Genetic Biochemical Studies of Plant Steroid Signaling

描述（由申请人提供）：激素和生长因子的信号传导是多细胞生物生长调节的基本机制。类固醇是调节植物和动物重要生理和发育过程的独特激素。类甾醇（BRs）是一种具有重要作用的植物甾体激素，与动物甾体激素具有相似的结构和功能，但通过不同的信号传导机制起作用。虽然动物类固醇激素通过核受体转录因子调节基因表达或通过膜结合受体激活非基因组反应，但BR结合细胞表面的受体激酶并通过信号转导级联调节核基因表达。下游BR信号转导涉及古老的信号蛋白，如GSK 3样激酶和14-3-3蛋白，以及植物特异性DNA结合蛋白。我的实验室使用拟南芥作为模型系统，以了解BR如何在生物化学，细胞生物学和生理水平上调节植物生长和发育。我们已经研究了BR如何通过控制关键转录因子BZR 1的磷酸化状态和活性来调节基因表达，并且我们已经证明了BZR 1如何调节BR应答基因的表达。我们计划继续我们的研究BR信号转导通路使用遗传和生物化学的方法，我们计划研究BR信号转导通路是如何连接到各种发育过程以及其他激素途径，调节共同的发育过程。这项研究将促进我们对植物生长调节以及类固醇信号传导的理解。由于类固醇激素与包括癌症在内的许多人类重大疾病有关，因此这项研究将对农业和人类健康产生广泛的影响。

DESCRIPTION (provided by applicant): Signaling by hormones and growth factors is an essential mechanism of growth regulation in multicellular organisms. Steroids are unique hormones that regulate important physiological and developmental processes in both plants and animals. Brassinosteroids (BRs), the plant steroid hormone with essential roles, share structural and functional similarities with animal steroid hormones but act through a distinct signaling mechanism. While animal steroid hormones act either through nuclear receptor transcription factors to regulate gene expression or through membrane-bound receptors to activate non-genomic responses, BRs bind to a receptor kinase at the cell surface and regulate nuclear gene expression through a signal transduction cascade. Downstream BR signaling involves both ancient signaling proteins, such as GSK3-like kinases and 14-3-3 proteins, and plant specific DNA binding proteins. My laboratory uses Arabidopsis as the model system to understand how BR regulates plant growth and development at the biochemical, cell biological, and physiological levels. We have studied how BRs regulate gene expression by controlling the phosphorylation status and activity of the key transcription factor BZR1, and we have demonstrated how BZR1 regulates the expression of BR-responsive genes. We plan to continue our study of the BR signal transduction pathway using genetic and biochemical approaches, and we plan to study how the BR signal transduction pathway is connected to various developmental processes as well as to other hormonal pathways that regulate common developmental processes. This study will advance our understanding of plant growth regulation as well as steroid signaling in general. Because steroid hormones are involved in many major diseases including cancer in human, this study will have broad implications for both agriculture and human health.