The functional specificity of ERECTA-family receptors in Arabidopsis stomatal development is ensured by molecular chaperones in the endoplasmic reticulum
The functional specificity of ERECTA-family receptors in Arabidopsis stomatal development is ensured by molecular chaperones in the endoplasmic reticulum
复制标题
内质网中的分子伴侣确保了 ERECTA 家族受体在拟南芥气孔发育中的功能特异性
作者：
Ke-Zhen Yang;Chao-Ran Zuo;Ya-Jun Leng;Jun-Ling Yue;Hui-Chao Liu;Zhi-Bin Fan;Xue-Yi Xue;Juan Dong;Li-Qun Chen;Jie Le
气孔是控制植物与大气之间气体交换的表皮孔。在拟南芥中，ERECTA家族（ERECTAf）受体，包括ERECTA、ERECTA-LIKE 1（ERL 1）和ERL 2，在执行“一个细胞间隔”规则中冗余地发挥关键作用。越来越多的证据表明，受体的功能特异性可能与它们的差异亚细胞动力学有关。内质网（ER）-驻留伴侣复合物SDF 2-ERdj 3B-BiP在植物发育的许多方面起作用。我们采用药物治疗结合细胞生物学和生物化学的方法来证明ERECTA的丰度在erdj 3b-1突变体中减少，但ERECTA的定位和动力学没有受到明显影响。相反，erdj 3b突变导致ERL 1/ERL 2在ER中的保留。此外，我们发现SDF 2-ERdj 3B-BiP的功能与ERECTAf受体的不同作用有关。我们的研究结果表明，ERECTAf受体介导的信号转导在气孔发育中是通过ER质量控制系统的活动来确保的，ER质量控制系统优先维持ERECTA的蛋白丰度和ERL 1/ERL 2的适当亚细胞动力学，在受体到达其目的地-质膜-之前执行其功能。
Stomata are epidermal pores that control gas exchange between plants and the atmosphere. In Arabidopsis, the ERECTA family (ERECTAf) receptors, including ERECTA, ERECTA-LIKE 1 (ERL1) and ERL2, redundantly play pivotal roles in enforcing the 'one-cell-spacing' rule. Accumulating evidence has demonstrated that the functional specificities of receptors are likely associated with their differential subcellular dynamics. The endoplasmic reticulum (ER)-resident chaperone complex SDF2-ERdj3B-BiP functions in many aspects of plant development. We employed pharmacological treatments combined with cell biological and biochemical approaches to demonstrate that the abundance of ERECTA was reduced in the erdj3b-1 mutant, but the localization and dynamics of ERECTA were not noticeably affected. By contrast, the erdj3b mutation caused the retention of ERL1/ERL2 in the ER. Furthermore, we found that the function of SDF2-ERdj3B-BiP is implicated with the distinct roles of ERECTAf receptors. Our findings establish that the ERECTAf receptor-mediated signaling in stomatal development is ensured by the activities of the ER quality control system, which preferentially maintains the protein abundance of ERECTA and proper subcellular dynamics of ERL1/ERL2, prior to the receptors reaching their destination - the plasma membrane - to execute their functions.