LET-502/ROCK Regulates Endocytic Recycling by Promoting Activation of RAB-5 in a Distinct Subpopulation of Sorting Endosomes

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

doi:10.1016/j.celrep.2020.108173

LET-502/ROCK Regulates Endocytic Recycling by Promoting Activation of RAB-5 in a Distinct Subpopulation of Sorting Endosomes

Cell Rep. 2020 Sep 22;32(12):108173. doi: 10.1016/j.celrep.2020.108173.

Authors

Wenjuan Zhang¹, Shimin Wang², Chao Yang², Can Hu², Dan Chen², Qian Luo², Zhen He², Yuhan Liao², Yuxin Yao², Juan Chen², Jun He², Junbo Hu³, Tian Xia⁴, Long Lin⁵, Anbing Shi⁶

Affiliations

¹ Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 Hubei, China; Department of Pathology, Maternal and Child Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430070 Hubei, China.
² Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 Hubei, China.
³ Department of Pathology, Maternal and Child Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430070 Hubei, China.
⁴ Department of Informatics Engineering, School of Electronic Information and Communications, Huazhong University of Science and Technology, Wuhan, 430074 Hubei, China.
⁵ Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 Hubei, China. Electronic address: [email protected].
⁶ Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 Hubei, China. Electronic address: [email protected].

PMID: 32966783
DOI: 10.1016/j.celrep.2020.108173

Abstract

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 of C. 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.

Keywords: C. elegans; CED-10/Rac1; LET-502/ROCK; RAB-5/Rab5; RABX-5; RME-6; TBC-2; endocytic recycling; endosome subpopulation; sorting endosome.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Caenorhabditis elegans / cytology*
Caenorhabditis elegans / metabolism*
Caenorhabditis elegans Proteins / chemistry
Caenorhabditis elegans Proteins / genetics
Caenorhabditis elegans Proteins / metabolism*
Cytosol / metabolism
Endocytosis*
Endosomes / metabolism*
Guanine Nucleotide Exchange Factors / metabolism
Guanosine Diphosphate / metabolism
Intestines / cytology
Mutation / genetics
Protein Binding
Protein Domains
Protein Transport
Vesicular Transport Proteins / metabolism*
rho-Associated Kinases / chemistry
rho-Associated Kinases / genetics
rho-Associated Kinases / metabolism*

Substances

Caenorhabditis elegans Proteins
Guanine Nucleotide Exchange Factors
Rab-5 protein, C elegans
Vesicular Transport Proteins
Guanosine Diphosphate
LET-502 protein, C elegans
rho-Associated Kinases