Oligomerization and Photo-Deoligomerization of HOOKLESS1 Controls Plant Differential Cell Growth
Oligomerization and Photo-Deoligomerization of HOOKLESS1 Controls Plant Differential Cell Growth
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HOOKLESS1 的寡聚化和光去寡聚化控制植物分化细胞生长
DOI：
10.1016/j.devcel.2019.08.007
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发表时间：
2019-10-07
影响因子：
11.8
通讯作者：
Zhong, Shangwei
中科院分区：
文献类型：
--
作者：
Lyu, Mohan;Shi, Hui;Zhong, Shangwei
顶钩曲率对埋苗的存活至关重要，是解剖分化细胞生长的极好模型。HOOKLESS1 （HLS1）对根尖钩的形成至关重要，是整合各种外部和内部信号的枢纽。然而，其作用机制尚不清楚。在这里，我们证明了HLS1蛋白作为低聚物存在于黑暗生长的幼苗的细胞核中。寡聚化是HLS1激活所必需的，因为突变的HLS1蛋白以无功能单体的形式存在。在光照下，光感受器phyB易位进入细胞核并与HLS1相互作用，破坏HLS1的自结合和寡聚化，启动钩子展开。值得注意的是，核定位的phyB基因表达足以使HLS1失活，导致黄化幼苗的钩曲率受损。总之，我们得出结论，HLS1蛋白在黑暗中以寡聚体形式活跃，在光线下实现变构光失活，为发育转变的分子开关提供了有趣的机制见解。
Apical hook curvature is crucial for buried seedling survival and a superb model for dissecting differential cell growth. HOOKLESS1 (HLS1) is essential for apical hook formation, acting as a hub integrating various external and internal signals. However, its functional mechanism remains unclear. Here, we demonstrate that HLS1 protein is present as an oligomer in the nucleus of dark-grown seedlings. Oligomerization is required for HLS1 activation, as the mutated HLS1 protein abolishing self-association exists as nonfunctional monomers. Upon light exposure, photoreceptor phyB translocates into the nucleus and interacts with HLS1, disrupting the self-association and oligomerization of HLS1 to initiate hook unfolding. Remarkably, genetic expression of nuclear-localized phyB is sufficient to inactivate HLS1, resulting in compromised hook curvature in etiolated seedlings. Together, we conclude that HLS1 protein is active as oligomeric form in darkness and achieves allosteric photo-deactivation upon light, providing intriguing mechanistic insight into the molecular switch for developmental transition.