Gemin5 delivers snRNA precursors to the SMN complex for snRNP biogenesis.
Mol Cell
; 38(4): 551-62, 2010 May 28.
Article
en En
| MEDLINE
| ID: mdl-20513430
ABSTRACT
The SMN complex assembles Sm cores on snRNAs, a key step in the biogenesis of snRNPs, the spliceosome's major components. Here, using SMN complex inhibitors identified by high-throughput screening and a ribo-proteomic strategy on formaldehyde crosslinked RNPs, we dissected this pathway in cells. We show that protein synthesis inhibition impairs the SMN complex, revealing discrete SMN and Gemin subunits and accumulating an snRNA precursor (pre-snRNA)-Gemin5 intermediate. By high-throughput sequencing of this transient intermediate's RNAs, we discovered the previously undetectable precursors of all the snRNAs and identified their Gemin5-binding sites. We demonstrate that pre-snRNA 3' sequences function to enhance snRNP biogenesis. The SMN complex is also inhibited by oxidation, and we show that it stalls an inventory-complete SMN complex containing pre-snRNAs. We propose a stepwise pathway of SMN complex formation and snRNP biogenesis, highlighting Gemin5's function in delivering pre-snRNAs as substrates for Sm core assembly and processing.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
ARN Nuclear Pequeño
/
Ribonucleoproteínas Nucleares Pequeñas
/
Proteínas del Complejo SMN
/
Precursores de Ácido Nucleico
Límite:
Humans
Idioma:
En
Revista:
Mol Cell
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2010
Tipo del documento:
Article
País de afiliación:
Estados Unidos