Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
Nat Cell Biol. 2013 May;15(5):491-501. doi: 10.1038/ncb2720. Epub 2013 Apr 21.
Organisms are constantly challenged by stresses and privations and require adaptive responses for their survival. The forkhead box O (FOXO) transcription factor DAF-16 (hereafter referred to as DAF-16/FOXO) is a central nexus in these responses, but despite its importance little is known about how it regulates its target genes. Proteomic identification of DAF-16/FOXO-binding partners in Caenorhabditis elegans and their subsequent functional evaluation by RNA interference revealed several candidate DAF-16/FOXO cofactors, most notably the chromatin remodeller SWI/SNF. DAF-16/FOXO and SWI/SNF form a complex and globally co-localize at DAF-16/FOXO target promoters. We show that specifically for gene activation, DAF-16/FOXO depends on SWI/SNF, facilitating SWI/SNF recruitment to target promoters, to activate transcription by presumed remodelling of local chromatin. For the animal, this translates into an essential role for SWI/SNF in DAF-16/FOXO-mediated processes, in particular dauer formation, stress resistance and the promotion of longevity. Thus, we give insight into the mechanisms of DAF-16/FOXO-mediated transcriptional regulation and establish a critical link between ATP-dependent chromatin remodelling and lifespan regulation.
生物体会不断受到压力和匮乏的挑战,需要适应反应才能生存。叉头框转录因子 O (FOXO) DAF-16(以下简称 DAF-16/FOXO)是这些反应的核心枢纽,但尽管它很重要,人们对它如何调节其靶基因知之甚少。通过蛋白质组学鉴定秀丽隐杆线虫中的 DAF-16/FOXO 结合伙伴,并通过 RNA 干扰对其进行后续功能评估,揭示了几个候选 DAF-16/FOXO 共因子,其中最突出的是染色质重塑 SWI/SNF。DAF-16/FOXO 和 SWI/SNF 形成复合物,并在 DAF-16/FOXO 靶启动子上全局共定位。我们表明,对于基因激活,DAF-16/FOXO 特别依赖于 SWI/SNF,通过假定局部染色质重塑来促进 SWI/SNF 招募到靶启动子,从而激活转录。对于动物来说,这意味着 SWI/SNF 在 DAF-16/FOXO 介导的过程中,特别是在 dauer 形成、应激抵抗和促进长寿中,起着至关重要的作用。因此,我们深入了解了 DAF-16/FOXO 介导的转录调控机制,并在 ATP 依赖性染色质重塑和寿命调节之间建立了关键联系。