title: Relationship between cytoplasmic and mitochondrial apparatus of protein synthesis in yeast Saccharomyces cerevisiae.
abstract: A conditional respiratory deficiency in yeast Saccharomyces cerevisiae is expressed as a result of a nuclear mutation in sup1 and sup2 genes (II and IV chromosomes, respectively), coding for a component of cytoplasmic ribosomes (Ter-Avanesyan et al. 1982). One such strain is studied here in detail. The strain is temperature-dependent and expresses a respiratory deficient phenotype at 20 degrees C but not at 30 degrees C. Moreover, the strain is simultaneously chloramphenicol-dependent and is able to grow on media containing glycerol or ethanol as a sole carbon source only in the presence of the drug. Chloramphenicol has a differential effect on protein synthesis in mitochondria of the parent strain and the mutant. Since chloramphenicol is a ribosome-targeting antibiotic we suggest that the differential effect of the drug on parent and mutant mitochondrial protein synthesis is due to the altered properties of mito-ribosomes of the mutant compared to those of the parent strain. Mitochondria of the mutant synthesize all the mitochondrially encoded polypeptides, however, in significantly lowered amounts. A suggestion is put forward for the existence of a common component (a ribosomal protein) for mito and cyto-ribosomes.
mesh_terms: D002701:Chloramphenicol / Q000494:pharmacology; D003593:Cytoplasm / Q000378:metabolism; D005656:Fungal Proteins / Q000096:biosynthesis*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009154:Mutation; D014176:Protein Biosynthesis; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D002701:Chloramphenicol