The CARBON CATABOLITE REPRESSION 4A ‐mediated RNA deadenylation pathway acts on the transposon RNAs that are not regulated by small RNAs

Wang, Ling; Li, Hui; Lei, Zhen; Jeong, Dong-Hoon; Cho, Jungnam

Abstract

Summary: Transposable elements (TEs) are mobile genetic elements that can impair the host genome stability and integrity. It has been well documented that activated transposons in plants are suppressed by small interfering (si) RNAs. However, transposon repression by the cytoplasmic RNA surveillance system is unknown. Here, we show that mRNA deadenylation is critical for controlling transposons in Arabidopsis. Trimming of poly(A) tail is a rate‐limiting step that precedes the RNA decay and is primarily mediated by the CARBON CATABOLITE REPRESSION 4 (CCR4)‐NEGATIVE ON TATA‐LESS (NOT) complex. We found that the loss of CCR4a leads to strong derepression and mobilization of TEs in Arabidopsis. Intriguingly, CCR4a regulates a largely distinct set of TEs from those controlled by RNA‐dependent RNA Polymerase 6 (RDR6), a key enzyme that produces cytoplasmic siRNAs. This indicates that the cytoplasmic RNA quality control mechanism targets the TEs that are poorly recognized by the previously well‐characterized RDR6‐mediated pathway, and thereby augments the host genome stability. Our study suggests a hitherto unknown mechanism for transposon repression mediated by RNA deadenylation and unveils a complex nature of the host's strategy to maintain the genome integrity.

Citation

Wang, L., Li, H., Lei, Z., Jeong, D., Jeong, D., & Cho, J. (2023). The CARBON CATABOLITE REPRESSION 4A ‐mediated RNA deadenylation pathway acts on the transposon RNAs that are not regulated by small RNAs. New Phytologist, https://doi.org/10.1111/nph.19435

• Journal Article Type: Article
• Acceptance Date: Nov 13, 2023
• Online Publication Date: Nov 27, 2023
• Publication Date: 2023-02
• Deposit Date: Nov 21, 2023
• Publicly Available Date: Nov 29, 2023
• Journal: New Phytologist
• Print ISSN: 0028-646X
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1111/nph.19435
• Keywords: RNA decay, Arabidopsis thaliana, long terminal repeat retrotransposon, mRNA poly(A) tail, RNA deadenylation
• Public URL: https://durham-repository.worktribe.com/output/1945289
• Publisher URL: https://nph.onlinelibrary.wiley.com/journal/14698137