Bioinformatics Insights on Viral Gene Expression Transactivation: From HIV-1 to SARS-CoV-2

Area of Science:

• Virology
• Molecular Biology
• Gene Expression Regulation

Background:

• Viruses offer insights into gene expression control mechanisms.
• Viral transactivators, such as lentiviral Tat proteins, regulate viral, other viral, and host gene expression, impacting pathogenesis and immune responses.
• Tat proteins bind transacting responsive regions (TARs) in RNA and recruit host proteins.

Purpose of the Study:

• To investigate potential transactivation mechanisms in coronaviruses, specifically SARS-CoV-2.
• To compare structural similarities between SARS-CoV-2 nucleocapsid and lentiviral Tat proteins.
• To explore the implications of potential coronavirus transactivation in viral pathogenesis and evolution.

Main Methods:

• Primary and secondary structural comparisons of viral RNA and protein sequences.
• Analysis of SARS-CoV-2 and other coronavirus leader sequences for TAR-like elements.
• Comparison of coronaviral nucleocapsid C-terminal domains and nonstructural protein 12 with lentiviral Tat protein domains.

Main Results:

• SARS-CoV-2 and other coronavirus leaders contain TAR-like sequences in stem-loops 2 and 3.
• Coronaviral nucleocapsid C-terminal domains share similarities with TAR-binding regions of lentiviral Tat proteins.
• Coronaviral nonstructural protein 12 possesses a cysteine-rich metal binding, dimerization domain, akin to lentiviral Tat proteins.

Conclusions:

• Structural evidence suggests coronaviruses, including SARS-CoV-2, may employ transactivation for gene expression.
• The SARS-CoV-2 nucleocapsid protein exhibits functional and structural parallels with lentiviral Tat proteins.
• Further experimental validation is needed to confirm coronavirus transactivation and elucidate its role in disease and viral evolution.