Phosphorylation of mitochondrial membrane proteins: effect of the surface potential on monoamine oxidase.
Proteins of mitochondrial membranes become phosphorylated when liver mitochondria are incubated with ATP in the presence of Mg2+. This is accompanied by an increase of the negative surface potential of mitochondrial membranes, as calculated from the dissociation constant of fluorescent probes, 8-anilino-1-naphthalene sulphonate and ethidium bromide, and by a decrease of the apparent Km-value of mitochondrial monoamine oxidase. Protein phosphorylation, the increase of the negative surface potential and the decrease of apparent Km of monoamine oxidase are greatly potentiated by cytoplasmic protein kinases in the presence of cyclic AMP.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D000242:Cyclic AMP / Q000494:pharmacology; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D008565:Membrane Proteins / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000201:enzymology / Q000378:metabolism*; D008962:Models, Theoretical; D008995:Monoamine Oxidase / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats
D008565:Membrane Proteins; D000255:Adenosine Triphosphate; D000242:Cyclic AMP; D008995:Monoamine Oxidase; D008274:Magnesium