10.6084/M9.FIGSHARE.20013979.V1
Peili Hou
Peili
Hou
Xuefeng Wang
Xuefeng
Wang
Hongmei Wang
Hongmei
Wang
Tiecheng Wang
Tiecheng
Wang
Zhangping Yu
Zhangping
Yu
Chunqing Xu
Chunqing
Xu
Yudong Zhao
Yudong
Zhao
Wenqi Wang
Wenqi
Wang
Yong Zhao
Yong
Zhao
Fengyun Chu
Fengyun
Chu
Huasong Chang
Huasong
Chang
Hongchao Zhu
Hongchao
Zhu
Jiahui Lu
Jiahui
Lu
Fuzhen Zhang
Fuzhen
Zhang
Xue Liang
Xue
Liang
Xingyu Li
Xingyu
Li
Song Wang
Song
Wang
Yuwei Gao
Yuwei
Gao
Hongbin He
Hongbin
He
The ORF7a protein of SARS-CoV-2 initiates autophagy and limits autophagosome-lysosome fusion via degradation of SNAP29 to promote virus replication
<p>Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is closely related to various cellular aspects associated with autophagy. However, how SARS-CoV-2 mediates the subversion of the macroautophagy/autophagy pathway remains largely unclear. In this study, we demonstrate that overexpression of the SARS-CoV-2 ORF7a protein activates LC3-II and leads to the accumulation of autophagosomes in multiple cell lines, while knockdown of the viral <i>ORF7a</i> gene via shRNAs targeting <i>ORF7a</i> sgRNA during SARS-CoV-2 infection decreased autophagy levels. Mechanistically, the ORF7a protein initiates autophagy via the AKT-MTOR-ULK1‐mediated pathway, but ORF7a limits the progression of autophagic flux by activating CASP3 (caspase 3) to cleave the SNAP29 protein at aspartic acid residue 30 (D30), ultimately impairing complete autophagy. Importantly, SARS-CoV-2 infection-induced accumulated autophagosomes promote progeny virus production, whereby ORF7a downregulates SNAP29, ultimately resulting in failure of autophagosome fusion with lysosomes to promote viral replication. Taken together, our study reveals a mechanism by which SARS-CoV-2 utilizes the autophagic machinery to facilitate its own propagation via ORF7a.<b>Abbreviations:</b>
3-MA: 3-methyladenine; ACE2: angiotensin converting enzyme 2; ACTB/β-actin: actin beta; ATG7: autophagy related 7; Baf A1: bafilomycin A<sub>1</sub>; BECN1: beclin 1; CASP3: caspase 3; COVID-19: coronavirus disease 2019; GFP: green fluorescent protein; hpi: hour post-infection; hpt: hour post-transfection; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MERS: Middle East respiratory syndrome; MTOR: mechanistic target of rapamycin kinase; ORF: open reading frame; PARP: poly(ADP-ribose) polymerase; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; shRNAs: short hairpin RNAs; siRNA: small interfering RNA; SNAP29: synaptosome associated protein 29; SQSTM1/p62: sequestosome 1; STX17: syntaxin 17; TCID<sub>50</sub>: tissue culture infectious dose; TEM: transmission electron microscopy; TUBB, tubulin, beta; ULK1: unc-51 like autophagy activating kinase 1.</p>
Biophysics
Biochemistry
Microbiology
Cell Biology
Genetics
Molecular Biology
Physiology
Science Policy
Immunology
Infectious Diseases
Plant Biology
Virology
Taylor & Francis
2022
2022-06-07
2024-02-08
Dataset
9896103 Bytes
10.6084/m9.figshare.20013979
10.1080/15548627.2022.2084686
CC BY 4.0