MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, University of Edinburgh, 5 Little France Drive, Edinburgh EH16 4UU, UK.
Centre for Discovery Brain Sciences, University of Edinburgh, 15 George Square, Edinburgh EH8 9XD, UK.
Development. 2020 Jun 22;147(12):dev184093. doi: 10.1242/dev.184093.
The intrinsic mechanisms that link extracellular signalling to the onset of neural differentiation are not well understood. In pluripotent mouse cells, BMP blocks entry into the neural lineage via transcriptional upregulation of inhibitor of differentiation (Id) factors. We have previously identified the major binding partner of Id proteins in pluripotent cells as the basic helix-loop-helix (bHLH) transcription factor (TF) E2A. Id1 can prevent E2A from forming heterodimers with bHLH TFs or from forming homodimers. Here, we show that overexpression of a forced E2A homodimer is sufficient to drive robust neural commitment in pluripotent cells, even under non-permissive conditions. Conversely, we find that E2A null cells display a defect in their neural differentiation capacity. E2A acts as an upstream activator of neural lineage genes, including and , and as a repressor of Nodal signalling. Our results suggest a crucial role for E2A in establishing neural lineage commitment in pluripotent cells.
细胞外信号与神经分化起始之间的内在机制尚不清楚。在多能性小鼠细胞中,BMP 通过转录上调分化抑制因子(Id)因子来阻止进入神经谱系。我们之前已经鉴定出多能性细胞中 Id 蛋白的主要结合伴侣是碱性螺旋-环-螺旋(bHLH)转录因子(TF)E2A。Id1 可以阻止 E2A 与 bHLH TF 形成异二聚体或形成同二聚体。在这里,我们表明,过量表达强制的 E2A 同二聚体足以在多能性细胞中驱动强大的神经定向,即使在非许可条件下也是如此。相反,我们发现 E2A 缺失细胞在其神经分化能力上存在缺陷。E2A 作为神经谱系基因的上游激活剂,包括 和 ,以及 Nodal 信号的抑制剂。我们的结果表明 E2A 在多能性细胞中建立神经谱系定向中起关键作用。