Jones Alan M
Department of Biology, CB# 3280, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA.
Curr Opin Plant Biol. 2002 Oct;5(5):402-7. doi: 10.1016/s1369-5266(02)00288-1.
With an essentially complete plant genome in hand, it is now possible to conclude that a single or possibly just two canonical heterotrimeric G-protein complexes are present in Arabidopsis. In stark contrast, more than one hundred such complexes are found in some metazoans. Nonetheless, it appears that heterotrimeric G-protein complexes couple or affect many different signaling pathways in plants. In addition, there are very few, if any, candidate G-protein-coupled receptors through which this single complex can couple to downstream effectors. Furthermore, some of the classical downstream effectors that are activated by heterotrimeric G proteins in metazoans are also lacking in plants. Thus, we are left with the urgent challenge to determine the novel mechanism of G-protein signaling in plant cells. Recent advances using reverse and molecular genetic approaches have re-opened this topic for plant biologists and the resulting tools will accelerate our progress.
由于已掌握了基本完整的植物基因组，现在可以得出结论：拟南芥中存在单个或可能仅两个典型的异源三聚体G蛋白复合物。与之形成鲜明对比的是，一些后生动物中发现了一百多个这样的复合物。尽管如此，异源三聚体G蛋白复合物似乎在植物中偶联或影响许多不同的信号通路。此外，能够使这个单一复合物与下游效应器偶联的候选G蛋白偶联受体极少，即便有也寥寥无几。此外，后生动物中由异源三聚体G蛋白激活的一些经典下游效应器在植物中也不存在。因此，我们面临着确定植物细胞中G蛋白信号传导新机制的紧迫挑战。最近使用反向和分子遗传学方法取得的进展为植物生物学家重新开启了这个话题，由此产生的工具将加速我们的研究进程。
