U.S.-France Cooperative Research: Regulation of Ferritin Expression in Plants

该奖项将支持北卡罗来纳州立大学的Elizabeth Theil博士和格勒诺布尔大学的Jean-Francois Briat博士在生物化学方面的合作研究。本研究的目的是探讨铁蛋白在植物中的表达调控。铁是关键反应（如细胞分裂和呼吸）以及植物特异性反应（如光合作用和固氮）所必需的。铁蛋白中铁储存的改变发生在黄化和线虫感染中。在动物中，铁蛋白编码在一个多基因家族中，受铁调控，并通过一个保守的翻译调控序列。在植物中缺乏类似的信息。最近的研究表明，豌豆和大豆铁蛋白与脊椎动物铁蛋白有55-65%的序列相同，但大豆铁蛋白mRNA也编码一个转运肽，这显然与铁蛋白的质体位置有关。铁对植物铁蛋白合成的影响主要是通过改变铁蛋白mRNA的浓度。在这个项目中，研究人员将结合美国和法国在铁蛋白和植物基因表达方面的专业知识，共同研究铁蛋白在铁胁迫、根瘤形成和种子发育过程中的调节和积累。铁蛋白cdna和抗体将用于检测：1)植物基因组中的铁蛋白序列（调控和编码），2)铁对铁蛋白mRNA含量和转录的影响，以及3)正常和异常结瘤、叶片成熟和种子形成过程中铁蛋白mRNA和蛋白质的积累。这一结果将对了解植物铁代谢和铁蛋白调控具有重要意义，并为未来研究与质体发育相关的细胞内运输提供一个模型。

This award will support collaborative research in biochemis- try between Dr. Elizabeth Theil, North Carolina State University, and Dr. Jean-Francois Briat, University of Grenoble. The objective of the research is to investigate the regulation of ferritin expression in plants. Iron is required for critical reactions (e.g. cell division and respiration), as well as plant-specific reactions (e.g. photosynthesis and nitrogen fixation). Alterations in iron storage in ferritin occur in chlorosis and nematode infection. In animals, ferritin is encoded in a multigene family and is regulated by iron and through a conserved translational regulatory sequence. Comparable information is lacking in plants. Recently the investigators have shown that pea and soybean ferritins share 55-65% sequence identify with vertebrate ferritins, but soybean ferritin mRNA also encodes a transit peptide apparently related to the plastid location of ferritin. The effect of iron on ferritin synthesis in plants is to change ferritin mRNA concentration. In this project, which combines US and French expertise on ferritin and on gene expression in plants, the investigators will carry out a joint study of ferritin regulation and accumulation in plants during iron stress, nodule formulation, and seed development. Ferritin cDNAs and antibodies will be used to examine: 1) ferritin sequences (regulatory and coding) in plant genomes, 2) the effect of iron on ferritin mRNA content and transcription, and 3) ferritin mRNA and protein accumulation during normal and abnormal nodulation, leaf maturation and seed formation. The results will be important for understanding iron metabolism and ferritin regulation in plants, as well as providing a model in the future for intracellular trafficking related to plastid development.