Non-coding Y RNAs as tethers and gates: Insights from bacteria

Area of Science:

• Molecular Biology
• RNA Biology
• Biochemistry

Background:

• Non-coding RNAs (ncRNAs) known as Y RNAs are found in both animal cells and bacteria.
• Y RNAs associate with the Ro 60 kDa (Ro60) autoantigen, a protein implicated in binding misfolded ncRNAs.
• The precise function of Ro60 ribonucleoprotein complexes (RNPs) has remained largely unknown.

Purpose of the Study:

• To investigate the function of Y RNAs and their association with Ro60 proteins.
• To explore the role of Y RNAs in bacterial RNA degradation pathways.
• To elucidate the structural and functional relationship between Y RNAs, Ro60, and PNPase.

Main Methods:

• Single particle electron microscopy was used to determine the structure of the RYPER complex.
• Biochemical assays were employed to assess the RNA degradation activity of RYPER.
• Literature review to synthesize existing knowledge on Y RNAs and Ro60 proteins.

Main Results:

• A novel bacterial RNA degradation machine, RYPER (Ro60/Y RNA/PNPase Exoribonuclease RNP), was identified.
• Y RNA acts as a tether, linking Ro60 to the exoribonuclease PNPase, enhancing degradation of structured RNAs.
• Structural analysis suggests RNA threading through Ro60 into PNPase, with Y RNAs potentially regulating substrate entry.

Conclusions:

• Y RNAs possess novel functions beyond their previously understood roles, acting as crucial components in RNA degradation.
• The bacterial RYPER complex provides a model for understanding Ro60 RNP function and RNA processing.
• Y RNAs may generally function to tether Ro60 to various RNA-binding proteins, suggesting conserved roles across species.