CYP3–15: An up-promoter mutation at the ISO-2 cytochrome c structural gene locus and its interaction with other independent regulatory mutations of cytochrome c synthesis in Saccharomyces cerevisiae

Abstract

The occurrence of “up promoter” mutations appears to be a general feature of eukaryotic gene regulation. Such mutations have been described in organisms as different as Yeast, Aspergillus, and Drosophila (Douglas and Hawthorne, 1966; Arst and Scazzochio, 1975; Hynes, 1975; Ciriacy, 1976; Chovnick et al., 1976), yet little is known about the underlying regulatory mechanisms. Some years ago, Clavilier et al. (Clavilier et al., 1969) discovered in S. cerevisiae regulatory mutations enhancing the synthesis of iso-2 cytochrome c. One of these mutations was found to entail a secondary phenotype prohibiting growth on a glucose medium containing high levels of chloramphenicol (Pere-Aubert, 1970). In this paper evidence is presented that: