Characterization of the gibberelic acid (GA) signaling proteins and identification of novel GA signaling components from Arabidopsis

在目前的建议中，我们希望使用生物化学，细胞生物学，遗传学和功能基因组学的结合来提高我们对赤霉素（GA）信号网络的理解。GA控制着重要的植物生长过程，如发芽、伸长生长和开花时间。GA反应需要DELLA抑制因子的蛋白水解，其以GA依赖的方式与GID1 GA受体相互作用。我们最近完成了三个拟南芥GID1 GA受体基因的遗传和分子表征，并表明GID1三重突变体在GA控制的DELLA蛋白降解和基因表达方面对GA不敏感。我们现在想要研究DELLA蛋白，GID1和E3连接酶亚基SLY1之间的蛋白质相互作用，它们的翻译后修饰，以及以前未表征的GA调节转录因子和信号蛋白在GA信号传导中的作用。该项目最终将扩大我们对GA信号及其与其他途径的串扰的理解。

In the present proposal, we want to use a combination of biochemistry, cell biology, genetics and functional genomics to improve our understanding of the gibberellic acid (GA) signaling network. GA controls important plant growth processes such as germination, elongation growth and flowering time. GA responses require the proteolysis of the DELLA repressors, which interact with the GID1 GA receptors in a GA-dependent manner. We have recently finished the genetic and molecular characterization of the three Arabidopsis GID1 GA receptor genes and shown that the gid1 triple mutant is GA insensitive with respect to GA-controlled DELLA protein degradation and gene expression. We now want to investigate the protein interactions between the DELLA proteins, GID1 and the E3 ligase subunit SLY1, their post-translational modifications, as well as the role of previously uncharacterized GA-regulated transcription factors and signaling proteins in GA signaling. The project ultimately will broaden our understanding of GA signaling and its cross-talk with other pathways.