The highly expressed methionine synthase gene of Neurospora crassa is positively regulated by its proximal heterochromatic region.
Nucleic Acids Res
; 42(10): 6183-95, 2014 Jun.
Article
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| MEDLINE
| ID: mdl-24711369
ABSTRACT
In Neurospora crassa, the methionine synthase gene met-8 plays a key role in methionine synthesis. In this study, we found that MET-8 protein levels were compromised in several mutants defective in proper heterochromatin formation. Bioinformatics analysis revealed a 50-kb AT-rich region adjacent to the met-8 promoter. ChIP assays confirmed that trimethylated H3K9 was enriched in this region, indicating that heterochromatin may form upstream of met-8. In an H3K9R mutant strain, the output of met-8 was dramatically reduced, similar to what we observed in mutant strains that had defective heterochromatin formation. Furthermore, the production of ectopically expressed met-8 at the his-3 locus in the absence of a normal heterochromatin environment was inefficient, whereas ectopic expression of met-8 downstream of two other heterochromatin domains was efficient. In addition, our data show that the expression of mig-6 was also controlled by an upstream 4.2-kb AT-rich region similar to that of the met-8 gene, and we demonstrate that the AT-rich regions adjacent to met-8 or mig-6 are required for their peak expression. Our study indicates that met-8 and mig-6 may represent a novel type of gene, whose expression relies on the proper formation of a nearby heterochromatin region.
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MEDLINE
Asunto principal:
5-Metiltetrahidrofolato-Homocisteína S-Metiltransferasa
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Proteínas Fúngicas
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Heterocromatina
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Regulación Fúngica de la Expresión Génica
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Neurospora crassa
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En
Revista:
Nucleic Acids Res
Año:
2014
Tipo del documento:
Article