Met31p and Met32p, two related zinc finger proteins, are involved in transcriptional regulation of yeast sulfur amino acid metabolism.
AUTOR(ES)
Blaiseau, P L
RESUMO
Sulfur amino acid metabolism in Saccharomyces cerevisiae is regulated by the level of intracellular S-adenosylmethionine (AdoMet). Two cis-acting elements have been previously identified within the 5' upstream regions of the structural genes of the sulfur network. The first contains the CACGTG motif and is the target of the transcription activation complex Cbflp-Met4p-Met28p. We report here the identification of two new factors, Met31p and Met32p, that recognize the second cis-acting element. Met31p was isolated through the use of the one-hybrid method, while Met32p was identified during the analysis of the yeast methionine transport system. Met31p and Met32p are highly related zinc finger-containing proteins. Both LexA-Met31p and LexA-Met32p fusion proteins activate the transcription of a LexAop-containing promoter in a Met4p-dependent manner. Northern blot analyses of cells that do not express either Met31p and/or Met32p suggest that the function of the two proteins during the transcriptional regulation of the sulfur network varies from one gene to the other. While the expression of both the MET3 and MET14 genes was shown to strictly depend upon the presence of either Met31p or Met32p, the transcription of the MET25 gene is constitutive in cells lacking both Met31p and Met32p. These results therefore emphasise the diversity of the mechanisms allowing regulation of the expression of the methionine biosynthetic genes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=232216Documentos Relacionados
- Two GTPase isoforms, Ypt31p and Ypt32p, are essential for Golgi function in yeast.
- A heteromeric complex containing the centromere binding factor 1 and two basic leucine zipper factors, Met4 and Met28, mediates the transcription activation of yeast sulfur metabolism.
- Regulation of the metC-cysK Operon, Involved in Sulfur Metabolism in Lactococcus lactis
- Variations of the C2H2 zinc finger motif in the yeast genome and classification of yeast zinc finger proteins.
- Sumoylation of heterogeneous nuclear ribonucleoproteins, zinc finger proteins, and nuclear pore complex proteins: A proteomic analysis