1
|
Aghayev M, Arias-Alvarado A, Ilchenko S, Lepp J, Scott I, Chen YR, Zhang GF, Tsai TH, Kasumov T. A high-fat diet increases hepatic mitochondrial turnover through restricted acetylation in a NAFLD mouse model. Am J Physiol Endocrinol Metab 2023; 325:E83-E98. [PMID: 37224468 PMCID: PMC10312330 DOI: 10.1152/ajpendo.00310.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 05/15/2023] [Accepted: 05/16/2023] [Indexed: 05/26/2023]
Abstract
Lysine acetylation of proteins has emerged as a key posttranslational modification (PTM) that regulates mitochondrial metabolism. Acetylation may regulate energy metabolism by inhibiting and affecting the stability of metabolic enzymes and oxidative phosphorylation (OxPhos) subunits. Although protein turnover can be easily measured, due to the low abundance of modified proteins, it has been difficult to evaluate the effect of acetylation on the stability of proteins in vivo. We applied 2H2O-metabolic labeling coupled with immunoaffinity and high-resolution mass spectrometry method to measure the stability of acetylated proteins in mouse liver based on their turnover rates. As a proof-of-concept, we assessed the consequence of high-fat diet (HFD)-induced altered acetylation in protein turnover in LDL receptor-deficient (LDLR-/-) mice susceptible to diet-induced nonalcoholic fatty liver disease (NAFLD). HFD feeding for 12 wk led to steatosis, the early stage of NAFLD. A significant reduction in acetylation of hepatic proteins was observed in NAFLD mice, based on immunoblot analysis and label-free quantification with mass spectrometry. Compared with control mice on a normal diet, NAFLD mice had overall increased turnover rates of hepatic proteins, including mitochondrial metabolic enzymes (0.159 ± 0.079 vs. 0.132 ± 0.068 day-1), suggesting their reduced stability. Also, acetylated proteins had slower turnover rates (increased stability) than native proteins in both groups (0.096 ± 0.056 vs. 0.170 ± 0.059 day-1 in control, and 0.111 ± 0.050 vs. 0.208 ± 0.074 day-1 in NAFLD). Furthermore, association analysis revealed a relationship between the HFD-induced decrease in acetylation and increased turnover rates for hepatic proteins in NAFLD mice. These changes were associated with increased expressions of the hepatic mitochondrial transcriptional factor (TFAM) and complex II subunit without any changes to other OxPhos proteins, suggesting that enhanced mitochondrial biogenesis prevented restricted acetylation-mediated depletion of mitochondrial proteins. We conclude that decreased acetylation of mitochondrial proteins may contribute to adaptive improved hepatic mitochondrial function in the early stages of NAFLD.NEW & NOTEWORTHY This is the first method to quantify acetylome dynamics in vivo. This method revealed acetylation-mediated altered hepatic mitochondrial protein turnover in response to a high-fat diet in a mouse model of NAFLD.
Collapse
Affiliation(s)
- Mirjavid Aghayev
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio, United States
| | - Andrea Arias-Alvarado
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio, United States
| | - Sergei Ilchenko
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio, United States
| | - Josephine Lepp
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio, United States
| | - Iain Scott
- Cardiology Division, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
| | - Yeong-Renn Chen
- Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, Ohio, United States
| | - Guo-Fang Zhang
- Division of Endocrinology, Metabolism and Nutrition, Duke Molecular Physiology Institute, Duke University, Durham North Carolina, United States
- Department of Medicine, Duke University, Durham North Carolina, United States
| | - Tsung-Heng Tsai
- Department of Mathematical Sciences, Kent State University, Kent, Ohio, United States
| | - Takhar Kasumov
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, Ohio, United States
| |
Collapse
|
2
|
Crystal structure of human NADK2 reveals a dimeric organization and active site occlusion by lysine acetylation. Mol Cell 2022; 82:3299-3311.e8. [PMID: 35868311 DOI: 10.1016/j.molcel.2022.06.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 06/08/2022] [Accepted: 06/21/2022] [Indexed: 11/23/2022]
Abstract
NAD+ kinases (NADKs) are metabolite kinases that phosphorylate NAD+ molecules to make NADP+, a limiting substrate for the generation of reducing power NADPH. NADK2 sustains mitochondrial NADPH production that enables proline biosynthesis and antioxidant defense. However, its molecular architecture and mechanistic regulation remain undescribed. Here, we report the crystal structure of human NADK2, revealing a substrate-driven mode of activation. We find that NADK2 presents an unexpected dimeric organization instead of the typical tetrameric assemblage observed for other NADKs. A specific extended segment (aa 325-365) is crucial for NADK2 dimerization and activity. Moreover, we characterize numerous acetylation events, including those on Lys76 and Lys304, which reside near the active site and inhibit NADK2 activity without disrupting dimerization, thereby reducing mitochondrial NADP(H) production, proline synthesis, and cell growth. These findings reveal important molecular insight into the structure and regulation of a vital enzyme in mitochondrial NADPH and proline metabolism.
Collapse
|
3
|
Stoppacciaro A, Di Vito S, Filetici P. Epigenetic Factors and Mitochondrial Biology in Yeast: A New Paradigm for the Study of Cancer Metabolism? Front Pharmacol 2018; 9:1349. [PMID: 30524288 PMCID: PMC6258771 DOI: 10.3389/fphar.2018.01349] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 11/02/2018] [Indexed: 12/14/2022] Open
Abstract
Bidirectional cross-talk between nuclear and mitochondrial DNA is fundamental for cell homeostasis. Epigenetic mechanisms regulate the inter-organelle communication between nucleus and mitochondria. Recent research highlights not only the retrograde activation of nuclear gene transcription in case of mitochondria dysfunction, but also the role of post-translational modifications of mitochondrial proteins in respiratory metabolism. Here we discuss some aspects and novel findings in Saccharomyces cerevisiae. In yeast, KAT-Gcn5 and DUB-Ubp8 have a role in respiration and are localized, as single proteins, into mitochondria. These findings, beside the canonical and widely known nuclear activity of SAGA complex in chromatin regulation, provide novel clues on promising aspects linking evolutionary conserved epigenetic factors to the re-programmed metabolism of cancer cells.
Collapse
Affiliation(s)
- Antonella Stoppacciaro
- Surgical Pathology Units, Department of Clinical and Molecular Medicine, Ospedale Sant'Andrea, Sapienza University of Rome, Rome, Italy
| | - Serena Di Vito
- Institute of Molecular Biology and Pathology, CNR, Sapienza University of Rome, Rome, Italy
| | - Patrizia Filetici
- Institute of Molecular Biology and Pathology, CNR, Sapienza University of Rome, Rome, Italy
| |
Collapse
|
4
|
Kumar S, Lombard DB. Functions of the sirtuin deacylase SIRT5 in normal physiology and pathobiology. Crit Rev Biochem Mol Biol 2018; 53:311-334. [PMID: 29637793 DOI: 10.1080/10409238.2018.1458071] [Citation(s) in RCA: 156] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Sirtuins are NAD+-dependent protein deacylases/ADP-ribosyltransferases that have emerged as candidate targets for new therapeutics to treat metabolic disorders and other diseases, including cancer. The sirtuin SIRT5 resides primarily in the mitochondrial matrix and catalyzes the removal of negatively charged lysine acyl modifications; succinyl, malonyl, and glutaryl groups. Evidence has now accumulated to document the roles of SIRT5 as a significant regulator of cellular homeostasis, in a context- and cell-type specific manner, as has been observed previously for other sirtuin family members. SIRT5 regulates protein substrates involved in glycolysis, the TCA cycle, fatty acid oxidation, electron transport chain, ketone body formation, nitrogenous waste management, and ROS detoxification, among other processes. SIRT5 plays pivotal roles in cardiac physiology and stress responses and is involved in the regulation of numerous aspects of myocardial energy metabolism. SIRT5 is implicated in neoplasia, as both a tumor promoter and suppressor in a context-specific manner, and may serve a protective function in the setting of neurodegenerative disorders. Here, we review the current understanding of functional impacts of SIRT5 on its metabolic targets, and its molecular functions in both normal and pathological conditions. Finally, we will discuss the potential utility of SIRT5 as a drug target and also summarize the current status, progress, and challenges in developing small molecule compounds to modulate SIRT5 activity with high potency and specificity.
Collapse
Affiliation(s)
- Surinder Kumar
- a Department of Pathology , University of Michigan , Ann Arbor , MI , USA
| | - David B Lombard
- a Department of Pathology , University of Michigan , Ann Arbor , MI , USA.,b Institute of Gerontology , University of Michigan , Ann Arbor , MI , USA
| |
Collapse
|
5
|
Dikalova AE, Itani HA, Nazarewicz RR, McMaster WG, Flynn CR, Uzhachenko R, Fessel JP, Gamboa JL, Harrison DG, Dikalov SI. Sirt3 Impairment and SOD2 Hyperacetylation in Vascular Oxidative Stress and Hypertension. Circ Res 2017; 121:564-574. [PMID: 28684630 DOI: 10.1161/circresaha.117.310933] [Citation(s) in RCA: 197] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 07/01/2017] [Accepted: 07/05/2017] [Indexed: 01/21/2023]
Abstract
RATIONALE Clinical studies have shown that Sirt3 (Sirtuin 3) expression declines by 40% by 65 years of age paralleling the increased incidence of hypertension and metabolic conditions further inactivate Sirt3 because of increased NADH (nicotinamide adenine dinucleotide, reduced form) and acetyl-CoA levels. Sirt3 impairment reduces the activity of a key mitochondrial antioxidant enzyme, superoxide dismutase 2 (SOD2) because of hyperacetylation. OBJECTIVE In this study, we examined whether the loss of Sirt3 activity increases vascular oxidative stress because of SOD2 hyperacetylation and promotes endothelial dysfunction and hypertension. METHODS AND RESULTS Hypertension was markedly increased in Sirt3-knockout (Sirt3-/-) and SOD2-depleted (SOD2+/-) mice in response to low dose of angiotensin II (0.3 mg/kg per day) compared with wild-type C57Bl/6J mice. Sirt3 depletion increased SOD2 acetylation, elevated mitochondrial O2· -, and diminished endothelial nitric oxide. Angiotensin II-induced hypertension was associated with Sirt3 S-glutathionylation, acetylation of vascular SOD2, and reduced SOD2 activity. Scavenging of mitochondrial H2O2 in mCAT mice expressing mitochondria-targeted catalase prevented Sirt3 and SOD2 impairment and attenuated hypertension. Treatment of mice after onset of hypertension with a mitochondria-targeted H2O2 scavenger, mitochondria-targeted hydrogen peroxide scavenger ebselen, reduced Sirt3 S-glutathionylation, diminished SOD2 acetylation, and reduced blood pressure in wild-type but not in Sirt3-/- mice, whereas an SOD2 mimetic, (2-[2,2,6,6-tetramethylpiperidin-1-oxyl-4-ylamino]-2-oxoethyl) triphenylphosphonium (mitoTEMPO), reduced blood pressure and improved vasorelaxation both in Sirt3-/- and wild-type mice. SOD2 acetylation had an inverse correlation with SOD2 activity and a direct correlation with the severity of hypertension. Analysis of human subjects with essential hypertension showed 2.6-fold increase in SOD2 acetylation and 1.4-fold decrease in Sirt3 levels, whereas SOD2 expression was not affected. CONCLUSIONS Our data suggest that diminished Sirt3 expression and redox inactivation of Sirt3 lead to SOD2 inactivation and contributes to the pathogenesis of hypertension.
Collapse
Affiliation(s)
- Anna E Dikalova
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Hana A Itani
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Rafal R Nazarewicz
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - William G McMaster
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Charles R Flynn
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Roman Uzhachenko
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Joshua P Fessel
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Jorge L Gamboa
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - David G Harrison
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN
| | - Sergey I Dikalov
- From the Division of Clinical Pharmacology (A.E.D., H.A.I., R.R.N., W.G.M., R.U., J.P.F., J.L.G., D.G.H., S.I.D.) and Department of Surgery (C.R.F.), Vanderbilt University Medical Center, Nashville, TN.
| |
Collapse
|
7
|
Kumar S, Lombard DB. For Certain, SIRT4 Activities! Trends Biochem Sci 2017; 42:499-501. [PMID: 28587732 DOI: 10.1016/j.tibs.2017.05.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 05/22/2017] [Indexed: 10/19/2022]
Abstract
Despite the fact that SIRT4 regulates important biological processes, its primary enzymatic activity has remained ambiguous. A recent study by Anderson, Huynh et al. has uncovered deacylase activities of SIRT4 towards newly described lysine modifications derived from reactive acyl-CoAs generated in leucine catabolism.
Collapse
Affiliation(s)
- Surinder Kumar
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - David B Lombard
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA; Institute of Gerontology, University of Michigan, Ann Arbor, MI 48109, USA.
| |
Collapse
|