The critical cis-acting element required for IMD2 feedback regulation by GDP is a TATA box located 202 nucleotides upstream of the transcription start site.
Guanylic nucleotides are essential cellular players, and the critical enzyme in their tightly regulated synthesis in Saccharomyces cerevisiae is encoded by the IMD2 gene. The transcription of IMD2 is subject to general repression by nutrient limitation through the cis nutrient-sensing element. It is also subject to specific feedback regulation by the end products of the guanylic nucleotide synthesis pathway. The critical cis element for this latter mechanism is the guanine response element (GRE), a TATAATA sequence which is located 202 nucleotides upstream of the transcription initiation site and which functions as the IMD2 TATA box. We show that the GRE functions in conjunction with a 52-nucleotide stretch near the transcription start site. This very unusual promoter structure ensures low, basal expression of IMD2 and the recruitment of TFIID to the GRE in response to guanylic nucleotide limitation.
Escobar-Henriques
Mafalda
M
Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, F-33077 Bordeaux Cedex, France.
Daignan-Fornier
Bertrand
B
Collart
Martine A
MA
D001483:Base Sequence; D025141:Drug Resistance, Fungal / Q000235:genetics; D025461:Feedback, Physiological / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D006147:Guanine / Q000378:metabolism; D006153:Guanosine Diphosphate / Q000378:metabolism*; D007168:IMP Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009173:Mycophenolic Acid / Q000494:pharmacology; D009711:Nucleotides / Q000235:genetics; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D020218:Response Elements / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D016385:TATA Box; D035362:Transcription Factor TFIID / Q000235:genetics / Q000378:metabolism; D024363:Transcription Initiation Site
D009711:Nucleotides; D029701:Saccharomyces cerevisiae Proteins; D035362:Transcription Factor TFIID; D006153:Guanosine Diphosphate; D006147:Guanine; C477283:IMD2 protein, S cerevisiae; D007168:IMP Dehydrogenase; D009173:Mycophenolic Acid