Regulation and Assembly of Plant Pyruvate Dehydrogenase Complex

9419489兰德尔光合作用、光呼吸和线粒体呼吸之间的主要相互作用点在丙酮酸脱氢酶复合体。这种多酶复合体是碳进入克雷布斯循环的主要入口点，用于能源生产和生物合成中间体的产生。PDC还提供脂肪酸生物合成的前体、支链氨基酸、异戊二烯类化合物和一些生长调节剂。本研究的目的是：研究PDC组成酶的表达及其线粒体在复合体中的输入、加工和组装；确定C3、C4和CAM植物发育和光合作用过程中PDC活性的事件、机制和调节器；扩展PDC的生化特性，建立体外和细胞器中的调控机制；以及研究PDC的长期调控/表达。豌豆和拟南芥是主要的实验系统。该项目将促进对以下概念的评估：线粒体基质多酶复合体(PDC)的进口和组装需要伴侣；PDC的可逆磷酸化是碳进入Krebs循环的主要控制机制；PDC在发育过程中以及C3、C4和CAM植物之间的调节机制不同。

9419489 Randall A major point of interaction between photosynthesis, photorespiration and mitochondrial respiration is at the pyruvate dehydrogenase complex (PDC). This multi-enzyme complex is the primary entry point for carbon into the Krebs cycle for energy production and the generation of biosynthetic intermediates. PDC also provides the precursor for fatty acid biosynthesis, branch chain amino acids, isoprenoid compounds and some growth regulators. Objectives of this research are: to characterize the expression of PDC component enzymes, their mitochondrial import, processing and assembly in the complex; to characterize events, mechanisms and modulators of PDC activity during development and photosynthesis in C3, C4, and CAM plants; to extend biochemical characterization of PDC and establish in vitro and in organello regulatory mechanisms; and, to examine the long-term regulation/expression of PDC. Pea and Arabidopsis are the primary experimental systems used. This project will facilitate evaluation of the following concepts: that import and assembly of the mitochondrial matrix multi-enzyme cmplex, PDC, requires chaperones; that reversible phosphorylation of PDC is a primary control mechanism for carbon entry into the Krebs cycle; that PDC regulatory mechanisms differ during development and between C3, C4 and CAM plants.