Selective Budding of SARS-CoV-Like Particles from Glycolipid-Enriched Membrane Lipid Rafts and Host Gene Modulation

TL;DR

The study shows that SARS-CoV-like particles selectively bud from lipid rafts and identifies host proteins involved in viral assembly.

Contribution

The study identifies glycolipid-enriched lipid rafts as critical sites for SARS-CoV-like particle budding and highlights raft-associated proteins in viral assembly.

Findings

SARS-CoV-like particles preferentially bud from glycolipid-enriched membrane lipid rafts.

Pharmacological disruption of lipid rafts reduces virus-like particle budding and S protein partitioning.

Lipid raft-associated proteins like FNRA, VIM, CD59, and RHOA modulate cellular responses for viral replication.

Abstract

Severe acute respiratory syndrome coronavirus (SARS-CoV) assembles and buds from the Golgi apparatus or the ER membrane, but the specific membrane microdomains utilized during this process remain underexplored. Here, we show that co-expression of the SARS-CoV structural proteins S, M, and N in HEK-293T cells is sufficient to generate genome-free SARS-CoV-like virus-like particles (VLPs), which preferentially bud from glycolipid-enriched membrane lipid raft microdomains. Immunofluorescence microscopy using raft-selective dyes (DiIC16) and spike-specific antibodies revealed strong co-localization of VLPs with lipid rafts. Detergent-resistant membrane analysis and sucrose gradient centrifugation further confirmed the presence of S protein in buoyant, raft-associated fractions alongside the raft marker CD44. Importantly, pharmacological disruption of rafts with methyl-β-cyclodextrin reduced VLP budding and S protein partitioning into raft domains, underscoring the requirement for intact lipid rafts in assembly. Additionally, our data support lipid raft-associated proteins’ (e.g., FNRA, VIM, CD59, RHOA) roles in modulating cellular responses conducive to viral replication and assembly. These findings highlight lipid rafts as crucial platforms for SARS-CoV morphogenesis and suggest new avenues for vaccine and antiviral development using VLPs and raft-targeting therapeutics.

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