The RAS/RAF/MEK/ERK pathway promotes gliogenesis but the kinetic role of RAF1, a key RAF kinase, in the induction of astrocytogenesis remains to be elucidated. To address this challenge, we determine the temporal functional outcome of RAF1 during mouse neural progenitor cell differentiation using an optogenetic RAF1 system (OptoRAF1). OptoRAF1 allows for reversible activation of the RAF/MEK/ERK pathway via plasma membrane recruitment of RAF1 based on blue light-sensitive protein dimerizer CRY2/CIB1. We found that early light-induced OptoRAF1 activation in neural progenitor cells promotes cell proliferation and increased expression of glial markers and glia-enriched genes. However, delayed OptoRAF1 activation in differentiated neural progenitor had little effect on glia marker expression, suggesting that RAF1 is required to promote astrocytogenesis only within a short time window. In addition, activation of OptoRAF1 did not have a significant effect on neurogenesis, but was able to promote neuronal neurite growth.

RAS / RAF / MEK / ERK途径促进神经胶质发生，但RAF1（一种关键的RAF激酶）在星形细胞生成的诱导中的动力学作用尚待阐明。为了解决这一挑战，我们使用光遗传RAF1系统（OptoRAF1）确定了小鼠神经祖细胞分化过程中RAF1的暂时功能结果。OptoRAF1允许RAF / MEK / ERK途径的激活可逆经由基于蓝光敏感蛋白二聚体CRY2 / CIB1的RAF1的质膜募集。我们发现早期的光诱导神经祖细胞中的OptoRAF1激活促进细胞增殖并增加神经胶质标志物和胶质细胞丰富基因的表达。然而，在分化的神经祖细胞中延迟的OptoRAF1激活对神经胶质标记表达几乎没有影响，这表明需要RAF1仅在短时间内促进星形细胞生成。此外，OptoRAF1的激活对神经发生没有明显影响，但能够促进神经突突生长。