Prokaryotic Light Responses and Regulatory Mechanisms

智力价值：这个项目将有助于更好地理解光合作用微生物如何感知和响应光环境的变化。这一过程知之甚少，但具有全球重要性，正在使用淡水丝状蓝藻Fremyella diplosiphon(Tolypothrix PCC 7601)进行研究。以前的研究表明，这种生物似乎使用了一种新的基因调控形式，涉及多种形式的翻译启动因子，称为IF3。许多蓝藻似乎含有多个IF3编码基因，这使得这种形式的调控很可能在这一群体中广泛存在。该项目将确认IF3介导的转录后控制形式是否调节双虹吸虫在称为互补染色适应的过程中对绿光存在的反应。如果这是真的，这将扩大对IF3活性的理解，从它在翻译启动中的传统角色扩展到也包括对环境提示反应的基因表达的调节。这项研究还将进一步确定编码在双虹吸藻基因组中的一个可能的蓝藻光敏色素感受器的活性和功能，令人惊讶的是，它的表达受到另一种蓝藻光敏色素的调节。对这一新排列的探索将为原核生物中的光敏色素信号通路提供新的见解。这项研究将提供两名博士和12名本科生在信号转导、分子生物学、微生物学和功能基因组学领域的培训。根据该实验室以前的学生培训历史，这些学生中有相当一部分可能来自代表性不足的群体。更广泛地说，由于该项目以前的工作也表明多种形式的IF3可能调节高等植物胚胎发生和衰老期间叶绿体中的基因表达，因此这项研究可能会改善农业实践和作物生产。这项研究是由分子和细胞生物科学(基因和基因组系统)和新兴前沿(生命转变中的生命)部门共同资助的。

Intellectual Merit: This project will contribute to a better understanding of how photosynthetic microorganisms sense and respond to changes in their light environment. This process, which is poorly understood but of global importance, is being examined using the freshwater, filamentous cyanobacterium Fremyella diplosiphon (Tolypothrix PCC 7601). Previous research demonstrated that this organism appears to be using a novel form of gene regulation that involves multiple forms of a translation initiation factor called IF3. Many cyanobacteria appear to contain multiple IF3-encoding genes, making it likely that this form of regulation is widespread within this group. This project will confirm whether an IF3-mediated form of post-transcriptional control regulates the response of F. diplosiphon to the presence of green light during a process called complementary chromatic adaptation. If true, this will expand understanding of IF3 activity from its traditional role in translation initiation to also include the regulation of gene expression in response to environmental cues. This research will also further define the activity and function of a putative cyanobacterial phytochrome photoreceptor encoded within the F. diplosiphon genome whose expression, surprisingly, is regulated by another cyanobacterial phytochrome. Exploration of this novel arrangement will provide new insights into phytochrome signaling pathways in prokaryotes.Broader Impacts. This research will offer two Ph.D. and twelve undergraduate students training in the fields of signal transduction, molecular biology, microbiology and functional genomics. Based on the prior history of student training for this laboratory, a significant number of these students are likely to be from underrepresented groups. More broadly, because previous work on this project has also suggested that multiple forms of IF3 may regulate gene expression in the chloroplasts of higher plants during embryogenesis and senescence, this research may lead to improved agriculture practices and crop production.This research is co-funded by the Divisions of Molecular and Cellular Biosciences (Genes and Genome Systems) and Emerging Frontiers (Life in Transition).