Pentatricopeptide repeat proteins stimulate mRNA adenylation/uridylation to activate mitochondrial translation in trypanosomes.
Mol Cell
; 42(1): 106-17, 2011 Apr 08.
Article
en En
| MEDLINE
| ID: mdl-21474072
ABSTRACT
The majority of trypanosomal mitochondrial pre-mRNAs undergo massive uridine insertion/deletion editing, which creates open reading frames. Although the pre-editing addition of short 3' A tails is known to stabilize transcripts during and after the editing, the processing event committing the fully edited mRNAs to translation remained unknown. Here, we show that a heterodimer of pentatricopeptide repeat-containing (PPR) proteins, termed kinetoplast polyadenylation/uridylation factors (KPAFs) 1 and 2, induces the postediting addition of A/U heteropolymers by KPAP1 poly(A) polymerase and RET1 terminal uridyltransferase. Edited transcripts bearing 200- to 300-nucleotide-long A/U tails, but not short A tails, were enriched in translating ribosomal complexes and affinity-purified ribosomal particles. KPAF1 repression led to a selective loss of A/U-tailed mRNAs and concomitant inhibition of protein synthesis. These results establish A/U extensions as the defining cis-elements of translation-competent mRNAs. Furthermore, we demonstrate that A/U-tailed mRNA preferentially interacts with the small ribosomal subunit, whereas edited substrates and complexes bind to the large subunit.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Trypanosoma brucei brucei
/
ARN Mensajero
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ARN Protozoario
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Mitocondrias
Idioma:
En
Revista:
Mol Cell
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2011
Tipo del documento:
Article
País de afiliación:
Estados Unidos