Analysis of gene induction and arrest site transcription in yeast with mutations in the transcription elongation machinery.
J Biol Chem
; 276(15): 11531-8, 2001 Apr 13.
Article
em En
| MEDLINE
| ID: mdl-11278887
ABSTRACT
In vitro, transcript elongation by RNA polymerase II is impeded by DNA sequences, DNA-bound proteins, and small ligands. Transcription elongation factor SII (TFIIS) assists RNA polymerase II to transcribe through these obstacles. There is however, little direct evidence that SII-responsive arrest sites function in living cells nor that SII facilitates readthrough in vivo. Saccharomyces cerevisiae strains lacking elongation factor SII and/or containing a point mutation in the second largest subunit of RNA polymerase II, which slows the enzyme's RNA elongation rate, grow slowly and have defects in mRNA metabolism, particularly in the presence of nucleotide-depleting drugs. Here we have examined transcriptional induction in strains lacking SII or containing the slow polymerase mutation. Both mutants and a combined double mutant were defective in induction of GAL1 and ENA1. This was not due to an increase in mRNA degradation and was independent of any drug treatment, although treatment with the nucleotide-depleting drug 6-azauracil exacerbated the effect preferentially in the mutants. These data are consistent with mutants in the Elongator complex, which show slow inductive responses. When a potent in vitro arrest site was transcribed in these strains, there was no perceptible effect upon mRNA accumulation. These data suggest that an alternative elongation surveillance mechanism exists in vivo to overcome arrest.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
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Transcrição Gênica
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RNA Polimerase II
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Proteínas de Transporte de Cátions
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Proteínas de Saccharomyces cerevisiae
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Mutação
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Estados Unidos