SOC1 translocated to the nucleus by interaction with AGL24 directly regulates LEAFY
SOC1 translocated to the nucleus by interaction with AGL24 directly regulates LEAFY
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DOI：
10.1111/j.1365-313x.2008.03552.x
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发表时间：
2008-09-01
期刊：
影响因子：
7.2
通讯作者：
Lee, Ilha
中科院分区：
文献类型：
--
作者：
Lee, Jungeun;Oh, Mijin;Lee, Ilha
SOC 1（supplementor OF OVEREXPRESSION OF constans 1）是植物成花途径中的一个整合子，它调控着LEAFY（LFY）的表达，而LEAFY的表达与植物成花诱导和花发育密切相关。然而，SOC 1，MADS盒蛋白，调节LFY的机制已被证明是难以捉摸的。在这里，我们表明，SOC 1直接结合到LFY启动子的远端和近端区域，其中关键的顺式元件位于。基因内抑制突变分析表明，SOC 1的MADS盒中的错义突变导致LFY启动子结合的丧失以及开花促进功能的抑制。在原生质体瞬时表达试验中，SOC 1蛋白单独表达时位于细胞质中，而与另一种开花途径整合子AGAMOUS-LIKE 24（AGL 24）和MADS盒蛋白一起表达时则位于细胞核中。结构域分析表明，SOC 1和AGL 24的共定位是由MADS盒和SOC 1的插入区域介导的。最后，我们发现LFY仅在SOC 1和AGL 24表达重叠的组织中表达。因此，我们认为SOC 1和AGL 24的异源二聚化是激活LFY表达的关键机制。
SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) is one of the flowering pathway integrators and regulates the expression of LEAFY (LFY), which links floral induction and floral development. However, the mechanism by which SOC1, a MADS box protein, regulates LFY has proved elusive. Here, we show that SOC1 directly binds to the distal and proximal region of the LFY promoter where critical cis-elements are located. Intragenic suppressor mutant analysis shows that a missense mutation in the MADS box of SOC1 causes loss of binding to the LFY promoter as well as suppression of the flowering promotion function. The full-length SOC1 protein locates in the cytoplasm if expressed alone in protoplast transient expression assay, but relocates to the nucleus if expressed with AGAMOUS-LIKE 24 (AGL24), another flowering pathway integrator and a MADS box protein. The domain analysis shows that co-localization of SOC1 and AGL24 is mediated by the MADS box and the intervening region of SOC1. Finally, we show that LFY is expressed only in those tissues where SOC1 and AGL24 expressions overlap. Thus, we propose that heterodimerization of SOC1 and AGL24 is a key mechanism in activating LFY expression.