| Structural highlights
Function
SIR3_HUMAN NAD-dependent protein deacetylase. Activates mitochondrial target proteins, including ACSS1, IDH2 and GDH by deacetylating key lysine residues. Contributes to the regulation of the cellular energy metabolism. Important for regulating tissue-specific ATP levels.[1] [2] [3] [4]
Publication Abstract from PubMed
The protein lysine deacylases of the NAD(+)-dependent Sirtuin family contribute to metabolic regulation, stress responses, and aging processes, and the human Sirtuin isoforms, Sirt1-7, are considered drug targets for aging-related diseases. The nuclear isoform Sirt1 deacetylates histones and transcription factors to regulate, e.g., metabolic adaptations and circadian mechanisms, and it is used as a therapeutic target for Huntington's disease and psoriasis. Sirt1 is regulated through a multitude of mechanisms, including the interaction with regulatory proteins such as the inhibitors Tat and Dbc1 or the activator AROS. Here, we describe a molecular characterization of AROS and how it regulates Sirt1. We find that AROS is a partly intrinsically disordered protein (IDP) that inhibits rather than activates Sirt1. A biochemical characterization of the interaction including binding and stability assays, NMR spectroscopy, mass spectrometry, and a crystal structure of Sirtuin/AROS peptide complex reveal that AROS acts as a competitive inhibitor, through binding to the Sirt1 substrate peptide site. Our results provide molecular insights in the physiological regulation of Sirt1 by a regulator protein and suggest the peptide site as an opportunity for Sirt1-targeted drug development.
Molecular Mechanism of Sirtuin 1 Modulation by the AROS Protein.,Weiss S, Adolph RS, Schweimer K, DiFonzo A, Meleshin M, Schutkowski M, Steegborn C Int J Mol Sci. 2022 Oct 23;23(21):12764. doi: 10.3390/ijms232112764. PMID:36361557[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Schwer B, Bunkenborg J, Verdin RO, Andersen JS, Verdin E. Reversible lysine acetylation controls the activity of the mitochondrial enzyme acetyl-CoA synthetase 2. Proc Natl Acad Sci U S A. 2006 Jul 5;103(27):10224-9. Epub 2006 Jun 20. PMID:16788062 doi:10.1073/pnas.0603968103
- ↑ Schlicker C, Gertz M, Papatheodorou P, Kachholz B, Becker CF, Steegborn C. Substrates and regulation mechanisms for the human mitochondrial sirtuins Sirt3 and Sirt5. J Mol Biol. 2008 Oct 10;382(3):790-801. doi: 10.1016/j.jmb.2008.07.048. Epub 2008, Jul 25. PMID:18680753 doi:10.1016/j.jmb.2008.07.048
- ↑ Ahn BH, Kim HS, Song S, Lee IH, Liu J, Vassilopoulos A, Deng CX, Finkel T. A role for the mitochondrial deacetylase Sirt3 in regulating energy homeostasis. Proc Natl Acad Sci U S A. 2008 Sep 23;105(38):14447-52. doi:, 10.1073/pnas.0803790105. Epub 2008 Sep 15. PMID:18794531 doi:10.1073/pnas.0803790105
- ↑ Jin L, Wei W, Jiang Y, Peng H, Cai J, Mao C, Dai H, Choy W, Bemis JE, Jirousek MR, Milne JC, Westphal CH, Perni RB. Crystal structures of human SIRT3 displaying substrate-induced conformational changes. J Biol Chem. 2009 Sep 4;284(36):24394-405. Epub 2009 Jun 16. PMID:19535340 doi:10.1074/jbc.M109.014928
- ↑ Weiss S, Adolph RS, Schweimer K, DiFonzo A, Meleshin M, Schutkowski M, Steegborn C. Molecular Mechanism of Sirtuin 1 Modulation by the AROS Protein. Int J Mol Sci. 2022 Oct 23;23(21):12764. PMID:36361557 doi:10.3390/ijms232112764
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