Splicing regulation at the second catalytic step by Sex-lethal involves 3' splice site recognition by SPF45.
Cell
; 109(3): 285-96, 2002 May 03.
Article
en En
| MEDLINE
| ID: mdl-12015979
ABSTRACT
The Drosophila protein Sex-lethal (SXL) promotes skipping of exon 3 from its own pre-mRNA. An unusual sequence arrangement of two AG dinucleotides and an intervening polypyrimidine (Py)-tract at the 3' end of intron 2 is important for Sxl autoregulation. Here we show that U2AF interacts with the Py-tract and downstream AG, whereas the spliceosomal protein SPF45 interacts with the upstream AG and activates it for the second catalytic step of the splicing reaction. SPF45 represents a new class of second step factors, and its interaction with SXL blocks splicing at the second step. These results are in contrast with other known mechanisms of splicing regulation, which target early events of spliceosome assembly. A similar role for SPF45 is demonstrated in the activation of a cryptic 3' ss generated by a mutation that causes human beta-thalassemia.
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Bases de datos:
MEDLINE
Asunto principal:
Ribonucleoproteínas
/
Proteínas Nucleares
/
Proteínas de Unión al ARN
/
Empalme Alternativo
/
Sitios de Empalme de ARN
/
Proteínas de Drosophila
/
Hormonas de Insectos
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Cell
Año:
2002
Tipo del documento:
Article
País de afiliación:
Alemania