title: The Arabidopsis class II sirtuin is a lysine deacetylase and interacts with mitochondrial energy metabolism.
abstract: The posttranslational regulation of proteins by lysine (Lys) acetylation has recently emerged to occur not only on histones, but also on organellar proteins in plants and animals. In particular, the catalytic activities of metabolic enzymes have been shown to be regulated by Lys acetylation. The Arabidopsis (Arabidopsis thaliana) genome encodes two predicted sirtuin-type Lys deacetylases, of which only Silent Information Regulator2 homolog (SRT2) contains a predicted presequence for mitochondrial targeting. Here, we have investigated the function of SRT2 in Arabidopsis. We demonstrate that SRT2 functions as a Lys deacetylase in vitro and in vivo. We show that SRT2 resides predominantly at the inner mitochondrial membrane and interacts with a small number of protein complexes mainly involved in energy metabolism and metabolite transport. Several of these protein complexes, such as the ATP synthase and the ATP/ADP carriers, show an increase in Lys acetylation in srt2 loss-of-function mutants. The srt2 plants display no growth phenotype but rather a metabolic phenotype with altered levels in sugars, amino acids, and ADP contents. Furthermore, coupling of respiration to ATP synthesis is decreased in these lines, while the ADP uptake into mitochondria is significantly increased. Our results indicate that SRT2 is important in fine-tuning mitochondrial energy metabolism.
authors.affiliation: Department I of Biology, Ludwig Maximilians University Munich, Grosshaderner Strasse 2, 82152 Martinsried, Germany.
authors.forename: Ann-Christine
authors.initials: AC
authors.lastname: König
authors.forename: Markus
authors.initials: M
authors.lastname: Hartl
authors.forename: Phuong Anh
authors.initials: PA
authors.lastname: Pham
authors.forename: Miriam
authors.initials: M
authors.lastname: Laxa
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Boersema
authors.forename: Anne
authors.initials: A
authors.lastname: Orwat
authors.forename: Ievgeniia
authors.initials: I
authors.lastname: Kalitventseva
authors.forename: Magdalena
authors.initials: M
authors.lastname: Plöchinger
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Braun
authors.forename: Dario
authors.initials: D
authors.lastname: Leister
authors.forename: Matthias
authors.initials: M
authors.lastname: Mann
authors.forename: Andreas
authors.initials: A
authors.lastname: Wachter
authors.forename: Alisdair R
authors.initials: AR
authors.lastname: Fernie
authors.forename: Iris
authors.initials: I
authors.lastname: Finkemeier
mesh_terms: D000107:Acetylation; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002247:Carbon Isotopes; D019069:Cell Respiration; D004734:Energy Metabolism; D055786:Gene Knockout Techniques; D006655:Histone Deacetylases / Q000378:metabolism*; D008239:Lysine / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D009243:NAD / Q000378:metabolism; D059365:Nonsense Mediated mRNA Decay / Q000235:genetics; D010641:Phenotype; D011485:Protein Binding; D021381:Protein Transport / Q000235:genetics; D012326:RNA Splicing / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D037761:Sirtuins / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D029681:Arabidopsis Proteins; D002247:Carbon Isotopes; D024101:Mitochondrial Proteins; D012333:RNA, Messenger; D009243:NAD; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; C000592615:SRT2 protein, Arabidopsis; D037761:Sirtuins; D006655:Histone Deacetylases; D008239:Lysine