Division of Biological Sciences, Section of Neurobiology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA.
Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA.
Cell. 2019 Oct 3;179(2):373-391.e27. doi: 10.1016/j.cell.2019.09.004.
Cells regulate gene expression in response to salient external stimuli. In neurons, depolarization leads to the expression of inducible transcription factors (ITFs) that direct subsequent gene regulation. Depolarization encodes both a neuron's action potential (AP) output and synaptic inputs, via excitatory postsynaptic potentials (EPSPs). However, it is unclear if distinct types of electrical activity can be transformed by an ITF into distinct modes of genomic regulation. Here, we show that APs and EPSPs in mouse hippocampal neurons trigger two spatially segregated and molecularly distinct induction mechanisms that lead to the expression of the ITF NPAS4. These two pathways culminate in the formation of stimulus-specific NPAS4 heterodimers that exhibit distinct DNA binding patterns. Thus, NPAS4 differentially communicates increases in a neuron's spiking output and synaptic inputs to the nucleus, enabling gene regulation to be tailored to the type of depolarizing activity along the somato-dendritic axis of a neuron.
细胞会对外界刺激做出反应,从而调节基因表达。在神经元中,去极化会导致诱导型转录因子(ITF)的表达,从而指导随后的基因调控。去极化通过兴奋性突触后电位(EPSP)编码神经元的动作电位(AP)输出和突触输入。然而,目前尚不清楚不同类型的电活动是否可以通过 ITF 转化为不同的基因组调控模式。在这里,我们表明,小鼠海马神经元中的 AP 和 EPSP 触发了两种空间分离且分子上不同的诱导机制,导致 ITF NPAS4 的表达。这两种途径最终形成了具有刺激特异性的 NPAS4 异二聚体,表现出不同的 DNA 结合模式。因此,NPAS4 将神经元的放电输出和突触输入的增加差异传递到细胞核,从而使基因调控能够针对神经元的体树突轴上的去极化活动类型进行调整。