Association of cytochrome b translational activator proteins with the mitochondrial membrane: implications for cytochrome b expression in yeast.
The products of the nuclear genes CBS1 and CBS2 are both required for translational activation of mitochondrial apocytochrome b in yeast. We report the intramitochondrial localization of both proteins by use of specific antisera. Based on its solubilization properties the CBS1 protein is presumed to be a component of the mitochondrial membrane; the detergent concentrations needed to release CBS1 from mitochondria are almost the same as for cytochrome c1. In contrast, CBS2 behaves like a soluble protein, with some characteristics of a membrane-associated protein. A model is presented for translational activation of cytochrome b, which might also be applicable to translational regulation of other mitochondrial genes.
Michaelis
U
U
Lehrstuhl Genetik, Universität München, FRG.
Körte
A
A
Rödel
G
G
D001059:Apoproteins / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D002458:Cell Fractionation; D002846:Chromatography, Affinity; D003573:Cytochrome b Group / Q000235:genetics* / Q000378:metabolism; D045303:Cytochromes b; D003902:Detergents; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000032:analysis*; D015870:Gene Expression; D005800:Genes, Fungal; D007425:Intracellular Membranes / Q000737:chemistry; D008565:Membrane Proteins / Q000032:analysis*; D008928:Mitochondria / Q000737:chemistry*; D024101:Mitochondrial Proteins; D009994:Osmolar Concentration; D014176:Protein Biosynthesis; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators / Q000032:analysis*
D001059:Apoproteins; C060724:CBS1 protein, S cerevisiae; D003573:Cytochrome b Group; D003902:Detergents; D005656:Fungal Proteins; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D045303:Cytochromes b