Cap-assisted internal initiation of translation of histone H4.
Mol Cell
; 41(2): 197-209, 2011 Jan 21.
Article
em En
| MEDLINE
| ID: mdl-21255730
ABSTRACT
In eukaryotes, a crucial step of translation initiation is the binding of the multifactor complex eIF4F to the 5' end of the mRNA, a prerequisite to recruitment of the activated small ribosomal 43S particle. Histone H4 mRNAs have short 5'UTRs, which do not conform to the conventional scanning-initiation model. Here we show that the ORF of histone mRNA contains two structural elements critical for translation initiation. One of the two structures binds eIF4E without the need of the cap. Ribosomal 43S particles become tethered to this site and directly loaded in the vicinity of the AUG. The other structure, 19 nucleotides downstream of the initiation codon, forms a three-way helix junction, which sequesters the m(7)G cap. This element facilitates direct positioning of the ribosome on the cognate start codon. This unusual translation initiation mode might be considered as a hybrid mechanism between the canonical and the IRES-driven translation initiation process.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Iniciação Traducional da Cadeia Peptídica
/
Capuzes de RNA
/
Histonas
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Mol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
França