一个受体激酶复合体通过TOR调控能量代谢的功能分析

Cell energy homeostasis affects processes such as plant growth and development, stress responses, and improves plant environmental adaptability. Target of rapamycin (TOR), an evolutionarily conserved serine/threonine protein kinase, plays a central role in maintaining cellular energy homeostasis. The receptor kinase FERONIA (FER), forming a complex with RIPK, is a master regulator of cell expansion and multiple stress responses. Applicant has found that similar to TOR kinase, FER is involved in carbon/nitrogen balance and partial amino acid response, and negatively regulates autophagy. Receptor kinase complex FER/RIPK interacts with TOR complex. It suggests that FER, coupled with TOR that a central regulator of energy metabolism, affects energy homeostasis and regulates autophagy. Based on this data, this application will explore: (1) the role of FER/RIPK kinase complex in plant energy metabolism; (2) the detailed biochemical mechanisms and genetic relation between FER/RIPK kinase complex and TOR; (3) the underlying mechanism of FER regulates autophagy through energy metabolism. If the subject is proved, it will for the first time connect the key regulatory network FER of cell expansion and stress response with the core component TOR of energy metabolism, which has potential value in crop trait improvement.

细胞能量稳态影响植物生长发育、逆境应答等过程，并提高植物环境适应性。TOR激酶是生物界保守的能量稳态调控核心组分。受体激酶FERONIA（FER）与RIPK形成复合体，是细胞伸长及多种逆境胁迫应答的关键调节子。申请人发现FER与TOR激酶类似，参与植物碳/氮平衡及部分氨基酸的响应，且负调控细胞自噬；同时FER/RIPK受体激酶复合体和TOR复合体相互作用。暗示FER通过与TOR这个能量代谢关键调控组分耦合，影响能量稳态并调节细胞自噬等过程。基于此，本课题拟分析：（1）FER/RIPK激酶复合体在植物能量代谢中的作用；（2）FER/RIPK复合体与能量代谢主要调节通路TOR的生化和遗传互作关系；（3）FER通过能量代谢调控细胞自噬的潜在机制。如课题得证，将首次把细胞伸长和逆境应答的关键调控网络FER与能量代谢的核心组分TOR联系起来，在农作物性状改良中具有潜在价值。

雷帕霉素靶标蛋白TOR能够整合营养、能量、激素、生长因子和环境输入来调控细胞的增殖、生长和代谢过程。然而，植物如何感知这些信号以激活TOR信号通路仍然知之甚少。本课题研究发现，在低氮营养条件下，位于细胞膜上的植物受体蛋白激酶FERONIA（FER）能与TOR相互作用调控营养（氮和氨基酸）信号。FER/RIPK复合体磷酸化TOR复合体组分RAPTOR1B，从而激活TOR信号通路。RALF1通过增强FER-TOR互作增加幼叶中TOR活性，从而促进低氮营养下拟南芥真叶的生长。该工作将调控植物生长的关键因子FER与调控营养的明星分子TOR联系起来，为理解植物生长与营养信号的协调机制提供了分子证据。