Met30p, a yeast transcriptional inhibitor that responds to S-adenosylmethionine, is an essential protein with WD40 repeats.
A specific repression mechanism regulates the biosynthesis of sulfur amino acids in Saccharomyces cerevisiae. When the intracellular S-adenosylmethionine (AdoMet) concentration increases, transcription of the sulfur genes is repressed. Using a specific reporter system, we have isolated mutations impairing the AdoMet-mediated transcriptional regulation of the sulfur network. These mutations identified a new gene, MET30, and were shown to also affect the regulation of the methyl cycle. The MET30 gene was isolated and sequenced. Sequence analysis reveals that Met30p contains five copies of the WD40 motif within its carboxy-terminal part, like the yeast transcriptional repressors Hir1p and Tup1p. We identified one target of Met30p as Met4p, a transcriptional activator regulating the sulfate assimilation pathway. By the two-hybrid method, we showed that Met30p interacts with Met4p and identified a region of Met4p involved in this interaction. Further analysis reveals that expression of Met30p is essential for cell viability.
Thomas
D
D
Centre de Génétique Moléculaire, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.
Kuras
L
L
Barbey
R
R
Cherest
H
H
Blaiseau
P L
PL
Surdin-Kerjan
Y
Y
D000595:Amino Acid Sequence; D001483:Base Sequence; D019757:Carbon-Oxygen Lyases; D003547:Cysteine Synthase; D044783:F-Box Proteins; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects*; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D005838:Genotype; D008190:Lyases / Q000378:metabolism; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes; D010088:Oxidoreductases / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D012097:Repressor Proteins / Q000096:biosynthesis* / Q000235:genetics; D015183:Restriction Mapping; D012436:S-Adenosylmethionine / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013430:Sulfate Adenylyltransferase / Q000378:metabolism; D043743:Ubiquitin-Protein Ligase Complexes
D044783:F-Box Proteins; C470285:MET30 protein, S cerevisiae; D009097:Multienzyme Complexes; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D012436:S-Adenosylmethionine; D010088:Oxidoreductases; C052449:3'-phosphoadenylyl-5'-phosphosulfate reductase; D043743:Ubiquitin-Protein Ligase Complexes; D003547:Cysteine Synthase; C103381:MET17 protein, S cerevisiae; C018725:O-acetylhomoserine (thiol)-lyase; D013430:Sulfate Adenylyltransferase; D008190:Lyases; D019757:Carbon-Oxygen Lyases