Regulation of Differential mRNA Stability in Plastids

本提案的目标是定义这种转录后调控的分子机制，作为了解细胞器基因表达控制和核基因组在这一过程中的作用的长期目标的一部分。Gruissem博士将详细研究在质体mrna 3'端倒置重复序列（IR）的功能。这些IR序列是普遍存在的，它们的序列在进化不同的植物之间是保守的，它们不作为有效的转录终止子，但通过加工建立了均匀的质体mRNA 3 '端。初步实验表明，蛋白质与3 ' IR序列结合，其丰度在植物发育过程中的变化与mRNA积累的差异有关。这种RNA与蛋白质的相互作用引起了人们的兴趣，因为它可能描述了一种控制质体基因表达的新调控机制。这项工作应该提供新的结果，以帮助填补目前存在于我们对翻译后调节机制的理解中的空白。此外，这些研究可能会对核基因组在控制细胞器表达中的作用产生新的见解。

The goal of this proposal is to define the molecular mechanisms of this posttranscriptional regulation as part of the long-term objective to understand the control of organelle gene expression and the role of the nuclear genome in this process. Dr. Gruissem will examine in detail the function of inverted repeat (IR) sequences at the 3' end on plastid mRNAs. These IR sequences are ubiquitous, their sequences is conserved between evolutionary divergent plants, and they do not act as efficient transcription terminators, but homogeneous plastid mRNA 3` ends are established by processing. Preliminary experiments suggest that proteins bind to the 3` IR sequences, and their abundance changes during plant development are correlated with differential mRNA accumulation. This RNA: protein interaction is of interest, because it may delinaeate a novel regulatory mechanism in the control of plastid gene expression. This work should provide new results to help fill the gap that currently exists in our understanding of posttranslational regulatory mechanisms. Additionally the studies may potentially lead to new insights into the role of the nuclear genome in the control of organelle expression.