U-box E3 ubiquitin ligase PUB8 attenuates abscisic acid responses during early seedling growth.
U-box E3 ubiquitin ligase PUB8 attenuates abscisic acid responses during early seedling growth.
复制标题
DOI：
10.1093/plphys/kiad044
复制
发表时间：
2023-04-03
期刊：
影响因子：
7.4
通讯作者：
Jiang, Yanjuan
中科院分区：
文献类型：
--
作者：
Li, Zhipeng;Li, Shaoqin;Jin, Dongjie;Yang, Yongping;Pu, Zhengyan;Han, Xiao;Hu, Yanru;Jiang, Yanjuan
脱落酸不敏感3（ABI3）和ABI5是脱落酸（ABA）信号传导中的2个关键转录因子，它们在蛋白质水平上的稳态在种子萌发和随后的幼苗生长中起着决定性作用。在这里，我们发现 PLANT U-BOX 8 (PUB8) 是一种 U-box E3 泛素连接酶，与 ABI3 和 ABI5 发生物理相互作用，并在早期拟南芥 (Arabidopsis thaliana) 幼苗生长过程中负向调节 ABA 反应。功能缺失的 pub8 突变体对 ABA 抑制的子叶绿化高度敏感，而过表达 PUB8 且 ABI5 蛋白丰度水平较低的品系对 ABA 不敏感。遗传分析表明，pub8 的 ABA 敏感表型需要 ABI3 和 ABI5，这表明 PUB8 在 ABI3 和 ABI5 的上游发挥功能，调节 ABA 反应。生化分析表明，PUB8 可以与 ABI3 和 ABI5 结合，通过泛素介导的 26S 蛋白酶体途径进行降解。相应地，PUB8 的功能丧失导致 ABI3 和 ABI5 稳定性增强，而 PUB8 的过度表达会损害 ABI3 和 ABI5 在植物中的积累。进一步的表型分析表明，PUB8 在幼苗早期生长过程中损害了 ABI5 的功能。综上所述，我们的结果揭示了 PUB8 通过控制 ABI3 和 ABI5 的稳态来调节早期幼苗生长的调节作用。拟南芥 U-box 在幼苗生长早期通过降解脱落酸不敏感 3 (ABI3) 和 ABI5 来减弱脱落酸反应。
ABSCISIC ACID-INSENSITIVE3 (ABI3) and ABI5 are 2 crucial transcription factors in abscisic acid (ABA) signaling, and their homeostasis at the protein level plays a decisive role in seed germination and subsequent seedling growth. Here, we found that PLANT U-BOX 8 (PUB8), a U-box E3 ubiquitin ligase, physically interacts with ABI3 and ABI5 and negatively regulates ABA responses during early Arabidopsis (Arabidopsis thaliana) seedling growth. Loss-of-function pub8 mutants were hypersensitive to ABA-inhibited cotyledon greening, while lines overexpressing PUB8 with low levels of ABI5 protein abundance were insensitive to ABA. Genetic analyses showed that ABI3 and ABI5 were required for the ABA-sensitive phenotype of pub8, indicating that PUB8 functions upstream of ABI3 and ABI5 to regulate ABA responses. Biochemical analyses showed that PUB8 can associate with ABI3 and ABI5 for degradation through the ubiquitin-mediated 26S proteasome pathway. Correspondingly, loss-of-function of PUB8 led to enhanced ABI3 and ABI5 stability, while overexpression of PUB8 impaired accumulation of ABI3 and ABI5 in planta. Further phenotypic analysis indicated that PUB8 compromised the function of ABI5 during early seedling growth. Taken together, our results reveal the regulatory role of PUB8 in modulating the early seedling growth by controlling the homeostasis of ABI3 and ABI5. Arabidopsis U-box attenuates abscisic acid responses by degrading ABSCISIC ACID-INSENSITIVE3 (ABI3) and ABI5 during early seedling growth.
登录
查看更多内容
影响因子：
11.6
作者：
Liu, Hongxia;Stone, Sophia L.
通讯作者：
Stone, Sophia L.
DOI：
10.1073/pnas.0505667103
发表时间：
2006-02-07
影响因子：
11.1
作者：
Furihata, T;Maruyama, K;Yamaguchi-Shinozaki, K
通讯作者：
Yamaguchi-Shinozaki, K
影响因子：
7.4
作者：
Brocard, IM;Lynch, TJ;Finkelstein, RR
通讯作者：
Finkelstein, RR
DOI：
10.1073/pnas.2109063118
发表时间：
2021-09-28
影响因子：
11.1
作者：
Li, Yang;Lu, Cheng Kai;Liang, Gang
通讯作者：
Liang, Gang
影响因子：
7.2
作者：
FINKELSTEIN, RR
通讯作者：
FINKELSTEIN, RR