RUI: The role of the AtcDPPIV Dipeptidyl Aminopeptidase in Photoacclimation

拟南芥AtcDPPIV基因编码叶绿体定位蛋白，其与动物蛋白酶具有同源性，所述动物蛋白酶从具有脯氨酸作为第二个氨基酸的底物的氨基末端切下前两个氨基酸。 AtcDPPIV mRNA是丰富的，当植物生长在低光，但大大减少后两天，在亚饱和中等光。 AtcDPPIV mRNA水平的下降时，没有观察到cch 1突变体从低到中等光转移。 cch 1突变体在中等光照下具有较小的光捕获复合物，因此在中等光照下比WT捕获更少的光。 这些观察结果表明，AtcDPPIV基因表达与光捕获相关，而不仅仅是光强度。 为了了解AtcDPPIV的功能，已经分析了两个具有独立的T-DNA插入AtcDPPIV基因的突变体。 这些线显示微妙的光适应表型表明AtcDPPIV二肽氨基肽酶可能发挥作用，在调整植物不同的光强度。 为了验证这一假设，提出了六个目标：1）证明两个插入系中的光适应表型是由于AtcDPPIV通过与AtcDPPIV互补而丢失。2）过表达AtcDPPIV和AtcDPPIV：：GFP以确定过表达是否导致光适应表型。3）过表达AtcDPPIV：：4）确定重组AtcDPPIV蛋白酶的底物特异性。5）使用酵母双链酶（酵母双链酶）和GFP，以确认预测的叶绿体定位并产生用于亚细胞器定位的AtcDPPIV抗体。鉴定与AtcDPPIV相互作用的蛋白质的杂交系统。6）更详细地表征在光适应期间观察到的扩展和紧凑的生长习性，并确定在AtcDPPIV插入系中是否发生细微的影响。关于光适应期间的信号传导知之甚少，AtcDPPIV二肽氨基肽酶可能是尚未描述的重要信号级联的一部分。 AtcDPPIV蛋白在双子叶植物、单子叶植物和许多环境细菌中是高度保守的，这表明它具有重要的保守功能。更广泛的影响这一建议的更广泛的影响包括在南加州少数民族校园的本科生和硕士生的培训。 增加研究职业中代表性不足的少数民族人数的最佳方法是在他们学习的早期阶段为他们提供一个有趣的，具有挑战性的，可行的项目。 还包括在有效的教学以及卓越的研究博士后研究人员的培训。 实验室中的许多项目已被列入生物科学本科课程的低年级和高年级课程，因此大量的学生受到这项工作的影响。 此外，PI协调三年级的科学教学项目，目前提供了一个为期八周的动手科学计划，以160三年级学生在长滩公立学校系统。

The Arabidopsis AtcDPPIV gene encodes a chloroplast-localized protein that has homology to animal proteases that cleave off the first two amino acids from the amino terminus of substrates that have a proline as the second amino acid. AtcDPPIV mRNA is abundant when plants are grown in low light, but is greatly reduced after two days at sub-saturating moderate light. The decrease in AtcDPPIV mRNA levels is not observed when the cch1 mutant is transferred from low to moderate light. The cch1 mutant has a smaller light harvesting complex under moderate light, and is therefore harvesting less light than WT under moderate light. These observations suggest that AtcDPPIV gene expression correlates with light harvesting, not just light intensity. To understand the function of AtcDPPIV, two mutants with independent T-DNA insertions into the AtcDPPIV gene have been analyzed. These lines show subtle photoacclimation phenotypes suggesting that the AtcDPPIV dipeptidyl aminopeptidase may play a role in adjusting plants to different light intensities. To test this hypothesis, six objectives are proposed: 1) Demonstrate that the photoacclimation phenotypes in the two insertion lines are due to loss of AtcDPPIV by complementation with AtcDPPIV.2) Overexpress AtcDPPIV and AtcDPPIV::GFP to determine if overexpression results in a photoacclimation phenotype.3) Overexpress AtcDPPIV::GFP to confirm predicted chloroplast localization and produce an AtcDPPIV antibody for suborganelle localization.4) Determine the substrate specificity of recombinant AtcDPPIV protease.5) Use the yeast two-hybrid system to identify proteins that interact with AtcDPPIV.6) Characterize the extended and compact growth habits observed during photoacclimation in more detail, and determine whether subtle effects are occurring in the AtcDPPIV insertion lines.Little is known about signaling during photoacclimation, and the AtcDPPIV dipeptidyl aminopeptidase could be part of an important signaling cascade that has not yet been described. The AtcDPPIV protein is highly conserved in dicots, monocots and in numerous environmental bacteria, suggesting that it has an important, conserved function.Broader ImpactsThe broader impacts of this proposal include the training of undergraduate and Masters students from a minority campus in Southern California. The best way to increase the numbers of underrepresented minorities in research careers is to offer them an interesting, challenging, feasible project at an early stage in their studies. Also included is the training of a postdoctoral researcher in effective teaching as well as excellence in research. Many of the projects in the laboratory have been included in the undergraduate curriculum in Biological Sciences in both lower and upper division courses, and thus a large number of students have been impacted by this work. In addition, the PI coordinates a third grade science teaching project that currently provides an eight-week hands-on science program to 160 third grade students in the Long Beach public school system.