The vacuolar compartment is required for sulfur amino acid homeostasis inSaccharomyces cerevisiae
- Cite this article as:
- Jacquemin-Faure, I., Thomas, D., Laporte, J. et al. Molec. Gen. Genet. (1994) 244: 519. doi:10.1007/BF00583903
In order to isolate new mutations impairing transcriptional regulation of sulfur metabolism inSaccharomyces cerevisiae, we used a potent genetic screen based on a gene fusion expressing XylE (fromPseudomonas putida) under the control of the promoter region ofMET25. This selection yielded strains mutated in various different genes. We describe in this paper the properties of one of them,MET27. Mutation or disruption ofMET27 leads to a methionine requirement and affects S-adenosylmethionine (AdoMet)-mediated transcriptional control of genes involved in sulfur metabolism. The cloning and sequencing ofMET27 showed that it is identical toVPS33. Disruptions or mutations of geneVPS33 are well known to impair the biogenesis and inheritance of the vacuolar compartment. However, the methionine requirement ofvps33 mutants has not been reported previously. We show here, moreover, that other vps mutants of class C (no apparent vacuoles) also require methionine for growth. Northern blotting experiments revealed that themet27-1 mutation delayed derepression of the transcription of genes involved in sulfur metabolism. By contrast, this delay was not observed in amet27 disrupted strain. Physiological and morphological analyses ofmet27-1 andmet27 disrupted strains showed that these results could be explained by alterations in the ability of the vacuole to transport or store AdoMet, the physiological effector of the transcriptional regulation of sulfur metabolism.