Weikum Emily R, Tuntland Micheal L, Murphy Michael N, Ortlund Eric A
Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322 USA.
Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322 USA.
J Mol Biol. 2016 Dec 4;428(24 Pt B):4981-4992. doi: 10.1016/j.jmb.2016.10.025. Epub 2016 Oct 27.
Oct4 is a transcription factor required for maintaining pluripotency and self-renewal in stem cells. Prior to differentiation, Oct4 must be silenced to allow for the development of the three germ layers in the developing embryo. This fine-tuning is controlled by the nuclear receptors (NRs), liver receptor homolog-1 (LRH-1) and germ cell nuclear factor (GCNF). Liver receptor homolog-1 is responsible for driving the expression of Oct4 where GCNF represses its expression upon differentiation. Both receptors bind to a DR0 motif located within the Oct4 promoter. Here, we present the first structure of mouse GCNF DNA-binding domain in complex with the Oct4 DR0. The overall structure revealed two molecules bound in a head-to-tail fashion on opposite sides of the DNA. Additionally, we solved the structure of the human LRH-1 DNA-binding domain bound to the same element. We explore the structural elements that govern Oct4 recognition by these two NRs.
八聚体结合转录因子4(Oct4)是维持干细胞多能性和自我更新所必需的转录因子。在分化之前,Oct4必须被沉默,以允许发育中的胚胎形成三个胚层。这种微调由核受体(NRs)、肝脏受体同源物1(LRH-1)和生殖细胞核因子(GCNF)控制。肝脏受体同源物1负责驱动Oct4的表达,而GCNF在分化时抑制其表达。这两种受体都与Oct4启动子内的DR0基序结合。在此,我们展示了与Oct4 DR0复合的小鼠GCNF DNA结合结构域的首个结构。整体结构显示两个分子以头对尾的方式结合在DNA的相对两侧。此外,我们解析了与同一元件结合的人LRH-1 DNA结合结构域的结构。我们探索了这两种核受体识别Oct4的结构元件。