The yeast splicing factor Prp40p contains functional leucine-rich nuclear export signals that are essential for splicing.
Genetics
; 166(1): 53-65, 2004 Jan.
Article
en En
| MEDLINE
| ID: mdl-15020406
ABSTRACT
To investigate the function of the essential U1 snRNP protein Prp40p, we performed a synthetic lethal screen in Saccharomyces cerevisiae. Using an allele of PRP40 that deletes 47 internal residues and causes only a slight growth defect, we identified aphenotypic mutations in three distinct complementation groups that conferred synthetic lethality. The synthetic phenotypes caused by these mutations were suppressed by wild-type copies of CRM1 (XPO1), YNL187w, and SME1, respectively. The strains whose synthetic phenotypes were suppressed by CRM1 contained no mutations in the CRM1 coding sequence or promoter. This indicates that overexpression of CRM1 confers dosage suppression of the synthetic lethality. Interestingly, PRP40 and YNL187w encode proteins with putative leucine-rich nuclear export signal (NES) sequences that fit the consensus sequence recognized by Crm1p. One of Prp40p's two NESs lies within the internal deletion. We demonstrate here that the NES sequences of Prp40p are functional for nuclear export in a leptomycin B-sensitive manner. Furthermore, mutation of these NES sequences confers temperature-sensitive growth and a pre-mRNA splicing defect. Although we do not expect that yeast snRNPs undergo compartmentalized biogenesis like their metazoan counterparts, our results suggest that Prp40p and Ynl187wp contain redundant NESs that aid in an important, Crm1p-mediated nuclear export event.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Saccharomyces cerevisiae
/
Ribonucleoproteína Nuclear Pequeña U1
/
Proteínas de Saccharomyces cerevisiae
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Genetics
Año:
2004
Tipo del documento:
Article
País de afiliación:
Estados Unidos