Sac3 is an mRNA export factor that localizes to cytoplasmic fibrils of nuclear pore complex.
Mol Biol Cell
; 14(3): 836-47, 2003 Mar.
Article
en En
| MEDLINE
| ID: mdl-12631707
In eukaryotes, mRNAs are transcribed in the nucleus and exported to the cytoplasm for translation to occur. Messenger RNAs complexed with proteins referred to as ribonucleoparticles are recognized for nuclear export in part by association with Mex67, a key Saccharomyces cerevisiae mRNA export factor and homolog of human TAP/NXF1. Mex67, along with its cofactor Mtr2, is thought to promote ribonucleoparticle translocation by interacting directly with components of the nuclear pore complex (NPC). Herein, we show that the nuclear pore-associated protein Sac3 functions in mRNA export. Using a mutant allele of MTR2 as a starting point, we have identified a mutation in SAC3 in a screen for synthetic lethal interactors. Loss of function of SAC3 causes a strong nuclear accumulation of mRNA and synthetic lethality with a number of mRNA export mutants. Furthermore, Sac3 can be coimmunoprecipitated with Mex67, Mtr2, and other factors involved in mRNA export. Immunoelectron microscopy analysis shows that Sac3 localizes exclusively to cytoplasmic fibrils of the NPC. Finally, Mex67 accumulates at the nuclear rim when SAC3 is mutated, suggesting that Sac3 functions in Mex67 translocation through the NPC.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Citoesqueleto
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ARN Mensajero
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Proteínas Nucleares
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Poro Nuclear
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Proteínas de Saccharomyces cerevisiae
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Mol Biol Cell
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2003
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos