Identification of virus-encoded circular RNA.

Area of Science:

• Virology
• Molecular Biology
• Non-coding RNA Research

Background:

• Circular RNAs (circRNAs) are emerging as critical regulators of gene expression in eukaryotes.
• The existence and function of viral circRNAs, particularly in large genome DNA viruses like Epstein-Barr virus (EBV), remain largely unexplored.

Purpose of the Study:

• To investigate the potential for large genome DNA viruses to generate circRNAs during human cell infection.
• To identify and characterize any EBV-encoded circRNAs and elucidate their cellular localization and potential functions.

Main Methods:

• RNA sequencing was performed on ribosomal RNA-depleted total RNA from multiple EBV-infected human cell lines (SNU-719, AGS-EBV, C666-1, Akata).
• Bioinformatic analysis was used to identify circRNAs, followed by validation of identified viral circRNAs.

Main Results:

• Identification of a novel EBV-encoded circRNA, designated ebv_circ_RPMS1, resulting from the head-to-tail splicing of exons 2-4 of the RPMS1 gene.
• Demonstration that ebv_circ_RPMS1 is present in both the cytoplasm and nucleus of infected cells.
• The identified viral circRNA represents a new class of viral regulatory molecules.

Conclusions:

• Epstein-Barr virus can encode circular RNAs during human cell infection.
• The novel EBV-encoded circRNA, ebv_circ_RPMS1, is localized in cellular compartments and has the potential to regulate host and/or viral gene expression.
• This discovery opens new avenues for understanding virus-host interactions and viral gene regulation.