Nuclear retention prevents premature cytoplasmic appearance of mRNA.
Mol Cell
; 48(1): 145-52, 2012 Oct 12.
Article
en En
| MEDLINE
| ID: mdl-22921936
ABSTRACT
In S. cerevisiae cells debilitated in mRNA nuclear export, transcripts are retained in nuclear foci ("dots"). The ultimate fate of dot-mRNA has remained elusive. Here, we use single molecule counting microscopy and (35)S-methionine pulse-labeling assays to quantify cytoplasmic HSP104 RNA levels and estimate HSP104 RNA translation status. HSP104 transcripts, retained in dots as a consequence of the mex67-5 mutation, are slowly released over time for cytoplasmic translation. Thus, dot-mRNA retains function. However, forcing its nuclear export, by overexpressing the Sub2p mRNA export factor, does not elevate Hsp104p protein levels but is instead paralleled by growth deficiency. Nuclear export and growth phenotypes are both counteracted by coexpressing the nuclear RNA quality control factor Rrp6p. Thus, prematurely released dot-mRNA is translationally inactive and possibly toxic. Accordingly, nuclear retention of mRNA may serve a precautionary role during stressful situations such as, e.g., decreased mRNA maturation competence.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Saccharomyces cerevisiae
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ARN de Hongos
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ARN Mensajero
Idioma:
En
Revista:
Mol Cell
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2012
Tipo del documento:
Article
País de afiliación:
Dinamarca