Rate-limiting steps in photorespiratory metabolism and their importance for metabolic regulation

光合作用和光呼吸形成了一个重叠的反应网络，其中光呼吸C2循环通常被认为是一个相当不受调节的代谢过程。同样，这两个过程之间的调控相互作用也没有得到很好的分析。我们的团队计划确定光呼吸碳通量的代谢限制，并分析其在该途径中的潜在调节重要性以及对CB循环的反馈调节。为此，我们正在研究一系列突变体和过表达细胞系在光呼吸和相关代谢和转录过程中的变化，以表征内部和跨网络碳通量和其他相互作用。收集到的定量数据用于建立光呼吸代谢的计算模型，并用于进一步改进和质疑该模型。在第一个项目期间，可以证明光呼吸途径和CB循环的反馈调节假设，并显示与其他主要代谢途径的相互作用。在下一阶段，重点将放在完成多层次表型研究和对已确定的调节现象的功能解剖上。

Photosynthesis and photorespiration form an overlapping reaction network in which the photorespiratory C2 cycle is generally regarded as a rather unregulated metabolic process. Similarly, regulatory interactions between the two processes have not been well analysed. Our group plans to identify metabolic constraints to photorespiratory carbon flux and analyse their potential regulatory importance within the pathway and for feed-back regulation of the CB cycle. To this end, we are examining a range of mutants and overexpressor lines for alterations in photorespiratory and related metabolic and transcriptional processes to characterize internal and cross-network carbon fluxes and other interactions. Collected quantitative data serve to develop a computational model of photorespiratory metabolism and used for further improvement and interrogation of the model. In the first project period, the hypothesized feedback regulation from the photorespiratory pathway and the CB cycle could be proven and interactions with other major metabolic pathways shown. In the next period, focus will be on the completion of the multi-level phenotyping studies and the functional dissection of the identified regulatory phenomena.