UpRoi1 - the phage-derived microRNA-size non-coding RNA molecule regulating both phage and its bacterial host...

Area of Science:

• Microbiology
• Molecular Biology
• Virology

Background:

• Bacteriophages, viruses that infect bacteria, play crucial roles in microbial ecosystems.
• Small RNAs (sRNAs) are key regulators of gene expression in both prokaryotes and eukaryotes.
• Shiga toxin-converting phages are significant pathogens, and their regulatory mechanisms are of great interest.

Purpose of the Study:

• To identify and characterize a novel small RNA (sRNA) encoded by the phage Φ24B.
• To investigate the regulatory role of this sRNA in phage-host interactions and bacterial processes.
• To explore the potential similarities between this phage sRNA and eukaryotic microRNAs.

Main Methods:

• Prophage induction and subsequent molecular identification of the sRNA.
• Bioinformatic analysis to predict interaction sites.
• RNA sequencing (RNA-seq) to assess gene expression changes.
• RNA binding assays to confirm direct interactions with target mRNAs.
• Analysis of the role of RNA chaperone protein ProQ.

Main Results:

• Identification of UpRoi1, a 30-nucleotide sRNA encoded by phage Φ24B.
• UpRoi1 significantly impacts host gene expression, particularly affecting bacterial motility.
• UpRoi1 directly binds to phage antirepressor mRNA and the bacterial flgL mRNA, influencing phage lytic cycle.
• Similarities were observed between UpRoi1 and herpesviral microRNAs.

Conclusions:

• UpRoi1 is an unusual prokaryotic sRNA with a significant regulatory role in phage-host interactions.
• This sRNA influences bacterial motility and facilitates the phage's switch to the lytic cycle.
• The findings suggest the presence of microRNA-like molecules in Shiga toxin-converting phages, with implications for understanding phage biology and pathogenesis.