摘要
Accumulating evidence indicates that early and essential events for receptor-like kinase(RLK)function involve both autophosphorylation and substrate phosphorylation.However,the structural and biochemical basis for these events is largely unclear.Here,we used RLK FERONIA(FER)as a model and crystallized its core kinase domain(FER-KD)and two FER-KD mutants(K565R,S525A)in complexes with ATP/ADP and Mg^(2+) in the unphosphorylated state.Unphosphorylated FER-KD was found to adopt an unexpected active conformation in its crystal structure.Moreover,unphosphorylated FER-KD mutants with reduced(S525A)or no catalytic activity(K565R)also adopt similar active conformations.Biochemical studies revealed that FER-KD is a dual-specificity kinase,and its autophosphorylation is accomplished via an intermolecular mechanism.Further investigations confirmed that initiating substrate phosphorylation requires autophosphorylation of the activation segment on T696,S701,and Y704.This study reveals the structural and biochemical basis for the activation and regulatory mechanism of FER,providing a paradigm for the early steps in RLK signaling initiation.
基金
supported by grants from the National Natural Science Foundation of China(32160064,31871396,31571444,and 32000916)
the State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources(SKLCUSA-a201806)
the China Postdoctoral Science Foundation(2019M662764)
the Hunan Provincial Natural Science Foundation of China(2021JJ40050)
the Guangxi Natural Science Foundation(2020GXNSFFA297007)
the Guangxi Key Laboratory for Sugarcane Biology(GXKLSCB-20190304).
