Regulation of cytoplasmic division of Xenopus embryo by rho p21 and its inhibitory GDP/GTP exchange protein (rho GDI).
Regulation of cytoplasmic division of Xenopus embryo by rho p21 and its inhibitory GDP/GTP exchange protein (rho GDI).
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DOI：
10.1083/jcb.120.5.1187
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发表时间：
1993-03
期刊：
影响因子：
--
通讯作者：
Takai Y
中科院分区：
文献类型：
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作者：
Kishi K;Sasaki T;Kuroda S;Itoh T;Takai Y
越来越多的证据表明，rho家族，一个成员的ras p21相关的小GTP结合蛋白超家族，调节细胞形态，细胞运动，平滑肌收缩，通过肌动球蛋白系统。肌动球蛋白系统也是细胞质分裂（胞质分裂）所必需的。在这项研究中，我们研究了rho p21，其抑制GDP/GTP交换蛋白，命名为rho GDI，其刺激GDP/GTP交换蛋白，命名为smg GDS，和肉毒杆菌ADP-核糖基转移酶C3，已知选择性ADP-核糖基化rho p21，并削弱其功能，在细胞质分裂爪蟾胚胎的行动。非洲爪蟾胚胎的精子诱导的细胞质分裂不受向胚胎中显微注射smg GDS或rho家族成员rhoA p21的鸟苷-5 '-（3-O-硫代）三磷酸（GTP gamma S）结合形式的影响，但完全被rho GDI或C3的显微注射抑制。在这些条件下，核分裂正常发生，但沟的形成，这是由收缩环组成的肌动球蛋白就在质膜下面，是受损的。rho GDI与rhoA p21的GTP γ S结合形式的共显微注射阻止了rho GDI的作用。此外，将C3核糖化的rhoA p21 pre-ADP-ribosylate注射到非洲爪蟾胚胎中，可以抑制精子诱导的非洲爪蟾胚胎细胞质分裂，这可能是内源性rho p21的显性负性抑制剂。这些结果表明，rho p21及其调节蛋白通过肌动球蛋白系统调节细胞质分裂。
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.