Weichao Huang's Abstract

Title: how cellular energetic currencies are trafficked among chloroplast and mitochondria


NAD(P)H and ATP are the common cellular currencies. Recently, the exportation of energies from chloroplast to the other compartments is becoming a hot topic. Studies on this subject provide promising possibilities for metabolic engineering. Intracellular transport of ATP/NAD(P)H form a complex traffic network, allowing metabolic pathways are connected. Photosynthetic organisms have two ATP producing organelles: chloroplasts and mitochondria. Light stimulates electron flow in chloroplasts that is coupled to the formation of NADPH and ATP. In the dark, the cells depend on mitochondrial electron transport to generate energy; NADH that is primarily generated from the Tricarboxylic Acid or Krebs Cycle is used by mitochondrial electron transport to synthesize ATP. However, these two energetic generating systems can communicate and under various conditions reductant can be shuttled from chloroplasts to mitochondria. Accumulating evidence suggests that under various conditions there is a strong coupling of chloroplast and mitochondrial electron flow that can function in balancing the production of reductant and ATP, dissipating excess excitation energy as heat and diminishing the production of reactive oxygen species. Although chloroplast and mitochondria cooperation was hypothesized, not a lot of experimental quantitative data was presented to support this important notion.  My project is aiming to address how these two energetic generating organelles do cross-talk by applying various genetic and molecular technologies. Metabolic and proteomic analysis will also be used.