The splicing regulators RBM5 and RBM10 are subunits of the U2 snRNP engaged with intron branch sites on chromatin.
Mol Cell
; 84(8): 1496-1511.e7, 2024 Apr 18.
Article
em En
| MEDLINE
| ID: mdl-38537639
ABSTRACT
Understanding the mechanisms of pre-mRNA splicing is limited by the technical challenges to examining spliceosomes in vivo. Here, we report the isolation of RNP complexes derived from precatalytic A or B-like spliceosomes solubilized from the chromatin pellet of mammalian cell nuclei. We found that these complexes contain U2 snRNP proteins and a portion of the U2 snRNA bound with protected RNA fragments that precisely map to intronic branch sites across the transcriptome. These U2 complexes also contained the splicing regulators RBM5 and RBM10. We found RBM5 and RBM10 bound to nearly all branch site complexes and not simply those at regulated exons. The deletion of a conserved RBM5/RBM10 peptide sequence, including a zinc finger motif, disrupted U2 interaction and rendered the proteins inactive for the repression of many alternative exons. We propose a model where RBM5 and RBM10 regulate splicing as components of the U2 snRNP complex following branch site base pairing.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Spliceossomos
/
Ribonucleoproteína Nuclear Pequena U2
Limite:
Animals
Idioma:
En
Revista:
Mol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2024
Tipo de documento:
Article