Spatiotemporal dynamics of GEF-H1 activation controlled by microtubule- and Src-mediated pathways
Spatiotemporal dynamics of GEF-H1 activation controlled by microtubule- and Src-mediated pathways
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DOI：
10.1083/jcb.201812073
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发表时间：
2019-09-01
影响因子：
7.8
通讯作者：
Danuser, Gaudenz
中科院分区：
文献类型：
--
作者：
Azoitei, Mihai L.;Noh, Jungsik;Danuser, Gaudenz
Rho家族GTP酶受鸟嘌呤核苷酸交换因子(GEF)的精确时空调控而被激活。鸟嘌呤交换因子H1是一种RhoA激活剂，在不同的细胞功能中被认为是微管和肌动蛋白动力学的整合因子。在这里，我们识别出一个全球环境基金-H1的自抑制序列，并利用它来制作一个激活生物传感器，以微米和秒的分辨率定量地探索迁移细胞中全球环境基金-H1的构象变化、RhoA活性和边缘运动之间的关系。同时对MT动力学和gef-h1活性进行成像显示，自身抑制的gef-h1定位于MTS，而亚邻近细胞皮质的MT解聚促进了gef-h1的激活，其作用类似于5微米宽的外周带。全球环境基金-H1进一步受到Src磷酸化的调节，在距离细胞边缘0-2微米的较窄带内激活环境基金-H1，与细胞突起协调。这表明MT动力学和Src信号在RhoA激活中通过全环基金-H1存在协同交集。
Rho family GTPases are activated with precise spatiotemporal control by guanine nucleotide exchange factors (GEFs). Guanine exchange factor H1 (GEF-H1), a RhoA activator, is thought to act as an integrator of microtubule (MT) and actin dynamics in diverse cell functions. Here we identify a GEF-H1 autoinhibitory sequence and exploit it to produce an activation biosensor to quantitatively probe the relationship between GEF-H1 conformational change, RhoA activity, and edge motion in migrating cells with micrometer- and second-scale resolution. Simultaneous imaging of MT dynamics and GEF-H1 activity revealed that autoinhibited GEF-H1 is localized to MTs, while MT depolymerization subadjacent to the cell cortex promotes GEF-H1 activation in an similar to 5-mu m-wide peripheral band. GEF-H1 is further regulated by Src phosphorylation, activating GEF-H1 in a narrower band similar to 0-2 mu m from the cell edge, in coordination with cell protrusions. This indicates a synergistic intersection between MT dynamics and Src signaling in RhoA activation through GEF-H1.