title: Regulation of MnSOD enzymatic activity by Sirt3 connects the mitochondrial acetylome signaling networks to aging and carcinogenesis.
abstract: CONCLUSIONS
  It is a well-established scientific observation that mammalian cells contain fidelity or watchdog proteins that maintain the correct function of cellular organelles.
  
  
  BACKGROUND
  Over the past several years, the Sirtuin deacetylase family protein Sirt3 has emerged as a mitochondrial fidelity protein that directs energy generation and regulates reactive oxygen species (ROS) scavenging proteins. Loss of function or genetic mutation of these fidelity proteins has been shown to create a cellular environment that is permissive for the development of cellular damage associated with processes such as aging and carcinogenesis.
  
  
  RESULTS
  Mitochondria are the primary organelles that direct oxidative metabolism for the production of ATP; however, this is also a significant source of ROS. Thus, it is reasonable to propose that mitochondria should contain proteins that would signal downstream target molecules and/or ROS scavenger enzymes to maintain mitochondrial and cellular homeostatic poise. It is also reasonable to hypothesize that the mitochondria contain fidelity proteins similar to those found in the nucleus and cytoplasm. We discuss a new role of Sirt3 in the direction of the primary superoxide scavenger protein, manganese superoxide dismutase (MnSOD), and how the acetylation or deacetylation of several specific lysines appears to direct MnSOD enzymatic dismutase activity.
  
  
  CONCLUSIONS
  Aberrant downstream regulation of MnSOD by Sirt3 may be a potential source of cellular damage that accumulates with aging to create a tumor-permissive phenotype. Future studies can explore the role of MnSOD in age-related illness using this new mechanism of enzymatic regulation.
authors.affiliation: 1 Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center , Houston, Texas.
authors.forename: Randa
authors.initials: R
authors.lastname: Tao
authors.forename: Athanassios
authors.initials: A
authors.lastname: Vassilopoulos
authors.forename: Loukia
authors.initials: L
authors.lastname: Parisiadou
authors.forename: Yufan
authors.initials: Y
authors.lastname: Yan
authors.forename: David
authors.initials: D
authors.lastname: Gius
mesh_terms: D000107:Acetylation; D000375:Aging; D000595:Amino Acid Sequence; D000818:Animals; D063646:Carcinogenesis / Q000378:metabolism*; D017124:Conserved Sequence; D015870:Gene Expression; D005786:Gene Expression Regulation; D006801:Humans; D018384:Oxidative Stress; D011499:Protein Processing, Post-Translational; D015398:Signal Transduction; D056566:Sirtuin 3 / Q000502:physiology*; D013482:Superoxide Dismutase / Q000378:metabolism*; D000099156:Superoxide Dismutase 2
chemical_list: D056566:Sirtuin 3; D013482:Superoxide Dismutase; D000099156:Superoxide Dismutase 2; C466093:SIRT3 protein, human