SARS-CoV-2 Codon Usage Bias Downregulates Host Expressed Genes With Similar Codon Usage

Area of Science:

• Virology
• Molecular Biology
• Genomics

Background:

• Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a global pandemic, effectively infecting pulmonary cells.
• Understanding viral mechanisms is crucial for combating SARS-CoV-2 and developing effective treatments.

Purpose of the Study:

• To investigate the codon composition of SARS-CoV-2 for viral protein synthesis.
• To analyze the relationship between viral codon usage and host protein synthesis.
• To explore the implications of this interaction on viral pathogenesis and host response.

Main Methods:

• Codon usage analysis of SARS-CoV-2.
• Integration of codon composition data with proteomic data from infected cells.
• Functional analysis of host genes affected by viral codon bias.

Main Results:

• SARS-CoV-2 preferentially utilizes codons with low G or C content at the third position.
• This viral codon bias leads to an imbalance in host tRNA pools, impairing host protein synthesis.
• Host proteins from highly expressed genes, sharing the viral codon usage bias, exhibit reduced translation rates.

Conclusions:

• The observed codon usage bias is a mechanism of viral epistasis, impacting host protein synthesis and potentially contributing to immune evasion.
• Findings provide insights into SARS-CoV-2 pathogeny and suggest potential targets for live attenuated vaccine strategies.