RNA 5-methylcytosine marks mitochondrial double-stranded RNAs for degradation and cytosolic release.
Mol Cell
; 84(15): 2935-2948.e7, 2024 Aug 08.
Article
en En
| MEDLINE
| ID: mdl-39019044
ABSTRACT
Mitochondria are essential regulators of innate immunity. They generate long mitochondrial double-stranded RNAs (mt-dsRNAs) and release them into the cytosol to trigger an immune response under pathological stress conditions. Yet the regulation of these self-immunogenic RNAs remains largely unknown. Here, we employ CRISPR screening on mitochondrial RNA (mtRNA)-binding proteins and identify NOP2/Sun RNA methyltransferase 4 (NSUN4) as a key regulator of mt-dsRNA expression in human cells. We find that NSUN4 induces 5-methylcytosine (m5C) modification on mtRNAs, especially on the termini of light-strand long noncoding RNAs. These m5C-modified RNAs are recognized by complement C1q-binding protein (C1QBP), which recruits polyribonucleotide nucleotidyltransferase to facilitate RNA turnover. Suppression of NSUN4 or C1QBP results in increased mt-dsRNA expression, while C1QBP deficiency also leads to increased cytosolic mt-dsRNAs and subsequent immune activation. Collectively, our study unveils the mechanism underlying the selective degradation of light-strand mtRNAs and establishes a molecular mark for mtRNA decay and cytosolic release.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
ARN Bicatenario
/
Estabilidad del ARN
/
Citosol
/
5-Metilcitosina
/
ARN Mitocondrial
/
Mitocondrias
Límite:
Animals
/
Humans
Idioma:
En
Año:
2024
Tipo del documento:
Article