1
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Miao Y, Wolfe MS. Emerging structures and dynamic mechanisms of γ-secretase for Alzheimer's disease. Neural Regen Res 2025; 20:174-180. [PMID: 38767485 DOI: 10.4103/nrr.nrr-d-23-01781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 01/11/2024] [Indexed: 05/22/2024] Open
Abstract
γ-Secretase, called "the proteasome of the membrane," is a membrane-embedded protease complex that cleaves 150+ peptide substrates with central roles in biology and medicine, including amyloid precursor protein and the Notch family of cell-surface receptors. Mutations in γ-secretase and amyloid precursor protein lead to early-onset familial Alzheimer's disease. γ-Secretase has thus served as a critical drug target for treating familial Alzheimer's disease and the more common late-onset Alzheimer's disease as well. However, critical gaps remain in understanding the mechanisms of processive proteolysis of substrates, the effects of familial Alzheimer's disease mutations, and allosteric modulation of substrate cleavage by γ-secretase. In this review, we focus on recent studies of structural dynamic mechanisms of γ-secretase. Different mechanisms, including the "Fit-Stay-Trim," "Sliding-Unwinding," and "Tilting-Unwinding," have been proposed for substrate proteolysis of amyloid precursor protein by γ-secretase based on all-atom molecular dynamics simulations. While an incorrect registry of the Notch1 substrate was identified in the cryo-electron microscopy structure of Notch1-bound γ-secretase, molecular dynamics simulations on a resolved model of Notch1-bound γ-secretase that was reconstructed using the amyloid precursor protein-bound γ-secretase as a template successfully captured γ-secretase activation for proper cleavages of both wildtype and mutant Notch, being consistent with biochemical experimental findings. The approach could be potentially applied to decipher the processing mechanisms of various substrates by γ-secretase. In addition, controversy over the effects of familial Alzheimer's disease mutations, particularly the issue of whether they stabilize or destabilize γ-secretase-substrate complexes, is discussed. Finally, an outlook is provided for future studies of γ-secretase, including pathways of substrate binding and product release, effects of modulators on familial Alzheimer's disease mutations of the γ-secretase-substrate complexes. Comprehensive understanding of the functional mechanisms of γ-secretase will greatly facilitate the rational design of effective drug molecules for treating familial Alzheimer's disease and perhaps Alzheimer's disease in general.
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Affiliation(s)
- Yinglong Miao
- Computational Medicine Program and Department of Pharmacology, University of North Carolina - Chapel Hill, Chapel Hill, NC, USA
| | - Michael S Wolfe
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS, USA
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2
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Saecker RM, Mueller AU, Malone B, Chen J, Budell WC, Dandey VP, Maruthi K, Mendez JH, Molina N, Eng ET, Yen LY, Potter CS, Carragher B, Darst SA. Early intermediates in bacterial RNA polymerase promoter melting visualized by time-resolved cryo-electron microscopy. Nat Struct Mol Biol 2024:10.1038/s41594-024-01349-9. [PMID: 38951624 DOI: 10.1038/s41594-024-01349-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 06/06/2024] [Indexed: 07/03/2024]
Abstract
During formation of the transcription-competent open complex (RPo) by bacterial RNA polymerases (RNAPs), transient intermediates pile up before overcoming a rate-limiting step. Structural descriptions of these interconversions in real time are unavailable. To address this gap, here we use time-resolved cryogenic electron microscopy (cryo-EM) to capture four intermediates populated 120 ms or 500 ms after mixing Escherichia coli σ70-RNAP and the λPR promoter. Cryo-EM snapshots revealed that the upstream edge of the transcription bubble unpairs rapidly, followed by stepwise insertion of two conserved nontemplate strand (nt-strand) bases into RNAP pockets. As the nt-strand 'read-out' extends, the RNAP clamp closes, expelling an inhibitory σ70 domain from the active-site cleft. The template strand is fully unpaired by 120 ms but remains dynamic, indicating that yet unknown conformational changes complete RPo formation in subsequent steps. Given that these events likely describe DNA opening at many bacterial promoters, this study provides insights into how DNA sequence regulates steps of RPo formation.
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Affiliation(s)
- Ruth M Saecker
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, USA
| | - Andreas U Mueller
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, USA
| | - Brandon Malone
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, USA
- Memorial Sloan Kettering Cancer Center, Sloan Kettering Institute, New York, NY, USA
| | - James Chen
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, USA
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - William C Budell
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Venkata P Dandey
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
- National Institute of Environmental Health Sciences, Durham, NC, USA
| | - Kashyap Maruthi
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Joshua H Mendez
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Nina Molina
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, USA
| | - Edward T Eng
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Laura Y Yen
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Clinton S Potter
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Chan Zuckerberg Imaging Institute, San Francisco, CA, USA
| | - Bridget Carragher
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Chan Zuckerberg Imaging Institute, San Francisco, CA, USA
| | - Seth A Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, USA.
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3
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Giraldo-Berrio D, Mendivil-Perez M, Velez-Pardo C, Jimenez-Del-Rio M. Rotenone Induces a Neuropathological Phenotype in Cholinergic-like Neurons Resembling Parkinson's Disease Dementia (PDD). Neurotox Res 2024; 42:28. [PMID: 38842585 PMCID: PMC11156752 DOI: 10.1007/s12640-024-00705-3] [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: 11/16/2023] [Revised: 04/12/2024] [Accepted: 05/01/2024] [Indexed: 06/07/2024]
Abstract
Parkinson's disease with dementia (PDD) is a neurological disorder that clinically and neuropathologically overlaps with Parkinson's disease (PD) and Alzheimer's disease (AD). Although it is assumed that alpha-synuclein ( α -Syn), amyloid beta (A β ), and the protein Tau might synergistically induce cholinergic neuronal degeneration, presently the pathological mechanism of PDD remains unclear. Therefore, it is essential to delve into the cellular and molecular aspects of this neurological entity to identify potential targets for prevention and treatment strategies. Cholinergic-like neurons (ChLNs) were exposed to rotenone (ROT, 10 μ M) for 24 h. ROT provokes loss of Δ Ψ m , generation of reactive oxygen species (ROS), phosphorylation of leucine-rich repeated kinase 2 (LRRK2 at Ser935) concomitantly with phosphorylation of α -synuclein ( α -Syn, Ser129), induces accumulation of intracellular A β (iA β ), oxidized DJ-1 (Cys106), as well as phosphorylation of TAU (Ser202/Thr205), increases the phosphorylation of c-JUN (Ser63/Ser73), and increases expression of proapoptotic proteins TP53, PUMA, and cleaved caspase 3 (CC3) in ChLNs. These neuropathological features resemble those reproduced in presenilin 1 (PSEN1) E280A ChLNs. Interestingly, anti-oxidant and anti-amyloid cannabidiol (CBD), JNK inhibitor SP600125 (SP), TP53 inhibitor pifithrin- α (PFT), and LRRK2 kinase inhibitor PF-06447475 (PF475) significantly diminish ROT-induced oxidative stress (OS), proteinaceous, and cell death markers in ChLNs compared to naïve ChLNs. In conclusion, ROT induces p- α -Syn, iA β , p-Tau, and cell death in ChLNs, recapitulating the neuropathology findings in PDD. Our report provides an excellent in vitro model to test for potential therapeutic strategies against PDD. Our data suggest that ROT induces a neuropathologic phenotype in ChLNs similar to that caused by the mutation PSEN1 E280A.
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Affiliation(s)
- Daniela Giraldo-Berrio
- Neuroscience Research Group, Medical Research Institute, Faculty of Medicine, University of Antioquia (UdeA), Calle 70 No. 52-21, and Calle 62 # 52-59, Building 1, Room 412, Medellin, Antioquia, Colombia
| | - Miguel Mendivil-Perez
- Neuroscience Research Group, Medical Research Institute, Faculty of Medicine, University of Antioquia (UdeA), Calle 70 No. 52-21, and Calle 62 # 52-59, Building 1, Room 412, Medellin, Antioquia, Colombia
| | - Carlos Velez-Pardo
- Neuroscience Research Group, Medical Research Institute, Faculty of Medicine, University of Antioquia (UdeA), Calle 70 No. 52-21, and Calle 62 # 52-59, Building 1, Room 412, Medellin, Antioquia, Colombia.
| | - Marlene Jimenez-Del-Rio
- Neuroscience Research Group, Medical Research Institute, Faculty of Medicine, University of Antioquia (UdeA), Calle 70 No. 52-21, and Calle 62 # 52-59, Building 1, Room 412, Medellin, Antioquia, Colombia.
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4
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Odorčić I, Hamed MB, Lismont S, Chávez-Gutiérrez L, Efremov RG. Apo and Aβ46-bound γ-secretase structures provide insights into amyloid-β processing by the APH-1B isoform. Nat Commun 2024; 15:4479. [PMID: 38802343 PMCID: PMC11130327 DOI: 10.1038/s41467-024-48776-2] [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: 08/29/2023] [Accepted: 05/07/2024] [Indexed: 05/29/2024] Open
Abstract
Deposition of amyloid-β (Aβ) peptides in the brain is a hallmark of Alzheimer's disease. Aβs are generated through sequential proteolysis of the amyloid precursor protein by the γ-secretase complexes (GSECs). Aβ peptide length, modulated by the Presenilin (PSEN) and APH-1 subunits of GSEC, is critical for Alzheimer's pathogenesis. Despite high relevance, mechanistic understanding of the proteolysis of Aβ, and its modulation by APH-1, remain incomplete. Here, we report cryo-EM structures of human GSEC (PSEN1/APH-1B) reconstituted into lipid nanodiscs in apo form and in complex with the intermediate Aβ46 substrate without cross-linking. We find that three non-conserved and structurally divergent APH-1 regions establish contacts with PSEN1, and that substrate-binding induces concerted rearrangements in one of the identified PSEN1/APH-1 interfaces, providing structural basis for APH-1 allosteric-like effects. In addition, the GSEC-Aβ46 structure reveals an interaction between Aβ46 and loop 1PSEN1, and identifies three other H-bonding interactions that, according to functional validation, are required for substrate recognition and efficient sequential catalysis.
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Affiliation(s)
- Ivica Odorčić
- Center for Structural Biology, VIB, Brussels, Belgium
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
- VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49 box 602, 3000, Leuven, Belgium
- Department of Neurosciences, Leuven Brain Institute, KU Leuven, Herestraat 49 box 602, 3000, Leuven, Belgium
| | - Mohamed Belal Hamed
- VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49 box 602, 3000, Leuven, Belgium
- Department of Neurosciences, Leuven Brain Institute, KU Leuven, Herestraat 49 box 602, 3000, Leuven, Belgium
| | - Sam Lismont
- VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49 box 602, 3000, Leuven, Belgium
- Department of Neurosciences, Leuven Brain Institute, KU Leuven, Herestraat 49 box 602, 3000, Leuven, Belgium
| | - Lucía Chávez-Gutiérrez
- VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49 box 602, 3000, Leuven, Belgium.
- Department of Neurosciences, Leuven Brain Institute, KU Leuven, Herestraat 49 box 602, 3000, Leuven, Belgium.
| | - Rouslan G Efremov
- Center for Structural Biology, VIB, Brussels, Belgium.
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium.
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5
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Wakabayashi T, Oide M, Nakasako M. CryoEM-sampling of metastable conformations appearing in cofactor-ligand association and catalysis of glutamate dehydrogenase. Sci Rep 2024; 14:11165. [PMID: 38750092 PMCID: PMC11096400 DOI: 10.1038/s41598-024-61793-x] [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: 12/22/2023] [Accepted: 05/09/2024] [Indexed: 05/18/2024] Open
Abstract
Kinetic aspects of enzymatic reactions are described by equations based on the Michaelis-Menten theory for the initial stage. However, the kinetic parameters provide little information on the atomic mechanism of the reaction. In this study, we analyzed structures of glutamate dehydrogenase in the initial and steady stages of the reaction using cryoEM at near-atomic resolution. In the initial stage, four metastable conformations displayed different domain motions and cofactor/ligand association modes. The most striking finding was that the enzyme-cofactor-substrate complex, treated as a single state in the enzyme kinetic theory, comprised at least three different metastable conformations. In the steady stage, seven conformations, including derivatives from the four conformations in the initial stage, made the reaction pathway complicated. Based on the visualized conformations, we discussed stage-dependent pathways to illustrate the dynamics of the enzyme in action.
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Grants
- JPMJPR22E2 Japan Science and Technology Agency
- jp13480214 Japan Society for the Promotion of Science
- jp19204042 Japan Society for the Promotion of Science
- jp22244054 Japan Society for the Promotion of Science
- jp21H01050 Japan Society for the Promotion of Science
- jp26800227 Japan Society for the Promotion of Science
- 18J11653 Japan Society for the Promotion of Science
- jp15076210 Ministry of Education, Culture, Sports, Science and Technology of Japan
- jp20050030 Ministry of Education, Culture, Sports, Science and Technology of Japan
- jp22018027 Ministry of Education, Culture, Sports, Science and Technology of Japan
- jp23120525, jp25120725 Ministry of Education, Culture, Sports, Science and Technology of Japan
- jp15H01647 Ministry of Education, Culture, Sports, Science and Technology of Japan
- jp17H05891 Ministry of Education, Culture, Sports, Science and Technology of Japan
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Affiliation(s)
- Taiki Wakabayashi
- Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoko-Ku, Yokohama, Kanagawa, 223-8522, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-Cho, Sayo-Gun, Hyogo, 679-5148, Japan
| | - Mao Oide
- Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoko-Ku, Yokohama, Kanagawa, 223-8522, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-Cho, Sayo-Gun, Hyogo, 679-5148, Japan
- PRESTO, Japan Science and Technology Agency, Chiyoda-Ku, Tokyo, 102-0076, Japan
- Protein Research Institute, Osaka University, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Masayoshi Nakasako
- Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoko-Ku, Yokohama, Kanagawa, 223-8522, Japan.
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-Cho, Sayo-Gun, Hyogo, 679-5148, Japan.
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6
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Nayak AR, Rangubpit W, Will AH, Hu Y, Castro-Hartmann P, Lobo JJ, Dryden K, Lamb GD, Sompornpisut P, Samsó M. Interplay between Mg 2+ and Ca 2+ at multiple sites of the ryanodine receptor. Nat Commun 2024; 15:4115. [PMID: 38750013 PMCID: PMC11096358 DOI: 10.1038/s41467-024-48292-3] [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: 12/31/2023] [Accepted: 04/26/2024] [Indexed: 05/18/2024] Open
Abstract
RyR1 is an intracellular Ca2+ channel important in excitable cells such as neurons and muscle fibers. Ca2+ activates it at low concentrations and inhibits it at high concentrations. Mg2+ is the main physiological RyR1 inhibitor, an effect that is overridden upon activation. Despite the significance of Mg2+-mediated inhibition, the molecular-level mechanisms remain unclear. In this work we determined two cryo-EM structures of RyR1 with Mg2+ up to 2.8 Å resolution, identifying multiple Mg2+ binding sites. Mg2+ inhibits at the known Ca2+ activating site and we propose that the EF hand domain is an inhibitory divalent cation sensor. Both divalent cations bind to ATP within a crevice, contributing to the precise transmission of allosteric changes within the enormous channel protein. Notably, Mg2+ inhibits RyR1 by interacting with the gating helices as validated by molecular dynamics. This structural insight enhances our understanding of how Mg2+ inhibition is overcome during excitation.
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Affiliation(s)
- Ashok R Nayak
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, USA
| | - Warin Rangubpit
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - Alex H Will
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, USA
| | - Yifan Hu
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, USA
| | - Pablo Castro-Hartmann
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, USA
- ThermoFisher Scientific, Cambridge, UK
| | - Joshua J Lobo
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, USA
| | - Kelly Dryden
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
- Department of Chemistry and Biochemistry, UC Santa Barbara, Santa Barbara, CA, USA
| | - Graham D Lamb
- Department of Microbiology, Anatomy, Physiology and Pharmacology, La Trobe University, Melbourne, VIC, Australia
| | - Pornthep Sompornpisut
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
| | - Montserrat Samsó
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, USA.
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7
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Guzmán-Ocampo DC, Aguayo-Ortiz R, Dominguez L. Understanding the Modulatory Role of E2012 on the γ-Secretase-Substrate Interaction. J Chem Inf Model 2024; 64:3855-3864. [PMID: 38623052 DOI: 10.1021/acs.jcim.3c01993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Allosteric modulation plays a critical role in enzyme functionality and requires a deep understanding of the interactions between the active and allosteric sites. γ-Secretase (GS) is a key therapeutic target in the treatment of Alzheimer's disease (AD), through its role in the synthesis of amyloid β peptides that accumulate in AD patients. This study explores the structure and dynamic effects of GS modulation by E2012 binding, employing well-tempered metadynamics and conventional molecular dynamics simulations across three binding scenarios: (1) GS enzyme with and without L458 inhibitor, (2) the GS-substrate complex together with the modulator E2012 in two different binding modes, and (3) E2012 interacting with a C99 substrate fragment. Our findings reveal that the presence of L458 induces conformational changes that contribute to stabilization of the GS enzyme dynamics, previously reported as a key factor that allowed the resolution of the cryo-EM structure and the enhanced binding of E2012. Furthermore, we identified the most favorable binding site for E2012 within the GS-substrate complex, uncovering significant modulatory effects and a complex network of interactions that influence the position of the substrate for catalysis. In addition, we explore a potential substrate-modulator binding before the formation of the enzyme-substrate complex. The insights gained from our study emphasize the importance of these interactions in the development of potential therapeutic interventions that target the functionality of the GS enzyme in AD.
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Affiliation(s)
- Dulce C Guzmán-Ocampo
- Departamento de Fisicoquímica, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico
| | - Rodrigo Aguayo-Ortiz
- Departamento de Farmacia, Facultad de Química,Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico
| | - Laura Dominguez
- Departamento de Fisicoquímica, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico
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8
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Akiyama N, Ishiguro K, Yokoyama T, Miyauchi K, Nagao A, Shirouzu M, Suzuki T. Structural insights into the decoding capability of isoleucine tRNAs with lysidine and agmatidine. Nat Struct Mol Biol 2024; 31:817-825. [PMID: 38538915 DOI: 10.1038/s41594-024-01238-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 01/31/2024] [Indexed: 05/21/2024]
Abstract
The anticodon modifications of transfer RNAs (tRNAs) finetune the codon recognition on the ribosome for accurate translation. Bacteria and archaea utilize the modified cytidines, lysidine (L) and agmatidine (agm2C), respectively, in the anticodon of tRNAIle to decipher AUA codon. L and agm2C contain long side chains with polar termini, but their functions remain elusive. Here we report the cryogenic electron microscopy structures of tRNAsIle recognizing the AUA codon on the ribosome. Both modifications interact with the third adenine of the codon via a unique C-A geometry. The side chains extend toward 3' direction of the mRNA, and the polar termini form hydrogen bonds with 2'-OH of the residue 3'-adjacent to the AUA codon. Biochemical analyses demonstrated that AUA decoding is facilitated by the additional interaction between the polar termini of the modified cytidines and 2'-OH of the fourth mRNA residue. We also visualized cyclic N6-threonylcarbamoyladenosine (ct6A), another tRNA modification, and revealed a molecular basis how ct6A contributes to efficient decoding.
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MESH Headings
- RNA, Transfer, Ile/chemistry
- RNA, Transfer, Ile/metabolism
- RNA, Transfer, Ile/genetics
- Cryoelectron Microscopy
- Anticodon/chemistry
- Anticodon/metabolism
- Ribosomes/metabolism
- Ribosomes/chemistry
- Nucleic Acid Conformation
- Models, Molecular
- Codon/genetics
- Lysine/metabolism
- Lysine/chemistry
- Lysine/analogs & derivatives
- Cytidine/analogs & derivatives
- Cytidine/chemistry
- Cytidine/metabolism
- RNA, Transfer/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- Protein Biosynthesis
- Pyrimidine Nucleosides
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Affiliation(s)
- Naho Akiyama
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Kensuke Ishiguro
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan
| | - Takeshi Yokoyama
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Kenjyo Miyauchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Asuteka Nagao
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Mikako Shirouzu
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan.
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9
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Zhang W, Liu Y, Jang H, Nussinov R. Slower CDK4 and faster CDK2 activation in the cell cycle. Structure 2024:S0969-2126(24)00138-2. [PMID: 38703777 DOI: 10.1016/j.str.2024.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 02/08/2024] [Accepted: 04/09/2024] [Indexed: 05/06/2024]
Abstract
Dysregulation of cyclin-dependent kinases (CDKs) impacts cell proliferation, driving cancer. Here, we ask why the cyclin-D/CDK4 complex governs cell cycle progression through the longer G1 phase, whereas cyclin-E/CDK2 regulates the shorter G1/S phase transition. We consider available experimental cellular and structural data including cyclin-E's high-level burst, sustained duration of elevated cyclin-D expression, and explicit solvent molecular dynamics simulations of the inactive monomeric and complexed states, to establish the conformational tendencies along the landscape of the distinct activation scenarios of cyclin-D/CDK4 and cyclin-E/CDK2 in the G1 phase and G1/S transition of the cell cycle, respectively. These lead us to propose slower activation of cyclin-D/CDK4 and rapid activation of cyclin-E/CDK2. We provide the mechanisms through which this occurs, offering innovative CDK4 drug design considerations. Our insightful mechanistic work addresses a compelling cell cycle regulation question and illuminates the distinct activation speeds between the G1 and the G1/S phases, which are crucial for function.
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Affiliation(s)
- Wengang Zhang
- Cancer Innovation Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Yonglan Liu
- Cancer Innovation Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Hyunbum Jang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA; Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
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10
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Moser C, Guschtschin-Schmidt N, Silber M, Flum J, Muhle-Goll C. Substrate Selection Criteria in Regulated Intramembrane Proteolysis. ACS Chem Neurosci 2024; 15:1321-1334. [PMID: 38525994 DOI: 10.1021/acschemneuro.4c00068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024] Open
Abstract
Alzheimer's disease is the most common form of dementia encountered in an aging population. Characteristic amyloid deposits of Aβ peptides in the brain are generated through cleavage of amyloid precursor protein (APP) by γ-secretase, an intramembrane protease. Cryo-EM structures of substrate γ-secretase complexes revealed details of the process, but how substrates are recognized and enter the catalytic site is still largely ignored. γ-Secretase cleaves a diverse range of substrate sequences without a common consensus sequence, but strikingly, single point mutations within the transmembrane domain (TMD) of specific substrates may greatly affect cleavage efficiencies. Previously, conformational flexibility was hypothesized to be the main criterion for substrate selection. Here we review the 3D structure and dynamics of several γ-secretase substrate TMDs and compare them with mutants shown to affect the cleavage efficiency. In addition, we present structural and dynamic data on ITGB1, a known nonsubstrate of γ-secretase. A comparison of biophysical details between these TMDs and changes generated by introducing crucial mutations allowed us to unravel common principles that differ between substrates and nonsubstrates. We identified three motifs in the investigated substrates: a highly flexible transmembrane domain, a destabilization of the cleavage region, and a basic signature at the end of the transmembrane helix. None of these appears to be exclusive. While conformational flexibility on its own may increase cleavage efficiency in well-known substrates like APP or Notch1, our data suggest that the three motifs seem to be rather variably combined to determine whether a transmembrane helix is efficiently recognized as a γ-secretase substrate.
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Affiliation(s)
- Celine Moser
- Institute for Biological Interfaces 4, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Nadja Guschtschin-Schmidt
- Institute for Biological Interfaces 4, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
- Institute of Organic Chemistry, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - Mara Silber
- Institute for Biological Interfaces 4, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Julia Flum
- Institute for Biological Interfaces 4, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Claudia Muhle-Goll
- Institute for Biological Interfaces 4, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
- Institute of Organic Chemistry, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
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11
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Perrin F, Sinha P, Mitchell SPC, Sadek M, Maesako M, Berezovska O. Identification of PS1/gamma-secretase and glutamate transporter GLT-1 interaction sites. J Biol Chem 2024; 300:107172. [PMID: 38499151 PMCID: PMC11015137 DOI: 10.1016/j.jbc.2024.107172] [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: 09/23/2023] [Revised: 02/02/2024] [Accepted: 03/05/2024] [Indexed: 03/20/2024] Open
Abstract
The recently discovered interaction between Presenilin 1 (PS1), a catalytic subunit of γ-secretase responsible for generating amyloid-β peptides, and GLT-1, a major glutamate transporter in the brain (EAAT2), provides a mechanistic link between these two key factors involved in Alzheimer's disease (AD) pathology. Modulating this interaction can be crucial to understand the consequence of such crosstalk in AD context and beyond. However, the interaction sites between these two proteins are unknown. Herein, we utilized an alanine scanning approach coupled with FRET-based fluorescence lifetime imaging microscopy to identify the interaction sites between PS1 and GLT-1 in their native environment within intact cells. We found that GLT-1 residues at position 276 to 279 (TM5) and PS1 residues at position 249 to 252 (TM6) are crucial for GLT-1-PS1 interaction. These results have been cross validated using AlphaFold Multimer prediction. To further investigate whether this interaction of endogenously expressed GLT-1 and PS1 can be prevented in primary neurons, we designed PS1/GLT-1 cell-permeable peptides (CPPs) targeting the PS1 or GLT-1 binding site. We used HIV TAT domain to allow for cell penetration which was assayed in neurons. First, we assessed the toxicity and penetration of CPPs by confocal microscopy. Next, to ensure the efficiency of CPPs, we monitored the modulation of GLT-1-PS1 interaction in intact neurons by fluorescence lifetime imaging microscopy. We saw significantly less interaction between PS1 and GLT-1 with both CPPs. Our study establishes a new tool to study the functional aspect of GLT-1-PS1 interaction and its relevance in normal physiology and AD models.
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Affiliation(s)
- Florian Perrin
- MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Priyanka Sinha
- MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Shane Patrick Clancy Mitchell
- MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Michael Sadek
- MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Masato Maesako
- MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Oksana Berezovska
- MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA.
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12
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Saecker RM, Mueller AU, Malone B, Chen J, Budell WC, Dandey VP, Maruthi K, Mendez JH, Molina N, Eng ET, Yen LY, Potter CS, Carragher B, Darst SA. Early intermediates in bacterial RNA polymerase promoter melting visualized by time-resolved cryo-electron microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.13.584744. [PMID: 38559232 PMCID: PMC10979975 DOI: 10.1101/2024.03.13.584744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
During formation of the transcription-competent open complex (RPo) by bacterial RNA polymerases (RNAP), transient intermediates pile up before overcoming a rate-limiting step. Structural descriptions of these interconversions in real time are unavailable. To address this gap, time-resolved cryo-electron microscopy (cryo-EM) was used to capture four intermediates populated 120 or 500 milliseconds (ms) after mixing Escherichia coli σ70-RNAP and the λPR promoter. Cryo-EM snapshots revealed the upstream edge of the transcription bubble unpairs rapidly, followed by stepwise insertion of two conserved nontemplate strand (nt-strand) bases into RNAP pockets. As nt-strand "read-out" extends, the RNAP clamp closes, expelling an inhibitory σ70 domain from the active-site cleft. The template strand is fully unpaired by 120 ms but remains dynamic, indicating yet unknown conformational changes load it in subsequent steps. Because these events likely describe DNA opening at many bacterial promoters, this study provides needed insights into how DNA sequence regulates steps of RPo formation.
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Affiliation(s)
- Ruth M. Saecker
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065 USA
| | - Andreas U. Mueller
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065 USA
| | - Brandon Malone
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065 USA
| | - James Chen
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065 USA
| | - William C. Budell
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
| | - Venkata P. Dandey
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
| | - Kashyap Maruthi
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
| | - Joshua H. Mendez
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
| | - Nina Molina
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065 USA
| | - Edward T. Eng
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
| | - Laura Y. Yen
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
| | - Clinton S. Potter
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY USA
| | - Bridget Carragher
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY USA
| | - Seth A. Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065 USA
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13
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De Strooper B, Karran E. New precision medicine avenues to the prevention of Alzheimer's disease from insights into the structure and function of γ-secretases. EMBO J 2024; 43:887-903. [PMID: 38396302 PMCID: PMC10943082 DOI: 10.1038/s44318-024-00057-w] [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: 11/18/2023] [Revised: 01/20/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
Two phase-III clinical trials with anti-amyloid peptide antibodies have met their primary goal, i.e. slowing of Alzheimer's disease (AD) progression. However, antibody therapy may not be the optimal therapeutic modality for AD prevention, as we will discuss in the context of the earlier small molecules described as "γ-secretase modulators" (GSM). We review here the structure, function, and pathobiology of γ-secretases, with a focus on how mutations in presenilin genes result in early-onset AD. Significant progress has been made in generating compounds that act in a manner opposite to pathogenic presenilin mutations: they stabilize the proteinase-substrate complex, thereby increasing the processivity of substrate cleavage and altering the size spectrum of Aβ peptides produced. We propose the term "γ-secretase allosteric stabilizers" (GSAS) to distinguish these compounds from the rather heterogenous class of GSM. The GSAS represent, in theory, a precision medicine approach to the prevention of amyloid deposition, as they specifically target a discrete aspect in a complex cell biological signalling mechanism that initiates the pathological processes leading to Alzheimer's disease.
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Affiliation(s)
- Bart De Strooper
- Dementia Research Institute, Institute of Neurology, University College London, at the Francis Crick Institute, London, NW1 AT, UK.
- Laboratory for the Research of Neurodegenerative Diseases, VIB Center for Brain & Disease Research, and Leuven Brain Institute, KU Leuven, Leuven, 3000, Belgium.
| | - Eric Karran
- Cambridge Research Center, AbbVie, Inc., Cambridge, MA, USA
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14
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Burke SM, Avstrikova M, Noviello CM, Mukhtasimova N, Changeux JP, Thakur GA, Sine SM, Cecchini M, Hibbs RE. Structural mechanisms of α7 nicotinic receptor allosteric modulation and activation. Cell 2024; 187:1160-1176.e21. [PMID: 38382524 PMCID: PMC10950261 DOI: 10.1016/j.cell.2024.01.032] [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: 08/31/2023] [Revised: 12/05/2023] [Accepted: 01/22/2024] [Indexed: 02/23/2024]
Abstract
The α7 nicotinic acetylcholine receptor is a pentameric ligand-gated ion channel that plays an important role in cholinergic signaling throughout the nervous system. Its unique physiological characteristics and implications in neurological disorders and inflammation make it a promising but challenging therapeutic target. Positive allosteric modulators overcome limitations of traditional α7 agonists, but their potentiation mechanisms remain unclear. Here, we present high-resolution structures of α7-modulator complexes, revealing partially overlapping binding sites but varying conformational states. Structure-guided functional and computational tests suggest that differences in modulator activity arise from the stable rotation of a channel gating residue out of the pore. We extend the study using a time-resolved cryoelectron microscopy (cryo-EM) approach to reveal asymmetric state transitions for this homomeric channel and also find that a modulator with allosteric agonist activity exploits a distinct channel-gating mechanism. These results define mechanisms of α7 allosteric modulation and activation with implications across the pentameric receptor superfamily.
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Affiliation(s)
- Sean M Burke
- Molecular Biophysics Graduate Program, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mariia Avstrikova
- Institut de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, 67081 Strasbourg Cedex, France
| | - Colleen M Noviello
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nuriya Mukhtasimova
- Receptor Biology Laboratory, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55902, USA; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55902, USA
| | - Jean-Pierre Changeux
- Neuroscience Department, Institut Pasteur, Collège de France, 75015 Paris, France
| | - Ganesh A Thakur
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
| | - Steven M Sine
- Receptor Biology Laboratory, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55902, USA; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55902, USA; Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN 55902, USA.
| | - Marco Cecchini
- Institut de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, 67081 Strasbourg Cedex, France.
| | - Ryan E Hibbs
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA; Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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15
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Jakowiecki J, Orzeł U, Miszta P, Młynarczyk K, Filipek S. Conformational Changes and Unfolding of β-Amyloid Substrates in the Active Site of γ-Secretase. Int J Mol Sci 2024; 25:2564. [PMID: 38473811 DOI: 10.3390/ijms25052564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 02/12/2024] [Accepted: 02/18/2024] [Indexed: 03/14/2024] Open
Abstract
Alzheimer's disease (AD) is the leading cause of dementia and is characterized by a presence of amyloid plaques, composed mostly of the amyloid-β (Aβ) peptides, in the brains of AD patients. The peptides are generated from the amyloid precursor protein (APP), which undergoes a sequence of cleavages, referred as trimming, performed by γ-secretase. Here, we investigated conformational changes in a series of β-amyloid substrates (from less and more amyloidogenic pathways) in the active site of presenilin-1, the catalytic subunit of γ-secretase. The substrates are trimmed every three residues, finally leading to Aβ40 and Aβ42, which are the major components of amyloid plaques. To study conformational changes, we employed all-atom molecular dynamics simulations, while for unfolding, we used steered molecular dynamics simulations in an implicit membrane-water environment to accelerate changes. We have found substantial differences in the flexibility of extended C-terminal parts between more and less amyloidogenic pathway substrates. We also propose that the positively charged residues of presenilin-1 may facilitate the stretching and unfolding of substrates. The calculated forces and work/energy of pulling were exceptionally high for Aβ40, indicating why trimming of this substrate is so infrequent.
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Affiliation(s)
- Jakub Jakowiecki
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 02-093 Warsaw, Poland
| | - Urszula Orzeł
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 02-093 Warsaw, Poland
| | - Przemysław Miszta
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 02-093 Warsaw, Poland
| | - Krzysztof Młynarczyk
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 02-093 Warsaw, Poland
| | - Sławomir Filipek
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 02-093 Warsaw, Poland
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16
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Feng M, Santhanam RK, Xing H, Zhou M, Jia H. Inhibition of γ-secretase/Notch pathway as a potential therapy for reversing cancer drug resistance. Biochem Pharmacol 2024; 220:115991. [PMID: 38135129 DOI: 10.1016/j.bcp.2023.115991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/30/2023] [Accepted: 12/15/2023] [Indexed: 12/24/2023]
Abstract
The mechanism of tumor drug resistance is complex and may involve stem cell maintenance, epithelial-mesenchymal transition, the activation of survival signaling pathways, transporter protein expression, and tumor microenvironment remodeling, all of which are linked to γ-secretase/Notch signaling. Increasing evidence has shown that the activation of the γ-secretase/Notch pathway is a key driver of cancer progression and drug resistance development and that γ-secretase inhibitors (GSIs) may be the most promising agents for reversing chemotherapy resistance of tumors by targeting the γ-secretase/Notch pathway. Here, we systematically summarize the roles in supporting γ-secretase/Notch activation-associated transformation of cancer cells into cancer stem cells, promotion of the EMT process, PI3K/Akt, MEK/ERK and NF-κB activation, enhancement of ABC transporter protein expression, and TME alteration in mediating tumor drug resistance. Subsequently, we analyze the mechanism of GSIs targeting the γ-secretase/Notch pathway to reverse tumor drug resistance and propose the outstanding advantages of GSIs in treating breast cancer drug resistance over other tumors. Finally, we emphasize that the development of GSIs for reversing tumor drug resistance is promising.
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Affiliation(s)
- Mei Feng
- Science and Experimental Research Center of Shenyang Medical College, Shenyang 110034, China; Shenyang Key Laboratory of Vascular Biology, Shenyang 110034, China
| | - Ramesh Kumar Santhanam
- Faculty of Science and Marine Environment, University Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia
| | - Huan Xing
- Science and Experimental Research Center of Shenyang Medical College, Shenyang 110034, China
| | - Mingsheng Zhou
- Science and Experimental Research Center of Shenyang Medical College, Shenyang 110034, China; Shenyang Key Laboratory of Vascular Biology, Shenyang 110034, China.
| | - Hui Jia
- School of Traditional Chinese Medicine, Shenyang Medical College, Shenyang 110034, China.
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17
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Ghanim GE, Sekne Z, Balch S, van Roon AMM, Nguyen THD. 2.7 Å cryo-EM structure of human telomerase H/ACA ribonucleoprotein. Nat Commun 2024; 15:746. [PMID: 38272871 PMCID: PMC10811338 DOI: 10.1038/s41467-024-45002-x] [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: 06/27/2023] [Accepted: 01/03/2024] [Indexed: 01/27/2024] Open
Abstract
Telomerase is a ribonucleoprotein (RNP) enzyme that extends telomeric repeats at eukaryotic chromosome ends to counterbalance telomere loss caused by incomplete genome replication. Human telomerase is comprised of two distinct functional lobes tethered by telomerase RNA (hTR): a catalytic core, responsible for DNA extension; and a Hinge and ACA (H/ACA) box RNP, responsible for telomerase biogenesis. H/ACA RNPs also have a general role in pseudouridylation of spliceosomal and ribosomal RNAs, which is critical for the biogenesis of the spliceosome and ribosome. Much of our structural understanding of eukaryotic H/ACA RNPs comes from structures of the human telomerase H/ACA RNP. Here we report a 2.7 Å cryo-electron microscopy structure of the telomerase H/ACA RNP. The significant improvement in resolution over previous 3.3 Å to 8.2 Å structures allows us to uncover new molecular interactions within the H/ACA RNP. Many disease mutations are mapped to these interaction sites. The structure also reveals unprecedented insights into a region critical for pseudouridylation in canonical H/ACA RNPs. Together, our work advances understanding of telomerase-related disease mutations and the mechanism of pseudouridylation by eukaryotic H/ACA RNPs.
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Affiliation(s)
| | - Zala Sekne
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
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18
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Kumar N, Sharma S, Kaushal PS. Cryo- EM structure of the mycobacterial 70S ribosome in complex with ribosome hibernation promotion factor RafH. Nat Commun 2024; 15:638. [PMID: 38245551 PMCID: PMC10799931 DOI: 10.1038/s41467-024-44879-y] [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: 06/02/2023] [Accepted: 01/04/2024] [Indexed: 01/22/2024] Open
Abstract
Ribosome hibernation is a key survival strategy bacteria adopt under environmental stress, where a protein, hibernation promotion factor (HPF), transitorily inactivates the ribosome. Mycobacterium tuberculosis encounters hypoxia (low oxygen) as a major stress in the host macrophages, and upregulates the expression of RafH protein, which is crucial for its survival. The RafH, a dual domain HPF, an orthologue of bacterial long HPF (HPFlong), hibernates ribosome in 70S monosome form, whereas in other bacteria, the HPFlong induces 70S ribosome dimerization and hibernates its ribosome in 100S disome form. Here, we report the cryo- EM structure of M. smegmatis, a close homolog of M. tuberculosis, 70S ribosome in complex with the RafH factor at an overall 2.8 Å resolution. The N- terminus domain (NTD) of RafH binds to the decoding center, similarly to HPFlong NTD. In contrast, the C- terminus domain (CTD) of RafH, which is larger than the HPFlong CTD, binds to a distinct site at the platform binding center of the ribosomal small subunit. The two domain-connecting linker regions, which remain mostly disordered in earlier reported HPFlong structures, interact mainly with the anti-Shine Dalgarno sequence of the 16S rRNA.
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Affiliation(s)
- Niraj Kumar
- Structural Biology & Translation Regulation Laboratory, UNESCO-DBT, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, 121 001, India
| | - Shivani Sharma
- Structural Biology & Translation Regulation Laboratory, UNESCO-DBT, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, 121 001, India
| | - Prem S Kaushal
- Structural Biology & Translation Regulation Laboratory, UNESCO-DBT, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, 121 001, India.
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19
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Wu P, Yang L. sRNA Structural Modeling Based on NMR Data. Methods Mol Biol 2024; 2741:383-397. [PMID: 38217664 DOI: 10.1007/978-1-0716-3565-0_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2024]
Abstract
Small non-coding RNAs (sRNAs) play vital roles in gene expression regulation and RNA interference. To comprehend their molecular mechanisms and develop therapeutic approaches, determining the accurate three-dimensional structure of sRNAs is crucial. Although nuclear magnetic resonance (NMR) spectroscopy is a powerful tool for structural biology, obtaining high-resolution structures of sRNAs using NMR data alone can be challenging. In such cases, structural modeling can provide additional details about RNA structures. In this context, we present a protocol for the structural modeling of sRNA using the SimRNA method based on sparse NMR constraints. To demonstrate the efficacy of our method, we provide selected examples of NMR spectra and RNA structures, specifically for the second stem-loop of DsrA sRNA.
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Affiliation(s)
- Pengzhi Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, People's Republic of China.
- Department of Biology, Institute of Biochemistry, ETH Zürich, Zürich, Switzerland.
| | - Lingna Yang
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
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20
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Gobet A, Moissonnier L, Chaptal V. CryoEM Data Analysis of Membrane Proteins. Practical Considerations on Amphipathic Belts, Ligands, and Variability Analysis. Methods Mol Biol 2024; 2715:471-483. [PMID: 37930545 DOI: 10.1007/978-1-0716-3445-5_28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2023]
Abstract
Membrane proteins data analysis by cryoEM shows some specificities, as can be found in other typical investigations such as biochemistry, biophysics, or X-ray crystallography. Membrane proteins are typically surrounded by an amphipathic belt that will have some degree of influence on the 3D reconstruction and analysis. In this chapter, we review our experience with the ABC transporter BmrA, as well as our statistical analysis of amphipathic belts around membrane proteins, to bring awareness on some particular features of membrane protein investigations by cryoEM.
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Affiliation(s)
- Alexia Gobet
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS University Lyon 1, Lyon, France
| | - Loïck Moissonnier
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS University Lyon 1, Lyon, France
| | - Vincent Chaptal
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS University Lyon 1, Lyon, France.
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21
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Vuillemot R, Harastani M, Hamitouche I, Jonic S. MDSPACE and MDTOMO Software for Extracting Continuous Conformational Landscapes from Datasets of Single Particle Images and Subtomograms Based on Molecular Dynamics Simulations: Latest Developments in ContinuousFlex Software Package. Int J Mol Sci 2023; 25:20. [PMID: 38203192 PMCID: PMC10779004 DOI: 10.3390/ijms25010020] [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: 11/06/2023] [Revised: 12/16/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
Cryo electron microscopy (cryo-EM) instrumentation allows obtaining 3D reconstruction of the structure of biomolecular complexes in vitro (purified complexes studied by single particle analysis) and in situ (complexes studied in cells by cryo electron tomography). Standard cryo-EM approaches allow high-resolution reconstruction of only a few conformational states of a molecular complex, as they rely on data classification into a given number of classes to increase the resolution of the reconstruction from the most populated classes while discarding all other classes. Such discrete classification approaches result in a partial picture of the full conformational variability of the complex, due to continuous conformational transitions with many, uncountable intermediate states. In this article, we present the software with a user-friendly graphical interface for running two recently introduced methods, namely, MDSPACE and MDTOMO, to obtain continuous conformational landscapes of biomolecules by analyzing in vitro and in situ cryo-EM data (single particle images and subtomograms) based on molecular dynamics simulations of an available atomic model of one of the conformations. The MDSPACE and MDTOMO software is part of the open-source ContinuousFlex software package (starting from version 3.4.2 of ContinuousFlex), which can be run as a plugin of the Scipion software package (version 3.1 and later), broadly used in the cryo-EM field.
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Affiliation(s)
| | | | | | - Slavica Jonic
- IMPMC-UMR 7590 CNRS, Sorbonne Université, MNHN, 75005 Paris, France
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22
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Zhao X, Ma D, Ishiguro K, Saito H, Akichika S, Matsuzawa I, Mito M, Irie T, Ishibashi K, Wakabayashi K, Sakaguchi Y, Yokoyama T, Mishima Y, Shirouzu M, Iwasaki S, Suzuki T, Suzuki T. Glycosylated queuosines in tRNAs optimize translational rate and post-embryonic growth. Cell 2023; 186:5517-5535.e24. [PMID: 37992713 DOI: 10.1016/j.cell.2023.10.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 08/14/2023] [Accepted: 10/26/2023] [Indexed: 11/24/2023]
Abstract
Transfer RNA (tRNA) modifications are critical for protein synthesis. Queuosine (Q), a 7-deaza-guanosine derivative, is present in tRNA anticodons. In vertebrate tRNAs for Tyr and Asp, Q is further glycosylated with galactose and mannose to generate galQ and manQ, respectively. However, biogenesis and physiological relevance of Q-glycosylation remain poorly understood. Here, we biochemically identified two RNA glycosylases, QTGAL and QTMAN, and successfully reconstituted Q-glycosylation of tRNAs using nucleotide diphosphate sugars. Ribosome profiling of knockout cells revealed that Q-glycosylation slowed down elongation at cognate codons, UAC and GAC (GAU), respectively. We also found that galactosylation of Q suppresses stop codon readthrough. Moreover, protein aggregates increased in cells lacking Q-glycosylation, indicating that Q-glycosylation contributes to proteostasis. Cryo-EM of human ribosome-tRNA complex revealed the molecular basis of codon recognition regulated by Q-glycosylations. Furthermore, zebrafish qtgal and qtman knockout lines displayed shortened body length, implying that Q-glycosylation is required for post-embryonic growth in vertebrates.
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Affiliation(s)
- Xuewei Zhao
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan
| | - Ding Ma
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan
| | - Kensuke Ishiguro
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan; Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan
| | - Hironori Saito
- RNA System Biochemistry Laboratory, Cluster for Pioneering Research, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - Shinichiro Akichika
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan
| | - Ikuya Matsuzawa
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan
| | - Mari Mito
- RNA System Biochemistry Laboratory, Cluster for Pioneering Research, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Toru Irie
- Faculty of Life Sciences, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555, Japan
| | - Kota Ishibashi
- Faculty of Life Sciences, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555, Japan
| | - Kimi Wakabayashi
- Faculty of Life Sciences, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555, Japan
| | - Yuriko Sakaguchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan
| | - Takeshi Yokoyama
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan; Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Yuichiro Mishima
- Faculty of Life Sciences, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555, Japan
| | - Mikako Shirouzu
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan
| | - Shintaro Iwasaki
- RNA System Biochemistry Laboratory, Cluster for Pioneering Research, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - Takeo Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan.
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan.
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23
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Koch M, Enzlein T, Chen S, Petit D, Lismont S, Zacharias M, Hopf C, Chávez‐Gutiérrez L. APP substrate ectodomain defines amyloid-β peptide length by restraining γ-secretase processivity and facilitating product release. EMBO J 2023; 42:e114372. [PMID: 37853914 PMCID: PMC10690472 DOI: 10.15252/embj.2023114372] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/19/2023] [Accepted: 09/25/2023] [Indexed: 10/20/2023] Open
Abstract
Sequential proteolysis of the amyloid precursor protein (APP) by γ-secretases generates amyloid-β (Aβ) peptides and defines the proportion of short-to-long Aβ peptides, which is tightly connected to Alzheimer's disease (AD) pathogenesis. Here, we study the mechanism that controls substrate processing by γ-secretases and Aβ peptide length. We found that polar interactions established by the APPC99 ectodomain (ECD), involving but not limited to its juxtamembrane region, restrain both the extent and degree of γ-secretases processive cleavage by destabilizing enzyme-substrate interactions. We show that increasing hydrophobicity, via mutation or ligand binding, at APPC99 -ECD attenuates substrate-driven product release and rescues the effects of Alzheimer's disease-associated pathogenic γ-secretase and APP variants on Aβ length. In addition, our study reveals that APPC99 -ECD facilitates the paradoxical production of longer Aβs caused by some γ-secretase inhibitors, which act as high-affinity competitors of the substrate. These findings assign a pivotal role to the substrate ECD in the sequential proteolysis by γ-secretases and suggest it as a sweet spot for the potential design of APP-targeting compounds selectively promoting its processing by these enzymes.
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Affiliation(s)
- Matthias Koch
- VIB/KU Leuven, VIB‐KU Leuven Center for Brain and Disease ResearchLeuvenBelgium
| | - Thomas Enzlein
- VIB/KU Leuven, VIB‐KU Leuven Center for Brain and Disease ResearchLeuvenBelgium
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS)Mannheim University of Applied SciencesMannheimGermany
| | - Shu‐Yu Chen
- Physics Department and Center of Functional Protein AssembliesTechnical University of MunichGarchingGermany
| | - Dieter Petit
- VIB/KU Leuven, VIB‐KU Leuven Center for Brain and Disease ResearchLeuvenBelgium
| | - Sam Lismont
- VIB/KU Leuven, VIB‐KU Leuven Center for Brain and Disease ResearchLeuvenBelgium
| | - Martin Zacharias
- Physics Department and Center of Functional Protein AssembliesTechnical University of MunichGarchingGermany
| | - Carsten Hopf
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS)Mannheim University of Applied SciencesMannheimGermany
- Mannheim Center for Translational Neuroscience (MCTN), Medical Faculty MannheimHeidelberg UniversityMannheimGermany
- Medical FacultyHeidelberg UniversityHeidelbergGermany
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24
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Suárez-González E, Sandoval-Ramírez J, Flores-Hernández J, Carrasco-Carballo A. Ginkgo biloba: Antioxidant Activity and In Silico Central Nervous System Potential. Curr Issues Mol Biol 2023; 45:9674-9691. [PMID: 38132450 PMCID: PMC10742658 DOI: 10.3390/cimb45120604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 10/07/2023] [Accepted: 10/10/2023] [Indexed: 12/23/2023] Open
Abstract
Ginkgo biloba (GB) extracts have been used in clinical studies as an alternative therapy for Alzheimer's disease (AD), but the exact bioaction mechanism has not yet been elucidated. In this work, an in silico study on GB metabolites was carried out using SwissTargetPrediction to determine the proteins associated with AD. The resulting proteins, AChE, MAO-A, MAO-B, β-secretase and γ-secretase, were studied by molecular docking, resulting in the finding that kaempferol, quercetin, and luteolin have multitarget potential against AD. These compounds also exhibit antioxidant activity towards reactive oxygen species (ROS), so antioxidant tests were performed on the extracts using the DPPH and ABTS techniques. The ethanol and ethyl acetate GB extracts showed an important inhibition percentage, higher than 80%, at a dose of 0.01 mg/mL. The effect of GB extracts on AD resulted in multitarget action through two pathways: firstly, inhibiting enzymes responsible for degrading neurotransmitters and forming amyloid plaques; secondly, decreasing ROS in the central nervous system (CNS), reducing its deterioration, and promoting the formation of amyloid plaques. The results of this work demonstrate the great potential of GB as a medicinal plant.
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Affiliation(s)
- Eduardo Suárez-González
- Laboratorio de Elucidación y Síntesis en Química Orgánica, ICUAP-BUAP, Puebla 72570, Mexico;
- Laboratorio de Neuromodulación, Instituto de Fisiología, BUAP, Puebla 72570, Mexico
| | - Jesús Sandoval-Ramírez
- Laboratorio de Síntesis y Modificación de Productos Naturales, FCQ-BUAP, Puebla 72570, Mexico;
| | | | - Alan Carrasco-Carballo
- Laboratorio de Elucidación y Síntesis en Química Orgánica, ICUAP-BUAP, Puebla 72570, Mexico;
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25
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Zielinski M, Peralta Reyes FS, Gremer L, Schemmert S, Frieg B, Schäfer LU, Willuweit A, Donner L, Elvers M, Nilsson LNG, Syvänen S, Sehlin D, Ingelsson M, Willbold D, Schröder GF. Cryo-EM of Aβ fibrils from mouse models find tg-APP ArcSwe fibrils resemble those found in patients with sporadic Alzheimer's disease. Nat Neurosci 2023; 26:2073-2080. [PMID: 37973869 PMCID: PMC10689242 DOI: 10.1038/s41593-023-01484-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 10/06/2023] [Indexed: 11/19/2023]
Abstract
The use of transgenic mice displaying amyloid-β (Aβ) brain pathology has been essential for the preclinical assessment of new treatment strategies for Alzheimer's disease. However, the properties of Aβ in such mice have not been systematically compared to Aβ in the brains of patients with Alzheimer's disease. Here, we determined the structures of nine ex vivo Aβ fibrils from six different mouse models by cryogenic-electron microscopy. We found novel Aβ fibril structures in the APP/PS1, ARTE10 and tg-SwDI models, whereas the human type II filament fold was found in the ARTE10, tg-APPSwe and APP23 models. The tg-APPArcSwe mice showed an Aβ fibril whose structure resembles the human type I filament found in patients with sporadic Alzheimer's disease. A detailed assessment of the Aβ fibril structure is key to the selection of adequate mouse models for the preclinical development of novel plaque-targeting therapeutics and positron emission tomography imaging tracers in Alzheimer's disease.
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Affiliation(s)
- Mara Zielinski
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
- JuStruct, Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
| | | | - Lothar Gremer
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany.
- JuStruct, Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany.
- Institut für Physikalische Biologie, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
| | - Sarah Schemmert
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | - Benedikt Frieg
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
- JuStruct, Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Luisa U Schäfer
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
- JuStruct, Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
- Life and Medical Sciences (LIMES) Institute, University of Bonn, Bonn, Germany
| | - Antje Willuweit
- Institute of Neuroscience and Medicine, Medical Imaging Physics (INM-4), Forschungszentrum Jülich, Jülich, Germany
| | - Lili Donner
- Department of Vascular and Endovascular Surgery, University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany
| | - Margitta Elvers
- Department of Vascular and Endovascular Surgery, University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany
| | - Lars N G Nilsson
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Stina Syvänen
- Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Dag Sehlin
- Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Martin Ingelsson
- Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
- Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada
- Tanz Centre for Research in Neurodegenerative Diseases, Departments of Medicine and Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Dieter Willbold
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany.
- JuStruct, Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany.
- Institut für Physikalische Biologie, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
| | - Gunnar F Schröder
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany.
- JuStruct, Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany.
- Physics Department, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
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26
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Wakabayashi T, Oide M, Kato T, Nakasako M. Coenzyme-binding pathway on glutamate dehydrogenase suggested from multiple-binding sites visualized by cryo-electron microscopy. FEBS J 2023; 290:5514-5535. [PMID: 37682540 DOI: 10.1111/febs.16951] [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: 11/24/2022] [Revised: 08/10/2023] [Accepted: 09/05/2023] [Indexed: 09/09/2023]
Abstract
The structure of hexameric glutamate dehydrogenase (GDH) in the presence of the coenzyme nicotinamide adenine dinucleotide phosphate (NADP) was visualized using cryogenic transmission electron microscopy to investigate the ligand-binding pathways to the active site of the enzyme. Each subunit of GDH comprises one hexamer-forming core domain and one nucleotide-binding domain (NAD domain), which spontaneously opens and closes the active-site cleft situated between the two domains. In the presence of NADP, the potential map of GDH hexamer, assuming D3 symmetry, was determined at a resolution of 2.4 Å, but the NAD domain was blurred due to the conformational variety. After focused classification with respect to the NAD domain, the potential maps interpreted as NADP molecules appeared at five different sites in the active-site cleft. The subunits associated with NADP molecules were close to one of the four metastable conformations in the unliganded state. Three of the five binding sites suggested a pathway of NADP molecules to approach the active-site cleft for initiating the enzymatic reaction. The other two binding modes may rarely appear in the presence of glutamate, as demonstrated by the reaction kinetics. Based on the visualized structures and the results from the enzymatic kinetics, we discussed the binding modes of NADP to GDH in the absence and presence of glutamate.
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Grants
- JPMJPR22E2 Japan Science and Technology Agency
- 18J11653 Japan Society for the Promotion of Science
- jp13480214 Japan Society for the Promotion of Science
- jp19204042 Japan Society for the Promotion of Science
- jp21H01050 Japan Society for the Promotion of Science
- jp22244054 Japan Society for the Promotion of Science
- jp26800227 Japan Society for the Promotion of Science
- jp15076210 Ministry of Education, Culture, Sports, Science and Technology
- jp15H01647 Ministry of Education, Culture, Sports, Science and Technology
- jp17H05891 Ministry of Education, Culture, Sports, Science and Technology
- jp20050030 Ministry of Education, Culture, Sports, Science and Technology
- jp22018027 Ministry of Education, Culture, Sports, Science and Technology
- jp23120525 Ministry of Education, Culture, Sports, Science and Technology
- jp25120725 Ministry of Education, Culture, Sports, Science and Technology
- 0436 Japan Agency for Medical Research and Development
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Affiliation(s)
- Taiki Wakabayashi
- Department of Physics, Faculty of Science and Technology, Keio University, Yokohama, Japan
- RIKEN SPring-8 Center, Sayo-gun, Hyogo, Japan
- RIKEN Cluster for Pioneering Research, Wako, Japan
| | - Mao Oide
- Department of Physics, Faculty of Science and Technology, Keio University, Yokohama, Japan
- RIKEN SPring-8 Center, Sayo-gun, Hyogo, Japan
- RIKEN Cluster for Pioneering Research, Wako, Japan
- PRESTO, Japan Science and Technology Agency, Tokyo, Japan
| | - Takayuki Kato
- Protein Research Institute, Osaka University, Suita, Japan
| | - Masayoshi Nakasako
- Department of Physics, Faculty of Science and Technology, Keio University, Yokohama, Japan
- RIKEN SPring-8 Center, Sayo-gun, Hyogo, Japan
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27
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Barchet C, Fréchin L, Holvec S, Hazemann I, von Loeffelholz O, Klaholz BP. Focused classifications and refinements in high-resolution single particle cryo-EM analysis. J Struct Biol 2023; 215:108015. [PMID: 37659578 DOI: 10.1016/j.jsb.2023.108015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 06/27/2023] [Accepted: 08/17/2023] [Indexed: 09/04/2023]
Abstract
Recent advances in cryo electron microscopy (cryo-EM) and image processing provide new opportunities to analyse drug targets at high resolution. However, structural heterogeneity limits resolution in many practical cases, hence restricting the level at which structural details can be analysed and drug design be performed. As structural disorder is not spread throughout the entire structure of a given macromolecular complex but instead is found in certain regions that move with respect to others and covering molecular scales from domain conformational changes up to the level of side chain conformations in ligand binding pockets, it is possible to focus the attention on those regions and the associated relative movements. Here we show how the usage of focused classifications and refinements provide insights into global conformational arrangements, exemplified on the human ribosome and on the cannabinoid G protein coupled receptor (GPCR), and how they can improve the local map resolution from an essentially disordered region to the 3-4 Å and finally to the 2 Å resolution range. A systematic analysis with variable spherical masks during focused refinement is presented showing that the choice of an optimal mask size helps refining to high resolution. This study covers several practical approaches on 4 examples illustrating how important mask size & shape and including neighbouring structural elements are for a focused analysis of a macromolecular complex. Such methods will be crucial for cryo-EM structure-based drug design of various medical targets and are applicable to single particle cryo-EM and electron tomography data.
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Affiliation(s)
- Charles Barchet
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Léo Fréchin
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Samuel Holvec
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Isabelle Hazemann
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Ottilie von Loeffelholz
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Bruno P Klaholz
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France.
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28
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Small GI, Fedorova O, Olinares PDB, Chandanani J, Banerjee A, Choi YJ, Molina H, Chait BT, Darst SA, Campbell EA. Structural and functional insights into the enzymatic plasticity of the SARS-CoV-2 NiRAN domain. Mol Cell 2023; 83:3921-3930.e7. [PMID: 37890482 PMCID: PMC10843261 DOI: 10.1016/j.molcel.2023.10.001] [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: 06/07/2023] [Revised: 08/28/2023] [Accepted: 10/03/2023] [Indexed: 10/29/2023]
Abstract
The enzymatic activity of the SARS-CoV-2 nidovirus RdRp-associated nucleotidyltransferase (NiRAN) domain is essential for viral propagation, with three distinct activities associated with modification of the nsp9 N terminus, NMPylation, RNAylation, and deRNAylation/capping via a GDP-polyribonucleotidyltransferase reaction. The latter two activities comprise an unconventional mechanism for initiating viral RNA 5' cap formation, while the role of NMPylation is unclear. The structural mechanisms for these diverse enzymatic activities have not been properly delineated. Here, we determine high-resolution cryoelectron microscopy (cryo-EM) structures of catalytic intermediates for the NMPylation and deRNAylation/capping reactions, revealing diverse nucleotide binding poses and divalent metal ion coordination sites to promote its repertoire of activities. The deRNAylation/capping structure explains why GDP is a preferred substrate for the capping reaction over GTP. Altogether, these findings enhance our understanding of the promiscuous coronaviral NiRAN domain, a therapeutic target, and provide an accurate structural platform for drug development.
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Affiliation(s)
- Gabriel I Small
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Olga Fedorova
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
| | - Paul Dominic B Olinares
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, USA
| | - Joshua Chandanani
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Anoosha Banerjee
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Tri-Institutional Program in Chemical Biology, The Rockefeller University, New York, New York, USA
| | - Young Joo Choi
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Henrik Molina
- Proteomics Resource Center, The Rockefeller University, New York, NY 10065, USA
| | - Brian T Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, USA
| | - Seth A Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Elizabeth A Campbell
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
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29
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Luo Z, Ni F, Wang Q, Ma J. OPUS-DSD: deep structural disentanglement for cryo-EM single-particle analysis. Nat Methods 2023; 20:1729-1738. [PMID: 37813988 PMCID: PMC10630141 DOI: 10.1038/s41592-023-02031-6] [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: 11/22/2022] [Accepted: 08/24/2023] [Indexed: 10/11/2023]
Abstract
Cryo-electron microscopy (cryo-EM) captures snapshots of dynamic macromolecules, collectively illustrating the involved structural landscapes. This provides an exciting opportunity to explore the structural variations of macromolecules under study. However, traditional cryo-EM single-particle analysis often yields static structures. Here we describe OPUS-DSD, an algorithm capable of efficiently reconstructing the structural landscape embedded in cryo-EM data. OPUS-DSD uses a three-dimensional convolutional encoder-decoder architecture trained with cryo-EM images, thereby encoding structural variations into a smooth and easily analyzable low-dimension space. This space can be traversed to reconstruct continuous dynamics or clustered to identify distinct conformations. OPUS-DSD can offer meaningful insights into the structural variations of macromolecules, filling in the gaps left by traditional cryo-EM structural determination, and potentially improves the reconstruction resolution by reliably clustering similar particles within the dataset. These functionalities are especially relevant to the study of highly dynamic biological systems. OPUS-DSD is available at https://github.com/alncat/opusDSD .
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Affiliation(s)
- Zhenwei Luo
- Multiscale Research Institute of Complex Systems, Fudan University, Shanghai, China
- Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai, China
- Shanghai AI Laboratory, Shanghai, China
| | - Fengyun Ni
- Multiscale Research Institute of Complex Systems, Fudan University, Shanghai, China
| | - Qinghua Wang
- Center for Biomolecular Innovation, Harcam Biomedicines, Shanghai, China
| | - Jianpeng Ma
- Multiscale Research Institute of Complex Systems, Fudan University, Shanghai, China.
- Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai, China.
- Shanghai AI Laboratory, Shanghai, China.
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30
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Liu X, Wang W. Asymmetric gating of a human hetero-pentameric glycine receptor. Nat Commun 2023; 14:6377. [PMID: 37821459 PMCID: PMC10567788 DOI: 10.1038/s41467-023-42051-6] [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: 12/16/2022] [Accepted: 09/28/2023] [Indexed: 10/13/2023] Open
Abstract
Hetero-pentameric Cys-loop receptors constitute a major type of neurotransmitter receptors that enable signal transmission and processing in the nervous system. Despite intense investigations into their working mechanism and pharmaceutical potentials, how neurotransmitters activate these receptors remains unclear due to the lack of high-resolution structural information in the activated open state. Here we report near-atomic resolution structures resolved in digitonin consistent with all principle functional states of the human α1β GlyR, which is a major Cys-loop receptor that mediates inhibitory neurotransmission in the central nervous system of adults. Glycine binding induces cooperative and symmetric structural rearrangements in the neurotransmitter-binding extracellular domain but asymmetrical pore dilation in the transmembrane domain. Symmetric response in the extracellular domain is consistent with electrophysiological data showing cooperative glycine activation and contribution from both α1 and β subunits. A set of functionally essential but differentially charged amino acid residues in the transmembrane domain of the α1 and β subunits explains asymmetric activation. These findings provide a foundation for understanding how the gating of the Cys-loop receptor family members diverges to accommodate specific physiological environments.
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Affiliation(s)
- Xiaofen Liu
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Weiwei Wang
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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31
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Singh V, Mujwar S, Singh M, Singh T, Ahmad SF. Computational Studies to Understand the Neuroprotective Mechanism of Action Basil Compounds. Molecules 2023; 28:7005. [PMID: 37894484 PMCID: PMC10609097 DOI: 10.3390/molecules28207005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 09/25/2023] [Accepted: 10/02/2023] [Indexed: 10/29/2023] Open
Abstract
Neurodegenerative diseases, such as Alzheimer's and Parkinson's, pose a significant global health challenge, emphasizing the need for novel neuroprotective agents. Basil (Ocimum spp.) has been recognized for its therapeutic potential, and numerous studies have reported neuroprotective effects. In this manuscript, we present a computational protocol to extricate the underlying mechanism of action of basil compounds in neuroprotective effects. Molecular docking-based investigation of the chemical interactions between selected bioactive compounds from basil and key neuroprotective targets, including AChE, GSK3β, γ-secretase, and sirtuin2. Our results demonstrate that basil compound myricerone caffeoyl ester possesses a high affinity of -10.01 and -8.85 kcal/mol against GSK3β and γ-secretase, respectively, indicating their potential in modulating various neurobiological processes. Additionally, molecular dynamics simulations were performed to explore the protein-ligand complexes' stability and to analyze the bound basil compounds' dynamic behavior. This comprehensive computational investigation enlightens the putative mechanistic basis for the neuroprotective effects of basil compounds, providing a rationale for their therapeutic use in neurodegenerative disorders after further experimental validation.
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Affiliation(s)
- Varinder Singh
- Department of Pharmaceutical Sciences and Technology, Maharaja Ranjit Singh Punjab Technical University, Bathinda 151001, Punjab, India
| | - Somdutt Mujwar
- Chitkara College of Pharmacy, Chitkara University, Rajpura 140401, Punjab, India
| | - Manjinder Singh
- Chitkara College of Pharmacy, Chitkara University, Rajpura 140401, Punjab, India
| | - Tanveer Singh
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, College Station, TX 77807, USA;
| | - Sheikh F. Ahmad
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
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Small GI, Fedorova O, Olinares PDB, Chandanani J, Banerjee A, Choi YJ, Molina H, Chait B, Darst SA, Campbell EA. Structural and functional insights into the enzymatic plasticity of the SARS-CoV-2 NiRAN Domain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.25.558837. [PMID: 37808858 PMCID: PMC10557602 DOI: 10.1101/2023.09.25.558837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The enzymatic activity of the SARS-CoV-2 nidovirus RdRp-associated nucleotidyltransferase (NiRAN) domain is essential for viral propagation, with three distinct activities associated with modification of the nsp9 N-terminus, NMPylation, RNAylation, and deRNAylation/capping via a GDP-polyribonucleotidyltransferase reaction. The latter two activities comprise an unconventional mechanism for initiating viral RNA 5'-cap formation, while the role of NMPylation is unclear. The structural mechanisms for these diverse enzymatic activities have not been properly delineated. Here we determine high-resolution cryo-electron microscopy structures of catalytic intermediates for the NMPylation and deRNAylation/capping reactions, revealing diverse nucleotide binding poses and divalent metal ion coordination sites to promote its repertoire of activities. The deRNAylation/capping structure explains why GDP is a preferred substrate for the capping reaction over GTP. Altogether, these findings enhance our understanding of the promiscuous coronaviral NiRAN domain, a therapeutic target, and provide an accurate structural platform for drug development.
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Affiliation(s)
- Gabriel I Small
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Olga Fedorova
- Department of Chemistry and Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
| | - Paul Dominic B Olinares
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, USA
| | - Joshua Chandanani
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Anoosha Banerjee
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Young Joo Choi
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
- Present address: University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Henrik Molina
- Proteomics Resource Center, The Rockefeller University, New York, NY 10065, USA
| | - Brian Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, USA
| | - Seth A Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Elizabeth A Campbell
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
- Lead contact:
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Song J, Gooding AR, Hemphill WO, Love BD, Robertson A, Yao L, Zon LI, North TE, Kasinath V, Cech TR. Structural basis for inactivation of PRC2 by G-quadruplex RNA. Science 2023; 381:1331-1337. [PMID: 37733873 PMCID: PMC11191771 DOI: 10.1126/science.adh0059] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 08/22/2023] [Indexed: 09/23/2023]
Abstract
Polycomb repressive complex 2 (PRC2) silences genes through trimethylation of histone H3K27. PRC2 associates with numerous precursor messenger RNAs (pre-mRNAs) and long noncoding RNAs (lncRNAs) with a binding preference for G-quadruplex RNA. In this work, we present a 3.3-Å-resolution cryo-electron microscopy structure of PRC2 bound to a G-quadruplex RNA. Notably, RNA mediates the dimerization of PRC2 by binding both protomers and inducing a protein interface composed of two copies of the catalytic subunit EZH2, thereby blocking nucleosome DNA interaction and histone H3 tail accessibility. Furthermore, an RNA-binding loop of EZH2 facilitates the handoff between RNA and DNA, another activity implicated in PRC2 regulation by RNA. We identified a gain-of-function mutation in this loop that activates PRC2 in zebrafish. Our results reveal mechanisms for RNA-mediated regulation of a chromatin-modifying enzyme.
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Affiliation(s)
- Jiarui Song
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Anne R. Gooding
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Wayne O. Hemphill
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Brittney D. Love
- Stem Cell and Regenerative Biology Department, Harvard University, Cambridge, MA 02138, USA
- Stem Cell Program, Division of Hematology/Oncology, Boston Children’s Hospital and Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Anne Robertson
- Stem Cell and Regenerative Biology Department, Harvard University, Cambridge, MA 02138, USA
- Stem Cell Program, Division of Hematology/Oncology, Boston Children’s Hospital and Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Liqi Yao
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Leonard I. Zon
- Stem Cell and Regenerative Biology Department, Harvard University, Cambridge, MA 02138, USA
- Stem Cell Program, Division of Hematology/Oncology, Boston Children’s Hospital and Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Trista E. North
- Stem Cell and Regenerative Biology Department, Harvard University, Cambridge, MA 02138, USA
- Stem Cell Program, Division of Hematology/Oncology, Boston Children’s Hospital and Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Vignesh Kasinath
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Thomas R. Cech
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80303, USA
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Pauli TM, Julius A, Costa F, Eschrig S, Moosmüller J, Fischer L, Schanzenbach C, Schmidt FC, Ortner M, Langosch D. Interaction of Substrates with γ-Secretase at the Level of Individual Transmembrane Helices-A Methodological Approach. Int J Mol Sci 2023; 24:14396. [PMID: 37762696 PMCID: PMC10531681 DOI: 10.3390/ijms241814396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/23/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023] Open
Abstract
Intramembrane proteases, such as γ secretase, typically recruit multiple substrates from an excess of single-span membrane proteins. It is currently unclear to which extent substrate recognition depends on specific interactions of their transmembrane domains (TMDs) with TMDs of a protease. Here, we investigated a large number of potential pairwise interactions between TMDs of γ secretase and a diverse set of its substrates using two different configurations of BLaTM, a genetic reporter system. Our results reveal significant interactions between TMD2 of presenilin, the enzymatic subunit of γ secretase, and the TMD of the amyloid precursor protein, as well as of several other substrates. Presenilin TMD2 is a prime candidate for substrate recruitment, as has been shown from previous studies. In addition, the amyloid precursor protein TMD enters interactions with presenilin TMD 4 as well as with the TMD of nicastrin. Interestingly, the Gly-rich interfaces between the amyloid precursor protein TMD and presenilin TMDs 2 and 4 are highly similar to its homodimerization interface. In terms of methodology, the economics of the newly developed library-based method could prove to be a useful feature in related future work for identifying heterotypic TMD-TMD interactions within other biological contexts.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Martin Ortner
- Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany; (T.M.P.); (A.J.); (F.C.); (S.E.); (J.M.); (L.F.); (C.S.); (F.C.S.)
| | - Dieter Langosch
- Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany; (T.M.P.); (A.J.); (F.C.); (S.E.); (J.M.); (L.F.); (C.S.); (F.C.S.)
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Xu Z, Feng J, Yu D, Huo Y, Ma X, Lam WH, Liu Z, Li XD, Ishibashi T, Dang S, Zhai Y. Synergism between CMG helicase and leading strand DNA polymerase at replication fork. Nat Commun 2023; 14:5849. [PMID: 37730685 PMCID: PMC10511561 DOI: 10.1038/s41467-023-41506-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 09/07/2023] [Indexed: 09/22/2023] Open
Abstract
The replisome that replicates the eukaryotic genome consists of at least three engines: the Cdc45-MCM-GINS (CMG) helicase that separates duplex DNA at the replication fork and two DNA polymerases, one on each strand, that replicate the unwound DNA. Here, we determined a series of cryo-electron microscopy structures of a yeast replisome comprising CMG, leading-strand polymerase Polε and three accessory factors on a forked DNA. In these structures, Polε engages or disengages with the motor domains of the CMG by occupying two alternative positions, which closely correlate with the rotational movement of the single-stranded DNA around the MCM pore. During this process, the polymerase remains stably coupled to the helicase using Psf1 as a hinge. This synergism is modulated by a concerted rearrangement of ATPase sites to drive DNA translocation. The Polε-MCM coupling is not only required for CMG formation to initiate DNA replication but also facilitates the leading-strand DNA synthesis mediated by Polε. Our study elucidates a mechanism intrinsic to the replisome that coordinates the activities of CMG and Polε to negotiate any roadblocks, DNA damage, and epigenetic marks encountered during translocation along replication forks.
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Affiliation(s)
- Zhichun Xu
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Jianrong Feng
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Daqi Yu
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Yunjing Huo
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Xiaohui Ma
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Wai Hei Lam
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Zheng Liu
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Xiang David Li
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Toyotaka Ishibashi
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Shangyu Dang
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China.
- HKUST-Shenzhen Research Institute, 518057, Nanshan, Shenzhen, China.
| | - Yuanliang Zhai
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China.
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Czerwonka A, Kałafut J, Nees M. Modulation of Notch Signaling by Small-Molecular Compounds and Its Potential in Anticancer Studies. Cancers (Basel) 2023; 15:4563. [PMID: 37760535 PMCID: PMC10526229 DOI: 10.3390/cancers15184563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/03/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023] Open
Abstract
Notch signaling is responsible for conveying messages between cells through direct contact, playing a pivotal role in tissue development and homeostasis. The modulation of Notch-related processes, such as cell growth, differentiation, viability, and cell fate, offer opportunities to better understand and prevent disease progression, including cancer. Currently, research efforts are mainly focused on attempts to inhibit Notch signaling in tumors with strong oncogenic, gain-of-function (GoF) or hyperactivation of Notch signaling. The goal is to reduce the growth and proliferation of cancer cells, interfere with neo-angiogenesis, increase chemosensitivity, potentially target cancer stem cells, tumor dormancy, and invasion, and induce apoptosis. Attempts to pharmacologically enhance or restore disturbed Notch signaling for anticancer therapies are less frequent. However, in some cancer types, such as squamous cell carcinomas, preferentially, loss-of-function (LoF) mutations have been confirmed, and restoring but not blocking Notch functions may be beneficial for therapy. The modulation of Notch signaling can be performed at several key levels related to NOTCH receptor expression, translation, posttranslational (proteolytic) processing, glycosylation, transport, and activation. This further includes blocking the interaction with Notch-related nuclear DNA transcription. Examples of small-molecular chemical compounds, that modulate individual elements of Notch signaling at the mentioned levels, have been described in the recent literature.
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Affiliation(s)
- Arkadiusz Czerwonka
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, 20-093 Lublin, Poland; (J.K.); (M.N.)
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37
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Benoit MP, Hunter B, Allingham JS, Sosa H. New insights into the mechanochemical coupling mechanism of kinesin-microtubule complexes from their high-resolution structures. Biochem Soc Trans 2023; 51:1505-1520. [PMID: 37560910 PMCID: PMC10586761 DOI: 10.1042/bst20221238] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/28/2023] [Accepted: 08/01/2023] [Indexed: 08/11/2023]
Abstract
Kinesin motor proteins couple mechanical movements in their motor domain to the binding and hydrolysis of ATP in their nucleotide-binding pocket. Forces produced through this 'mechanochemical' coupling are typically used to mobilize kinesin-mediated transport of cargos along microtubules or microtubule cytoskeleton remodeling. This review discusses the recent high-resolution structures (<4 Å) of kinesins bound to microtubules or tubulin complexes that have resolved outstanding questions about the basis of mechanochemical coupling, and how family-specific modifications of the motor domain can enable its use for motility and/or microtubule depolymerization.
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Affiliation(s)
| | - Byron Hunter
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7L 3N6, Canada
| | - John S. Allingham
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Hernando Sosa
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, U.S.A
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38
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Zhang W, Liu Y, Jang H, Nussinov R. Cell cycle progression mechanisms: slower cyclin-D/CDK4 activation and faster cyclin-E/CDK2. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.16.553605. [PMID: 37790340 PMCID: PMC10542123 DOI: 10.1101/2023.08.16.553605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Dysregulation of cyclin-dependent kinases (CDKs) impacts cell proliferation, driving cancer. Here, we ask why the cyclin-D/CDK4 complex governs cell cycle progression through the longer G1 phase, whereas cyclin-E/CDK2 regulates the short G1/S phase transition. We consider the experimentally established high-level bursting of cyclin-E, and sustained duration of elevated cyclin-D expression in the cell, available experimental cellular and structural data, and comprehensive explicit solvent molecular dynamics simulations to provide the mechanistic foundation of the distinct activation scenarios of cyclin-D/CDK4 and cyclin-E/CDK2 in the G1 phase and G1/S transition of the cell cycle, respectively. These lead us to propose slower activation of cyclin-D/CDK4 and rapid activation of cyclin-E/CDK2. Importantly, we determine the mechanisms through which this occurs, offering innovative CDK4 drug design considerations. Our insightful mechanistic work addresses the compelling cell cycle regulation question and illuminates the distinct activation speeds in the G1 versus G1/S phases, which are crucial for cell function.
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Affiliation(s)
- Wengang Zhang
- Cancer Innovation Laboratory, National Cancer Institute, Frederick, MD 21702, U.S.A
| | - Yonglan Liu
- Cancer Innovation Laboratory, National Cancer Institute, Frederick, MD 21702, U.S.A
| | - Hyunbum Jang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, U.S.A
| | - Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, U.S.A
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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39
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Nasef M, Parker L, Kizziah J, Dokland T. Structure of the Streptococcus pneumoniae 70S Ribosome at 2.9 Å Resolution using Cryo-EM. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:938-940. [PMID: 37613388 DOI: 10.1093/micmic/ozad067.467] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Mohamed Nasef
- Department of Microbiology, The University of Alabama in Birmingham, Birmingham, AL, United States
| | - Laura Parker
- Department of Microbiology, The University of Alabama in Birmingham, Birmingham, AL, United States
| | - James Kizziah
- Department of Microbiology, The University of Alabama in Birmingham, Birmingham, AL, United States
| | - Terje Dokland
- Department of Microbiology, The University of Alabama in Birmingham, Birmingham, AL, United States
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40
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Chen SY, Feilen LP, Chávez-Gutiérrez L, Steiner H, Zacharias M. Enzyme-substrate hybrid β-sheet controls geometry and water access to the γ-secretase active site. Commun Biol 2023; 6:670. [PMID: 37355752 PMCID: PMC10290658 DOI: 10.1038/s42003-023-05039-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 06/12/2023] [Indexed: 06/26/2023] Open
Abstract
γ-Secretase is an aspartyl intramembrane protease that cleaves the amyloid precursor protein (APP) involved in Alzheimer's disease pathology and other transmembrane proteins. Substrate-bound structures reveal a stable hybrid β-sheet immediately following the substrate scissile bond consisting of β1 and β2 from the enzyme and β3 from the substrate. Molecular dynamics simulations and enhanced sampling simulations demonstrate that the hybrid β-sheet stability is strongly correlated with the formation of a stable cleavage-compatible active geometry and it also controls water access to the active site. The hybrid β-sheet is only stable for substrates with 3 or more C-terminal residues beyond the scissile bond. The simulation model allowed us to predict the effect of Pro and Phe mutations that weaken the formation of the hybrid β-sheet which were confirmed by experimental testing. Our study provides a direct explanation why γ-secretase preferentially cleaves APP in steps of 3 residues and how the hybrid β-sheet facilitates γ-secretase proteolysis.
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Affiliation(s)
- Shu-Yu Chen
- Center of Functional Protein Assemblies, Technical University of Munich, Garching, Germany
| | - Lukas P Feilen
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Lucía Chávez-Gutiérrez
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), KU Leuven, Leuven, Belgium
| | - Harald Steiner
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Biomedical Center (BMC), Division of Metabolic Biochemistry, Faculty of Medicine, LMU Munich, Germany
| | - Martin Zacharias
- Center of Functional Protein Assemblies, Technical University of Munich, Garching, Germany.
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Abstract
The insulin receptor (IR) is a type II receptor tyrosine kinase that plays essential roles in metabolism, growth, and proliferation. Dysregulation of IR signaling is linked to many human diseases, such as diabetes and cancers. The resolution revolution in cryo-electron microscopy has led to the determination of several structures of IR with different numbers of bound insulin molecules in recent years, which have tremendously improved our understanding of how IR is activated by insulin. Here, we review the insulin-induced activation mechanism of IR, including (a) the detailed binding modes and functions of insulin at site 1 and site 2 and (b) the insulin-induced structural transitions that are required for IR activation. We highlight several other key aspects of the activation and regulation of IR signaling and discuss the remaining gaps in our understanding of the IR activation mechanism and potential avenues of future research.
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Affiliation(s)
- Eunhee Choi
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA;
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA;
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42
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Wang K, Zhang S, Go EP, Ding H, Wang WL, Nguyen HT, Kappes JC, Desaire H, Sodroski J, Mao Y. Asymmetric conformations of cleaved HIV-1 envelope glycoprotein trimers in styrene-maleic acid lipid nanoparticles. Commun Biol 2023; 6:535. [PMID: 37202420 PMCID: PMC10195785 DOI: 10.1038/s42003-023-04916-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 05/04/2023] [Indexed: 05/20/2023] Open
Abstract
During virus entry, the pretriggered human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer initially transits into a default intermediate state (DIS) that remains structurally uncharacterized. Here, we present cryo-EM structures at near-atomic resolution of two cleaved full-length HIV-1 Env trimers purified from cell membranes in styrene-maleic acid lipid nanoparticles without antibodies or receptors. The cleaved Env trimers exhibited tighter subunit packing than uncleaved trimers. Cleaved and uncleaved Env trimers assumed remarkably consistent yet distinct asymmetric conformations, with one smaller and two larger opening angles. Breaking conformational symmetry is allosterically coupled with dynamic helical transformations of the gp41 N-terminal heptad repeat (HR1N) regions in two protomers and with trimer tilting in the membrane. The broken symmetry of the DIS potentially assists Env binding to two CD4 receptors-while resisting antibody binding-and promotes extension of the gp41 HR1 helical coiled-coil, which relocates the fusion peptide closer to the target cell membrane.
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Affiliation(s)
- Kunyu Wang
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China
- Peking-Tsinghua Joint Center for Life Science, Peking University, Beijing, China
| | - Shijian Zhang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Eden P Go
- Department of Chemistry, University of Kansas, Lawrence, KS, USA
| | - Haitao Ding
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Wei Li Wang
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China
| | - Hanh T Nguyen
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - John C Kappes
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
- Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, AL, USA
| | - Heather Desaire
- Department of Chemistry, University of Kansas, Lawrence, KS, USA
| | - Joseph Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA.
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
| | - Youdong Mao
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China.
- Peking-Tsinghua Joint Center for Life Science, Peking University, Beijing, China.
- Center for Quantitative Biology, Academy of Advanced Interdisciplinary Studies, Peking University, Beijing, China.
- National Biomedical Imaging Center, Peking University, Beijing, China.
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Serneels L, Narlawar R, Benito LP, Municoy M, Guallar V, T'Syen D, Dewilde M, Bischoff F, Fraiponts E, Tresadern G, Roevens PWM, Gijsen HJM, De Strooper B. Selective inhibitors of the PSEN1-gamma-secretase complex. J Biol Chem 2023:104794. [PMID: 37164155 DOI: 10.1016/j.jbc.2023.104794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/28/2023] [Accepted: 05/02/2023] [Indexed: 05/12/2023] Open
Abstract
Clinical development of γ-secretases, a family of intramembrane cleaving proteases, as therapeutic targets for a variety of disorders including cancer and Alzheimer's disease, was aborted because of serious mechanism based side effects in phase III trials of unselective inhibitors. Selective inhibition of specific γ-secretase complexes, containing either PSEN1 or PSEN2 as catalytic subunit and APH1A or APH1B as supporting subunits, do provide a feasible therapeutic window in preclinical models of these disorders. We explore here the pharmacophoric features required for PSEN1 versus PSEN2 selective inhibition. We synthesized a series of brain penetrant 2-azabicyclo[2,2,2]octane sulfonamides and identified a compound with low nanomolar potency and high selectivity (>250-fold) towards the PSEN1-APH1B sub-complex versus PSEN2 sub-complexes. We used modelling and site directed mutagenesis to identify critical amino acids along the entry part of this inhibitor into the catalytic site of PSEN1. Specific targeting one of the different γ-secretase complexes might provide safer drugs in the future.
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Affiliation(s)
- Lutgarde Serneels
- VIB Center for Brain and Disease Research and KU Leuven, Department of Neurosciences, Leuven, Belgium
| | - Rajeshwar Narlawar
- VIB Center for Brain and Disease Research and KU Leuven, Department of Neurosciences, Leuven, Belgium; Discovery Chemistry, Janssen Research & Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Laura Perez Benito
- Computational Chemistry, Janssen Research & Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Marti Municoy
- Nostrum Biodiscovery, Jordi Girona 29, Nexus II D128, 08034, Barcelona, Spain
| | - Victor Guallar
- Barcelona Supercomputing Center, Jordi Girona 29, E-08034 Barcelona, Spain; ICREA, Passeig Lluís Companys 23, E-08010 Barcelona, Spain
| | - Dries T'Syen
- VIB Center for Brain and Disease Research and KU Leuven, Department of Neurosciences, Leuven, Belgium
| | - Maarten Dewilde
- VIB Center for Brain and Disease Research and KU Leuven, Department of Neurosciences, Leuven, Belgium
| | - François Bischoff
- Discovery Chemistry, Janssen Research & Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Erwin Fraiponts
- Charles River Laboratories, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Gary Tresadern
- Computational Chemistry, Janssen Research & Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Peter W M Roevens
- Campus Strategy & Partnerships, Janssen Pharmaceutica NV, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Harrie J M Gijsen
- Discovery Chemistry, Janssen Research & Development, Janssen Pharmaceutica NV, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Bart De Strooper
- VIB Center for Brain and Disease Research and KU Leuven, Department of Neurosciences, Leuven, Belgium; Dementia Research Institute, University College London, London, UK.
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44
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Wang L, Hall C, Li J, Choi E, Bai XC. Structural basis of the alkaline pH-dependent activation of insulin receptor-related receptor. Nat Struct Mol Biol 2023; 30:661-669. [PMID: 37055497 PMCID: PMC10465182 DOI: 10.1038/s41594-023-00974-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 03/20/2023] [Indexed: 04/15/2023]
Abstract
The insulin receptor (IR) family is a subfamily of receptor tyrosine kinases that controls metabolic homeostasis and cell growth. Distinct from IR and insulin-like growth factor 1 receptor, whose activation requires ligand binding, insulin receptor-related receptor (IRR)-the third member of the IR family-is activated by alkaline pH. However, the molecular mechanism underlying alkaline pH-induced IRR activation remains unclear. Here, we present cryo-EM structures of human IRR in both neutral pH inactive and alkaline pH active states. Combined with mutagenesis and cellular assays, we show that, upon pH increase, electrostatic repulsion of the pH-sensitive motifs of IRR disrupts its autoinhibited state and promotes a scissor-like rotation between two protomers, leading to a T-shaped active conformation. Together, our study reveals an unprecedented alkaline pH-dependent activation mechanism of IRR, opening up opportunities to understand the structure-function relationship of this important receptor.
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Affiliation(s)
- Liwei Wang
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Catherine Hall
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Jie Li
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Eunhee Choi
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA.
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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45
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Schmidt FC, Fitz K, Feilen LP, Okochi M, Steiner H, Langosch D. Different transmembrane domains determine the specificity and efficiency of the cleavage activity of the γ-secretase subunit presenilin. J Biol Chem 2023; 299:104626. [PMID: 36944398 PMCID: PMC10164903 DOI: 10.1016/j.jbc.2023.104626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/07/2023] [Accepted: 03/11/2023] [Indexed: 03/23/2023] Open
Abstract
The γ-secretase complex catalyzes the intramembrane cleavage of C99, a carboxy-terminal fragment of the amyloid precursor protein. Two paralogs of its catalytic subunit presenilin (PS1 and PS2) are expressed which are autocatalytically cleaved into an N-terminal and a C-terminal fragment during maturation of γ-secretase. In this study, we compared the efficiency and specificity of C99 cleavage by PS1- and PS2-containing γ-secretases. Mass spectrometric analysis of cleavage products obtained in cell-free and cell-based assays revealed that the previously described lower amyloid-β (Aβ)38 generation by PS2 is accompanied by a reciprocal increase in Aβ37 production. We further found PS1 and PS2 to show different preferences in the choice of the initial cleavage site of C99. However, the differences in Aβ38 and Aβ37 generation appear to mainly result from altered subsequent stepwise cleavage of Aβ peptides. Apart from these differences in cleavage specificity, we confirmed a lower efficiency of initial C99 cleavage by PS2 using a detergent-solubilized γ-secretase system. By investigating chimeric PS1/2 molecules, we show that the membrane-embedded, nonconserved residues of the N-terminal fragment mainly account for the differential cleavage efficiency and specificity of both presenilins. At the level of individual transmembrane domains (TMDs), TMD3 was identified as a major modulator of initial cleavage site specificity. The efficiency of endoproteolysis strongly depends on nonconserved TMD6 residues at the interface to TMD2, i.e., at a putative gate of substrate entry. Taken together, our results highlight the role of individual presenilin TMDs in the cleavage of C99 and the generation of Aβ peptides.
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Affiliation(s)
- Fabian C Schmidt
- Biopolymer Chemistry, Technical University of Munich, Freising, Germany
| | - Katja Fitz
- Biopolymer Chemistry, Technical University of Munich, Freising, Germany
| | - Lukas P Feilen
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Masayasu Okochi
- Neuropsychiatry, Division of Internal Medicine, Department of Integrated Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Harald Steiner
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; Division of Metabolic Biochemistry, Faculty of Medicine, Biomedical Center (BMC), Ludwig-Maximilians-University, Munich, Germany
| | - Dieter Langosch
- Biopolymer Chemistry, Technical University of Munich, Freising, Germany.
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46
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Zhang H, Li H, Zhang F, Zhu P. A strategy combining denoising and cryo-EM single particle analysis. Brief Bioinform 2023; 24:7140293. [PMID: 37096633 DOI: 10.1093/bib/bbad148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/21/2023] [Accepted: 03/28/2023] [Indexed: 04/26/2023] Open
Abstract
In cryogenic electron microscopy (cryo-EM) single particle analysis (SPA), high-resolution three-dimensional structures of biological macromolecules are determined by iteratively aligning and averaging a large number of two-dimensional projections of molecules. Since the correlation measures are sensitive to the signal-to-noise ratio, various parameter estimation steps in SPA will be disturbed by the high-intensity noise in cryo-EM. However, denoising algorithms tend to damage high frequencies and suppress mid- and high-frequency contrast of micrographs, which exactly the precise parameter estimation relies on, therefore, limiting their application in SPA. In this study, we suggest combining a cryo-EM image processing pipeline with denoising and maximizing the signal's contribution in various parameter estimation steps. To solve the inherent flaws of denoising algorithms, we design an algorithm named MScale to correct the amplitude distortion caused by denoising and propose a new orientation determination strategy to compensate for the high-frequency loss. In the experiments on several real datasets, the denoised particles are successfully applied in the class assignment estimation and orientation determination tasks, ultimately enhancing the quality of biomacromolecule reconstruction. The case study on classification indicates that our strategy not only improves the resolution of difficult classes (up to 5 Å) but also resolves an additional class. In the case study on orientation determination, our strategy improves the resolution of the final reconstructed density map by 0.34 Å compared with conventional strategy. The code is available at https://github.com/zhanghui186/Mscale.
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Affiliation(s)
- Hui Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongjia Li
- University of Chinese Academy of Sciences, Beijing 100049, China
- High Performance Computer Research Center, Institute of Computing Technology, Chinese Academy of Sciences, Beijing 100190, China
| | - Fa Zhang
- School of Medical Technology, Beijing Institute of Technology, Beijing, 100081, China
| | - Ping Zhu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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47
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Mueller AU, Chen J, Wu M, Chiu C, Nixon BT, Campbell EA, Darst SA. A general mechanism for transcription bubble nucleation in bacteria. Proc Natl Acad Sci U S A 2023; 120:e2220874120. [PMID: 36972428 PMCID: PMC10083551 DOI: 10.1073/pnas.2220874120] [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: 12/08/2022] [Accepted: 03/01/2023] [Indexed: 03/29/2023] Open
Abstract
Bacterial transcription initiation requires σ factors for nucleation of the transcription bubble. The canonical housekeeping σ factor, σ70, nucleates DNA melting via recognition of conserved bases of the promoter -10 motif, which are unstacked and captured in pockets of σ70. By contrast, the mechanism of transcription bubble nucleation and formation during the unrelated σN-mediated transcription initiation is poorly understood. Herein, we combine structural and biochemical approaches to establish that σN, like σ70, captures a flipped, unstacked base in a pocket formed between its N-terminal region I (RI) and extra-long helix features. Strikingly, RI inserts into the nascent bubble to stabilize the nucleated bubble prior to engagement of the obligate ATPase activator. Our data suggest a general paradigm of transcription initiation that requires σ factors to nucleate an early melted intermediate prior to productive RNA synthesis.
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Affiliation(s)
- Andreas U. Mueller
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY10065
| | - James Chen
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY10065
| | - Mengyu Wu
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY10065
| | - Courtney Chiu
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY10065
| | - B. Tracy Nixon
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, PA16802
| | | | - Seth A. Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY10065
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48
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Flacht L, Lunelli M, Kaszuba K, Chen ZA, Reilly FJO, Rappsilber J, Kosinski J, Kolbe M. Integrative structural analysis of the type III secretion system needle complex from Shigella flexneri. Protein Sci 2023; 32:e4595. [PMID: 36790757 PMCID: PMC10019453 DOI: 10.1002/pro.4595] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 01/31/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023]
Abstract
The type III secretion system (T3SS) is a large, transmembrane protein machinery used by various pathogenic gram-negative bacteria to transport virulence factors into the host cell during infection. Understanding the structure of T3SSs is crucial for future developments of therapeutics that could target this system. However, much of the knowledge about the structure of T3SS is available only for Salmonella, and it is unclear how this large assembly is conserved across species. Here, we combined cryo-electron microscopy, cross-linking mass spectrometry, and integrative modeling to determine the structure of the T3SS needle complex from Shigella flexneri. We show that the Shigella T3SS exhibits unique features distinguishing it from other structurally characterized T3SSs. The secretin pore complex adopts a new fold of its C-terminal S domain and the pilotin MxiM[SctG] locates around the outer surface of the pore. The export apparatus structure exhibits a conserved pseudohelical arrangement but includes the N-terminal domain of the SpaS[SctU] subunit, which was not present in any of the previously published virulence-related T3SS structures. Similar to other T3SSs, however, the apparatus is anchored within the needle complex by a network of flexible linkers that either adjust conformation to connect to equivalent patches on the secretin oligomer or bind distinct surface patches at the same height of the export apparatus. The conserved and unique features delineated by our analysis highlight the necessity to analyze T3SS in a species-specific manner, in order to fully understand the underlying molecular mechanisms of these systems. The structure of the type III secretion system from Shigella flexneri delineates conserved and unique features, which could be used for the development of broad-range therapeutics.
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Affiliation(s)
- Lara Flacht
- Department for Structural Infection BiologyCenter for Structural Systems Biology (CSSB) & Helmholtz Centre for Infection Research (HZI)HamburgGermany
- Dynamics of Viral Structures, Leibniz Institute for Virology (LIV)HamburgGermany
| | - Michele Lunelli
- Department for Structural Infection BiologyCenter for Structural Systems Biology (CSSB) & Helmholtz Centre for Infection Research (HZI)HamburgGermany
| | - Karol Kaszuba
- Department for Structural Infection BiologyCenter for Structural Systems Biology (CSSB) & Helmholtz Centre for Infection Research (HZI)HamburgGermany
- Centre for Structural Systems Biology (CSSB) & European Molecular Biology Laboratory (EMBL)HamburgGermany
| | - Zhuo Angel Chen
- Technische Universität Berlin, Institute of Biotechnology, Chair of BioanalyticsBerlinGermany
| | - Francis J. O'. Reilly
- Technische Universität Berlin, Institute of Biotechnology, Chair of BioanalyticsBerlinGermany
| | - Juri Rappsilber
- Technische Universität Berlin, Institute of Biotechnology, Chair of BioanalyticsBerlinGermany
- University of Edinburgh, Wellcome Centre for Cell BiologyEdinburghUK
| | - Jan Kosinski
- Centre for Structural Systems Biology (CSSB) & European Molecular Biology Laboratory (EMBL)HamburgGermany
- Structural and Computational Biology Unit, European Molecular Biology LaboratoryHeidelbergGermany
| | - Michael Kolbe
- Department for Structural Infection BiologyCenter for Structural Systems Biology (CSSB) & Helmholtz Centre for Infection Research (HZI)HamburgGermany
- MIN‐FacultyUniversity HamburgHamburgGermany
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49
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Li YL, Langley CA, Azumaya CM, Echeverria I, Chesarino NM, Emerman M, Cheng Y, Gross JD. The structural basis for HIV-1 Vif antagonism of human APOBEC3G. Nature 2023; 615:728-733. [PMID: 36754086 PMCID: PMC10033410 DOI: 10.1038/s41586-023-05779-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 02/02/2023] [Indexed: 02/10/2023]
Abstract
The APOBEC3 (A3) proteins are host antiviral cellular proteins that hypermutate the viral genome of diverse viral families. In retroviruses, this process requires A3 packaging into viral particles1-4. The lentiviruses encode a protein, Vif, that antagonizes A3 family members by targeting them for degradation. Diversification of A3 allows host escape from Vif whereas adaptations in Vif enable cross-species transmission of primate lentiviruses. How this 'molecular arms race' plays out at the structural level is unknown. Here, we report the cryogenic electron microscopy structure of human APOBEC3G (A3G) bound to HIV-1 Vif, and the hijacked cellular proteins that promote ubiquitin-mediated proteolysis. A small surface explains the molecular arms race, including a cross-species transmission event that led to the birth of HIV-1. Unexpectedly, we find that RNA is a molecular glue for the Vif-A3G interaction, enabling Vif to repress A3G by ubiquitin-dependent and -independent mechanisms. Our results suggest a model in which Vif antagonizes A3G by intercepting it in its most dangerous form for the virus-when bound to RNA and on the pathway to packaging-to prevent viral restriction. By engaging essential surfaces required for restriction, Vif exploits a vulnerability in A3G, suggesting a general mechanism by which RNA binding helps to position key residues necessary for viral antagonism of a host antiviral gene.
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Affiliation(s)
- Yen-Li Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA
| | - Caroline A Langley
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA, USA
| | - Caleigh M Azumaya
- Fred Hutchinson Cancer Center, Electron Microscopy Shared Resource, Seattle, WA, USA
| | - Ignacia Echeverria
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
- Quantitative Bioscience Institute, University of California, San Francisco, CA, USA
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA, USA
| | - Nicholas M Chesarino
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Michael Emerman
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Yifan Cheng
- Quantitative Bioscience Institute, University of California, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California, San Francisco, CA, USA
| | - John D Gross
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA.
- Quantitative Bioscience Institute, University of California, San Francisco, CA, USA.
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50
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Amstrup SK, Ong SC, Sofos N, Karlsen JL, Skjerning RB, Boesen T, Enghild JJ, Hove-Jensen B, Brodersen DE. Structural remodelling of the carbon-phosphorus lyase machinery by a dual ABC ATPase. Nat Commun 2023; 14:1001. [PMID: 36813778 PMCID: PMC9947105 DOI: 10.1038/s41467-023-36604-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 02/08/2023] [Indexed: 02/24/2023] Open
Abstract
In Escherichia coli, the 14-cistron phn operon encoding carbon-phosphorus lyase allows for utilisation of phosphorus from a wide range of stable phosphonate compounds containing a C-P bond. As part of a complex, multi-step pathway, the PhnJ subunit was shown to cleave the C-P bond via a radical mechanism, however, the details of the reaction could not immediately be reconciled with the crystal structure of a 220 kDa PhnGHIJ C-P lyase core complex, leaving a significant gap in our understanding of phosphonate breakdown in bacteria. Here, we show using single-particle cryogenic electron microscopy that PhnJ mediates binding of a double dimer of the ATP-binding cassette proteins, PhnK and PhnL, to the core complex. ATP hydrolysis induces drastic structural remodelling leading to opening of the core complex and reconfiguration of a metal-binding and putative active site located at the interface between the PhnI and PhnJ subunits.
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Affiliation(s)
- Søren K Amstrup
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, DK-8000, Aarhus C, Denmark.,Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, DK-2200, Copenhagen N, Denmark
| | - Sui Ching Ong
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, DK-8000, Aarhus C, Denmark
| | - Nicholas Sofos
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, DK-8000, Aarhus C, Denmark.,Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, DK-2200, Copenhagen N, Denmark
| | - Jesper L Karlsen
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, DK-8000, Aarhus C, Denmark
| | - Ragnhild B Skjerning
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, DK-8000, Aarhus C, Denmark
| | - Thomas Boesen
- Interdisciplinary Nanoscience Centre (iNANO) Aarhus University, Gustav Wieds Vej 14, DK-8000, Aarhus C, Denmark
| | - Jan J Enghild
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, DK-8000, Aarhus C, Denmark
| | - Bjarne Hove-Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, DK-8000, Aarhus C, Denmark
| | - Ditlev E Brodersen
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, DK-8000, Aarhus C, Denmark.
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