ADAR-mediated tolerance and SOS splicing-mediated excision of transposable elements
1International Cancer Institute, Health Science Center, Peking University, Beijing, China.
Transcription
|February 26, 2026
Summary
A new RNA defense system, SOS splicing, excises DNA transposons from mRNA, repairing gene sequences. This complements ADAR editing, which tolerates transposons by suppressing immune responses, revealing an evolutionary balance.
Area of Science:
- Genomics
- Molecular Biology
- Evolutionary Biology
Background:
- Transposable elements (TEs) pose risks to genomic integrity.
- Existing silencing mechanisms for TEs are limited.
- The discovery of the SOS splicing system offers a new perspective on TE defense.
Purpose of the Study:
- To investigate the SOS splicing system as an RNA-level defense against DNA transposons.
- To compare the roles of SOS splicing and ADAR-mediated RNA editing in managing TEs.
- To understand the evolutionary implications of these mechanisms.
Main Methods:
- Identification and characterization of the SOS splicing pathway.
- Analysis of the interaction between SOS splicing and ADAR editing.
- Evolutionary analysis of TE tolerance and transcriptomic rescue.
Main Results:
- SOS splicing, mediated by AKAP17A, CAAP1, and RTCB, excises DNA transposons from mRNAs.
- This spliceosome-independent pathway restores gene sequences by recognizing and religating dsRNA hairpins.
- ADAR editing tolerates TEs by suppressing immune responses, while SOS splicing actively repairs damage.
Conclusions:
- SOS splicing represents a post-transcriptional error-correction mechanism against TE insertions.
- ADAR and SOS splicing highlight an evolutionary balance between TE tolerance and transcriptomic repair.
- The lethality of ADAR loss suggests its crucial role in mitigating purifying selection on TEs.
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