Endoribonucleolytic Cleavage of m⁶A-Containing RNAs by RNase P/MRP Complex

Area of Science:

• Molecular Biology
• RNA Biology
• Biochemistry

Background:

• N-methyladenosine (m6A) is the most abundant internal RNA modification, regulating diverse biological processes.
• The precise molecular mechanisms of m6A-mediated gene regulation remain incompletely understood.
• YTHDF2 is an m6A reader protein, but its role in RNA degradation pathways is still being elucidated.

Purpose of the Study:

• To elucidate the molecular mechanism of m6A-mediated RNA degradation.
• To identify the proteins involved in the cleavage of m6A-containing RNAs.
• To investigate the function of HRSP12 and RNase P/MRP in m6A RNA regulation.

Main Methods:

• Biochemical assays to study protein-RNA interactions.
• RNA cleavage assays using purified proteins and RNA substrates.
• Transcriptome-wide analyses to identify targeted RNAs.
• Analysis of circular RNAs association with m6A machinery.

Main Results:

• m6A-containing RNAs are degraded via endoribonucleolytic cleavage mediated by YTHDF2, HRSP12, and RNase P/MRP.
• HRSP12 acts as an adaptor, bridging YTHDF2 and RNase P/MRP to promote rapid degradation of YTHDF2-bound RNAs.
• Transcriptome-wide analysis revealed specific binding and cleavage site requirements for HRSP12 and RNase P/MRP on targeted m6A RNAs.
• A subset of m6A-containing circular RNAs are downregulated by RNase P/MRP in an HRSP12-dependent manner.

Conclusions:

• The study reveals a novel mechanism for m6A-mediated RNA degradation through endoribonucleolytic cleavage.
• HRSP12 is identified as a crucial adaptor protein in this pathway.
• The findings expand the known functions of RNase P/MRP to include the cleavage of m6A-modified RNAs.
• This work provides new insights into the regulatory roles of m6A in gene expression.