Protein/RNA Interactions in Translational Regulation

本项目的总体目标是确定细胞器mRNAs的光激活翻译机制。以前的生化和遗传学实验已经确定了叶绿体PSBA mRNA翻译所需的关键成分。根据这一建议，我们将继续PSBA翻译的特征，最终目标是确定叶绿体mRNAs翻译所需的一整套蛋白质和RNA元件。我们还将研究导致光激活翻译的这些成分的分子相互作用。这组实验的完成应该为细胞器mRNAs翻译的详细分子模型提供基础。理解叶绿体翻译也可能被证明是理解原核翻译和理解氧化还原调节基因表达的分子基础的范例。这些研究还应该影响我们利用植物叶绿体作为表达重组蛋白的载体的能力，这些重组蛋白可能被用作人类健康的治疗剂。这些针对叶绿体翻译的实验可以分为五个特定的目的：1.确定叶绿体聚(A)结合蛋白激活PSBA翻译的机制。2.分离出一套完整的PSBA mRNA结合蛋白，克隆其编码基因。3.确定PSBA翻译所需的RNA元件，并表征这些元件的作用机制。4.通过遗传分析确定PSBA相关蛋白在翻译中的作用。5.表征RNA元件和反式作用因子在翻译起始复合体形成中的作用

The general aims of this project are to identify the mechanisms of light activated translation of organelle mRNAs. Previous biochemical and genetic experiments have identified key components required for translation of the chloroplast psbA mRNA. Under this proposal we will continue the characterization of psbA translation with the ultimate goal of identifying the complete set of proteins and RNA elements required for translation of chloroplast mRNAs. We will also investigate the molecular interactions of these components that result in light activated translation. The completion of this set of experiments should provide the basis for a detailed molecular model of translation of organelle mRNAs. Understanding chloroplast translation may also prove to be a paradigm for understanding prokaryotic translation, and for understanding the molecular basis of redox regulation of gene expression. These studies should also impact our ability to exploit plant chloroplasts as a vehicle for the expression of recombinant proteins, that potentially could be used as therapeutic agents in human health. The sets of experiments to address chloroplast translation can be divided into five specific aims: 1. Identify the mechanism by which the chloroplast poly(A) binding protein activates psbA translation. 2. Isolate a complete set of psbA mRNA binding proteins, and clone the encoding genes. 3. Identify the RNA elements required for psbA translation, and characterize the mechanism by which these elements function. 4. Identify the roles of psbA associated proteins in translation by genetic analysis. 5. Characterize the role of RNA elements and trans-acting factors in translation initiation complex formation