LET-502/ROCK Regulates Endocytic Recycling by Promoting Activation of RAB-5 in a Distinct Subpopulation of Sorting Endosomes
LET-502/ROCK Regulates Endocytic Recycling by Promoting Activation of RAB-5 in a Distinct Subpopulation of Sorting Endosomes
复制标题
LET-502/ROCK 通过促进分选内体的不同亚群中 RAB-5 的激活来调节内吞再循环
DOI：
10.1016/j.celrep.2020.108173
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发表时间：
2020
期刊：
影响因子：
8.8
通讯作者：
Anbing Shi
中科院分区：
文献类型：
--
作者：
Wenjuan Zhang;Shimin Wang;Chao Yang;Can Hu;Dan Chen;Qian Luo;Zhen He;Yuhan Liao;Yuxin Yao;Juan Chen;Jun He;Junbo Hu;Tian Xia;Long Lin;Anbing Shi
为了探索Rab 5/RAB-5在内吞再循环过程中的激活机制，我们进行了全基因组RNAi筛选并鉴定了再循环调节因子LET-502/ROCK。LET-502优先与RAB-5（GDP）相互作用，并激活RABX-5对RAB-5的GEF活性，推测是通过破坏RABX-5的自抑制构象。此外，我们发现LET-502和另一种CED-10效应物TBC-2/RAB-5-GAP的伴随丢失导致RAB-5的内体积聚，这表明CED-10指导TBC-2介导的RAB-5失活并重新激活RAB-5随后通过LET-502激活。然后，我们比较了LET-502与RME-6/RAB-5-GEF的功能位置。LET-502-RABX-5模块或RME-6的丢失导致空间上不同的内体组中RAB-5的存在减少。我们的结论是，在肠道线虫，RAB-5驻留在离散的内体亚群。在CED-10的监督下，LET-502与RABX-5协同作用，使深层细胞溶质中的一部分内体上的RAB-5恢复活力，确保基底外侧再循环的进展。
To explore the mechanism of Rab5/RAB-5 activation during endocytic recycling, we perform a genome-wide RNAi screen and identify a recycling regulator, LET-502/ROCK. LET-502 preferentially interacts with RAB-5(GDP) and activates RABX-5 GEF activity toward RAB-5, presumably by disrupting the self-inhibiting conformation of RABX-5. Furthermore, we find that the concomitant loss of LET-502 and another CED-10 effector, TBC-2/RAB-5-GAP, results in an endosomal buildup of RAB-5, indicating that CED-10 directs TBC-2-mediated RAB-5 inactivation and re-activates RAB-5 via LET-502 afterward. Then, we compare the functional position of LET-502 with that of RME-6/RAB-5-GEF. Loss of LET-502-RABX-5 module or RME-6 leads to diminished RAB-5 presence in spatially distinct endosome groups. We conclude that in the intestine ofC. elegans, RAB-5 resides in discrete endosome subpopulations. Under the oversight of CED-10, LET-502 synergizes with RABX-5 to revitalize RAB-5 on a subset of endosomes in the deep cytosol, ensuring the progress of basolateral recycling.