The allosteric ATP‐inhibition of cytochrome c oxidase activity is reversibly switched on by cAMP‐dependent phosphorylation

FEBS Letters

Bender, Elisabeth¹  Kadenbach, Bernhard¹ 

[1] Fachbereich Chemie, Philipps-Universität, D-35032 Marburg, Germany

关键词: Cytochrome c oxidase;    cAMP-dependent phosphorylation;    Respiratory control;    Allosteric effector;    Protein kinase A;    Ca2+-activated protein phosphatase;    PEP;    phosphoenolpyruvate;    PK;    pyruvate kinase;    PKA;    protein kinase A;    PP1;    protein phosphatase 1;    SDS–PAGE;    sodium dodecylsulfate polyacrylamide gel electrophoresis;   

DOI  :  10.1016/S0014-5793(99)01773-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In previous studies the allosteric inhibition of cytochrome c oxidase at high intramitochondrial ATP/ADP-ratios via binding of the nucleotides to the matrix domain of subunit IV was demonstrated. Here we show that the allosteric ATP-inhibition of the isolated bovine heart enzyme is switched on by cAMP-dependent phosphorylation with protein kinase A of subunits II (and/or III) and Vb, and switched off by subsequent incubation with protein phosphatase 1. It is suggested that after cAMP-dependent phosphorylation of cytochrome c oxidase mitochondrial respiration is controlled by the ATP/ADP-ratio keeping the proton motive force Δp low, and the efficiency of energy transduction high. After Ca²⁺-induced dephosphorylation this control is lost, accompanied by increase of Δp, slip of proton pumping (decreased H⁺/e⁻ stoichiometry), and increase of the rate of respiration and ATP-synthesis at a decreased efficiency of energy transduction.

【 授权许可】

Unknown