G-quadruplex structures within the 3' UTR of LINE-1 elements stimulate retrotransposition

Area of Science:

• Genomics
• Molecular Biology
• Evolutionary Biology

Background:

• Long Interspersed Nuclear Elements (LINEs) are abundant transposable elements crucial for genome evolution in eukaryotes.
• LINE-1 elements, particularly hominoid-specific variants, play a significant role in shaping primate genomes.
• The mechanisms regulating LINE-1 activity and speciation are not fully understood.

Purpose of the Study:

• To investigate the role of guanine-rich sequences in the 3' UTRs of hominoid-specific LINE-1 elements.
• To explore the contribution of G-quadruplex (G4) structures to LINE-1 retrotransposition and speciation.
• To determine if G4 structure stabilization can modulate LINE-1 activity.

Main Methods:

• Bioinformatic analysis of guanine-rich sequences in LINE-1 3' UTRs.
• G-quadruplex structure prediction and analysis.
• Experimental validation of G4 formation and its impact on retrotransposition.
• Treatment with small-molecule ligands to stabilize G4 motifs.

Main Results:

• Guanine-rich sequences in hominoid-specific LINE-1 3' UTRs are associated with retrotransposon speciation.
• These sequences can form G-quadruplex (G4) structures, contributing to retrotransposition.
• Stabilization of a human-specific LINE-1 G4 motif using small-molecule ligands significantly stimulates retrotransposition.

Conclusions:

• G-quadruplex structures within LINE-1 3' UTRs are key regulatory elements in retrotransposon evolution and speciation.
• Targeting G4 motifs represents a potential strategy to modulate LINE-1 activity.
• This finding provides insights into the molecular mechanisms driving genome evolution in higher eukaryotes.