CAREER: Molecular Genetic and Biochemical Analysis of Biliprotein-Regulated Photomorphogenesis in Cyanobacteria

为了使生长和发育最大化，光合生物感知并响应其光环境的变化。许多蓝细菌具有改变其捕光复合物的蛋白质组成的能力，以响应其环境中普遍存在的光颜色的变化。这个过程被称为互补色适应（CCA），在Fremyella diplosiphon，是最响应红色和绿色照明。CCA由感光胆蛋白RcaE（色适应调节因子）控制。为了增加对CCA分子基础的了解，本项目的目标是：（1）研究RcaE的生物合成;（2）阐明RcaE感知红光和绿色光的分子机制;（3）表征RcaE将感知的光信号传递到的下游效应物。分子遗传学和生物化学方法将被用来实现这些目标。由于RcaE是与一种离散的生理现象密切相关的光敏色素相关蛋白质的原核类中仅有的几个成员之一，因此，阐明RcaE调控基因网络控制对光响应的生长和发育，有望为光合系统中胆蛋白调控的光形态建成的运作机制提供深入了解。除了对研究生和博士后学者的培训外，这项研究的更广泛影响还包括对本科理科专业和代表性不足群体的学生的影响，包括妇女和密歇根州立大学查尔斯·德鲁科学丰富计划的参与者。该研究的培训部分将在一定程度上旨在培养这些学生分析性和批判性思维的能力。这个职业发展计划还包括利用教学方法，提高学生的批判性思维能力，科学素养和技术熟练程度。教育的重点包括在本科生生物化学调查课程的使用和评价主动学习的方法。

In order to maximize growth and development, photosynthetic organisms sense and respond to changes in their photoenvironment. Many cyanobacteria possess the ability to alter the protein composition of their light-harvesting complexes in response to changes in the prevalent colors of light in their environment. This process is termed complementary chromatic adaptation (CCA) and, in Fremyella diplosiphon, is most responsive to red and green illumination. CCA is controlled by a photosensory biliprotein, RcaE (regulator of chromatic adaptation). To increase knowledge about the molecular basis of CCA, the goals of this project are: (1) to investigate the biosynthesis of RcaE; (2) to elucidate the molecular mechanism by which RcaE perceives red and green light; and (3) to characterize the downstream effectors to which RcaE transmits the perceived light signal. Molecular genetic and biochemical approaches will be employed to accomplish these goals. As RcaE is one of only a few members of the prokaryotic class of phytochrome-related proteins closely linked to a discrete physiological phenomenon, elucidation of the RcaE regulatory gene network that controls growth and development in response to light is expected to provide insight into the mechanisms of operation of biliprotein-regulated photomorphogenesis in photosynthetic systems.Broader Impacts:In addition to the training of graduate students and postdoctoral scholars, broader impacts of the research will include an influence on undergraduate science majors and students from underrepresented groups, including women and participants in the Charles Drew Science Enrichment Program at Michigan State University. A training component of the research will be designed, in part, to develop the ability of these students to think analytically and critically. This career development plan also includes the utilization of instructional methods that enhance students' critical thinking skills, scientific literacy, and technical proficiency. The educational focus incorporates the use and evaluation of active learning pedagogies in an undergraduate biochemistry survey course.