The deubiquitinases UBP12 and UBP13 integrate with the E3 ubiquitin ligase XBAT35.2 to modulate VPS23A stability in ABA signaling

第一作者：GUANGCHAO LIU

第一单位：中科院遗传与发育生物学研究所

通讯作者：FEIFEI YU

 Abstarct 

背景+问题：Ubiquitination-mediated protein degradation in both the 26S proteasome and vacuole is an important process in abscisic acid (ABA) signaling. However, the role of deubiquitination in this process remains elusive. 

在26S蛋白酶体和液泡中，泛素化介导的蛋白降解是脱落酸（ABA）信号转导的一个重要过程。然而，去泛素化在这一过程中的作用仍然不清楚。

主要发现：Here, we demonstrate that two deubiquitinating enzymes (DUBs), ubiquitin-specific protease 12 (UBP12) and UBP13, modulate ABA signaling and drought tolerance by deubiquitinating and stabilizing the endosomal sorting complex required for transport-I (ESCRT-I) component vacuolar protein sorting 23A (VPS23A) and thereby affect the stability of ABA receptors in Arabidopsis thaliana. 

本文中，作者发现在拟南芥中，两个去泛素化酶UBP12和UBP13通过去泛素化和稳定内膜分选复合体ESCRT-I组分VPS23A蛋白，进而影响ABA受体的稳定性，最终调控ABA信号转导和干旱耐受性。

结果1-VPS23A恢复UBP12/13突变体表型：Genetic analysis showed that VPS23A overexpression could rescue the ABA hypersensitive and drought tolerance phenotypes of ubp12-2w or ubp13-1. 

遗传分析表明，VPS23A过表达可以恢复ubp12-2w或ubp13-1的ABA超敏和耐旱表型。

结果2-UBP12/13-XBAT35.2：In addition to the direct regulation of VPS23A, we found that UBP12 and UBP13 also stabilized the E3 ligase XB3 ortholog 5 in A. thaliana (XBAT35.2) in response to ABA treatment. 

除了对VPS23A的直接调控，作者还发现UBP12和UBP13能够响应于ABA的处理，稳定拟南芥中E3连接酶XBAT35.2蛋白。

结论：Hence, we demonstrated that UBP12 and UBP13 are previously unidentified rheostatic regulators of ABA signaling and revealed a mechanism by which deubiquitination precisely monitors the XBAT35/VPS23A ubiquitination module in the ABA response.

因此，本文的研究表明UBP12和UBP13是ABA信号转导的变阻器式调节因子，揭示了一种植物在ABA响应过程中去泛素化精确监测XBAT35/VPS23A泛素化模块的分子机制。

** 于菲菲 **

doi: https://doi.org/10.1126/sciadv.abl5765

Journal: Science Advances

Published date: April 06, 2022