title: Further investigations regarding the role of trimethyllysine for cytochrome c uptake into mitochondria.
abstract: 1. A mutant of the iso-1-cytochrome c gene from Saccharomyces cerevisiae has been constructed which contains an Arg codon, replacing the normal trimethylated Lys at position 77. 2. This mutated gene was cloned into a pGem 1 vector and used for the in vitro translation of yeast iso-1-cytochrome c. 3. Utilizing an in vitro mitochondria binding assay, it was found that the mutant cytochrome c could transverse the yeast mitochondrial membrane, however the amount of protein incorporated was 3-fold less that of the trimethylated wild type. 4. Omission of the protein methyltransferase from assays containing the wild type cytochrome c caused only a slight reduction (15%) in the amount of protein incorporated. 5. These results suggest while the lysine residue 77 of apocytochrome c is important for mitochondria uptake, the methylation of this residue seems to play a relatively minor role.
authors.affiliation: Department of Chemistry, Ohio University, Athens 45701.
authors.forename: K J
authors.initials: KJ
authors.lastname: Cessay
authors.forename: L W
authors.initials: LW
authors.lastname: Bergman
authors.forename: M T
authors.initials: MT
authors.lastname: Tuck
mesh_terms: D000818:Animals; D001120:Arginine; D001483:Base Sequence; D003001:Cloning, Molecular; D003062:Codon; D003574:Cytochrome c Group / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D045304:Cytochromes c; D008239:Lysine / Q000031:analogs & derivatives*; D008745:Methylation; D008928:Mitochondria / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D051381:Rats; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins; D013329:Structure-Activity Relationship; D014158:Transcription, Genetic
chemical_list: C014059:CYC1 protein, S cerevisiae; D003062:Codon; D003574:Cytochrome c Group; D029701:Saccharomyces cerevisiae Proteins; C003712:trimethyllysine; D045304:Cytochromes c; D001120:Arginine; D008239:Lysine