title: Mitochondrial Sirtuin Network Reveals Dynamic SIRT3-Dependent Deacetylation in Response to Membrane Depolarization.
abstract: Mitochondrial sirtuins, SIRT3-5, are NAD+-dependent deacylases and ADP-ribosyltransferases that are critical for stress responses. However, a comprehensive understanding of sirtuin targets, regulation of sirtuin activity, and the relationships between sirtuins remains a key challenge in mitochondrial physiology. Here, we employ systematic interaction proteomics to elucidate the mitochondrial sirtuin protein interaction landscape. This work reveals sirtuin interactions with numerous functional modules within mitochondria, identifies candidate sirtuin substrates, and uncovers a fundamental role for sequestration of SIRT3 by ATP synthase in mitochondrial homeostasis. In healthy mitochondria, a pool of SIRT3 binds ATP synthase, but upon matrix pH reduction with concomitant loss of mitochondrial membrane potential, SIRT3 dissociates. This release correlates with rapid deacetylation of matrix proteins, and SIRT3 is required for recovery of membrane potential. In vitro reconstitution experiments, as well as analysis of CRISPR/Cas9-engineered cells, indicate that pH-dependent SIRT3 release requires H135 in the ATP5O subunit of ATP synthase. Our SIRT3-5 interaction network provides a framework for discovering novel biological functions regulated by mitochondrial sirtuins.
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Wen
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Cardiovascular and Metabolic Drug Discovery Unit, Takeda Pharmaceutical Company Limited, Kanagawa 251-8555, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Nagasawa
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Münch
authors.affiliation: Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Kyle
authors.initials: K
authors.lastname: Satterstrom
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Seungmin
authors.initials: S
authors.lastname: Jeong
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Sebastian D
authors.initials: SD
authors.lastname: Hayes
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Jedrychowski
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: F Sejal
authors.initials: FS
authors.lastname: Vyas
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Elma
authors.initials: E
authors.lastname: Zaganjor
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Virginia
authors.initials: V
authors.lastname: Guarani
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Alison E
authors.initials: AE
authors.lastname: Ringel
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Gygi
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: J Wade
authors.initials: JW
authors.lastname: Harper
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA. Electronic address: marcia_haigis@hms.harvard.edu.
authors.forename: Marcia C
authors.initials: MC
authors.lastname: Haigis
mesh_terms: D000107:Acetylation; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism; D025261:Mitochondrial Proton-Translocating ATPases; D060066:Protein Interaction Maps; D056566:Sirtuin 3 / Q000378:metabolism*; D037761:Sirtuins / Q000145:classification / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; C466093:SIRT3 protein, human; D056566:Sirtuin 3; D037761:Sirtuins; D000251:Adenosine Triphosphatases; D025261:Mitochondrial Proton-Translocating ATPases; C020439:oligomycin sensitivity-conferring protein
keywords: ATP synthase; Acetylation; Deacetylation; Energy homeostasis; Interactome; Membrane potential; Mitochondria; Protein-protein interaction; Sirtuin; pH