Y.
In: Journal of Biological Chemistry, Vol. 268, No. 32, 1993, p. 23959-23963.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Consequences of weak interaction of rho GDI with the GTP-bound forms of rho p21 and rac p21
AU - Sasaki, T.
AU - Kato, Masaki
AU - Takai, Y.
PY - 1993
Y1 - 1993
N2 - rho GDI is an inhibitory GDP/GTP exchange protein for the rho family. Recently, rho GDI has been reported to interact with the GTP-bound form of G25K and rac1 p21 and to inhibit their basal and GTPase-activating protein (GAP)-stimulated GTPase activity. Here, we examined whether rho GDI interacts with the GTP-bound form of rho p21 and rac p21 and inhibits their basal and rho GAP-stimulated GTPase activity. rho GDI interacted with both the GDP- and GTP-bound forms of rhoA p21 and rac1 p21 as estimated by measuring its ability to form a complex with both forms and to inhibit the membrane- binding activity of both forms. The efficiency of rho GDI for interaction with the GTP-bound form was, however, about 10% that for interaction with the GDP-bound form. Moreover, rho GDI inhibited both the basal and rho GAP- stimulated GTPase activity of rhoA p21 and rac1 p21 in a dose-dependent manner. The doses of rho GDI necessary for this action were, however, about 10-fold higher than those necessary for the action to inhibit their GDP/GTP exchange reaction. These results indicate that rho GDI interacts with the GTP-bound form of its substrate small G proteins, as well as with the GDP- bound form, but much less efficiently than with the GDP-bound form.
AB - rho GDI is an inhibitory GDP/GTP exchange protein for the rho family. Recently, rho GDI has been reported to interact with the GTP-bound form of G25K and rac1 p21 and to inhibit their basal and GTPase-activating protein (GAP)-stimulated GTPase activity. Here, we examined whether rho GDI interacts with the GTP-bound form of rho p21 and rac p21 and inhibits their basal and rho GAP-stimulated GTPase activity. rho GDI interacted with both the GDP- and GTP-bound forms of rhoA p21 and rac1 p21 as estimated by measuring its ability to form a complex with both forms and to inhibit the membrane- binding activity of both forms. The efficiency of rho GDI for interaction with the GTP-bound form was, however, about 10% that for interaction with the GDP-bound form. Moreover, rho GDI inhibited both the basal and rho GAP- stimulated GTPase activity of rhoA p21 and rac1 p21 in a dose-dependent manner. The doses of rho GDI necessary for this action were, however, about 10-fold higher than those necessary for the action to inhibit their GDP/GTP exchange reaction. These results indicate that rho GDI interacts with the GTP-bound form of its substrate small G proteins, as well as with the GDP- bound form, but much less efficiently than with the GDP-bound form.
UR - http://www.scopus.com/inward/record.url?scp=0027437622&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027437622&partnerID=8YFLogxK
M3 - Article
C2 - 8226937
AN - SCOPUS:0027437622
VL - 268
SP - 23959
EP - 23963
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 32
ER -