Functions of the Acidic Ribosomal Proteins of Maize

9315015 Bailey-Serres蛋白质合成是一个多步骤过程，在玉米和所有其他生物体中受到多个水平的调节。 幼苗根的低氧（低氧）胁迫反应涉及快速抑制起始，然后选择性启动和延长mRNA翻译。 低氧应激反应为研究低能量条件下蛋白质合成的调节提供了模型。 该项目的重点是酸性核糖体蛋白（ARPs）在缺氧反应中的修饰。 三种酸性磷酸化蛋白质，称为P0、P1和P2，作为多聚体结构存在于核糖体的活性位点，在该活性位点，mRNA、tRNA和翻译因子之间的相互作用发生在翻译的后期起始、延伸和终止阶段。 生物化学的目标是确定P0，P1和P2的玉米，分析的化学计量的三种类型的ARPs在单核糖体和多核糖体的有氧和缺氧的根，在控制和缺氧条件下的ARPs的体内磷酸化的特征，并分析其他修改的ARPs响应缺氧。 本研究的分子目标是鉴定和测序玉米ARPs编码基因，并对ARPs基因的磷酸化位点进行定点突变。 长期目标是测试阿普修饰在玉米根尖体外翻译系统中的作用。 这些实验将为阐明高等植物蛋白质合成机制中核糖体结构与功能的关系奠定基础。 该项目涉及与墨西哥城墨西哥国立自治大学的Estela Sanchez de Jimenez博士的合作。 ***

9315015 Bailey-Serres Protein synthesis is a multi-step process that is regulated at numerous levels in maize as well as in all other organisms. The hypoxic (low-oxygen) stress response of seedling roots involves the rapid inhibition of initiation, followed by selective initiation and elongation of mRNA translation. The hypoxic stress response provides a model for studying modulation of protein synthesis under low energy conditions. This project focuses on modifications of acidic ribosomal proteins (ARPs) in response to hypoxia. Three acidic-phosphorylated proteins, known as P0, P1 and P2, are present as a multimeric structure in the active site of the ribosome where interactions between mRNA, tRNA and translation factors occur during the late-initiation, elongation and termination phases of translation. The biochemical objectives are to identify P0, P1 and P2 of maize, analyze the stoichiometry of the three-types of ARPs in monoribosomes and polyribosomes of aerobic and hypoxic roots, characterize the in vivo phosphorylation of ARPs under control and hypoxic conditions, and analyze other modifications of ARPs in response to hypoxia. The molecular objectives are to identify and sequence the genes encoding the ARPs of maize, and to initiate site-directed mutagenesis of the phosphorylation sites of the ARPs genes. The long-term goal is to test the role of ARP modification in an in vitro translation system from maize root tips. These experiments will provide the foundation for the elucidation of ribosome structure-function relationships in mechanisms of protein synthesis in higher plants. This project involves a collaboration with Dr. Estela Sanchez de Jimenez at National Autonomous University of Mexico, Mexico City. ***