1
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Shukla VK, Siemons L, Hansen DF. Intrinsic structural dynamics dictate enzymatic activity and inhibition. Proc Natl Acad Sci U S A 2023; 120:e2310910120. [PMID: 37782780 PMCID: PMC10576142 DOI: 10.1073/pnas.2310910120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 08/14/2023] [Indexed: 10/04/2023] Open
Abstract
Enzymes are known to sample various conformations, many of which are critical for their biological function. However, structural characterizations of enzymes predominantly focus on the most populated conformation. As a result, single-point mutations often produce structures that are similar or essentially identical to those of the wild-type enzyme despite large changes in enzymatic activity. Here, we show for mutants of a histone deacetylase enzyme (HDAC8) that reduced enzymatic activities, reduced inhibitor affinities, and reduced residence times are all captured by the rate constants between intrinsically sampled conformations that, in turn, can be obtained independently by solution NMR spectroscopy. Thus, for the HDAC8 enzyme, the dynamic sampling of conformations dictates both enzymatic activity and inhibitor potency. Our analysis also dissects the functional role of the conformations sampled, where specific conformations distinct from those in available structures are responsible for substrate and inhibitor binding, catalysis, and product dissociation. Precise structures alone often do not adequately explain the effect of missense mutations on enzymatic activity and drug potency. Our findings not only assign functional roles to several conformational states of HDAC8 but they also underscore the paramount role of dynamics, which will have general implications for characterizing missense mutations and designing inhibitors.
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Affiliation(s)
- Vaibhav Kumar Shukla
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, LondonWC1E 6BT, United Kingdom
| | - Lucas Siemons
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, LondonWC1E 6BT, United Kingdom
| | - D. Flemming Hansen
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, LondonWC1E 6BT, United Kingdom
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2
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Toro TB, Bornes KE, Watt TJ. Lysine Deacetylase Substrate Selectivity: Distinct Interaction Surfaces Drive Positive and Negative Selection for Residues Following Acetyllysine. Biochemistry 2023; 62:1464-1483. [PMID: 37043688 PMCID: PMC10157890 DOI: 10.1021/acs.biochem.3c00001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Lysine acetylation is a post-translational modification that is reversed by lysine deacetylases (KDACs). The goal of this work was to identify determinants of substrate specificity for KDACs, focusing on short-range interactions occurring with residues immediately following the acetyllysine. Using a fluorescence-based in vitro assay, we determined the activity for each enzyme with a limited panel of derivative substrate peptides, revealing a distinct reactivity profile for each enzyme. We mapped the interaction surface for KDAC6, KDAC8, and KDAC1 with the +1 and +2 substrate residues (with respect to acetyllysine) based on enzyme-substrate interaction pairs observed in molecular dynamics simulations. Characteristic residues in each KDAC interact preferentially with particular substrate residues and correlate with either enhanced or inhibited activity. Although nonpolar aromatic residues generally enhanced activity with all KDACs, the manner in which each enzyme interacted with these residues is distinct. Furthermore, each KDAC has distinctive interactions that correlate with lower activity, primarily ionic in nature. KDAC8 exhibited the most diverse and widest range of effects, while KDAC6 was sensitive only to the +1 position and KDAC1 selectivity was primarily driven by negative selection. The substrate preferences were validated for KDAC6 and KDAC8 using a set of peptides derived from known acetylated proteins. Overall, we determined how KDAC6, KDAC8, and KDAC1 achieve substrate specificity with residues following the acetyllysine. These new insights into KDAC specificity will be critical for identifying novel substrates of particular KDACs, designing KDAC-specific inhibitors, and demonstrate a general framework for understanding substrate specificity for other enzyme classes.
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Affiliation(s)
- Tasha B Toro
- Department of Chemistry, Xavier University of Louisiana, 1 Drexel Drive, New Orleans, Louisiana 70125-1098, United States
| | - Kiara E Bornes
- Department of Chemistry, Xavier University of Louisiana, 1 Drexel Drive, New Orleans, Louisiana 70125-1098, United States
| | - Terry J Watt
- Department of Chemistry, Xavier University of Louisiana, 1 Drexel Drive, New Orleans, Louisiana 70125-1098, United States
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3
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Zhao P, Malik S. The phosphorylation to acetylation/methylation cascade in transcriptional regulation: how kinases regulate transcriptional activities of DNA/histone-modifying enzymes. Cell Biosci 2022; 12:83. [PMID: 35659740 PMCID: PMC9164400 DOI: 10.1186/s13578-022-00821-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/27/2022] [Indexed: 11/30/2022] Open
Abstract
Transcription factors directly regulate gene expression by recognizing and binding to specific DNA sequences, involving the dynamic alterations of chromatin structure and the formation of a complex with different kinds of cofactors, like DNA/histone modifying-enzymes, chromatin remodeling factors, and cell cycle factors. Despite the significance of transcription factors, it remains unclear to determine how these cofactors are regulated to cooperate with transcription factors, especially DNA/histone modifying-enzymes. It has been known that DNA/histone modifying-enzymes are regulated by post-translational modifications. And the most common and important modification is phosphorylation. Even though various DNA/histone modifying-enzymes have been classified and partly explained how phosphorylated sites of these enzymes function characteristically in recent studies. It still needs to find out the relationship between phosphorylation of these enzymes and the diseases-associated transcriptional regulation. Here this review describes how phosphorylation affects the transcription activity of these enzymes and other functions, including protein stability, subcellular localization, binding to chromatin, and interaction with other proteins.
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Pang N, Sun J, Che S, Yang N. Structural characterization of fungus-specific histone deacetylase Hos3 provides insights into developing selective inhibitors with antifungal activity. J Biol Chem 2022; 298:102068. [PMID: 35623387 PMCID: PMC9201020 DOI: 10.1016/j.jbc.2022.102068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 11/28/2022] Open
Abstract
Fungal infection has long been a chronic and even life-threatening problem for humans. The demand for new antifungal drugs has increased dramatically as fungal infections have continued to increase, yet no new classes of drugs have been approved for nearly 15 years due to either high toxicity or development of drug resistance. Thus, validating new drug targets, especially fungus-specific targets, may facilitate future drug design. Here, we report the crystal structure of yeast Hos3 (ScHos3), a fungus-specific histone deacetylase (HDAC) that plays an important role in the life span of fungi. As acetylation modifications are important to many aspects of fungal infection, the species specificity of Hos3 makes it an ideal target for the development of new antifungal drugs. In this study, we show that ScHos3 forms a functional homodimer in solution, and key residues for dimerization crucial for its deacetylation activity were identified. We used molecular dynamics simulation and structural comparison with mammalian hHDAC6 to determine unique features of the ScHos3 catalytic core. In addition, a small-molecule inhibitor with a preference for ScHos3 was identified through structure-based virtual screening and in vitro enzymatic assays. The structural information and regulatory interferences of ScHos3 reported here provide new insights for the design of selective inhibitors that target fungal HDAC with high efficiency and low toxicity or that have the potential to overcome the prevailing problem of drug resistance in combination therapy with other drugs.
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Affiliation(s)
- Ningning Pang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Key Laboratory of Medical Data Analysis and Statistical Research of Tianjin, Nankai University, Tianjin, China
| | - Jixue Sun
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Key Laboratory of Medical Data Analysis and Statistical Research of Tianjin, Nankai University, Tianjin, China
| | - Shiyou Che
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Key Laboratory of Medical Data Analysis and Statistical Research of Tianjin, Nankai University, Tianjin, China; College of Chemistry, Tianjin Normal University, Tianjin, China
| | - Na Yang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Key Laboratory of Medical Data Analysis and Statistical Research of Tianjin, Nankai University, Tianjin, China.
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Shukla VK, Siemons L, Gervasio FL, Hansen DF. Aromatic side-chain flips orchestrate the conformational sampling of functional loops in human histone deacetylase 8. Chem Sci 2021; 12:9318-9327. [PMID: 34349901 PMCID: PMC8278956 DOI: 10.1039/d1sc01929e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/27/2021] [Indexed: 12/12/2022] Open
Abstract
Human histone deacetylase 8 (HDAC8) is a key hydrolase in gene regulation and an important drug-target. High-resolution structures of HDAC8 in complex with substrates or inhibitors are available, which have provided insights into the bound state of HDAC8 and its function. Here, using long all-atom unbiased molecular dynamics simulations and Markov state modelling, we show a strong correlation between the conformation of aromatic side chains near the active site and opening and closing of the surrounding functional loops of HDAC8. We also investigated two mutants known to allosterically downregulate the enzymatic activity of HDAC8. Based on experimental data, we hypothesise that I19S-HDAC8 is unable to release the product, whereas both product release and substrate binding are impaired in the S39E-HDAC8 mutant. The presented results deliver detailed insights into the functional dynamics of HDAC8 and provide a mechanism for the substantial downregulation caused by allosteric mutations, including a disease causing one.
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Affiliation(s)
- Vaibhav Kumar Shukla
- Department of Structural and Molecular Biology, Division of Biosciences, University College London London WC1E 6BT UK
| | - Lucas Siemons
- Department of Structural and Molecular Biology, Division of Biosciences, University College London London WC1E 6BT UK
| | - Francesco L Gervasio
- Department of Chemistry, University College London London WC1E 6BT UK
- Pharmaceutical Sciences, University of Geneva Geneva CH-1211 Switzerland
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva Geneva CH-1211 Switzerland
| | - D Flemming Hansen
- Department of Structural and Molecular Biology, Division of Biosciences, University College London London WC1E 6BT UK
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6
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Luo Y, Li H. Structure-Based Inhibitor Discovery of Class I Histone Deacetylases (HDACs). Int J Mol Sci 2020; 21:E8828. [PMID: 33266366 PMCID: PMC7700698 DOI: 10.3390/ijms21228828] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/13/2020] [Accepted: 11/16/2020] [Indexed: 12/17/2022] Open
Abstract
Class I histone deacetylases (HDACs) are promising targets for epigenetic therapies for a range of diseases such as cancers, inflammations, infections and neurological diseases. Although six HDAC inhibitors are now licensed for clinical treatments, they are all pan-inhibitors with little or no HDAC isoform selectivity, exhibiting undesirable side effects. A major issue with the currently available HDAC inhibitors is that they have limited specificity and target multiple deacetylases. Except for HDAC8, Class I HDACs (1, 2 and 3) are recruited to large multiprotein complexes to function. Therefore, there are rising needs to develop new, hopefully, therapeutically efficacious HDAC inhibitors with isoform or complex selectivity. Here, upon the introduction of the structures of Class I HDACs and their complexes, we provide an up-to-date overview of the structure-based discovery of Class I HDAC inhibitors, including pan-, isoform-selective and complex-specific inhibitors, aiming to provide an insight into the discovery of additional HDAC inhibitors with greater selectivity, specificity and therapeutic utility.
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Affiliation(s)
- Yuxiang Luo
- School of Pharmaceutical Sciences, Sun Yat-sen University, No.132 Wai Huan Dong lu, Guangzhou Higher Education Mega Center, Guangzhou 510006, Guangdong, China;
| | - Huilin Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, No.132 Wai Huan Dong lu, Guangzhou Higher Education Mega Center, Guangzhou 510006, Guangdong, China;
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, Guangdong, China
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Toro TB, Watt TJ. Critical review of non-histone human substrates of metal-dependent lysine deacetylases. FASEB J 2020; 34:13140-13155. [PMID: 32862458 DOI: 10.1096/fj.202001301rr] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/29/2020] [Accepted: 08/03/2020] [Indexed: 12/15/2022]
Abstract
Lysine acetylation is a posttranslational modification that occurs on thousands of human proteins, most of which are cytoplasmic. Acetylated proteins are involved in numerous cellular processes and human diseases. Therefore, how the acetylation/deacetylation cycle is regulated is an important question. Eleven metal-dependent lysine deacetylases (KDACs) have been identified in human cells. These enzymes, along with the sirtuins, are collectively responsible for reversing lysine acetylation. Despite several large-scale studies which have characterized the acetylome, relatively few of the specific acetylated residues have been matched to a proposed KDAC for deacetylation. To understand the function of lysine acetylation, and its association with diseases, specific KDAC-substrate pairs must be identified. Identifying specific substrates of a KDAC is complicated both by the complexity of assaying relevant activity and by the non-catalytic interactions of KDACs with cellular proteins. Here, we discuss in vitro and cell-based experimental strategies used to identify KDAC-substrate pairs and evaluate each for the purpose of directly identifying non-histone substrates of metal-dependent KDACs. We propose criteria for a combination of reproducible experimental approaches that are necessary to establish a direct enzymatic relationship. This critical analysis of the literature identifies 108 proposed non-histone substrate-KDAC pairs for which direct experimental evidence has been reported. Of these, five pairs can be considered well-established, while another thirteen pairs have both cell-based and in vitro evidence but lack independent replication and/or sufficient cell-based evidence. We present a path forward for evaluating the remaining substrate leads and reliably identifying novel KDAC substrates.
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Affiliation(s)
- Tasha B Toro
- Department of Chemistry, Xavier University of Louisiana, New Orleans, LA, USA
| | - Terry J Watt
- Department of Chemistry, Xavier University of Louisiana, New Orleans, LA, USA
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8
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Werbeck ND, Shukla VK, Kunze MBA, Yalinca H, Pritchard RB, Siemons L, Mondal S, Greenwood SOR, Kirkpatrick J, Marson CM, Hansen DF. A distal regulatory region of a class I human histone deacetylase. Nat Commun 2020; 11:3841. [PMID: 32737323 PMCID: PMC7395746 DOI: 10.1038/s41467-020-17610-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 07/09/2020] [Indexed: 01/05/2023] Open
Abstract
Histone deacetylases (HDACs) are key enzymes in epigenetics and important drug targets in cancer biology. Whilst it has been established that HDACs regulate many cellular processes, far less is known about the regulation of these enzymes themselves. Here, we show that HDAC8 is allosterically regulated by shifts in populations between exchanging states. An inactive state is identified, which is stabilised by a range of mutations and resembles a sparsely-populated state in equilibrium with active HDAC8. Computational models show that the inactive and active states differ by small changes in a regulatory region that extends up to 28 Å from the active site. The regulatory allosteric region identified here in HDAC8 corresponds to regions in other class I HDACs known to bind regulators, thus suggesting a general mechanism. The presented results pave the way for the development of allosteric HDAC inhibitors and regulators to improve the therapy for several disease states.
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Affiliation(s)
- Nicolas D Werbeck
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK
- Nuvisan ICB GmbH, Innovation Campus Berlin, Müllerstraße 178, 13353, Berlin, Germany
| | - Vaibhav Kumar Shukla
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Micha B A Kunze
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Havva Yalinca
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Ruth B Pritchard
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Lucas Siemons
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Somnath Mondal
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Simon O R Greenwood
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK
- Department of Chemistry, University College London, London, WC1E 6BT, UK
| | - John Kirkpatrick
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Charles M Marson
- Department of Chemistry, University College London, London, WC1E 6BT, UK
| | - D Flemming Hansen
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK.
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