Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.4.2.30 (PARP)
 13,611 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Evidence is accumulating that rho p21, a ras p21-related small GTP-binding protein (G protein), regulates the actomyosin system. The actomyosin system is known to be essential for cell motility. In the present study, we examined the action of rho p21, its inhibitory GDP/GTP exchange protein (named rho GDI), its stimulatory GDP/GTP exchange protein (named smg GDS), and Clostridium botulinum ADP-ribosyltransferase C3, known to selectively ADP-ribosylate rho p21 and to impair its function, in cell motility (chemokinesis) of Swiss 3T3 cells. We quantitated the capacity of cell motility by measuring cell tracks by phagokinesis. Microinjection of the GTP gamma S-bound active form of rhoA p21 or smg GDS into Swiss 3T3 cells did not affect cell motility, but microinjection of rho GDI into the cells did inhibit cell motility. This rho GDI action was prevented by comicroinjection of rho GDI with the GTP gamma S-bound form of rhoA p21 but not with the same form of rhoA p21 lacking the C-terminal three amino acids which was not posttranslationally modified with lipids. The rho GDI action was not prevented by Ki-rasVal-12 p21 or any of the GTP gamma S-bound form of other small GTP-binding proteins including rac1 p21, G25K, and smg p21B. Among these small G proteins, rhoA p21, rac1 p21, and G25K are known to be substrates for rho GDI. The rho GDI action was not prevented by comicroinjection of rho GDI with smg GDS. Microinjection of C3 into Swiss 3T3 cells also inhibited cell motility. These results indicate that the rho GDI-rho p21 system regulates cell motility, presumably through the actomyosin system.
 ...
PMID:Involvement of rho p21 and its inhibitory GDP/GTP exchange protein (rho GDI) in cell motility. 841 62

Evidence is accumulating that the rho family, a member of the ras p21-related small GTP-binding protein superfamily, regulates cell morphology, cell motility, and smooth muscle contraction through the actomyosin system. The actomyosin system is also known to be essential for cytoplasmic division of cells (cytokinesis). In this study, we examined the action of rho p21, its inhibitory GDP/GTP exchange protein, named rho GDI, its stimulatory GDP/GTP exchange protein, named smg GDS, and botulinum ADP-ribosyltransferase C3, known to selectively ADP-ribosylate rho p21 and to impair its function, in the cytoplasmic division using Xenopus embryos. The sperm-induced cytoplasmic division of Xenopus embryos was not affected by microinjection into the embryos of either smg GDS or the guanosine-5'-(3-O-thio)triphosphate (GTP gamma S)-bound form of rhoA p21, one member of the rho family, but completely inhibited by microinjection of rho GDI or C3. Under these conditions, nuclear division occurred normally but the furrow formation, which was induced by the contractile ring consisting of actomyosin just beneath the plasma membrane, was impaired. Comicroinjection of rho GDI with the GTP gamma S-bound form of rhoA p21 prevented the rho GDI action. Moreover, the sperm-induced cytoplasmic division of Xenopus embryos was inhibited by microinjection into the embryos of the rhoA p21 pre-ADP-ribosylated by C3 which might serve as a dominant negative inhibitor of endogenous rho p21. These results indicate that rho p21 together with its regulatory proteins regulates the cytoplasmic division through the actomyosin system.
 ...
PMID:Regulation of cytoplasmic division of Xenopus embryo by rho p21 and its inhibitory GDP/GTP exchange protein (rho GDI). 843 90