Rahman, M., Nirala, N.K., Singh, A., Zhu, L.J., Taguchi, K., Bamba, T., Fukusaki, E., Shaw, L.M., Lambright, D.G., Acharya, J.K., Acharya, U.R. (2014). Drosophila Sirt2/mammalian SIRT3 deacetylates ATP synthase β and regulates complex V activity.  J. Cell Biol. 206(2): 289--305.

FBrf0225716

Research paper

Adenosine triphosphate (ATP) synthase β, the catalytic subunit of mitochondrial complex V, synthesizes ATP. We show that ATP synthase β is deacetylated by a human nicotinamide adenine dinucleotide (NAD(+))-dependent protein deacetylase, sirtuin 3, and its Drosophila melanogaster homologue, dSirt2. dsirt2 mutant flies displayed increased acetylation of specific Lys residues in ATP synthase β and decreased complex V activity. Overexpression of dSirt2 increased complex V activity. Substitution of Lys 259 and Lys 480 with Arg in human ATP synthase β, mimicking deacetylation, increased complex V activity, whereas substitution with Gln, mimicking acetylation, decreased activity. Mass spectrometry and proteomic experiments from wild-type and dsirt2 mitochondria identified the Drosophila mitochondrial acetylome and revealed dSirt2 as an important regulator of mitochondrial energy metabolism. Additionally, we unravel a ceramide-NAD(+)-sirtuin axis wherein increased ceramide, a sphingolipid known to induce stress responses, resulted in depletion of NAD(+) and consequent decrease in sirtuin activity. These results provide insight into sirtuin-mediated regulation of complex V and reveal a novel link between ceramide and Drosophila acetylome.

PMC4107778 (PMC) (EuropePMC)