C‐terminal conformational changes in SCF‐D3 / MAX2 ubiquitin ligase are required for KAI2 ‐mediated signaling
C‐terminal conformational changes in SCF‐D3 / MAX2 ubiquitin ligase are required for KAI2 ‐mediated signaling
复制标题
SCF–D3 / MAX2 泛素连接酶中的 C– 末端构象变化是 KAI2– 介导的信号传导所必需的
DOI：
10.1111/nph.19101
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发表时间：
2023
期刊：
影响因子：
9.4
通讯作者：
Shabek, Nitzan
中科院分区：
文献类型：
--
作者：
Tal, Lior;Guercio, Angelica M.;Varshney, Kartikye;Young, Aleczander;Gutjahr, Caroline;Shabek, Nitzan
Karrikins（KARs）是来自燃烧植物的生物活性分子。植物通过α/β水解酶KARRIKIN INSENSITIVE 2（KAI 2）感知KAR，KAI 2与F-box蛋白泛素连接酶MORE AXILLARY GROWTH 2（MAX 2）相互作用。MAX2还在独脚金内酯（SL）的感知和信号激活中起作用，独脚金内酯（SL）是一种控制植物中各种发育过程的植物激素。SL还充当根际信号，以激活丛枝菌根真菌，可以利用寄生plants.kai2knockouts表现出明显的发育缺陷，因此KAI 2假设感知一个身份不明的内源性配体暂时称为KAI 2-配体（KL）。在KAR/KL感知后，KAI 2-MAX2的蛋白复合物靶向MAX2-1/2（SMAX 1）/SMXL 2的供应物用于蛋白酶体降解。尽管在KAR/KL信号传导中识别了关键组分KAI 2、MAX2和SMAX 1，但它们的相互作用和调节模式仍然难以捉摸。近年来，MAX2 C末端螺旋（CTH）构象转换在SL信号转导中的调节作用已被证实，但其在KAR/KL信号转导中的作用尚不清楚。在这里，我们解决的功能MAX2-CTH动力学在体外和在植物中，并表明CTH的中心作用是保守的SL和KAR/KL信号通路。
Karrikins (KARs) are bioactive molecules derived from burning vegetation. Plants perceive KARs through the α/β hydrolase KARRIKIN INSENSITIVE 2 (KAI2) that interacts with the F-box protein ubiquitin ligase MORE AXILLARY GROWTH 2 (MAX2). MAX2 also plays a role in the perception and signal activation by Strigolactone (SL), a phytohormone controlling various developmental processes in plants. SL also acts as a rhizosphere signal to activate arbuscular mycorrhiza fungi that can be exploited by parasitic plants.kai2knockouts exhibit distinct developmental defects and therefore KAI2 is hypothesized to perceive an unidentified endogenous ligand provisionally termed KAI2-Ligand (KL). Upon KAR/KL perception, the protein complex of KAI2-MAX2 targets SUPPRESSOR OF MAX2-1/2 (SMAX1)/SMXL2 for proteasomal degradation. Despite the identification of the key components KAI2, MAX2, and SMAX1 in KAR/KL signaling, their mode of interaction and regulation remains elusive. Recently, the regulatory function of the conformational switch of MAX2 C-terminal helix (CTH) in SL signaling has been demonstrated however its role in KAR/KL signaling remained unknown. Here we address the function of MAX2-CTH dynamics bothin vitroandin plantaand show that the central role of CTH is conserved between SL and KAR/KL signaling pathway.