A multiprotein complex mediates the ATP-dependent assembly of spliceosomal U snRNPs.
Nat Cell Biol
; 3(11): 945-9, 2001 Nov.
Article
en En
| MEDLINE
| ID: mdl-11715014
ABSTRACT
The spliceosomal snRNPs U1, U2, U4 and U5 contain a common RNP structure termed the Sm core that is formed by the binding of Sm proteins onto the U snRNA. Although isolated Sm proteins assemble spontaneously onto U snRNAs in vitro, there is increasing evidence that SMN and its interactor Gemin2 are involved in this process in vivo. Here, we describe a cell-free assay system for the assembly of U snRNPs that closely reproduces in vivo conditions. Using this system, we show that assembly of U1 snRNP depends on ATP. Immunodepletion of SMN-Gemin2 from the extract abolished assembly even though the extract contained high levels of Sm proteins. An affinity-purified macromolecular SMN complex consisting of 16 components including all Sm proteins restored assembly in the immunodepleted extract. These data provide the first direct evidence that a complex containing SMN and Gemin2 mediates the active assembly of spliceosomal U snRNPs.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Autoantígenos
/
Adenosina Trifosfato
/
Empalmosomas
/
Ribonucleoproteína Nuclear Pequeña U1
/
Ribonucleoproteínas Nucleares Pequeñas
/
Proteínas del Tejido Nervioso
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Nat Cell Biol
Año:
2001
Tipo del documento:
Article
País de afiliación:
Alemania