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Updated: Aug 1, 2025

Production of a SARS-CoV-2 Virus-Like-Particle System to Investigate Viral Life Cycles In Vitro
Published on: June 6, 2025
Reticulons promote formation of ER-derived double-membrane vesicles that facilitate SARS-CoV-2 replication
Jeffrey M Williams1, Yu-Jie Chen1, Woo Jung Cho2
1Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA.
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) hijacks host cell endoplasmic reticulum (ER) proteins, reticulon-3 (RTN3) and RTN4, to build replication organelles. These RTNs are essential for viral replication and infection by SARS-CoV-2 variants.
Area of Science:
- Virology
- Cell Biology
- Molecular Biology
Background:
- Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causes COVID-19 and relies on host cell machinery for replication.
- SARS-CoV-2 induces the formation of double-membrane vesicles (DMVs) from the endoplasmic reticulum (ER) to support viral replication.
Purpose of the Study:
- To elucidate the role of host factors in the formation of SARS-CoV-2-induced replication organelles (DMVs).
- To identify specific host proteins involved in hijacking ER membranes for viral replication.
Main Methods:
- Investigated the function of ER morphogenic proteins, specifically reticulon-3 (RTN3) and RTN4, in SARS-CoV-2 replication.
- Examined the interaction between RTN proteins and viral non-structural proteins (NSPs) like NSP3 and NSP4.
- Assessed the impact of RTN proteins on DMV biogenesis and viral replication across different SARS-CoV-2 variants.
Main Results:
- The ER morphogenic proteins RTN3 and RTN4 were found to drive the formation of DMVs, facilitating SARS-CoV-2 replication.
- The reticulon homology domain (RHD) of RTNs is sufficient for supporting viral replication and interacts with viral proteins NSP3 and NSP4.
- This RTN-dependent pathway is utilized by various SARS-CoV-2 variants, including the delta variant, for productive infection.
Conclusions:
- Host ER morphogenic proteins RTN3 and RTN4 are critical factors promoting the biogenesis of SARS-CoV-2 replication organelles (DMVs).
- RTNs physically engage viral proteins to facilitate the construction of these viral replication platforms, highlighting a key host-virus interaction.
- Targeting the RTN-dependent pathway could offer strategies to inhibit SARS-CoV-2 replication.
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