1
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Shibata K, Oda K, Nishizawa T, Hazama Y, Ono R, Takaramoto S, Bagherzadeh R, Yawo H, Nureki O, Inoue K, Akiyama H. Twisting and Protonation of Retinal Chromophore Regulate Channel Gating of Channelrhodopsin C1C2. J Am Chem Soc 2023; 145:10779-10789. [PMID: 37129501 DOI: 10.1021/jacs.3c01879] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Channelrhodopsins (ChRs) are light-gated ion channels and central optogenetic tools that can control neuronal activity with high temporal resolution at the single-cell level. Although their application in optogenetics has rapidly progressed, it is unsolved how their channels open and close. ChRs transport ions through a series of interlocking elementary processes that occur over a broad time scale of subpicoseconds to seconds. During these processes, the retinal chromophore functions as a channel regulatory domain and transfers the optical input as local structural changes to the channel operating domain, the helices, leading to channel gating. Thus, the core question on channel gating dynamics is how the retinal chromophore structure changes throughout the photocycle and what rate-limits the kinetics. Here, we investigated the structural changes in the retinal chromophore of canonical ChR, C1C2, in all photointermediates using time-resolved resonance Raman spectroscopy. Moreover, to reveal the rate-limiting factors of the photocycle and channel gating, we measured the kinetic isotope effect of all photoreaction processes using laser flash photolysis and laser patch clamp, respectively. Spectroscopic and electrophysiological results provided the following understanding of the channel gating: the retinal chromophore highly twists upon the retinal Schiff base (RSB) deprotonation, causing the surrounding helices to move and open the channel. The ion-conducting pathway includes the RSB, where inflowing water mediates the proton to the deprotonated RSB. The twisting of the retinal chromophore relaxes upon the RSB reprotonation, which closes the channel. The RSB reprotonation rate-limits the channel closing.
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Affiliation(s)
- Keisei Shibata
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Kazumasa Oda
- Department of Biological Sciences Graduate School of Science, The University of Tokyo, Tokyo 113-0034, Japan
| | - Tomohiro Nishizawa
- Department of Biological Sciences Graduate School of Science, The University of Tokyo, Tokyo 113-0034, Japan
| | - Yuji Hazama
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Ryohei Ono
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - Shunki Takaramoto
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Reza Bagherzadeh
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Hiromu Yawo
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Osamu Nureki
- Department of Biological Sciences Graduate School of Science, The University of Tokyo, Tokyo 113-0034, Japan
| | - Keiichi Inoue
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Hidefumi Akiyama
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
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2
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Kuroi K, Tsukamoto T, Honda N, Sudo Y, Furutani Y. Concerted primary proton transfer reactions in a thermophilic rhodopsin studied by time-resolved infrared spectroscopy at high temperature. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148980. [PMID: 37080329 DOI: 10.1016/j.bbabio.2023.148980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 04/06/2023] [Accepted: 04/12/2023] [Indexed: 04/22/2023]
Abstract
The primary proton transfer reactions of thermophilic rhodopsin, which was first discovered in an extreme thermophile, Thermus thermophilus JL-18, were investigated using time-resolved Fourier transform infrared spectroscopy at various temperatures ranging from 298 to 343 K (25 to 70 °C) and proton transport activity analysis. The analyses were performed using counterion (D95E, D95N, D229E, and D229N) and proton donor mutants (E106D and E106Q) as well. First, the initial proton transfer from the protonated retinal Schiff base (PRSB) to D95 was identified. The temperature dependency showed that the proton transfer reaction in the intermediate states dramatically changed above 318 K (45 °C). In addition, the proton transfer reaction correlated well with the structural change from turn to β-strand in the protein moiety, suggesting that this step may be regulated by the rigidity of the loop region. We also elucidated that the proton transfer reaction from proton donor E106 to the retinal Schiff base occurred synchronously with the primary proton transfer from the PRSB to D95. Surprisingly, we discovered that the direction of proton transfer was regulated by the secondary counterion, D229. Comparative analysis of Gloeobacter rhodopsin from the mesophile, Gloeobacter violaceus, highlighted that the primary proton transfer reactions in thermophilic rhodopsin were optimized at high temperatures partly due to the specific turn to β-strand structural change. This was not observed in Gloeobacter rhodopsin and other related proteins such as bacteriorhodopsin.
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Affiliation(s)
- Kunisato Kuroi
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
| | - Takashi Tsukamoto
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-Naka, Okayama 700-8530, Japan; Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-Naka, Okayama 700-8530, Japan
| | - Naoya Honda
- Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-Naka, Okayama 700-8530, Japan
| | - Yuki Sudo
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-Naka, Okayama 700-8530, Japan; Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-Naka, Okayama 700-8530, Japan.
| | - Yuji Furutani
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan; Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
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3
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Oda K, Nomura T, Nakane T, Yamashita K, Inoue K, Ito S, Vierock J, Hirata K, Maturana AD, Katayama K, Ikuta T, Ishigami I, Izume T, Umeda R, Eguma R, Oishi S, Kasuya G, Kato T, Kusakizako T, Shihoya W, Shimada H, Takatsuji T, Takemoto M, Taniguchi R, Tomita A, Nakamura R, Fukuda M, Miyauchi H, Lee Y, Nango E, Tanaka R, Tanaka T, Sugahara M, Kimura T, Shimamura T, Fujiwara T, Yamanaka Y, Owada S, Joti Y, Tono K, Ishitani R, Hayashi S, Kandori H, Hegemann P, Iwata S, Kubo M, Nishizawa T, Nureki O. Time-resolved serial femtosecond crystallography reveals early structural changes in channelrhodopsin. eLife 2021; 10:62389. [PMID: 33752801 PMCID: PMC7987342 DOI: 10.7554/elife.62389] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 02/15/2021] [Indexed: 01/17/2023] Open
Abstract
Channelrhodopsins (ChRs) are microbial light-gated ion channels utilized in optogenetics to control neural activity with light . Light absorption causes retinal chromophore isomerization and subsequent protein conformational changes visualized as optically distinguished intermediates, coupled with channel opening and closing. However, the detailed molecular events underlying channel gating remain unknown. We performed time-resolved serial femtosecond crystallographic analyses of ChR by using an X-ray free electron laser, which revealed conformational changes following photoactivation. The isomerized retinal adopts a twisted conformation and shifts toward the putative internal proton donor residues, consequently inducing an outward shift of TM3, as well as a local deformation in TM7. These early conformational changes in the pore-forming helices should be the triggers that lead to opening of the ion conducting pore.
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Affiliation(s)
- Kazumasa Oda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Takashi Nomura
- Graduate School of Life Science, University of Hyogo, Hyogo, Japan
| | - Takanori Nakane
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Keitaro Yamashita
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Keiichi Inoue
- Graduate School of Engineering, Nagoya Institute of Technology, Nagoya, Japan
| | - Shota Ito
- Graduate School of Engineering, Nagoya Institute of Technology, Nagoya, Japan
| | - Johannes Vierock
- Institute of Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Kunio Hirata
- RIKEN SPring-8 Center, Hyogo, Japan.,Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Kawaguchi, Japan
| | - Andrés D Maturana
- Department of Bioengineering Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Kota Katayama
- Graduate School of Engineering, Nagoya Institute of Technology, Nagoya, Japan
| | - Tatsuya Ikuta
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Itsuki Ishigami
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Tamaki Izume
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Rie Umeda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Ryuun Eguma
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Satomi Oishi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Go Kasuya
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Takafumi Kato
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Tsukasa Kusakizako
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Wataru Shihoya
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Hiroto Shimada
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Tomoyuki Takatsuji
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Mizuki Takemoto
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Reiya Taniguchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Atsuhiro Tomita
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Ryoki Nakamura
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Masahiro Fukuda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Hirotake Miyauchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yongchan Lee
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Eriko Nango
- RIKEN SPring-8 Center, Hyogo, Japan.,Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Rie Tanaka
- RIKEN SPring-8 Center, Hyogo, Japan.,Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Tomoyuki Tanaka
- RIKEN SPring-8 Center, Hyogo, Japan.,Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | | | - Tetsunari Kimura
- Department of Chemistry, Graduate School of Science, Kobe University, Kobe, Japan
| | - Tatsuro Shimamura
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Takaaki Fujiwara
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Yasuaki Yamanaka
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Shigeki Owada
- RIKEN SPring-8 Center, Hyogo, Japan.,Japan Synchrotron Radiation Research Institute, Hyogo, Japan
| | - Yasumasa Joti
- RIKEN SPring-8 Center, Hyogo, Japan.,Japan Synchrotron Radiation Research Institute, Hyogo, Japan
| | - Kensuke Tono
- RIKEN SPring-8 Center, Hyogo, Japan.,Japan Synchrotron Radiation Research Institute, Hyogo, Japan
| | - Ryuichiro Ishitani
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Shigehiko Hayashi
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Hideki Kandori
- Graduate School of Engineering, Nagoya Institute of Technology, Nagoya, Japan
| | - Peter Hegemann
- Institute of Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Berlin, Germany
| | - So Iwata
- RIKEN SPring-8 Center, Hyogo, Japan.,Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Minoru Kubo
- Graduate School of Life Science, University of Hyogo, Hyogo, Japan
| | - Tomohiro Nishizawa
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.,Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Kawaguchi, Japan
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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4
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Fakhoury M. Optogenetics: A revolutionary approach for the study of depression. Prog Neuropsychopharmacol Biol Psychiatry 2021; 106:110094. [PMID: 32890694 DOI: 10.1016/j.pnpbp.2020.110094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/13/2020] [Accepted: 08/30/2020] [Indexed: 10/24/2022]
Abstract
Depression is a severe and chronic mental disorder that affects millions of individuals worldwide. Symptoms include depressed mood, loss of interest, reduced motivation and suicidal thoughts. Even though findings from genetic, molecular and imaging studies have helped provide some clues regarding the mechanisms underlying depression-like behaviors, there are still many unanswered questions that need to be addressed. Optogenetics, a technique developed in the early 2000s, has proved effective in the study and treatment of depression and depression-like behaviors and has revolutionized already known experimental techniques. This technique employs light and genetic tools to either inhibit or excite specific neurons or pathways within the brain. In this review paper, an up-to-date understanding of the use of optogenetics in the study of depression-like behaviors is provided, along with suggestions for future research directions.
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Affiliation(s)
- Marc Fakhoury
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut Campus, Lebanon.
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5
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Structure-Function Relationship of Channelrhodopsins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1293:35-53. [PMID: 33398806 DOI: 10.1007/978-981-15-8763-4_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Ion-translocating rhodopsins, especially channelrhodopsins (ChRs), have attracted broad attention as a powerful tool to modulate the membrane potential of cells with light (optogenetics). Because of recent biophysical, spectroscopic, and computational studies, including the structural determination of cation and anion ChRs, our understanding of the molecular mechanism underlying light-gated ion conduction has been greatly advanced. In this chapter, I first describe the background of rhodopsin family proteins including ChR, and how the optogenetics technology has been established from the discovery of first ChR in 2002. I later introduce the recent findings of the structure-function relationship of ChR by comparing the crystal structures of cation and anion ChRs. I further discuss the future goal in the fields of ChR research and optogenetic tool development.
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6
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Cheng J, Zhang W, Zhou S, Ran X, Shang Y, Lo GV, Dou Y, Yuan S. The effect on ion channel of different protonation states of E90 in channelrhodopsin-2: a molecular dynamics simulation. RSC Adv 2021; 11:14542-14551. [PMID: 35424009 PMCID: PMC8697799 DOI: 10.1039/d1ra01879e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 04/13/2021] [Indexed: 11/21/2022] Open
Abstract
Channelrhodopsin-2 (ChR2) is a cationic channel protein that has been extensively studied in optogenetics. The ion channel is opened via a series of proton transfers and H-bond changes during the photocycle but the detailed mechanism is still unknown. Molecular dynamics (MD) simulations with enhanced sampling were performed on the dark-adapted state (i.e., D470) and two photocycle intermediates (P1500 and P2390) to study the proton transfer path of the Schiff base and the subsequent conformational changes. The results suggest there are two possible proton transfer pathways from the Schiff base to proton acceptors (i.e., E123 or D253), depending on the protonation of E90. If E90 is protonated in the P1500 state, the proton on the Schiff base will transfer to E123. The polyene chain of 13-cis retinal tilts and opens the channel that detours the blocking central gate (CG) and forms a narrow channel through the transmembrane helices (TM) 2, 3, 6 and 7. In contrast, if E90 deprotonates after retinal isomerization, the primary proton acceptor is D253, and an almost-open channel through TM1, 2, 3 and 7 is generated. The channel diameter is very close to the experimental value. The potential mean force (PMF) suggests that the free energy is extremely low for ions passing through this channel. With E90 protonated, the proton acceptor of RSBH+ is E123 with a narrow channel along TM3; while with E90 deprotonated, proton transfer from RSBH+ to D253 generates an approximately open channel along TM2.![]()
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Affiliation(s)
- Jie Cheng
- Chongqing Key Laboratory of Big Data for Bio Intelligence
- Chongqing University of Posts and Telecommunications
- Chongqing 40065
- China
| | - Wenying Zhang
- Chongqing Key Laboratory of Big Data for Bio Intelligence
- Chongqing University of Posts and Telecommunications
- Chongqing 40065
- China
| | - Shuangyan Zhou
- Chongqing Key Laboratory of Big Data for Bio Intelligence
- Chongqing University of Posts and Telecommunications
- Chongqing 40065
- China
| | - Xu Ran
- Chongqing Key Laboratory of Big Data for Bio Intelligence
- Chongqing University of Posts and Telecommunications
- Chongqing 40065
- China
| | - Yiwen Shang
- Chongqing Key Laboratory of Big Data for Bio Intelligence
- Chongqing University of Posts and Telecommunications
- Chongqing 40065
- China
| | - Glenn V. Lo
- Department of Chemistry and Physical Sciences
- Nicholls State University
- Thibodaux
- USA
| | - Yusheng Dou
- Department of Chemistry and Physical Sciences
- Nicholls State University
- Thibodaux
- USA
| | - Shuai Yuan
- Chongqing Key Laboratory of Big Data for Bio Intelligence
- Chongqing University of Posts and Telecommunications
- Chongqing 40065
- China
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7
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Nagasaka Y, Hososhima S, Kubo N, Nagata T, Kandori H, Inoue K, Yawo H. Gate-keeper of ion transport-a highly conserved helix-3 tryptophan in a channelrhodopsin chimera, C1C2/ChRWR. Biophys Physicobiol 2020; 17:59-70. [PMID: 33173715 PMCID: PMC7593130 DOI: 10.2142/biophysico.bsj-2020007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 05/27/2020] [Indexed: 12/01/2022] Open
Abstract
Microbial rhodopsin is a large family of membrane proteins having seven transmembrane helices (TM1-7) with an all-trans retinal (ATR) chromophore that is covalently bound to Lys in the TM7. The Trp residue in the middle of TM3, which is homologous to W86 of bacteriorhodopsin (BR), is highly conserved among microbial rhodopsins with various light-driven functions. However, the significance of this Trp for the ion transport function of microbial rhodopsins has long remained unknown. Here, we replaced the W163 (BR W86 counterpart) of a channelrhodopsin (ChR), C1C2/ChRWR, which is a chimera between ChR1 and 2, with a smaller aromatic residue, Phe to verify its role in the ion transport. Under whole-cell patch clamp recordings from the ND7/23 cells that were transfected with the DNA plasmid coding human codon optimized C1C2/ChRWR (hWR) or its W163F mutant (hWR-W163F), the photocurrents were evoked by a pulsatile light at 475 nm. The ion-transporting activity of hWR was strongly altered by the W163F mutation in 3 points: (1) the H+ leak at positive membrane potential (Vm) and its light-adaptation, (2) the attenuation of cation channel activity and (3) the manifestation of outward H+ pump activity. All of these results strongly suggest that W163 has a role in stabilizing the structure involved in the gating-on and -off of the cation channel, the role of “gate keeper”. We can attribute the attenuation of cation channel activity to the incomplete gating-on and the H+ leak to the incomplete gating-off.
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Affiliation(s)
- Yujiro Nagasaka
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.,Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Shoko Hososhima
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya 466-8555, Japan
| | - Naoko Kubo
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.,Department of Physiology, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8575, Japan
| | - Takashi Nagata
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.,Precursory Research for Embryonic Science and Technology (PRESTO) , Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya 466-8555, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Keiichi Inoue
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Hiromu Yawo
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
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8
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Abstract
Infrared difference spectroscopy probes vibrational changes of proteins upon their perturbation. Compared with other spectroscopic methods, it stands out by its sensitivity to the protonation state, H-bonding, and the conformation of different groups in proteins, including the peptide backbone, amino acid side chains, internal water molecules, or cofactors. In particular, the detection of protonation and H-bonding changes in a time-resolved manner, not easily obtained by other techniques, is one of the most successful applications of IR difference spectroscopy. The present review deals with the use of perturbations designed to specifically change the protein between two (or more) functionally relevant states, a strategy often referred to as reaction-induced IR difference spectroscopy. In the first half of this contribution, I review the technique of reaction-induced IR difference spectroscopy of proteins, with special emphasis given to the preparation of suitable samples and their characterization, strategies for the perturbation of proteins, and methodologies for time-resolved measurements (from nanoseconds to minutes). The second half of this contribution focuses on the spectral interpretation. It starts by reviewing how changes in H-bonding, medium polarity, and vibrational coupling affect vibrational frequencies, intensities, and bandwidths. It is followed by band assignments, a crucial aspect mostly performed with the help of isotopic labeling and site-directed mutagenesis, and complemented by integration and interpretation of the results in the context of the studied protein, an aspect increasingly supported by spectral calculations. Selected examples from the literature, predominately but not exclusively from retinal proteins, are used to illustrate the topics covered in this review.
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9
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Imamoto Y, Sasayama H, Harigai M, Furutani Y, Kataoka M. Regulation of Photocycle Kinetics of Photoactive Yellow Protein by Modulating Flexibility of the β-Turn. J Phys Chem B 2020; 124:1452-1459. [PMID: 32017565 DOI: 10.1021/acs.jpcb.9b11879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The role of the significant flexibility of the β-turn in photoactive yellow protein (PYP) due to Gly115 was studied. G115A and G115P mutations were observed to accelerate the photocycle and shift the equilibrium between the late photocycle intermediate (pB) and its precursor (pR) toward pR. Thermodynamic analysis of dark-state recovery from pB demonstrated that the transition state (pB⧧) has a negative change in transition heat capacity, suggesting that an exposed hydrophobic surface of pB is buried in pB⧧. Fourier transform infrared spectroscopy showed that the structural ensemble of pB is populated by the compact structure in G115P. Taken together, the rigid structure induced by mutation of Gly115 facilitates its transition to pB⧧, which adopts a substantially more compact structure as opposed to the ensemble-averaged structure of pB. The photocycle kinetics of PYP may be fine-tuned by modulating the flexibility of the 115 loop to activate an appropriate number of transducer proteins.
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Affiliation(s)
- Yasushi Imamoto
- Department of Biophysics, Graduate School of Science , Kyoto University , Kyoto 606-8502 , Japan
| | - Hiroaki Sasayama
- Graduate School of Materials Science , Nara Institute of Science and Technology , Ikoma , Nara 630-0192 , Japan
| | - Miki Harigai
- Graduate School of Materials Science , Nara Institute of Science and Technology , Ikoma , Nara 630-0192 , Japan
| | - Yuji Furutani
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science , National Institutes of Natural Sciences , 38 Nishigo-Naka, Myodaiji , Okazaki 444-8585 , Japan.,Department of Structural Molecular Science , The Graduate University for Advanced Studies (SOKENDAI) , 38 Nishigo-Naka, Myodaiji , Okazaki 444-8585 , Japan
| | - Mikio Kataoka
- Graduate School of Materials Science , Nara Institute of Science and Technology , Ikoma , Nara 630-0192 , Japan
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10
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Buhrke D, Hildebrandt P. Probing Structure and Reaction Dynamics of Proteins Using Time-Resolved Resonance Raman Spectroscopy. Chem Rev 2019; 120:3577-3630. [PMID: 31814387 DOI: 10.1021/acs.chemrev.9b00429] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The mechanistic understanding of protein functions requires insight into the structural and reaction dynamics. To elucidate these processes, a variety of experimental approaches are employed. Among them, time-resolved (TR) resonance Raman (RR) is a particularly versatile tool to probe processes of proteins harboring cofactors with electronic transitions in the visible range, such as retinal or heme proteins. TR RR spectroscopy offers the advantage of simultaneously providing molecular structure and kinetic information. The various TR RR spectroscopic methods can cover a wide dynamic range down to the femtosecond time regime and have been employed in monitoring photoinduced reaction cascades, ligand binding and dissociation, electron transfer, enzymatic reactions, and protein un- and refolding. In this account, we review the achievements of TR RR spectroscopy of nearly 50 years of research in this field, which also illustrates how the role of TR RR spectroscopy in molecular life science has changed from the beginning until now. We outline the various methodological approaches and developments and point out current limitations and potential perspectives.
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Affiliation(s)
- David Buhrke
- Technische Universität Berlin, Institut für Chemie, Sekr. PC14, Straße des 17, Juni 135, D-10623 Berlin, Germany
| | - Peter Hildebrandt
- Technische Universität Berlin, Institut für Chemie, Sekr. PC14, Straße des 17, Juni 135, D-10623 Berlin, Germany
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11
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Watari M, Ikuta T, Yamada D, Shihoya W, Yoshida K, Tsunoda SP, Nureki O, Kandori H. Spectroscopic study of the transmembrane domain of a rhodopsin-phosphodiesterase fusion protein from a unicellular eukaryote. J Biol Chem 2019; 294:3432-3443. [PMID: 30622140 DOI: 10.1074/jbc.ra118.006277] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/31/2018] [Indexed: 02/02/2023] Open
Abstract
The choanoflagellate Salpingoeca rosetta contains a chimeric rhodopsin protein composed of an N-terminal rhodopsin (Rh) domain and a C-terminal cyclic nucleotide phosphodiesterase (PDE) domain. The Rh-PDE enzyme light-dependently decreases the concentrations of cyclic nucleotides such as cGMP and cAMP. Photoexcitation of purified full-length Rh-PDE yields an "M" intermediate with a deprotonated Schiff base, and its recovery is much faster than that of the enzyme domain. To gain structural and mechanistic insights into the Rh domain, here we expressed and purified the transmembrane domain of Rh-PDE, Rh-PDE(TMD), and analyzed it with transient absorption, light-induced difference UV-visible, and FTIR spectroscopy methods. These analyses revealed that the "K" intermediate forms within 0.005 ms and converts into the M intermediate with a time constant of 4 ms, with the latter returning to the original state within 4 s. FTIR spectroscopy revealed that all-trans to 13-cis photoisomerization occurs as the primary event during which chromophore distortion is located at the middle of the polyene chain, allowing the Schiff base to form a stronger hydrogen bond. We also noted that the peptide backbone of the α-helix becomes deformed upon M intermediate formation. Results from site-directed mutagenesis suggested that Glu-164 is protonated and that Asp-292 acts as the only Schiff base counterion in Rh-PDE. A strong reduction of enzymatic activity in a D292N variant, but not in an E164Q variant, indicated an important catalytic role of the negative charge at Asp-292. Our findings provide further mechanistic insights into rhodopsin-mediated, light-dependent regulation of second-messenger levels in eukaryotic microbes.
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Affiliation(s)
- Masahito Watari
- From the Department of Life Science and Applied Chemistry and
| | - Tatsuya Ikuta
- the Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan, and
| | - Daichi Yamada
- From the Department of Life Science and Applied Chemistry and
| | - Wataru Shihoya
- the Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan, and
| | - Kazuho Yoshida
- From the Department of Life Science and Applied Chemistry and
| | - Satoshi P Tsunoda
- From the Department of Life Science and Applied Chemistry and.,the OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan.,PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Osamu Nureki
- the Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan, and
| | - Hideki Kandori
- From the Department of Life Science and Applied Chemistry and .,the OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
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12
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Cheng C, Kamiya M, Takemoto M, Ishitani R, Nureki O, Yoshida N, Hayashi S. An Atomistic Model of a Precursor State of Light-Induced Channel Opening of Channelrhodopsin. Biophys J 2018; 115:1281-1291. [PMID: 30236783 PMCID: PMC6170652 DOI: 10.1016/j.bpj.2018.08.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 08/11/2018] [Accepted: 08/13/2018] [Indexed: 01/01/2023] Open
Abstract
Channelrhodopsins (ChRs) are microbial light-gated ion channels with a retinal chromophore and are widely utilized in optogenetics to precisely control neuronal activity with light. Despite increasing understanding of their structures and photoactivation kinetics, the atomistic mechanism of light gating and ion conduction remains elusive. Here, we present an atomic structural model of a chimeric ChR in a precursor state of the channel opening determined by an accurate hybrid molecular simulation technique and a statistical theory of internal water distribution. The photoactivated structure features extensive tilt of the chromophore accompanied by redistribution of water molecules in its binding pocket, which is absent in previously known photoactivated structures of analogous photoreceptors, and widely agrees with structural and spectroscopic experimental evidence of ChRs. The atomistic model manifests a photoactivated ion-conduction pathway that is markedly different from a previously proposed one and successfully explains experimentally observed mutagenic effects on key channel properties.
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Affiliation(s)
- Cheng Cheng
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Motoshi Kamiya
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Mizuki Takemoto
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Ryuichiro Ishitani
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Norio Yoshida
- Department of Chemistry, Graduate School of Science, Kyushu University, Fukuoka, Japan.
| | - Shigehiko Hayashi
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan.
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13
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Volkov O, Kovalev K, Polovinkin V, Borshchevskiy V, Bamann C, Astashkin R, Marin E, Popov A, Balandin T, Willbold D, Büldt G, Bamberg E, Gordeliy V. Structural insights into ion conduction by channelrhodopsin 2. Science 2018; 358:358/6366/eaan8862. [PMID: 29170206 DOI: 10.1126/science.aan8862] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 10/30/2017] [Indexed: 11/02/2022]
Abstract
The light-gated ion channel channelrhodopsin 2 (ChR2) from Chlamydomonas reinhardtii is a major optogenetic tool. Photon absorption starts a well-characterized photocycle, but the structural basis for the regulation of channel opening remains unclear. We present high-resolution structures of ChR2 and the C128T mutant, which has a markedly increased open-state lifetime. The structure reveals two cavities on the intracellular side and two cavities on the extracellular side. They are connected by extended hydrogen-bonding networks involving water molecules and side-chain residues. Central is the retinal Schiff base that controls and synchronizes three gates that separate the cavities. Separate from this network is the DC gate that comprises a water-mediated bond between C128 and D156 and interacts directly with the retinal Schiff base. Comparison with the C128T structure reveals a direct connection of the DC gate to the central gate and suggests how the gating mechanism is affected by subtle tuning of the Schiff base's interactions.
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Affiliation(s)
- Oleksandr Volkov
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Juelich, Juelich, Germany
| | - Kirill Kovalev
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Juelich, Juelich, Germany.,Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France.,Moscow Institute of Physics and Technology, Dolgoprudny, Russia.,Institute of Crystallography, University of Aachen, Aachen, Germany
| | - Vitaly Polovinkin
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Juelich, Juelich, Germany.,Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France.,Moscow Institute of Physics and Technology, Dolgoprudny, Russia.,ELI Beamlines, Institute of Physics, Czech Academy of Sciences, 18221 Prague, Czech Republic
| | | | | | - Roman Astashkin
- Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France.,Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Egor Marin
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Alexander Popov
- European Synchrotron Radiation Facility, 38027 Grenoble, France
| | - Taras Balandin
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Juelich, Juelich, Germany
| | - Dieter Willbold
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Juelich, Juelich, Germany.,Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France.,Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Georg Büldt
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Ernst Bamberg
- Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
| | - Valentin Gordeliy
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Juelich, Juelich, Germany. .,Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France.,Moscow Institute of Physics and Technology, Dolgoprudny, Russia
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14
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Abstract
Channelrhodopsin-2 (ChR2) is a light-sensitive ion channel widely used in optogenetics. Photoactivation triggers a trans-to-cis isomerization of a covalently bound retinal. Ensuing conformational changes open a cation-selective channel. We explore the structural dynamics in the early photocycle leading to channel opening by classical (MM) and quantum mechanical (QM) molecular simulations. With QM/MM simulations, we generated a protein-adapted force field for the retinal chromophore, which we validated against absorption spectra. In a 4-µs MM simulation of a dark-adapted ChR2 dimer, water entered the vestibules of the closed channel. Retinal all-trans to 13-cis isomerization, simulated with metadynamics, triggered a major restructuring of the charge cluster forming the channel gate. On a microsecond time scale, water penetrated the gate to form a membrane-spanning preopen pore between helices H1, H2, H3, and H7. This influx of water into an ion-impermeable preopen pore is consistent with time-resolved infrared spectroscopy and electrophysiology experiments. In the retinal 13-cis state, D253 emerged as the proton acceptor of the Schiff base. Upon proton transfer from the Schiff base to D253, modeled by QM/MM simulations, we obtained an early-M/P2390-like intermediate. Rapid rotation of the unprotonated Schiff base toward the cytosolic side effectively prevents its reprotonation from the extracellular side. From MM and QM simulations, we gained detailed insight into the mechanism of ChR2 photoactivation and early events in pore formation. By rearranging the network of charges and hydrogen bonds forming the gate, water emerges as a key player in light-driven ChR2 channel opening.
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Affiliation(s)
- Albert Ardevol
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany;
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany;
- Department of Physics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
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15
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Zheng W, Zhou J, Luan Y, Yang J, Ge Y, Wang M, Wu B, Wu Z, Chen X, Li F, Li Z, Vakal S, Guo W, Chen JF. Spatiotemporal Control of GPR37 Signaling and Its Behavioral Effects by Optogenetics. Front Mol Neurosci 2018; 11:95. [PMID: 29643766 PMCID: PMC5882850 DOI: 10.3389/fnmol.2018.00095] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 03/12/2018] [Indexed: 12/18/2022] Open
Abstract
Despite the progress in deorphanization of G Protein-Coupled Receptors (GPCRs), ≈100 GPCRs are still classified as orphan receptors without identified endogenous ligands and with unknown physiological functions. The lack of endogenous ligands triggering GPCR signaling has hampered the study of orphan GPCR functions. Using GPR37 as an example, we provide here the first demonstration of the channelrhodopsin 2 (ChR2)-GPCR approach to bypass the endogenous ligand and selectively activate the orphan GPCR signal by optogenetics. Inspired by the opto-XR approach, we designed the ChR2-GPR37 chimera, in which the corresponding parts of GPR37 replaced the intracellular portions of ChR2. We showed that optogenetic activation of ChR2/opto-GPR37 elicited specific GPR37 signaling, as evidenced by reduced cAMP level, enhanced ERK phosphorylation and increased motor activity, confirming the specificity of opto-GPR37 signaling. Besides, optogenetic activation of opto-GPR37 uncovered novel aspects of GPR37 signaling (such as IP-3 signaling) and anxiety-related behavior. Optogenetic activation of opto-GPR37 permits the causal analysis of GPR37 activity in the defined cells and behavioral responses of freely moving animals. Importantly, given the evolutionarily conserved seven-helix transmembrane structures of ChR2 and orphan GPCRs, we propose that opto-GPR37 approach can be readily applied to other orphan GPCRs for their deorphanization in freely moving animals.
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Affiliation(s)
- Wu Zheng
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Optometry & Vision Science, Wenzhou, China
| | - Jianhong Zhou
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Optometry & Vision Science, Wenzhou, China
| | - Yanan Luan
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Jianglan Yang
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Yuanyuan Ge
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Muran Wang
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Beibei Wu
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Zhongnan Wu
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xingjun Chen
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Optometry & Vision Science, Wenzhou, China
| | - Fei Li
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Zhihui Li
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Optometry & Vision Science, Wenzhou, China
| | - Sergii Vakal
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Wei Guo
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Optometry & Vision Science, Wenzhou, China
| | - Jiang-Fan Chen
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Optometry & Vision Science, Wenzhou, China.,Department of Neurology, Boston University School of Medicine, Boston University, Boston, MA, United States
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16
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Tsukamoto H, Higashi M, Motoki H, Watanabe H, Ganser C, Nakajo K, Kubo Y, Uchihashi T, Furutani Y. Structural properties determining low K + affinity of the selectivity filter in the TWIK1 K + channel. J Biol Chem 2018; 293:6969-6984. [PMID: 29545310 DOI: 10.1074/jbc.ra118.001817] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/14/2018] [Indexed: 11/06/2022] Open
Abstract
Canonical K+ channels are tetrameric and highly K+-selective, whereas two-pore-domain K+ (K2P) channels form dimers, but with a similar pore architecture. A two-pore-domain potassium channel TWIK1 (KCNK1 or K2P1) allows permeation of Na+ and other monovalent ions, resulting mainly from the presence of Thr-118 in the P1 domain. However, the mechanistic basis for this reduced selectivity is unclear. Using ion-exchange-induced difference IR spectroscopy, we analyzed WT TWIK1 and T118I (highly K+-selective) and L228F (substitution in the P2 domain) TWIK1 variants and found that in the presence of K+ ions, WT and both variants exhibit an amide-I band at 1680 cm-1 This band corresponds to interactions of the backbone carbonyls in the selectivity filter with K+, a feature very similar to that of the canonical K+ channel KcsA. Computational analysis indicated that the relatively high frequency for the amide-I band is well explained by impairment of hydrogen bond formation with water molecules. Moreover, concentration-dependent spectral changes indicated that the K+ affinity of the WT selectivity filter was much lower than those of the variants. Furthermore, only the variants displayed a higher frequency shift of the 1680-cm-1 band upon changes from K+ to Rb+ or Cs+ conditions. High-speed atomic force microscopy disclosed that TWIK1's surface morphology largely does not change in K+ and Na+ solutions. Our results reveal the local conformational changes of the TWIK1 selectivity filter and suggest that the amide-I bands may be useful "molecular fingerprints" for assessing the properties of other K+ channels.
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Affiliation(s)
- Hisao Tsukamoto
- From the Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, and.,Departments of Structural Molecular Science and
| | - Masahiro Higashi
- the Department of Chemistry, Biology and Marine Science, University of the Ryukyus, 1 Senbaru, Nishihara, Nakagami, Okinawa 903-0213
| | - Hideyoshi Motoki
- the Department of Chemistry, Biology and Marine Science, University of the Ryukyus, 1 Senbaru, Nishihara, Nakagami, Okinawa 903-0213
| | - Hiroki Watanabe
- the Department of Physics and Structural Biology Research Center, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, and
| | - Christian Ganser
- the Department of Physics and Structural Biology Research Center, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, and
| | - Koichi Nakajo
- the Division of Biophysics and Neurobiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan.,Physiological Sciences, SOKENDAI (Graduate University for Advanced Studies), 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585
| | - Yoshihiro Kubo
- the Division of Biophysics and Neurobiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan.,Physiological Sciences, SOKENDAI (Graduate University for Advanced Studies), 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585
| | - Takayuki Uchihashi
- the Department of Physics and Structural Biology Research Center, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, and
| | - Yuji Furutani
- From the Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, and .,Departments of Structural Molecular Science and
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17
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Kaufmann JCD, Krause BS, Grimm C, Ritter E, Hegemann P, Bartl FJ. Proton transfer reactions in the red light-activatable channelrhodopsin variant ReaChR and their relevance for its function. J Biol Chem 2017; 292:14205-14216. [PMID: 28659342 PMCID: PMC5572910 DOI: 10.1074/jbc.m117.779629] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 06/27/2017] [Indexed: 11/06/2022] Open
Abstract
Channelrhodopsins (ChRs) are light-gated ion channels widely used for activating selected cells in large cellular networks. ChR variants with a red-shifted absorption maximum, such as the modified Volvox carteri ChR1 red-activatable channelrhodopsin ("ReaChR," λmax = 527 nm), are of particular interest because longer wavelengths allow optical excitation of cells in deeper layers of organic tissue. In all ChRs investigated so far, proton transfer reactions and hydrogen bond changes are crucial for the formation of the ion-conducting pore and the selectivity for protons versus cations, such as Na+, K+, and Ca2+ (1). By using a combination of electrophysiological measurements and UV-visible and FTIR spectroscopy, we characterized the proton transfer events in the photocycle of ReaChR and describe their relevance for its function. 1) The central gate residue Glu130 (Glu90 in Chlamydomonas reinhardtii (Cr) ChR2) (i) undergoes a hydrogen bond change in D → K transition and (ii) deprotonates in K → M transition. Its negative charge in the open state is decisive for proton selectivity. 2) The counter-ion Asp293 (Asp253 in CrChR2) receives the retinal Schiff base proton during M-state formation. Starting from M, a photocycle branching occurs involving (i) a direct M → D transition and (ii) formation of late photointermediates N and O. 3) The DC pair residue Asp196 (Asp156 in CrChR2) deprotonates in N → O transition. Interestingly, the D196N mutation increases 15-syn-retinal at the expense of 15-anti, which is the predominant isomer in the wild type, and abolishes the peak current in electrophysiological measurements. This suggests that the peak current is formed by 15-anti species, whereas 15-syn species contribute only to the stationary current.
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Affiliation(s)
- Joel C D Kaufmann
- From the Institut für medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany,.
| | | | | | | | | | - Franz J Bartl
- From the Institut für medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany,; Institut für Biologie, Biophysikalische Chemie, Humboldt-Universität zu Berlin, Invalidenstrasse 42, 10115 Berlin, Germany.
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18
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Yamauchi Y, Konno M, Ito S, Tsunoda SP, Inoue K, Kandori H. Molecular properties of a DTD channelrhodopsin from Guillardia theta. Biophys Physicobiol 2017. [PMID: 28630812 PMCID: PMC5468465 DOI: 10.2142/biophysico.14.0_57] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Microbial rhodopsins are membrane proteins found widely in archaea, eubacteria and eukaryotes (fungal and algal species). They have various functions, such as light-driven ion pumps, light-gated ion channels, light sensors and light-activated enzymes. A light-driven proton pump bacteriorhodopsin (BR) contains a DTD motif at positions 85, 89, and 96, which is unique to archaeal proton pumps. Recently, channelrhodopsins (ChRs) containing the DTD motif, whose sequential identity is ~20% similar to BR and to cation ChRs in Chlamydomonas reinhardtii (CrCCRs), were found. While extensive studies on ChRs have been performed with CrCCR2, the molecular properties of DTD ChRs remain an intrigue. In this paper, we studied a DTD rhodopsin from G. theta (GtCCR4) using electrophysiological measurements, flash photolysis, and low-temperature difference FTIR spectroscopy. Electrophysiological measurements clearly showed that GtCCR4 functions as a light-gated cation channel, similar to other G. theta DTD ChRs (GtCCR1-3). Light-driven proton pump activity was also suggested for GtCCR4. Both electrophysiological and flash photolysis experiments showed that channel closing occurs upon reprotonation of the Schiff base, suggesting that the dynamics of retinal and channels are tightly coupled in GtCCR4. From Fourier transform infrared (FTIR) spectroscopy at 77 K, we found that the primary reaction is an all-trans to a 13-cis photoisomerization, like other microbial rhodopsins, although perturbations in the secondary structure were much smaller in GtCCR4 than in CrCCR2.
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Affiliation(s)
- Yumeka Yamauchi
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
| | - Masae Konno
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
| | - Shota Ito
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
| | - Satoshi P Tsunoda
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan
| | - Keiichi Inoue
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan.,Frontier Research Institute for Material Science, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
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19
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Zamani A, Sakuragi S, Ishizuka T, Yawo H. Kinetic characteristics of chimeric channelrhodopsins implicate the molecular identity involved in desensitization. Biophys Physicobiol 2017; 14:13-22. [PMID: 28409086 PMCID: PMC5289414 DOI: 10.2142/biophysico.14.0_13] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 12/29/2016] [Indexed: 12/01/2022] Open
Abstract
Channelrhodopsin (ChR)-1 and ChR2 were the first-identified members of ChRs which are a growing subfamily of microbial-type rhodopsins. Light absorption drives the generation of a photocurrent in cell membranes expressing ChR2. However, the photocurrent amplitude attenuates and becomes steady-state during prolonged irradiation. This process, called desensitization or inactivation, has been attributed to the accumulation of intermediates less conductive to cations. Here we provided evidence that the dark-adapted (DA) photocurrent before desensitization is kinetically different from the light-adapted (LA) one after desensitization, that is, the deceleration of both basal-to-conductive and conductive-to-basal transitions. When the kinetics were compared between the DA and LA photocurrents for the ChR1/2 chimeras, the transmembrane helices, TM1 and TM2, were the determinants of both basal-to-conductive and conductive-to-basal transitions, whereas TM4 may contribute to the basal-to-conductive transitions and TM5 may contribute to the conductive-to-basal transitions, respectively. The fact that the desensitization-dependent decrease of the basal-to-conductive and conductive-to-basal transitions was facilitated by the TM1 exchange from ChR2 to ChR1 and reversed by the further TM2 exchange suggests that the conformation change for the channel gating is predominantly regulated by the interaction between TM1 and TM2. Although the exchange of TM1 from ChR2 to ChR1 showed no obvious influence on the spectral sensitivity, this exchange significantly induced the desensitization-dependent blue shift. Therefore, the TM1 and 2 are the main structures involved in two features of the desensitization, the stabilization of protein conformation and the charge distribution around the retinal-Schiff base (RSB+).
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Affiliation(s)
- Alemeh Zamani
- Department of Developmental Biology and Neurosciences, Tohoku University Graduate School of Life Sciences, Sendai, Miyagi 980-8577, Japan
| | - Shigeo Sakuragi
- Department of Developmental Biology and Neurosciences, Tohoku University Graduate School of Life Sciences, Sendai, Miyagi 980-8577, Japan
| | - Toru Ishizuka
- Department of Developmental Biology and Neurosciences, Tohoku University Graduate School of Life Sciences, Sendai, Miyagi 980-8577, Japan
| | - Hiromu Yawo
- Department of Developmental Biology and Neurosciences, Tohoku University Graduate School of Life Sciences, Sendai, Miyagi 980-8577, Japan.,Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8575, Japan
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20
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Yi A, Mamaeva N, Li H, Spudich JL, Rothschild KJ. Resonance Raman Study of an Anion Channelrhodopsin: Effects of Mutations near the Retinylidene Schiff Base. Biochemistry 2016; 55:2371-80. [PMID: 27039989 DOI: 10.1021/acs.biochem.6b00104] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Optogenetics relies on the expression of specific microbial rhodopsins in the neuronal plasma membrane. Most notably, this includes channelrhodopsins, which when heterologously expressed in neurons function as light-gated cation channels. Recently, a new class of microbial rhodopsins, termed anion channel rhodopsins (ACRs), has been discovered. These proteins function as efficient light-activated channels strictly selective for anions. They exclude the flow of protons and other cations and cause hyperpolarization of the membrane potential in neurons by allowing the inward flow of chloride ions. In this study, confocal near-infrared resonance Raman spectroscopy (RRS) along with hydrogen/deuterium exchange, retinal analogue substitution, and site-directed mutagenesis were used to study the retinal structure as well as its interactions with the protein in the unphotolyzed state of an ACR from Guillardia theta (GtACR1). These measurements reveal that (i) the retinal chromophore exists as an all-trans configuration with a protonated Schiff base (PSB) very similar to that of bacteriorhodopsin (BR), (ii) the chromophore RRS spectrum is insensitive to changes in pH from 3 to 11, whereas above this pH the Schiff base (SB) is deprotonated, (iii) when Ser97, the homologue to Asp85 in BR, is replaced with a Glu, it remains in a neutral form (i.e., as a carboxylic acid) but is deprotonated at higher pH to form a blue-shifted species, (iv) Asp234, the homologue of the protonated retinylidene SB counterion Asp212 in BR, does not serve as the primary counteranion for the protonated SB, and (v) substitution of Glu68 with an Gln increases the pH at which SB deprotonation is observed. These results suggest that Glu68 and Asp234 located near the SB exist in a neutral state in unphotolyzed GtACR1 and indicate that other unidentified negative charges stabilize the protonated state of the GtACR1 SB.
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Affiliation(s)
- Adrian Yi
- Molecular Biophysics Laboratory, Photonics Center, and Department of Physics, Boston University , Boston, Massachusetts 02215, United States
| | - Natalia Mamaeva
- Molecular Biophysics Laboratory, Photonics Center, and Department of Physics, Boston University , Boston, Massachusetts 02215, United States
| | - Hai Li
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, McGovern Medical School , Houston, Texas 77030, United States
| | - John L Spudich
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, McGovern Medical School , Houston, Texas 77030, United States
| | - Kenneth J Rothschild
- Molecular Biophysics Laboratory, Photonics Center, and Department of Physics, Boston University , Boston, Massachusetts 02215, United States
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21
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Hršak D, Marefat Khah A, Christiansen O, Hättig C. Polarizable Embedded RI-CC2 Method for Two-Photon Absorption Calculations. J Chem Theory Comput 2015; 11:3669-78. [PMID: 26574450 DOI: 10.1021/acs.jctc.5b00496] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We present a novel polarizable embedded resolution-of-identity coupled cluster singles and approximate doubles (PERI-CC2) method for calculation of two-photon absorption (TPA) spectra of large molecular systems. The method was benchmarked for three types of systems: a water-solvated molecule of formamide, a uracil molecule in aqueous solution, and a set of mutants of the channelrhodopsin (ChR) protein. The first test case shows that the PERI-CC2 method is in excellent agreement with the PE-CC2 method and in good agreement with the PE-CCSD method. The uracil test case indicates that the effects of hydrogen bonding on the TPA of a chromophore with the nearest environment is well-described with the PERI-CC2 method. Finally, the ChR calculation shows that the PERI-CC2 method is well-suited and efficient for calculations on proteins with medium-sized chromophores.
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Affiliation(s)
- Dalibor Hršak
- Center for Oxygen Microscopy and Imaging, Aarhus University , Langelandsgade 140, 8000 Aarhus, Denmark
| | - Alireza Marefat Khah
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum , Universitätsstraße 150, 44801 Bochum, Germany
| | - Ove Christiansen
- Center for Oxygen Microscopy and Imaging, Aarhus University , Langelandsgade 140, 8000 Aarhus, Denmark
| | - Christof Hättig
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum , Universitätsstraße 150, 44801 Bochum, Germany
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22
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Resler T, Schultz BJ, Lórenz-Fonfría VA, Schlesinger R, Heberle J. Kinetic and vibrational isotope effects of proton transfer reactions in channelrhodopsin-2. Biophys J 2015; 109:287-97. [PMID: 26200864 PMCID: PMC4621815 DOI: 10.1016/j.bpj.2015.06.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 05/12/2015] [Accepted: 06/10/2015] [Indexed: 12/25/2022] Open
Abstract
Channelrhodopsins (ChRs) are light-gated cation channels. After blue-light excitation, the protein undergoes a photocycle with different intermediates. Here, we have recorded transient absorbance changes of ChR2 from Chlamydomonas reinhardtii in the visible and infrared regions with nanosecond time resolution, the latter being accomplished using tunable quantum cascade lasers. Because proton transfer reactions play a key role in channel gating, we determined vibrational as well as kinetic isotope effects (VIEs and KIEs) of carboxylic groups of various key aspartic and glutamic acid residues by monitoring their C=O stretching vibrations in H2O and in D2O. D156 exhibits a substantial KIE (>2) in its deprotonation and reprotonation, which substantiates its role as the internal proton donor to the retinal Schiff base. The unusual VIE of D156, upshifted from 1736 cm(-1) to 1738 cm(-1) in D2O, was scrutinized by studying the D156E variant. The C=O stretch of E156 shifted down by 8 cm(-1) in D2O, providing evidence for the accessibility of the carboxylic group. The C=O stretching band of E90 exhibits a VIE of 9 cm(-1) and a KIE of ∼2 for the de- and the reprotonation reactions during the lifetime of the late desensitized state. The KIE of 1 determined in the time range from 20 ns to 5 ms is incompatible with early deprotonation of E90.
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Affiliation(s)
- Tom Resler
- Experimental Molecular Biophysics, Freie Universität Berlin, Berlin, Germany
| | | | | | - Ramona Schlesinger
- Genetic Biophysics at Department of Physics, Freie Universität Berlin, Berlin, Germany
| | - Joachim Heberle
- Experimental Molecular Biophysics, Freie Universität Berlin, Berlin, Germany.
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23
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Takemoto M, Kato HE, Koyama M, Ito J, Kamiya M, Hayashi S, Maturana AD, Deisseroth K, Ishitani R, Nureki O. Molecular Dynamics of Channelrhodopsin at the Early Stages of Channel Opening. PLoS One 2015; 10:e0131094. [PMID: 26114863 PMCID: PMC4482709 DOI: 10.1371/journal.pone.0131094] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 05/28/2015] [Indexed: 11/25/2022] Open
Abstract
Channelrhodopsin (ChR) is a light-gated cation channel that responds to blue light. Since ChR can be readily expressed in specific neurons to precisely control their activities by light, it has become a powerful tool in neuroscience. Although the recently solved crystal structure of a chimeric ChR, C1C2, provided the structural basis for ChR, our understanding of the molecular mechanism of ChR still remains limited. Here we performed electrophysiological analyses and all-atom molecular dynamics (MD) simulations, to investigate the importance of the intracellular and central constrictions of the ion conducting pore observed in the crystal structure of C1C2. Our electrophysiological analysis revealed that two glutamate residues, Glu122 and Glu129, in the intracellular and central constrictions, respectively, should be deprotonated in the photocycle. The simulation results suggested that the deprotonation of Glu129 in the central constriction leads to ion leakage in the ground state, and implied that the protonation of Glu129 is important for preventing ion leakage in the ground state. Moreover, we modeled the 13-cis retinal bound; i.e., activated C1C2, and performed MD simulations to investigate the conformational changes in the early stage of the photocycle. Our simulations suggested that retinal photoisomerization induces the conformational change toward channel opening, including the movements of TM6, TM7 and TM2. These insights into the dynamics of the ground states and the early photocycle stages enhance our understanding of the channel function of ChR.
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Affiliation(s)
- Mizuki Takemoto
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113–0033, Japan
| | - Hideaki E. Kato
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113–0033, Japan
| | - Michio Koyama
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113–0033, Japan
| | - Jumpei Ito
- Department of Bioengineering Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464–8601, Japan
| | - Motoshi Kamiya
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606–8502, Japan
| | - Shigehiko Hayashi
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606–8502, Japan
| | - Andrés D. Maturana
- Department of Bioengineering Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464–8601, Japan
| | - Karl Deisseroth
- Department of Bioengineering and Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, United States of America
| | - Ryuichiro Ishitani
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113–0033, Japan
- * E-mail: (ON); (RI)
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113–0033, Japan
- * E-mail: (ON); (RI)
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Dokukina I, Weingart O. Spectral properties and isomerisation path of retinal in C1C2 channelrhodopsin. Phys Chem Chem Phys 2015; 17:25142-50. [DOI: 10.1039/c5cp02650d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Computed torsion profiles along the reactive coordinate in S1reveal a two-path deactivation mechanism for retinal in C1C2 channelrhodopsin.
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Affiliation(s)
- I. Dokukina
- Institut für Theoretische Chemie und Computerchemie
- Heinrich-Heine-Universität Düsseldorf
- 40225 Düsseldorf
- Germany
| | - O. Weingart
- Institut für Theoretische Chemie und Computerchemie
- Heinrich-Heine-Universität Düsseldorf
- 40225 Düsseldorf
- Germany
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