Ma H
Cold Spring Harbor Laboratory, NY 11724.
Plant Mol Biol. 1994 Dec;26(5):1611-36. doi: 10.1007/BF00016493.
Regulatory guanine nucleotide-binding proteins (G proteins) have been studied extensively in animal and microbial organisms, and they are divided into the heterotrimeric and the small (monomeric) classes. Heterotrimeric G proteins are known to mediate signal responses in a variety of pathways in animals and simple eukaryotes, while small G proteins perform diverse functions including signal transduction, secretion, and regulation of cytoskeleton. In recent years, biochemical analyses have produced a large amount of information on the presence and possible functions of G proteins in plants. Further, molecular cloning has clearly demonstrated that plants have both heterotrimeric and small G proteins. Although the functions of the plant heterotrimeric G proteins are yet to be determined, expression analysis of an Arabidopsis G alpha protein suggests that it may be involved in the regulation of cell division and differentiation. In contrast to the very few genes cloned thus far that encode heterotrimeric G proteins in plants, a large number of small G proteins have been identified by molecular cloning from various plants. In addition, several plant small G proteins have been shown to be functional homologues of their counterparts in animals and yeasts. Future studies using a number of approaches are likely to yield insights into the role plant G proteins play.
调节性鸟嘌呤核苷酸结合蛋白（G蛋白）已在动物和微生物中得到广泛研究，它们分为异源三聚体和小（单体）两类。已知异源三聚体G蛋白在动物和简单真核生物的多种信号通路中介导信号反应，而小G蛋白则执行多种功能，包括信号转导、分泌和细胞骨架调节。近年来，生化分析已产生了大量关于植物中G蛋白的存在及其可能功能的信息。此外，分子克隆已清楚地表明植物同时具有异源三聚体和小G蛋白。虽然植物异源三聚体G蛋白的功能尚未确定，但对拟南芥Gα蛋白的表达分析表明它可能参与细胞分裂和分化的调节。与目前为止克隆的植物中编码异源三聚体G蛋白的极少基因相比，通过分子克隆已从各种植物中鉴定出大量小G蛋白。此外，已证明几种植物小G蛋白是其在动物和酵母中的对应物的功能同源物。未来使用多种方法进行的研究可能会深入了解植物G蛋白所起的作用。
