title: Mitochondrial cytochrome c oxidase subunit IV is phosphorylated by an endogenous kinase.
abstract: 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.
authors.affiliation: Department of Biochemistry, McGill University, Montreal, Que., Canada.
authors.forename: N A
authors.initials: NA
authors.lastname: Steenaart
authors.forename: G C
authors.initials: GC
authors.lastname: Shore
mesh_terms: 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
chemical_list: D010761:Phosphorus Radioisotopes; D000255:Adenosine Triphosphate; D003576:Electron Transport Complex IV; D011494:Protein Kinases