Swi/SNF-GCN5-dependent chromatin remodelling determines induced expression of GDH3, one of the paralogous genes responsible for ammonium assimilation and glutamate biosynthesis in Saccharomyces cerevisiae.
It is accepted that Saccharomyces cerevisiae genome arose from complete duplication of eight ancestral chromosomes; functionally normal ploidy was recovered because of the massive loss of 90% of duplicated genes. There is evidence that indicates that part of this selective conservation of gene pairs is compelling to yeast facultative metabolism. As an example, the duplicated NADP-glutamate dehydrogenase pathway has been maintained because of the differential expression of the paralogous GDH1 and GDH3 genes, and the biochemical specialization of the enzymes they encode. The present work has been aimed to the understanding of the regulatory mechanisms that modulate GDH3 transcriptional activation. Our results show that GDH3 expression is repressed in glucose-grown cultures, as opposed to what has been observed for GDH1, and induced under respiratory conditions, or under stationary phase. Although GDH3 pertains to the nitrogen metabolic network, and its expression is Gln3p-regulated, complete derepression is ultimately determined by the carbon source through the action of the SAGA and SWI/SNF chromatin remodelling complexes. GDH3 carbon-mediated regulation is over-imposed to that exerted by the nitrogen source, highlighting the fact that operation of facultative metabolism requires strict control of enzymes, like Gdh3p, involved in biosynthetic pathways that use tricarboxylic acid cycle intermediates.
Avendaño
Amaranta
A
Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 Mexico City, México.
Riego
Lina
L
DeLuna
Alexander
A
Aranda
Cristina
C
Romero
Guillermo
G
Ishida
Cecilia
C
Vázquez-Acevedo
Miriam
M
Rodarte
Beatriz
B
Recillas-Targa
Félix
F
Valenzuela
Lourdes
L
Zonszein
Sergio
S
González
Alicia
A
D000251:Adenosine Triphosphatases; D001483:Base Sequence; D042002:Chromatin Assembly and Disassembly / Q000235:genetics*; D003470:Culture Media; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005947:Glucose / Q000378:metabolism; D018086:Glutamate Dehydrogenase (NADP+) / Q000235:genetics* / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism*; D051548:Histone Acetyltransferases; D008969:Molecular Sequence Data; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D000099224:p300-CBP-Associated Factor
D000251:Adenosine Triphosphatases; D003470:Culture Media; D004268:DNA-Binding Proteins; D000431:Ethanol; D005656:Fungal Proteins; D005947:Glucose; D018086:Glutamate Dehydrogenase (NADP+); D018698:Glutamic Acid; D051548:Histone Acetyltransferases; D011494:Protein Kinases; D000644:Quaternary Ammonium Compounds; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C090575:ADA2 protein, S cerevisiae; C071664:GLN3 protein, S cerevisiae; C118425:SAGA protein, Emericella nidulans; C501392:GCN5 protein, S cerevisiae; D000099224:p300-CBP-Associated Factor; C499333:SNF2 protein, S cerevisiae