Journal
MOLECULAR AND CELLULAR BIOCHEMISTRY
Volume 234, Issue 1, Pages 63-70Publisher
SPRINGER
DOI: 10.1023/A:1015921513720
Keywords
allosteric ATP-inhibition; cAMP-dependent phosphorylation; cytochrome c oxidase; mechanism of respiratory control; mitochondrial membrane protential; ROS formation
Categories
Ask authors/readers for more resources
Phosphorylation of isolated cytochrome c oxidase from bovine kidney and heart, and of the reconstituted heart enzyme, with protein kinase A, cAMP and ATP turns on the allosteric ATP-inhibition at high ATP/ADP ratios. Also incubation of isolated bovine liver mitochondria only with cAMP and ATP turns on, and subsequent incubation with Ca-2+ turns off the allosteric ATP-inhibition of cytochrome c oxidase. In the bovine heart enzyme occur only three consensus sequences for cAMP-dependent phosphorylation (in subunits I, III and Vb). The evolutionary conservation of RRYS441 at the cytosolic side of subunit I, together with the above results, suggest that phosphorylation of Ser(441) turns on the allosteric ATP-inhibition of cytochrome c oxidase. The results support the 'molecular-physiological hypothesis' [29], which proposes a low mitochondrial membrane potential through the allosteric ATP-inhibition. A hormone- or agonist-stimulated increase of cellular [Ca2+] is suggested to activate a mitochondrial protein phosphatase which dephosphorylates cytochrome c oxidase, turns off the allosteric ATP-inhibition and results in increase of mitochondrial membrane potential and ROS formation.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available