PKA Phosphorylates the ATPase Inhibitory Factor 1 and Inactivates Its Capacity to Bind and Inhibit the Mitochondrial H+-ATP Synthase

Javier García-Bermúdez, María Sánchez-Aragó, Beatriz Soldevilla, Araceli del Arco, Cristina Nuevo-Tapioles, José M. Cuezva

Research output: Contribution to journalArticlepeer-review

68 Scopus citations

Abstract

The mitochondrial H+-ATP synthase synthesizes most of cellular ATP requirements by oxidative phosphorylation (OXPHOS). The ATPase Inhibitory Factor 1 (IF1) is known to inhibit the hydrolase activity of the H+-ATP synthase in situations that compromise OXPHOS. Herein, we demonstrate that phosphorylation of S39 in IF1 by mitochondrial protein kinase A abolishes its capacity to bind the H+-ATP synthase. Only dephosphorylated IF1 binds and inhibits both the hydrolase and synthase activities of the enzyme. The phosphorylation status of IF1 regulates the flux of aerobic glycolysis and ATP production through OXPHOS in hypoxia and during the cell cycle. Dephosphorylated IF1 is present in human carcinomas. Remarkably, mouse heart contains a large fraction of dephosphorylated IF1 that becomes phosphorylated and inactivated upon in vivo β-adrenergic stimulation. Overall, we demonstrate the essential function of the phosphorylation of IF1 in regulating energy metabolism and speculate that dephosho-IF1 might play a role in signaling mitohormesis.

Original languageEnglish (US)
Pages (from-to)2143-2155
Number of pages13
JournalCell Reports
Volume12
Issue number12
DOIs
StatePublished - Sep 29 2015
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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