Eukaryotes utilize fatty acids by b-oxidation, which occurs in the mitochondria and peroxisomes in higher organisms and in the peroxisomes in yeast. The AMP-activated protein kinase regulates this process in mammalian cells, and its homolog Snf1, together with the transcription factors Adr1, Oaf1 and Pip2, regulates peroxisome proliferation and b-oxidation in yeast. A constitutive allele of Adr1 (Adr1c) lacking the glucose- and Snf1-regulated phosphorylation substrate Ser230 was found to be Snf1-independent for regulation of peroxisomal genes. In addition, it could compensate for, and even suppress the requirement for Oaf1 or Pip2 for gene induction. Peroxisomal genes were found to be regulated by oleate in the presence of glucose, as long as Adr1c was expressed, suggesting that the Oaf1/Pip2 heterodimer is Snf1-independent. Consistent with this observation, Oaf1 binding to promoters in the presence of oleate was not reduced in a snf1 strain. Exploring the mechanism by which Adr1c permits Snf1-independent peroxisomal gene induction, we found that strength of promoter binding did not correlate with transcription, suggesting that stable binding is not a prerequisite for enhanced transcription. Instead, enhanced transcriptional activation, and suppression of Oaf1, Pip2 and Snf1 by Adr1c may be related to the ability of Adr1c to suppress the requirement for, and enhance the recruitment of transcriptional coactivators in a promoter- and growth-medium-dependent manner.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Annotation Extension||Reference|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Assay||Construct||Conditions||Strain Background||Reference|