mRNAs containing the histone 3' stem-loop are degraded primarily by decapping mediated by oligouridylation of the 3' end.
RNA
; 19(1): 1-16, 2013 Jan.
Article
en En
| MEDLINE
| ID: mdl-23188809
ABSTRACT
Metazoan replication-dependent histone mRNAs are only present in S-phase, due partly to changes in their stability. These mRNAs end in a unique stem-loop (SL) that is required for both translation and cell-cycle regulation. Previous studies showed that histone mRNA degradation occurs through both 5'â3' and 3'â5' processes, but the relative contributions are not known. The 3' end of histone mRNA is oligouridylated during its degradation, although it is not known whether this is an essential step. We introduced firefly luciferase reporter mRNAs containing the histone 3' UTR SL (Luc-SL) and either a normal or hDcp2-resistant cap into S-phase HeLa cells. Both mRNAs were translated, and translation initially protected the mRNAs from degradation, but there was a lag of â¼40 min with the uncleavable cap compared to â¼8 min for the normal cap before rapid decay. Knockdown of hDcp2 resulted in a similar longer lag for Luc-SL containing a normal cap, indicating that 5'â3' decay is important in this system. Inhibition of DNA replication with hydroxyurea accelerated the degradation of Luc-SL. Knockdown of terminal uridyltransferase (TUTase) 4 but not TUTase 3 slowed the decay process, but TUTase 4 knockdown had no effect on destabilization of the mRNA by hydroxyurea. Both Luc-SL and its 5' decay intermediates were oligouridylated. Preventing oligouridylation by 3'-deoxyadenosine (cordycepin) addition to the mRNA slowed degradation, in the presence or absence of hydroxyurea, suggesting oligouridylation initiates degradation. The spectrum of oligouridylated fragments suggests the 3'â5' degradation machinery stalls during initial degradation, whereupon reuridylation occurs.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Oligorribonucleótidos
/
Nucleótidos de Uracilo
/
ARN Mensajero
/
Estabilidad del ARN
Límite:
Humans
Idioma:
En
Revista:
RNA
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2013
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
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US
/
USA