1
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Michalski K, Furukawa H. Structure and function of GluN1-3A NMDA receptor excitatory glycine receptor channel. SCIENCE ADVANCES 2024; 10:eadl5952. [PMID: 38598639 PMCID: PMC11006217 DOI: 10.1126/sciadv.adl5952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 03/05/2024] [Indexed: 04/12/2024]
Abstract
N-methyl-d-aspartate receptors (NMDARs) and other ionotropic glutamate receptors (iGluRs) mediate most of the excitatory signaling in the mammalian brains in response to the neurotransmitter glutamate. Uniquely, NMDARs composed of GluN1 and GluN3 are activated exclusively by glycine, the neurotransmitter conventionally mediating inhibitory signaling when it binds to pentameric glycine receptors. The GluN1-3 NMDARs are vital for regulating neuronal excitability, circuit function, and specific behaviors, yet our understanding of their functional mechanism at the molecular level has remained limited. Here, we present cryo-electron microscopy structures of GluN1-3A NMDARs bound to an antagonist, CNQX, and an agonist, glycine. The structures show a 1-3-1-3 subunit heterotetrameric arrangement and an unprecedented pattern of GluN3A subunit orientation shift between the glycine-bound and CNQX-bound structures. Site-directed disruption of the unique subunit interface in the glycine-bound structure mitigated desensitization. Our study provides a foundation for understanding the distinct structural dynamics of GluN3 that are linked to the unique function of GluN1-3 NMDARs.
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2
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Durham RJ, Jayaraman V. Single-Molecule FRET Analyses of NMDA Receptors. Methods Mol Biol 2024; 2799:225-242. [PMID: 38727910 PMCID: PMC11164542 DOI: 10.1007/978-1-0716-3830-9_12] [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] [Indexed: 05/22/2024]
Abstract
Single-molecule fluorescence resonance energy transfer (smFRET) enables the real-time observation of conformational changes in a single protein molecule of interest. These observations are achieved by attaching fluorophores to proteins of interest in a site-specific manner and investigating the FRET between the fluorophores. Here we describe the method wherein the FRET is studied by adhering the protein molecules to a slide using affinity-based interactions and measuring the fluorophores' fluorescence intensity from a single molecule over time. The resulting information can be used to derive distance values for a point-to-point measurement within a protein or to calculate kinetic transition rates between various conformational states of a protein. Comparing these parameters between different conditions such as the presence of protein binding partners, application of ligands, or changes in the primary sequence of the protein can provide insights into protein structural changes as well as kinetics of these changes (if in the millisecond to second timescale) that underlie functional effects. Here we describe the procedure for conducting analyses of NMDA receptor conformational changes using the above methodology and provide a discussion of various considerations that affect the design, execution, and interpretation of similar smFRET studies.
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Affiliation(s)
- Ryan J Durham
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Vasanthi Jayaraman
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX, USA.
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3
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Zheng W, Liu X. Modeling and Simulation of the NMDA Receptor at Coarse-Grained and Atomistic Levels. Methods Mol Biol 2024; 2799:269-280. [PMID: 38727913 DOI: 10.1007/978-1-0716-3830-9_15] [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: 06/01/2024]
Abstract
N-Methyl-D-aspartate (NMDA) receptors are glutamate-gated excitatory channels that play essential roles in brain functions. While high-resolution structures were solved for an allosterically inhibited form of functional NMDA receptor, other key functional states (particularly the active open-channel state) have not yet been resolved at atomic resolutions. To decrypt the molecular mechanism of the NMDA receptor activation, structural modeling and simulation are instrumental in providing detailed information about the dynamics and energetics of the receptor in various functional states. In this chapter, we describe coarse-grained modeling of the NMDA receptor using an elastic network model and related modeling/analysis tools (e.g., normal mode analysis, flexibility and hotspot analysis, cryo-EM flexible fitting, and transition pathway modeling) based on available structures. Additionally, we show how to build an atomistic model of the active-state receptor with targeted molecular dynamics (MD) simulation and explore its energetics and dynamics with conventional MD simulation. Taken together, these modeling and simulation can offer rich structural and dynamic information which will guide experimental studies of the activation of this key receptor.
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Affiliation(s)
- Wenjun Zheng
- Department of Physics, State University of New York at Buffalo, Buffalo, NY, USA.
| | - Xing Liu
- Department of Physics, State University of New York at Buffalo, Buffalo, NY, USA
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4
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Paudyal N, Das A, Carrillo E, Berka V, Jayaraman V. Partial agonism in heteromeric GLUK2/GLUK5 kainate receptor. Proteins 2023:10.1002/prot.26565. [PMID: 37526035 PMCID: PMC10830895 DOI: 10.1002/prot.26565] [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: 05/31/2023] [Revised: 07/13/2023] [Accepted: 07/21/2023] [Indexed: 08/02/2023]
Abstract
Kainate receptors are a subtype of ionotropic glutamate receptors that form transmembrane channels upon binding glutamate. Here, we have investigated the mechanism of partial agonism in heteromeric GluK2/K5 receptors, where the GluK2 and GluK5 subunits have distinct agonist binding profiles. Using single-molecule Förster resonance energy transfer, we found that at the bi-lobed agonist-binding domain, the partial agonist AMPA-bound receptor occupied intermediate cleft closure conformational states at the GluK2 cleft, compared to the more open cleft conformations in apo form and more closed cleft conformations in the full agonist glutamate-bound form. In contrast, there is no significant difference in cleft closure states at the GluK5 agonist-binding domain between the partial agonist AMPA- and full agonist glutamate-bound states. Additionally, unlike the glutamate-bound state, the dimer interface at the agonist-binding domain is not decoupled in the AMPA-bound state. Our findings suggest that partial agonism observed with AMPA binding is mediated primarily due to differences in the GluK2 subunit, highlighting the distinct contributions of the subunits towards activation.
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Affiliation(s)
- Nabina Paudyal
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX 77030
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Anindita Das
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Elisa Carrillo
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Vladimir Berka
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Vasanthi Jayaraman
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX 77030
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5
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Chen W, Gunther TR, Baughman HER, Komives EA. Site-specific incorporation of biophysical probes into NF-ĸB with non-canonical amino acids. Methods 2023; 213:18-25. [PMID: 36940840 PMCID: PMC10688598 DOI: 10.1016/j.ymeth.2023.03.004] [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: 12/13/2022] [Revised: 03/14/2023] [Accepted: 03/16/2023] [Indexed: 03/23/2023] Open
Abstract
The transcription factor NF-ĸB is a central mediator of immune and inflammatory responses. To understand the regulation of NF-ĸB, it is important to probe the underlying thermodynamics, kinetics, and conformational dynamics of the NF-ĸB/IĸBα/DNA interaction network. The development of genetic incorporation of non-canonical amino acids (ncAA) has enabled the installation of biophysical probes into proteins with site specificity. Recent single-molecule FRET (smFRET) studies of NF-ĸB with site-specific labeling via ncAA incorporation revealed the conformational dynamics for kinetic control of DNA-binding mediated by IĸBα. Here we report the design and protocols for incorporating the ncAA p-azidophenylalanine (pAzF) into NF-ĸB and site-specific fluorophore labeling with copper-free click chemistry for smFRET. We also expanded the ncAA toolbox of NF-ĸB to include p-benzoylphenylalanine (pBpa) for UV crosslinking mass spectrometry (XL-MS) and incorporated both pAzF and pBpa into the full-length NF-ĸB RelA subunit which includes the intrinsically disordered transactivation domain.
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Affiliation(s)
- Wei Chen
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA.
| | - Tristan R Gunther
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA
| | - Hannah E R Baughman
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA
| | - Elizabeth A Komives
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA.
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6
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Zhang J, Tang W, Bhatia NK, Xu Y, Paudyal N, Liu D, Kim S, Song R, XiangWei W, Shaulsky G, Myers SJ, Dobyns W, Jayaraman V, Traynelis SF, Yuan H, Bozarth X. A de novo GRIN1 Variant Associated With Myoclonus and Developmental Delay: From Molecular Mechanism to Rescue Pharmacology. Front Genet 2021; 12:694312. [PMID: 34413877 PMCID: PMC8369916 DOI: 10.3389/fgene.2021.694312] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/21/2021] [Indexed: 12/17/2022] Open
Abstract
N-Methyl-D-aspartate receptors (NMDARs) are highly expressed in brain and play important roles in neurodevelopment and various neuropathologic conditions. Here, we describe a new phenotype in an individual associated with a novel de novo deleterious variant in GRIN1 (c.1595C>A, p.Pro532His). The clinical phenotype is characterized with developmental encephalopathy, striking stimulus-sensitive myoclonus, and frontal lobe and frontal white matter hypoplasia, with no apparent seizures detected. NMDARs that contained the P532H within the glycine-binding domain of GluN1 with either the GluN2A or GluN2B subunits were evaluated for changes in their pharmacological and biophysical properties, which surprisingly revealed only modest changes in glycine potency but a significant decrease in glutamate potency, an increase in sensitivity to endogenous zinc inhibition, a decrease in response to maximally effective concentrations of agonists, a shortened synaptic-like response time course, a decreased channel open probability, and a reduced receptor cell surface expression. Molecule dynamics simulations suggested that the variant can lead to additional interactions across the dimer interface in the agonist-binding domains, resulting in a more open GluN2 agonist-binding domain cleft, which was also confirmed by single-molecule fluorescence resonance energy transfer measurements. Based on the functional deficits identified, several positive modulators were evaluated to explore potential rescue pharmacology.
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Affiliation(s)
- Jin Zhang
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Weiting Tang
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Nidhi K. Bhatia
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center, Houston, TX, United States
| | - Yuchen Xu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Nabina Paudyal
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center, Houston, TX, United States
| | - Ding Liu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Sukhan Kim
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, United States
| | - Rui Song
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Wenshu XiangWei
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Gil Shaulsky
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Scott J. Myers
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, United States
| | - William Dobyns
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States
| | - Vasanthi Jayaraman
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center, Houston, TX, United States
| | - Stephen F. Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, United States
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, United States
| | - Xiuhua Bozarth
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States
- Division of Pediatric Neurology, Department of Neurology, Seattle Children’s Hospital, University of Washington, Seattle, WA, United States
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7
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Paudyal N, Bhatia NK, Jayaraman V. Single molecule FRET methodology for investigating glutamate receptors. Methods Enzymol 2021; 652:193-212. [PMID: 34059282 DOI: 10.1016/bs.mie.2021.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Single molecule Förster Resonance Energy Transfer (smFRET) allows us to measure variation in distances between donor and acceptor fluorophores attached to a protein, providing the conformational landscape of the protein with respect to this specific distance. smFRET can be performed on freely diffusing molecules or on tethered molecules. Here, we describe the tethered method used to study ionotropic glutamate receptors, which allows us to track the changes in FRET as a function of time, thus providing information on the conformations sampled and kinetics of conformational changes in the millisecond to second time scale. Strategies for attaching fluorophores to the proteins, methods for acquiring and analyzing the smFRET trajectories, and limitations are discussed.
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Affiliation(s)
- Nabina Paudyal
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, University of Texas Health Science Center at Houston, Houston, TX, United States; MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Nidhi Kaur Bhatia
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Vasanthi Jayaraman
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, University of Texas Health Science Center at Houston, Houston, TX, United States; MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX, United States.
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8
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Chou TH, Tajima N, Romero-Hernandez A, Furukawa H. Structural Basis of Functional Transitions in Mammalian NMDA Receptors. Cell 2020; 182:357-371.e13. [PMID: 32610085 PMCID: PMC8278726 DOI: 10.1016/j.cell.2020.05.052] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 04/22/2020] [Accepted: 05/27/2020] [Indexed: 12/18/2022]
Abstract
Excitatory neurotransmission meditated by glutamate receptors including N-methyl-D-aspartate receptors (NMDARs) is pivotal to brain development and function. NMDARs are heterotetramers composed of GluN1 and GluN2 subunits, which bind glycine and glutamate, respectively, to activate their ion channels. Despite importance in brain physiology, the precise mechanisms by which activation and inhibition occur via subunit-specific binding of agonists and antagonists remain largely unknown. Here, we show the detailed patterns of conformational changes and inter-subunit and -domain reorientation leading to agonist-gating and subunit-dependent competitive inhibition by providing multiple structures in distinct ligand states at 4 Å or better. The structures reveal that activation and competitive inhibition by both GluN1 and GluN2 antagonists occur by controlling the tension of the linker between the ligand-binding domain and the transmembrane ion channel of the GluN2 subunit. Our results provide detailed mechanistic insights into NMDAR pharmacology, activation, and inhibition, which are fundamental to the brain physiology.
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Affiliation(s)
- Tsung-Han Chou
- WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Nami Tajima
- WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Annabel Romero-Hernandez
- WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Hiro Furukawa
- WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
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9
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Durham RJ, Paudyal N, Carrillo E, Bhatia NK, Maclean DM, Berka V, Dolino DM, Gorfe AA, Jayaraman V. Conformational spread and dynamics in allostery of NMDA receptors. Proc Natl Acad Sci U S A 2020; 117:3839-3847. [PMID: 32015122 PMCID: PMC7035515 DOI: 10.1073/pnas.1910950117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Allostery can be manifested as a combination of repression and activation in multidomain proteins allowing for fine tuning of regulatory mechanisms. Here we have used single molecule fluorescence resonance energy transfer (smFRET) and molecular dynamics simulations to study the mechanism of allostery underlying negative cooperativity between the two agonists glutamate and glycine in the NMDA receptor. These data show that binding of one agonist leads to conformational flexibility and an increase in conformational spread at the second agonist site. Mutational and cross-linking studies show that the dimer-dimer interface at the agonist-binding domain mediates the allostery underlying the negative cooperativity. smFRET on the transmembrane segments shows that they are tightly coupled in the unliganded and single agonist-bound form and only upon binding both agonists the transmembrane domain explores looser packing which would facilitate activation.
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Affiliation(s)
- Ryan J Durham
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX 77030
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Nabina Paudyal
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX 77030
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Elisa Carrillo
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Nidhi Kaur Bhatia
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - David M Maclean
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642
| | - Vladimir Berka
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Drew M Dolino
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX 77030
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Alemayehu A Gorfe
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX 77030
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Vasanthi Jayaraman
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX 77030;
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX 77030
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10
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Chatterjee S, Dutta C, Carrejo NC, Landes CF. Mechanistic Understanding of the Phosphorylation-Induced Conformational Rigidity at the AMPA Receptor C-terminal Domain. ACS OMEGA 2019; 4:14211-14218. [PMID: 31508543 PMCID: PMC6732983 DOI: 10.1021/acsomega.9b01384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/06/2019] [Indexed: 06/10/2023]
Abstract
Phosphorylation at the intracellular C-terminal domain (CTD) of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors induces conformational rigidity. Such intracellular alterations to the AMPA receptor influence its functional responses, which are involved in multiple synaptic processes and neuronal signaling. The structure of the CTD still remains unresolved, which poses challenges toward providing a mechanism for the process of phosphorylation and deciphering the role of each phosphorylation step in causing the resultant conformational behavior. Herein, we utilize smFRET spectroscopy to understand the mechanism of phosphorylation, with the help of strategic point mutations that mimic phosphorylation. Our results reveal that first, phosphorylation at three target sites (S818, S831, and T840) is necessary for the change in the secondary structure of the existing disordered native sequence. Also, the results suggest that the formation of the tertiary structure through electrostatic interaction involving one specific phosphorylation site (S831) stabilizes the structure and renders conformational rigidity.
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Affiliation(s)
- Sudeshna Chatterjee
- Department
of Chemistry and Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
| | - Chayan Dutta
- Department
of Chemistry and Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
| | - Nicole C. Carrejo
- Department
of Chemistry and Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
| | - Christy F. Landes
- Department
of Chemistry and Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
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11
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Litwin DB, Durham RJ, Jayaraman V. Single-Molecule FRET Methods to Study Glutamate Receptors. Methods Mol Biol 2019; 1941:3-16. [PMID: 30707423 DOI: 10.1007/978-1-4939-9077-1_1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Single-molecule fluorescence energy transfer methods allow us to determine the complete structural landscape between the donor and acceptor fluorophores introduced on the protein of interest. This method is particularly attractive to study ion channel proteins as single-molecule current recordings have been used to study the function of these proteins for several decades. Here we describe the smFRET method used to study glutamate receptors.
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Affiliation(s)
- Douglas B Litwin
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Ryan J Durham
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Vasanthi Jayaraman
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX, USA.
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12
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Chatterjee S, Ade C, Nurik CE, Carrejo NC, Dutta C, Jayaraman V, Landes CF. Phosphorylation Induces Conformational Rigidity at the C-Terminal Domain of AMPA Receptors. J Phys Chem B 2019; 123:130-137. [PMID: 30537817 DOI: 10.1021/acs.jpcb.8b10749] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The intracellular C-terminal domain (CTD) of AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptor undergoes phosphorylation at specific locations during long-term potentiation. This modification enhances conductance through the AMPA receptor ion channel and thus potentially plays a crucial role in modulating receptor trafficking and signaling. However, because the CTD structure is largely unresolved, it is difficult to establish if phosphorylation induces conformational changes that might play a role in enhancing channel conductance. Herein, we utilize single-molecule Förster resonance energy transfer (smFRET) spectroscopy to probe the conformational changes of a section of the AMPA receptor CTD, under the conditions of point-mutated phosphomimicry. Multiple analysis algorithms fail to identify stable conformational states within the smFRET distributions, consistent with a lack of well-defined secondary structure. Instead, our results show that phosphomimicry induces conformational rigidity to the CTD, and such rigidity is electrostatically tunable.
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Affiliation(s)
- Sudeshna Chatterjee
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - Carina Ade
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - Caitlin E Nurik
- Department of Biochemistry and Molecular Biology , University of Texas Health Medical School , Houston , Texas 77005 , United States
| | - Nicole C Carrejo
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - Chayan Dutta
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - Vasanthi Jayaraman
- Department of Biochemistry and Molecular Biology , University of Texas Health Medical School , Houston , Texas 77005 , United States
| | - Christy F Landes
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States.,Department of Electrical and Computer Engineering , Rice University , Houston , Texas 77005 , United States
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13
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Moringo NA, Shen H, Bishop LDC, Wang W, Landes CF. Enhancing Analytical Separations Using Super-Resolution Microscopy. Annu Rev Phys Chem 2018; 69:353-375. [PMID: 29490205 DOI: 10.1146/annurev-physchem-052516-045018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Super-resolution microscopy is becoming an invaluable tool to investigate structure and dynamics driving protein interactions at interfaces. In this review, we highlight the applications of super-resolution microscopy for quantifying the physics and chemistry that occur between target proteins and stationary-phase supports during chromatographic separations. Our discussion concentrates on the newfound ability of super-resolved single-protein spectroscopy to inform theoretical parameters via quantification of adsorption-desorption dynamics, protein unfolding, and nanoconfined transport.
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Affiliation(s)
| | - Hao Shen
- Department of Chemistry, Rice University, Houston, Texas 77251, USA;
| | - Logan D C Bishop
- Department of Chemistry, Rice University, Houston, Texas 77251, USA;
| | - Wenxiao Wang
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77251, USA
| | - Christy F Landes
- Department of Chemistry, Rice University, Houston, Texas 77251, USA; .,Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77251, USA.,Smalley-Curl Institute, Rice University, Houston, Texas 77251, USA
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14
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Krieger J, Lee JY, Greger IH, Bahar I. Activation and desensitization of ionotropic glutamate receptors by selectively triggering pre-existing motions. Neurosci Lett 2018; 700:22-29. [PMID: 29481851 PMCID: PMC6107436 DOI: 10.1016/j.neulet.2018.02.050] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 02/15/2018] [Accepted: 02/22/2018] [Indexed: 01/03/2023]
Abstract
Ionotropic glutamate receptors (iGluRs) are ligand-gated ion channels that are key players in synaptic transmission and plasticity. They are composed of four subunits, each containing four functional domains, the quaternary packing and collective structural dynamics of which are important determinants of their molecular mechanism of function. With the explosion of structural studies on different members of the family, including the structures of activated open channels, the mechanisms of action of these central signaling machines are now being elucidated. We review the current state of computational studies on two major members of the family, AMPA and NMDA receptors, with focus on molecular simulations and elastic network model analyses that have provided insights into the coupled movements of extracellular and transmembrane domains. We describe the newly emerging mechanisms of activation, allosteric signaling and desensitization, as mainly a selective triggering of pre-existing soft motions, as deduced from computational models and analyses that leverage structural data on intact AMPA and NMDA receptors in different states.
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Affiliation(s)
- James Krieger
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, 3501 Fifth Ave, Suite 3064 BST3, Pittsburgh, PA, 15260, United States
| | - Ji Young Lee
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, 3501 Fifth Ave, Suite 3064 BST3, Pittsburgh, PA, 15260, United States
| | - Ingo H Greger
- Neurobiology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, United Kingdom
| | - Ivet Bahar
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, 3501 Fifth Ave, Suite 3064 BST3, Pittsburgh, PA, 15260, United States.
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15
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Tavakoli M, Taylor JN, Li CB, Komatsuzaki T, Pressé S. Single Molecule Data Analysis: An Introduction. ADVANCES IN CHEMICAL PHYSICS 2017. [DOI: 10.1002/9781119324560.ch4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Meysam Tavakoli
- Physics Department; Indiana University-Purdue University Indianapolis; Indianapolis IN 46202 USA
| | - J. Nicholas Taylor
- Research Institute for Electronic Science; Hokkaido University; Kita 20 Nishi 10 Kita-Ku Sapporo 001-0020 Japan
| | - Chun-Biu Li
- Research Institute for Electronic Science; Hokkaido University; Kita 20 Nishi 10 Kita-Ku Sapporo 001-0020 Japan
- Department of Mathematics; Stockholm University; 106 91 Stockholm Sweden
| | - Tamiki Komatsuzaki
- Research Institute for Electronic Science; Hokkaido University; Kita 20 Nishi 10 Kita-Ku Sapporo 001-0020 Japan
| | - Steve Pressé
- Physics Department; Indiana University-Purdue University Indianapolis; Indianapolis IN 46202 USA
- Department of Chemistry and Chemical Biology; Indiana University-Purdue University Indianapolis; Indianapolis IN 46202 USA
- Department of Cell and Integrative Physiology; Indiana University School of Medicine; Indianapolis IN 46202 USA
- Department of Physics and School of Molecular Sciences; Arizona State University; Tempe AZ 85287 USA
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16
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The structure-energy landscape of NMDA receptor gating. Nat Chem Biol 2017; 13:1232-1238. [PMID: 28991238 PMCID: PMC5698143 DOI: 10.1038/nchembio.2487] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 08/28/2017] [Indexed: 01/26/2023]
Abstract
N-Methyl-D-aspartate (NMDA) receptors are the main calcium-permeable excitatory receptors in the mammalian central nervous system. The NMDA receptor gating is complex, exhibiting multiple closed, open, and desensitized states; however, central questions regarding the conformations and energetics of the transmembrane domains as they relate to the gating states are still unanswered. Here, using single-molecule Förster resonance energy transfer (smFRET), we map the energy landscape of the first transmembrane segment of the Rattus norvegicus NMDA receptor under resting and various liganded conditions. These results show kinetically and structurally distinct changes associated with apo, agonist-bound, and inhibited receptors linked by a linear mechanism of gating at this site. Furthermore, the smFRET data suggest that allosteric inhibition by zinc occurs by an uncoupling of the agonist-induced changes at the extracellular domains from the gating motions leading to an apo-like state, while dizocilpine, a pore blocker, stabilizes multiple closely packed transmembrane states.
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17
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Zheng W, Wen H, Iacobucci GJ, Popescu GK. Probing the Structural Dynamics of the NMDA Receptor Activation by Coarse-Grained Modeling. Biophys J 2017. [PMID: 28636915 DOI: 10.1016/j.bpj.2017.04.043] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
N-Methyl-D-aspartate (NMDA) receptors are glutamate-gated excitatory channels that play essential roles in brain functions. High-resolution structures have been solved for an allosterically inhibited and agonist-bound form of a functional NMDA receptor; however, other key functional states (particularly the active open-channel state) were only resolved at moderate resolutions by cryo-electron microscopy (cryo-EM). To decrypt the mechanism of the NMDA receptor activation, structural modeling is essential to provide presently missing information about structural dynamics. We performed systematic coarse-grained modeling using an elastic network model and related modeling/analysis tools (e.g., normal mode analysis, flexibility and hotspot analysis, cryo-EM flexible fitting, and transition pathway modeling) based on an active-state cryo-EM map. We observed extensive conformational changes that allosterically couple the extracellular regulatory and agonist-binding domains to the pore-forming trans-membrane domain (TMD), and validated these, to our knowledge, new observations against known mutational and functional studies. Our results predict two key modes of collective motions featuring shearing/twisting of the extracellular domains relative to the TMD, reveal subunit-specific flexibility profiles, and identify functional hotspot residues at key domain-domain interfaces. Finally, by examining the conformational transition pathway between the allosterically inhibited form and the active form, we predict a discrete sequence of domain motions, which propagate from the extracellular domains to the TMD. In summary, our results offer rich structural and dynamic information, which is consistent with the literature on structure-function relationships in NMDA receptors, and will guide in-depth studies on the activation dynamics of this important neurotransmitter receptor.
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Affiliation(s)
- Wenjun Zheng
- Department of Physics, State University of New York at Buffalo, Buffalo, New York.
| | - Han Wen
- Department of Physics, State University of New York at Buffalo, Buffalo, New York
| | - Gary J Iacobucci
- Department of Biochemistry, State University of New York at Buffalo, Buffalo, New York
| | - Gabriela K Popescu
- Department of Biochemistry, State University of New York at Buffalo, Buffalo, New York
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18
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Iacobucci GJ, Popescu GK. NMDA receptors: linking physiological output to biophysical operation. Nat Rev Neurosci 2017; 18:236-249. [PMID: 28303017 DOI: 10.1038/nrn.2017.24] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
NMDA receptors are preeminent neurotransmitter-gated channels in the CNS, which respond to glutamate in a manner that integrates multiple external and internal cues. They belong to the ionotropic glutamate receptor family and fulfil unique and crucial roles in neuronal development and function. These roles depend on characteristic response kinetics, which reflect the operation of the receptors. Here, we review biologically salient features of the NMDA receptor signal and its mechanistic origins. Knowledge of distinctive NMDA receptor biophysical properties, their structural determinants and physiological roles is necessary to understand the physiological and neurotoxic actions of glutamate and to design effective therapeutics.
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Affiliation(s)
- Gary J Iacobucci
- Department of Biochemistry, University of Buffalo, State University of New York (SUNY), 144 Farber Hall, 3435 Main street, Buffalo, New York 14214, USA
| | - Gabriela K Popescu
- Department of Biochemistry, University of Buffalo, State University of New York (SUNY), 144 Farber Hall, 3435 Main street, Buffalo, New York 14214, USA
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19
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Sinitskiy AV, Stanley NH, Hackos DH, Hanson JE, Sellers BD, Pande VS. Computationally Discovered Potentiating Role of Glycans on NMDA Receptors. Sci Rep 2017; 7:44578. [PMID: 28378791 PMCID: PMC5381272 DOI: 10.1038/srep44578] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 02/09/2017] [Indexed: 01/10/2023] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) are glycoproteins in the brain central to learning and memory. The effects of glycosylation on the structure and dynamics of NMDARs are largely unknown. In this work, we use extensive molecular dynamics simulations of GluN1 and GluN2B ligand binding domains (LBDs) of NMDARs to investigate these effects. Our simulations predict that intra-domain interactions involving the glycan attached to residue GluN1-N440 stabilize closed-clamshell conformations of the GluN1 LBD. The glycan on GluN2B-N688 shows a similar, though weaker, effect. Based on these results, and assuming the transferability of the results of LBD simulations to the full receptor, we predict that glycans at GluN1-N440 might play a potentiator role in NMDARs. To validate this prediction, we perform electrophysiological analysis of full-length NMDARs with a glycosylation-preventing GluN1-N440Q mutation, and demonstrate an increase in the glycine EC50 value. Overall, our results suggest an intramolecular potentiating role of glycans on NMDA receptors.
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Affiliation(s)
- Anton V Sinitskiy
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Nathaniel H Stanley
- Stanford ChEM-H, Stanford University, Stanford, CA 94305, USA.,Department of Discovery Chemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - David H Hackos
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Jesse E Hanson
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Benjamin D Sellers
- Department of Discovery Chemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Vijay S Pande
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA.,Department of Computer Science and Department of Structural Biology, Stanford University, Stanford, CA 94305, USA
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20
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Dolino DM, Rezaei Adariani S, Shaikh SA, Jayaraman V, Sanabria H. Conformational Selection and Submillisecond Dynamics of the Ligand-binding Domain of the N-Methyl-d-aspartate Receptor. J Biol Chem 2016; 291:16175-85. [PMID: 27226581 PMCID: PMC4965566 DOI: 10.1074/jbc.m116.721274] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Indexed: 01/22/2023] Open
Abstract
The N-methyl-d-aspartate (NMDA) receptors are heteromeric non-selective cation channels that require the binding of glycine and glutamate for gating. Based on crystal structures, the mechanism of partial agonism at the glycine-binding site is thought to be mediated by a shift in the conformational equilibrium between an open clamshell and a closed clamshell-like structure of the bilobed ligand-binding domain (LBD). Using single-molecule Förster resonance energy transfer (smFRET) and multiparameter fluorescence detection, which allows us to study the conformational states and dynamics in the submillisecond time scale, we show that there are at least three conformational states explored by the LBD: the low FRET, medium FRET, and high FRET states. The distance of the medium and low FRET states corresponds to what has been observed in crystallography structures. We show that the high FRET state, which would represent a more closed clamshell conformation than that observed in the crystal structure, is most likely the state initiating activation, as evidenced by the fact that the fraction of the protein in this state correlates well with the extent of activation. Furthermore, full agonist bound LBDs show faster dynamic motions between the medium and high FRET states, whereas they show slower dynamics when bound to weaker agonists or to antagonists.
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Affiliation(s)
- Drew M Dolino
- From the Department of Biochemistry and Molecular Biology, Center for Membrane Biology, University of Texas Health Science Center, Graduate School for Biomedical Sciences, Houston, Texas 77030 and
| | | | - Sana A Shaikh
- From the Department of Biochemistry and Molecular Biology, Center for Membrane Biology, University of Texas Health Science Center, Graduate School for Biomedical Sciences, Houston, Texas 77030 and
| | - Vasanthi Jayaraman
- From the Department of Biochemistry and Molecular Biology, Center for Membrane Biology, University of Texas Health Science Center, Graduate School for Biomedical Sciences, Houston, Texas 77030 and
| | - Hugo Sanabria
- the Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634
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21
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Lee TC, Kang M, Kim CH, Schultz PG, Chapman E, Deniz AA. Dual Unnatural Amino Acid Incorporation and Click-Chemistry Labeling to Enable Single-Molecule FRET Studies of p97 Folding. Chembiochem 2016; 17:981-4. [PMID: 27115850 DOI: 10.1002/cbic.201500695] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Indexed: 01/01/2023]
Abstract
Many cellular functions are critically dependent on the folding of complex multimeric proteins, such as p97, a hexameric multidomain AAA+ chaperone. Given the complex architecture of p97, single-molecule (sm) FRET would be a powerful tool for studying folding while avoiding ensemble averaging. However, dual site-specific labeling of such a large protein for smFRET is a significant challenge. Here, we address this issue by using bioorthogonal azide-alkyne chemistry to attach an smFRET dye pair to site-specifically incorporated unnatural amino acids, allowing us to generate p97 variants reporting on inter- or intradomain structural features. An initial proof-of-principle set of smFRET results demonstrated the strengths of this labeling method. Our results highlight this as a powerful tool for structural studies of p97 and other large protein machines.
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Affiliation(s)
- Taehyung C Lee
- The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Minjin Kang
- College of Pharmacy, Department of Pharmacology and Toxicology, The University of Arizona, Tucson, AZ, 85721, USA
| | - Chan Hyuk Kim
- The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Peter G Schultz
- The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Eli Chapman
- College of Pharmacy, Department of Pharmacology and Toxicology, The University of Arizona, Tucson, AZ, 85721, USA.
| | - Ashok A Deniz
- The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA.
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22
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Goldschen-Ohm MP, Klenchin VA, White DS, Cowgill JB, Cui Q, Goldsmith RH, Chanda B. Structure and dynamics underlying elementary ligand binding events in human pacemaking channels. eLife 2016; 5:e20797. [PMID: 27858593 PMCID: PMC5115869 DOI: 10.7554/elife.20797] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 11/01/2016] [Indexed: 01/07/2023] Open
Abstract
Although molecular recognition is crucial for cellular signaling, mechanistic studies have relied primarily on ensemble measures that average over and thereby obscure underlying steps. Single-molecule observations that resolve these steps are lacking due to diffraction-limited resolution of single fluorophores at relevant concentrations. Here, we combined zero-mode waveguides with fluorescence resonance energy transfer (FRET) to directly observe binding at individual cyclic nucleotide-binding domains (CNBDs) from human pacemaker ion channels critical for heart and brain function. Our observations resolve the dynamics of multiple distinct steps underlying cyclic nucleotide regulation: a slow initial binding step that must select a 'receptive' conformation followed by a ligand-induced isomerization of the CNBD. X-ray structure of the apo CNBD and atomistic simulations reveal that the isomerization involves both local and global transitions. Our approach reveals fundamental mechanisms underpinning ligand regulation of pacemaker channels, and is generally applicable to weak-binding interactions governing a broad spectrum of signaling processes.
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Affiliation(s)
| | - Vadim A Klenchin
- Department of Neuroscience, University of Wisconsin-Madison, Madison, United States
| | - David S White
- Department of Neuroscience, University of Wisconsin-Madison, Madison, United States,Department of Chemistry, University of Wisconsin-Madison, Madison, United States
| | - John B Cowgill
- Department of Neuroscience, University of Wisconsin-Madison, Madison, United States
| | - Qiang Cui
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, Madison, United States
| | - Randall H Goldsmith
- Department of Chemistry, University of Wisconsin-Madison, Madison, United States
| | - Baron Chanda
- Department of Neuroscience, University of Wisconsin-Madison, Madison, United States,Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, United States,
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23
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