Pentatricopeptide repeat poly(A) binding protein KPAF4 stabilizes mitochondrial mRNAs in Trypanosoma brucei.
Nat Commun
; 10(1): 146, 2019 01 11.
Article
en En
| MEDLINE
| ID: mdl-30635574
ABSTRACT
In Trypanosoma brucei, most mitochondrial mRNAs undergo editing, and 3' adenylation and uridylation. The internal sequence changes and terminal extensions are coordinated pre-editing addition of the short (A) tail protects the edited transcript against 3'-5' degradation, while post-editing A/U-tailing renders mRNA competent for translation. Participation of a poly(A) binding protein (PABP) in coupling of editing and 3' modification processes has been inferred, but its identity and mechanism of action remained elusive. We report identification of KPAF4, a pentatricopeptide repeat-containing PABP which sequesters the A-tail and impedes mRNA degradation. Conversely, KPAF4 inhibits uridylation of A-tailed transcripts and, therefore, premature A/U-tailing of partially-edited mRNAs. This quality check point likely prevents translation of incompletely edited mRNAs. We also find that RNA editing substrate binding complex (RESC) mediates the interaction between the 5' end-bound pyrophosphohydrolase MERS1 and 3' end-associated KPAF4 to enable mRNA circularization. This event appears to be critical for edited mRNA stability.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Trypanosoma brucei brucei
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ARN Mensajero
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ARN Protozoario
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Edición de ARN
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Estabilidad del ARN
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Proteínas de Unión a Poli(A)
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ARN Mitocondrial
Idioma:
En
Revista:
Nat Commun
Asunto de la revista:
BIOLOGIA
/
CIENCIA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Estados Unidos