Cell-Intrinsic Adaptation Arising from Chronic Ablation of a Key Rho GTPase Regulator
Cell-Intrinsic Adaptation Arising from Chronic Ablation of a Key Rho GTPase Regulator
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DOI：
10.1016/j.devcel.2016.08.020
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发表时间：
2016-10-10
影响因子：
11.8
通讯作者：
Schiebel, Elmar
中科院分区：
文献类型：
--
作者：
Cerikan, Berati;Shaheen, Ranad;Schiebel, Elmar
基因组编辑技术可以系统地使人类基因失活。敲除表型是否总是反映急性RNAi所决定的基因功能是一个重要的问题。在这里，我们展示了编码RAC1/CDC42鸟核苷酸交换因子的亚当斯-奥利弗综合征(AOS)基因DOCK6的急性敲除如何导致与基因组DOCK6中断所产生的表型显著不同的表型。细胞内源性适应补偿DOCK6功能的丧失。DOCK6长时间缺失影响MRTF-A/SRF转录因子，降低泛素样修饰物ISG15的水平。IOGAP1蛋白ISG化水平的降低增加了活性CDC42和RAC1的水平，以补偿DOCK6的中断。DOCK6 AOS患者细胞中ISG15的类似下调表明，这种适应可以补偿发育过程中的遗传缺陷。因此，基因失活的表型严重依赖于时间尺度，因为急性敲除反映了适应新平衡的瞬时状态，这种状态是在补偿后达到的。
Genome-editing technologies allow systematic inactivation of human genes. Whether knockout phenotypes always reflect gene functions as determined by acute RNAi is an important question. Here we show how the acute knockdown of the Adams-Oliver syndrome (AOS) gene DOCK6, coding for a RAC1/CDC42 guanine nucleotide exchange factor, results in strikingly different phenotypes to those generated by genomic DOCK6 disruption. Cell-intrinsic adaptation compensates for loss of DOCK6 function. Prolonged DOCK6 loss impacts upon the MRTF-A/SRF transcription factor, reducing levels of the ubiquitin-like modifier ISG15. Reduced ISGylation of the IOGAP1 protein increases levels of active CDC42 and RAC1 to compensate for DOCK6 disruption. Similar downregulation of ISG15 in cells from DOCK6 AOS patients indicates that such adaptation can compensate for genetic defects during development. Thus, phenotypes of gene inactivation are critically dependent on the timescale, as acute knockdown reflects a transient state of adjustment to a new equilibrium that is attained following compensation.