Environmental regulation of retinal and bacteriochlorophyll biosynthesis

视网膜和细菌叶绿素生物合成的环境调节

• 批准号: 1335269
• 负责人: Sergio Sanudo-Wilhelmy
• 金额: $ 82.76万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1335269&HistoricalAwards=false
• 关键词: Environmental; regulation; retinal; bacteriochlorophyll; biosynthesis

Rhodopsins are the simplest energy-harvesting photoproteins and community metagenomics have revealed that their synthesis genes are ubiquitous throughout the world oceans. These include microbial rhodopsin (proteorhodopsin (PR)), which occur in an estimated 75% of marine bacteria and archaea in oceanic surface waters. The discovery of this abundant and widespread photoprotein in the surface ocean has challenged the notion that solar energy can only be converted into chemical energy for growth in marine ecosystems through chlorophyll-based photosynthesis. Although the potential of light-driven energy flux in ocean ecosystems through PR could be significant, the physiological and ecological functions of this type of rhodopsin remains undetermined, mainly due to the lack of a technique for a direct measurement of this photoprotein. To evaluate the ecological relevance of PR in the marine environment, The investigators have developed a new analytical technique to measure the concentrations of the light-sensitive pigment in the PR, the chromophore retinal. Because rhodopsins have a single retinal chromophore associated with the polypeptide opsin, the total number of retinal molecules is equivalent to the total number of PR.Intellectual Merit:This project will employ the PI's newly developed protocol to examine the effects of light, organic carbon and trace metals availability on PR and bacteriochlorophyll synthesis using field and laboratory manipulations. Such experiments will establish the impact of abiotic factors on the two known bacterial photoheterotrophic metabolisms. The laboratory studies will be complemented with the analyses of those pigments in field samples collected along spatial and temporal gradients in light intensity, organic carbon and trace metals in different oceanographic regimes. Gene expression patterns will be determined in concert with changes in retinal and bacteriochlorophyll concentrations and microbial growth responses in the field and in the laboratory. Therefore, the combination of observational and manipulative approaches, will address fundamental questions in regard to the impact of retinal-based photochemical energy transformation in the ocean, a process that still is not well understood.Broader Impacts:Undergraduate and graduate education at USC will be furthered through active participation in the joint laboratory experiments and field work. The PIs research program includes a commitment to undergraduate student training by requesting support to target qualified underrepresented students from other L.A.-area schools, as well as active mentoring of undergraduate senior research theses at USC. In support of this effort Sanudo-Wilhelmy is starting a new initiative for minority recruitment at USC, using the Society for Advancement of Chicanos and Native Americans in Science meetings and publications as a platform. This project will also completely support the dissertation work of one USC graduate student and provide the funding for publication of his results, as well as to allow him to present his work at national meetings. The scientific and societal impacts of this project include elucidating the ecological importance of energy-transforming PR, without which we will never have a complete understanding of all of the essential mechanisms sustaining major biological processes in the world ocean.

动蛋白是最简单的能量收获的光蛋白，社区宏基因组学揭示了它们的合成基因在世界上无处不在。其中包括微生物视紫红质（蛋白淡季（PR）），估计在海洋地表水中估计有75％的海洋细菌和古细菌。在地面海洋中发现这种丰富且广泛的光蛋白的发现挑战了这样一种观念，即只能通过基于叶绿素的光合作用将太阳能只能转化为海洋生态系统生长的化学能。尽管通过PR中的光驱动能量通量的潜力可能很重要，但这种类型的Rhodopsin的生理和生态功能仍未确定，这主要是由于缺乏直接测量该光蛋白的技术。为了评估PR在海洋环境中的生态相关性，研究人员开发了一种新的分析技术，以测量PR PR敏感色素的浓度，即发色团视网膜。由于视紫红蛋白具有与多肽opsin相关的单个视网膜发色团，因此视网膜分子的总数等同于PR.Intlectual功能的总数：该项目将采用PI新开发的协议来检查光，有机碳和痕量金属对PR和CACTERIOCHERIOPHERIOPHALICE of FIELDLIOPLOPHAL使用现场和实验室的效果。这样的实验将建立非生物因素对两个已知的细菌光旋转代谢的影响。实验室研究将与对不同海洋学状态下的光强度，有机碳和微量金属在空间和时间梯度沿空间和时间梯度收集的现场样品中的这些颜料进行补充。基因表达模式将与视网膜和细菌绿化浓度的变化以及在实验室和实验室中的微生物生长反应一起确定。因此，观察性和操纵方法的结合将解决有关海洋基于视网膜的光化学能量转化的影响的基本问题，这一过程仍未得到充分理解。Broader的影响：USC的本科和研究生教育将通过积极参与共同的实验室实验和现场工作来进一步进一步。 PIS研究计划包括对本科生培训的承诺，要求对来自其他洛杉矶地区学校的准代表性不足的学生提供支持，并积极地指导USC的本科高级研究。为了支持这项努力，Sanudo-Wilhelmy正在使用奇卡诺斯和美洲原住民协会在科学会议和出版物中作为一个平台，在南加州大学开始了一项新的少数民族招聘计划。该项目还将完全支持一名USC研究生的论文工作，并为发布结果提供资金，并允许他在全国会议上介绍他的工作。该项目的科学和社会影响包括阐明能量转换PR的生态重要性，没有这些PR，我们将永远无法完全了解维持世界海洋中主要生物过程的所有基本机制。