Effect of enzymatic methylation of apocytochrome c on holocytochrome c formation and proteolysis.
1. Methylation of the lysine at residue 72 of yeast apocytochrome c increases its import into mitochondria. 2. Using methylated and unmethylated apocytochrome c as substrate and intact yeast mitochondria and a solubilized mitochondrial fraction as a source of cytochrome c heme lyase, the results show that the methylation state of the apoprotein has no significant effect on its conversion to holoprotein. 3. The above result suggests that the import mechanism is separate from the heme-attaching activity. 4. Unmethylated apocytochrome c was less resistant to a yeast homogenate fraction that methylated apocytochrome c, suggesting that methylation of apocytochrome c alters the conformation of the whole protein.
Frost
B
B
Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA 19140.
Park
K S
KS
Kim
S
S
Paik
W K
WK
D001059:Apoproteins / Q000096:biosynthesis / Q000378:metabolism*; D003574:Cytochrome c Group / Q000096:biosynthesis* / Q000378:metabolism*; D045304:Cytochromes c; D004591:Electrophoresis, Polyacrylamide Gel; D011495:Histone-Lysine N-Methyltransferase / Q000378:metabolism*; D007525:Isoelectric Focusing; D008190:Lyases / Q000378:metabolism; D008745:Methylation; D008928:Mitochondria / Q000201:enzymology; D011496:Protein Methyltransferases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology
D001059:Apoproteins; D003574:Cytochrome c Group; D045304:Cytochromes c; D011496:Protein Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; D008190:Lyases; C031581:cytochrome C synthetase