High-resolution HIV-1 m⁶A epitranscriptome reveals isoform-dependent methylation clusters and unique 2-LTR transcript...

Area of Science:

• Virology
• Molecular Biology
• Epigenetics

Background:

• N6-methyladenosine (m6A) is a key RNA modification in HIV-1.
• Previous detection methods lacked precision, leaving the exact number and location of m6A sites unclear.

Purpose of the Study:

• To precisely identify and map m6A modification sites on HIV-1 RNA.
• To investigate differential methylation patterns across splicing isoforms.
• To characterize a novel RNA species derived from circular DNA and its m6A sites.

Main Methods:

• Utilized Nanopore sequencing with direct m6A base-calling.
• Performed single-molecule analysis of RNA transcripts.
• Analyzed RNA species transcribed from circular viral DNA.

Main Results:

• Identified 18 m6A sites on HIV-1 RNA: 14 in the 3' region and 4 centrally.
• Observed differential methylation across splicing isoforms and clustered methylation profiles.
• Discovered a ~732 nt RNA species with six m6A sites, five highly methylated and one unique, suggesting a specific role in infection.

Conclusions:

• Provides a high-resolution map of the HIV-1 m6A transcriptome.
• Highlights a novel RNA species and unique m6A sites with potential significance in the HIV-1 life cycle.
• Establishes a foundation for future research into the functional roles of m6A modifications in HIV-1.