Department of New Biology, DGIST, Daegu 711-873, Republic of Korea.
Cell Rep. 2013 Mar 28;3(3):671-7. doi: 10.1016/j.celrep.2013.02.021. Epub 2013 Mar 21.
Many organisms, including plants, use the circadian clock to measure the duration of day and night. Daily rhythms in the plant circadian system are generated by multiple interlocked transcriptional/translational loops and also by spatial regulations such as nuclear translocation. GIGANTEA (GI), one of the key clock components in Arabidopsis, makes distinctive nuclear bodies like other nuclear-localized circadian regulators. However, little is known about the dynamics or roles of GI subnuclear localization. Here, we characterize GI subnuclear compartmentalization and identify unexpected dynamic changes under diurnal conditions. We further identify EARLY FLOWERING 4 (ELF4) as a regulator of GI nuclear distribution through a physical interaction. ELF4 sequesters GI from the nucleoplasm, where GI binds the promoter of CONSTANS (CO), to discrete nuclear bodies. We suggest that the subnuclear compartmentalization of GI by ELF4 contributes to the regulation of photoperiodic flowering.
许多生物，包括植物，都利用生物钟来测量白天和黑夜的持续时间。植物生物钟系统的日常节律是由多个相互连锁的转录/翻译环以及核易位等空间调节产生的。GIGANTEA（GI）是拟南芥中关键的生物钟成分之一，它像其他核定位生物钟调节剂一样形成独特的核体。然而，关于 GI 亚核定位的动态或作用知之甚少。在这里，我们描述了 GI 的亚核区室化，并在昼夜条件下鉴定了意想不到的动态变化。我们进一步鉴定 EARLY FLOWERING 4（ELF4）作为通过物理相互作用调节 GI 核分布的调节剂。ELF4 将 GI 从核质中隔离出来，在核质中，GI 结合 COSTANZ（CO）的启动子，形成离散的核体。我们认为，ELF4 通过亚核区室化 GI 有助于调控光周期开花。
