Translational termination-reinitiation in RNA viruses

Area of Science:

• Virology
• Molecular Biology
• Genetics

Background:

• Viruses employ translational control on polycistronic mRNAs to regulate viral protein expression.
• Termination-dependent reinitiation is a key mechanism observed in both negative- and positive-strand RNA viruses.
• Dicistronic RNAs often feature overlapping stop and start codons for upstream and downstream open reading frames (ORFs).

Purpose of the Study:

• To review the mechanisms of termination-dependent reinitiation in RNA viruses.
• To highlight the role of mRNA-ribosomal RNA interactions in facilitating reinitiation.
• To discuss viral reinitiation strategies, including those independent of direct mRNA-rRNA interactions.

Main Methods:

• Literature review of viral translational control mechanisms.
• Analysis of specific viral RNA structures and sequences involved in reinitiation.
• Comparative study of reinitiation strategies across different RNA virus families.

Main Results:

• Termination-dependent reinitiation is a conserved viral strategy.
• mRNA-rRNA interactions are crucial for tethering ribosomal subunits, aiding reinitiation.
• Examples include influenza B and caliciviruses, showcasing specific sequence overlaps (e.g., UAAUG).

Conclusions:

• mRNA-rRNA interactions play a significant role in viral translational control.
• Understanding these mechanisms provides insights into viral replication and gene expression.
• Diverse strategies exist for viral reinitiation, with or without direct RNA-RNA contact.