title: Effect of mitochondrial cytochromes and haem content on cytochrome P450 in Saccharomyces cerevisiae.
abstract: It is well established that the mitochondrial and the microsomal cytochromes in Saccharomyces cerevisiae are regulated differently. Mutations affecting the mitochondrial cytochromes aa3 or c had no effect on the concentration of the microsomal cytochrome P450 even during haem limitation. Moreover, a defect in the cytochrome P450 gene did not affect mitochondrial cytochromes. However, a regulatory mutation present in strain SG1 decreased both mitochondrial and microsomal cytochrome contents. This mutation also affected the intracellular haem concentration. The haem precursor 5-aminolaevulinate increased both mitochondrial and microsomal cytochrome contents. Our results indicate that carbon source and haem concentration are involved in the regulation of cytochrome P450.
mesh_terms: D000622:Aminolevulinic Acid / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D003580:Cytochromes / Q000378:metabolism*; D003576:Electron Transport Complex IV / Q000378:metabolism; D006418:Heme / Q000378:metabolism*; D008861:Microsomes / Q000032:analysis; D008928:Mitochondria / Q000032:analysis*; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*
chemical_list: D003580:Cytochromes; D006418:Heme; D000622:Aminolevulinic Acid; D003577:Cytochrome P-450 Enzyme System; D003576:Electron Transport Complex IV