Summary The endoplasmic reticulum‐associated degradation (ERAD) system eliminates misfolded and short‐lived proteins to maintain physiological homeostasis in the cell. We have previously reported that ERAD is involved in salt tolerance in Arabidopsis. Given the central role of the phytohormone abscisic acid (ABA) in plant stress responses, we sought to identify potential intersections between the ABA and the ERAD pathways in plant stress response. By screening for the ABA response of a wide array of ERAD mutants, we isolated a gain‐of‐function mutant, doa10a‐1, which conferred ABA hypersensitivity to seedlings. Genetic and biochemical assays showed that DOA10A is a functional E3 ubiquitin ligase which, by acting in concert with specific E2 enzymes, mediates mono‐ubiquitination of the ABA receptor, followed by their relocalization to the plasma membrane. This in turn leads to enhanced ABA perception. In summary, we report here the identification of a novel RING‐type E3 ligase, DOA10A, which regulates ABA perception by affecting the localization and the activity of ABA receptors through their mono‐ubiquitination.

中文翻译：

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拟南芥 E3 泛素连接酶 DOA10A 通过 ABA 信号传导中的单泛素化促进脱落酸 （ABA） 受体定位到膜上


摘要 内质网相关降解 （ERAD） 系统消除了错误折叠和短寿命的蛋白质，以维持细胞中的生理稳态。我们之前已经报道过 ERAD 参与拟南芥的耐盐性。鉴于植物激素脱落酸 （ABA） 在植物胁迫响应中的核心作用，我们试图确定植物胁迫响应中 ABA 和 ERAD 通路之间的潜在交叉点。通过筛选多种 ERAD 突变体的 ABA 反应，我们分离出一个功能获得性突变体 doa10a-1，它赋予 ABA 对幼苗的超敏反应。遗传学和生化测定表明，DOA10A 是一种功能性 E3 泛素连接酶，它与特异性 E2 酶协同作用，介导 ABA 受体的单泛素化，然后它们重新定位到质膜。这反过来又导致增强的 ABA 感知。总之，我们在这里报告了一种新型 RING 型 E3 连接酶 DOA10A 的鉴定，它通过单泛素化影响 ABA 受体的定位和活性来调节 ABA 感知。