Mitochondrial cytochrome c oxidase subunit IV is phosphorylated by an endogenous kinase.
This study was undertaken to identify novel mitochondrial membrane proteins that are potential targets for phosphorylation. Mitochondrial membranes were incubated in the presence of [gamma-32P]ATP and the Triton X-114 extractable protein was subjected to ion-exchange and polyacrylamide gel chromatography to purify a major phosphorylated protein of approximately 17000 Da. The determined peptide sequence of the purified phosphoprotein corresponded to a segment of cytochrome c oxidase subunit IV, an inner membrane protein of 17160 Da. The identity of the phosphoprotein was confirmed by two-dimensional electrophoresis and Western blotting. The results identify mitochondrial cytochrome c oxidase subunit IV as a protein which is phosphorylated by an endogenous kinase.
Steenaart
N A
NA
Department of Biochemistry, McGill University, Montreal, Que., Canada.
Shore
G C
GC
D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002852:Chromatography, Ion Exchange; D004285:Dogs; D003576:Electron Transport Complex IV / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D007425:Intracellular Membranes / Q000201:enzymology; D008861:Microsomes / Q000201:enzymology; D008929:Mitochondria, Heart / Q000201:enzymology*; D008930:Mitochondria, Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D010179:Pancreas / Q000201:enzymology; D010761:Phosphorus Radioisotopes / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017386:Sequence Homology, Amino Acid
D010761:Phosphorus Radioisotopes; D000255:Adenosine Triphosphate; D003576:Electron Transport Complex IV; D011494:Protein Kinases