1
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Xiao S, Ibrahim MT, Verkhivker GM, Zoltowski BD, Tao P. β-sheets mediate the conformational change and allosteric signal transmission between the AsLOV2 termini. J Comput Chem 2024; 45:1493-1504. [PMID: 38476039 DOI: 10.1002/jcc.27344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 02/09/2024] [Accepted: 02/16/2024] [Indexed: 03/14/2024]
Abstract
Avena sativa phototropin 1 light-oxygen-voltage 2 domain (AsLOV2) is a model protein of Per-Arnt-Sim (PAS) superfamily, characterized by conformational changes in response to external environmental stimuli. This conformational change begins with the unfolding of the N-terminal A'α helix in the dark state followed by the unfolding of the C-terminal Jα helix. The light state is characterized by the unfolded termini and the subsequent modifications in hydrogen bond patterns. In this photoreceptor, β-sheets are identified as crucial components for mediating allosteric signal transmission between the two termini. Through combined experimental and computational investigations, the Hβ and Iβ strands are recognized as the most critical and influential β-sheets in AsLOV2's allosteric mechanism. To elucidate the role of these β-sheets, we introduced 13 distinct mutations (F490L, N492A, L493A, F494L, H495L, L496F, Q497A, R500A, F509L, Q513A, L514A, D515V, and T517V) and conducted comprehensive molecular dynamics simulations. In-depth hydrogen bond analyses emphasized the role of two hydrogen bonds, Asn482-Leu453 and Gln479-Val520, in the observed distinct behaviors of L493A, L496F, Q497A, and D515V mutants. This illustrates the role of β-sheets in the transmission of the allosteric signal upon the photoactivation of the light state.
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Affiliation(s)
- Sian Xiao
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, USA
| | - Mayar Tarek Ibrahim
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, USA
| | - Gennady M Verkhivker
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California, USA
| | - Brian D Zoltowski
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, USA
| | - Peng Tao
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, USA
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2
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García de Fuentes A, Möglich A. Reduction midpoint potential of a paradigm light-oxygen-voltage receptor and its modulation by methionine residues. RSC Chem Biol 2024; 5:530-543. [PMID: 38846079 PMCID: PMC11151830 DOI: 10.1039/d4cb00056k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 04/08/2024] [Indexed: 06/09/2024] Open
Abstract
Light-dependent adaptations of organismal physiology, development, and behavior abound in nature and depend on sensory photoreceptors. As one class, light-oxygen-voltage (LOV) photoreceptors harness flavin-nucleotide chromophores to sense blue light. Photon absorption drives the LOV receptor to its signaling state, characterized by a metastable thioadduct between the flavin and a conserved cysteine residue. With this cysteine absent, LOV receptors instead undergo photoreduction to the flavin semiquinone which however can still elicit downstream physiological responses. Irrespective of the cysteine presence, the LOV photochemical response thus entails a formal reduction of the flavin. Against this backdrop, we here investigate the reduction midpoint potential E 0 in the paradigmatic LOV2 domain from Avena sativa phototropin 1 (AsLOV2), and how it can be deliberately varied. Replacements of residues at different sites near the flavin by methionine consistently increase E 0 from its value of around -280 mV by up to 40 mV. Moreover, methionine introduction invariably impairs photoactivation efficiency and thus renders the resultant AsLOV2 variants less light-sensitive. Although individual methionine substitutions also affect the stability of the signaling state and downstream allosteric responses, no clear-cut correlation with the redox properties emerges. With a reduction midpoint potential near -280 mV, AsLOV2 and, by inference, other LOV receptors may be partially reduced inside cells which directly affects their light responsiveness. The targeted modification of the chromophore environment, as presently demonstrated, may mitigate this effect and enables the design of LOV receptors with stratified redox sensitivities.
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Affiliation(s)
| | - Andreas Möglich
- Department of Biochemistry, University of Bayreuth 95447 Bayreuth Germany
- Bayreuth Center for Biochemistry & Molecular Biology, Universität Bayreuth 95447 Bayreuth Germany
- North-Bavarian NMR Center, Universität Bayreuth 95447 Bayreuth Germany
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3
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Flores-Ibarra A, Maia RNA, Olasz B, Church JR, Gotthard G, Schapiro I, Heberle J, Nogly P. Light-Oxygen-Voltage (LOV)-sensing Domains: Activation Mechanism and Optogenetic Stimulation. J Mol Biol 2024; 436:168356. [PMID: 37944792 DOI: 10.1016/j.jmb.2023.168356] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 10/11/2023] [Accepted: 11/02/2023] [Indexed: 11/12/2023]
Abstract
The light-oxygen-voltage (LOV) domains of phototropins emerged as essential constituents of light-sensitive proteins, helping initiate blue light-triggered responses. Moreover, these domains have been identified across all kingdoms of life. LOV domains utilize flavin nucleotides as co-factors and undergo structural rearrangements upon exposure to blue light, which activates an effector domain that executes the final output of the photoreaction. LOV domains are versatile photoreceptors that play critical roles in cellular signaling and environmental adaptation; additionally, they can noninvasively sense and control intracellular processes with high spatiotemporal precision, making them ideal candidates for use in optogenetics, where a light signal is linked to a cellular process through a photoreceptor. The ongoing development of LOV-based optogenetic tools, driven by advances in structural biology, spectroscopy, computational methods, and synthetic biology, has the potential to revolutionize the study of biological systems and enable the development of novel therapeutic strategies.
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Affiliation(s)
- Andrea Flores-Ibarra
- Dioscuri Center for Structural Dynamics of Receptors, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland
| | - Raiza N A Maia
- Department of Chemistry, The University of Texas at Austin, 78712-1224 Austin, TX, USA
| | - Bence Olasz
- Dioscuri Center for Structural Dynamics of Receptors, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland
| | - Jonathan R Church
- Institute of Chemistry, The Hebrew University of Jerusalem, 91905 Jerusalem, Israel
| | | | - Igor Schapiro
- Institute of Chemistry, The Hebrew University of Jerusalem, 91905 Jerusalem, Israel
| | - Joachim Heberle
- Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Przemyslaw Nogly
- Dioscuri Center for Structural Dynamics of Receptors, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland.
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4
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Hemmer S, Siedhoff NE, Werner S, Ölçücü G, Schwaneberg U, Jaeger KE, Davari MD, Krauss U. Machine Learning-Assisted Engineering of Light, Oxygen, Voltage Photoreceptor Adduct Lifetime. JACS AU 2023; 3:3311-3323. [PMID: 38155650 PMCID: PMC10751770 DOI: 10.1021/jacsau.3c00440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 11/07/2023] [Accepted: 11/07/2023] [Indexed: 12/30/2023]
Abstract
Naturally occurring and engineered flavin-binding, blue-light-sensing, light, oxygen, voltage (LOV) photoreceptor domains have been used widely to design fluorescent reporters, optogenetic tools, and photosensitizers for the visualization and control of biological processes. In addition, natural LOV photoreceptors with engineered properties were recently employed for optimizing plant biomass production in the framework of a plant-based bioeconomy. Here, the understanding and fine-tuning of LOV photoreceptor (kinetic) properties is instrumental for application. In response to blue-light illumination, LOV domains undergo a cascade of photophysical and photochemical events that yield a transient covalent FMN-cysteine adduct, allowing for signaling. The rate-limiting step of the LOV photocycle is the dark-recovery process, which involves adduct scission and can take between seconds and days. Rational engineering of LOV domains with fine-tuned dark recovery has been challenging due to the lack of a mechanistic model, the long time scale of the process, which hampers atomistic simulations, and a gigantic protein sequence space covering known mutations (combinatorial challenge). To address these issues, we used machine learning (ML) trained on scarce literature data and iteratively generated and implemented experimental data to design LOV variants with faster and slower dark recovery. Over the three prediction-validation cycles, LOV domain variants were successfully predicted, whose adduct-state lifetimes spanned 7 orders of magnitude, yielding optimized tools for synthetic (opto)biology. In summary, our results demonstrate ML as a viable method to guide the design of proteins even with limited experimental data and when no mechanistic model of the underlying physical principles is available.
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Affiliation(s)
- Stefanie Hemmer
- Institute
of Molecular Enzyme Technology, Heinrich
Heine University Düsseldorf, Wilhelm Johnen Strasse, Jülich 52426, Germany
| | - Niklas Erik Siedhoff
- Institute
of Biotechnology, RWTH Aachen University, Worringer Weg 3, 52074 Aachen, Germany
- DWI-Leibniz
Institute for Interactive Materials, Forckenbeckstraße 50, 52074 Aachen, Germany
| | - Sophia Werner
- Institute
of Molecular Enzyme Technology, Heinrich
Heine University Düsseldorf, Wilhelm Johnen Strasse, Jülich 52426, Germany
| | - Gizem Ölçücü
- Institute
of Molecular Enzyme Technology, Heinrich
Heine University Düsseldorf, Wilhelm Johnen Strasse, Jülich 52426, Germany
| | - Ulrich Schwaneberg
- Institute
of Biotechnology, RWTH Aachen University, Worringer Weg 3, 52074 Aachen, Germany
- DWI-Leibniz
Institute for Interactive Materials, Forckenbeckstraße 50, 52074 Aachen, Germany
| | - Karl-Erich Jaeger
- Institute
of Molecular Enzyme Technology, Heinrich
Heine University Düsseldorf, Wilhelm Johnen Strasse, Jülich 52426, Germany
- Institute
of Bio-and Geosciences IBG 1: Biotechnology, Forschungszentrum Jülich GmbH, Wilhelm Johnen Strasse, Jülich 52426, Germany
| | - Mehdi D. Davari
- Department
of Bioorganic Chemistry, Leibniz Institute
of Plant Biochemistry, Weinberg 3, 06120 Halle, Germany
| | - Ulrich Krauss
- Institute
of Molecular Enzyme Technology, Heinrich
Heine University Düsseldorf, Wilhelm Johnen Strasse, Jülich 52426, Germany
- Institute
of Bio-and Geosciences IBG 1: Biotechnology, Forschungszentrum Jülich GmbH, Wilhelm Johnen Strasse, Jülich 52426, Germany
- Department
of Biochemistry, University of Bayreuth, 95447 Bayreuth, Germany
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5
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Xiao S, Ibrahim MT, Verkhivker GM, Zoltowski BD, Tao P. Microsecond Molecular Dynamics Simulations and Markov State Models of Mutation-Induced Allosteric Mechanisms for the Light-Oxygen-Voltage 2 Protein : Revealing Structural Basis of Signal Transmission Induced by Photoactivation of the Light Protein State. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.22.573121. [PMID: 38187662 PMCID: PMC10769362 DOI: 10.1101/2023.12.22.573121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Avena Sativa phototropin 1 Light-oxygen-voltage 2 domain (AsLOV2) is the model protein of Per-Arnt-Sim (PAS) superfamily, characterized by conformational changes in response to external environmental stimuli. This conformational change is initiated by the unfolding of the N-terminal helix in the dark state followed by the unfolding of the C-terminal helix. The light state is defined by the unfolded termini and the subsequent modifications in hydrogen bond patterns. In this photoreceptor, β-sheets have been identified as crucial components for mediating allosteric signal transmission between the two termini. In this study, we combined microsecond all-atm molecular dynamics simulations and Markov state modeling of conformational states to quantify molecular basis of mutation-induced allostery in the AsLOV2 protein. Through a combination of computational investigations, we determine that the Hβ and Iβ strands are the most critical structural elements involved in the allosteric mechanism. To elucidate the role of these β-sheets, we introduced 13 distinct mutations (F490L, N492A, L493A, F494L, H495L, L496F, Q497A, R500A, F509L, Q513A, L514A, D515V, and T517V) and conducted comprehensive simulation analysis. The results highlighted the role of two hydrogen bond Asn482-Leu453 and Gln479-Val520 in the observed distinct behaviors of L493A, L496F, Q497A, and D515V mutants. The comprehensive atomistic-level analysis of the conformational landscapes revealed the critical functional role of β-sheet segments in the transmission of the allosteric signal upon the photoactivation of the light state.
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6
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Arshi SA, Chauhan M, Sharma A. Disruption of the FMN-A524 interaction cascade and Glu513-induced collapse of the hydrophobic barrier promotes light-induced Jα-helix unfolding in AsLOV2. Biophys J 2023; 122:4670-4685. [PMID: 37978801 PMCID: PMC10754690 DOI: 10.1016/j.bpj.2023.11.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 10/10/2023] [Accepted: 11/14/2023] [Indexed: 11/19/2023] Open
Abstract
The C-terminal Jα-helix of the Avena sativa's Light Oxygen and Voltage (AsLOV2) protein, unfolds on exposure to blue light. This characteristic seeks relevance in applications related to engineering novel biological photoswitches. Using molecular dynamics simulations and the Markov state modeling (MSM) approach we provide the mechanism that explains the stepwise unfolding of the Jα-helix. The unfolding was resolved into seven steps represented by the structurally distinguishable states distributed over the initiation and the post initiation phases. Whereas, the initiation phase occurs due to the collapse of the interaction cascade FMN-Q513-N492-L480-W491-Q479-V520-A524, the onset of the post initiation phase is marked by breaking of the hydrophobic interactions between the Jα-helix and the Iβ-strand. This study indicates that the displacement of N492 out of the FMN binding pocket, not necessarily requiring Q513, is essential for the initiation of the Jα-helix unfolding. Rather, the structural reorientation of Q513 activates the protein to cross the hydrophobic barrier and enter the post initiation phase. Similarly, the structural deviations in N482, rather than its integral role in unfolding, could enhance the unfolding rates. Furthermore, the MSM studies on the wild-type and the Q513 mutant, provide the spatiotemporal roadmap that lay out the possible pathways of structural transition between the dark and the light states of the protein. Overall, the study provides insights useful to enhance the performance of AsLOV2-based photoswitches.
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Affiliation(s)
- Syeda Amna Arshi
- Multidisciplinary Centre for Advance Research and Studies, Jamia Millia Islamia, New Delhi, India
| | - Manisha Chauhan
- Multidisciplinary Centre for Advance Research and Studies, Jamia Millia Islamia, New Delhi, India
| | - Amit Sharma
- Multidisciplinary Centre for Advance Research and Studies, Jamia Millia Islamia, New Delhi, India.
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7
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Zhu L, McNamara HM, Toettcher JE. Light-switchable transcription factors obtained by direct screening in mammalian cells. Nat Commun 2023; 14:3185. [PMID: 37268649 PMCID: PMC10238501 DOI: 10.1038/s41467-023-38993-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 05/24/2023] [Indexed: 06/04/2023] Open
Abstract
Optogenetic tools can provide fine spatial and temporal control over many biological processes. Yet the development of new light-switchable protein variants remains challenging, and the field still lacks general approaches to engineering or discovering protein variants with light-switchable biological functions. Here, we adapt strategies for protein domain insertion and mammalian-cell expression to generate and screen a library of candidate optogenetic tools directly in mammalian cells. The approach is based on insertion of the AsLOV2 photoswitchable domain at all possible positions in a candidate protein of interest, introduction of the library into mammalian cells, and light/dark selection for variants with photoswitchable activity. We demonstrate the approach's utility using the Gal4-VP64 transcription factor as a model system. Our resulting LightsOut transcription factor exhibits a > 150-fold change in transcriptional activity between dark and blue light conditions. We show that light-switchable function generalizes to analogous insertion sites in two additional Cys6Zn2 and C2H2 zinc finger domains, providing a starting point for optogenetic regulation of a broad class of transcription factors. Our approach can streamline the identification of single-protein optogenetic switches, particularly in cases where structural or biochemical knowledge is limited.
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Affiliation(s)
- Liyuan Zhu
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Harold M McNamara
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
- Lewis Sigler Institute, Princeton University, Princeton, NJ, 08544, USA
| | - Jared E Toettcher
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
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8
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Panda R, Panda PK, Krishnamoorthy J, Kar RK. Network analysis of chromophore binding site in LOV domain. Comput Biol Med 2023; 161:106996. [PMID: 37201443 DOI: 10.1016/j.compbiomed.2023.106996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 03/16/2023] [Accepted: 05/01/2023] [Indexed: 05/20/2023]
Abstract
Photoreceptor proteins are versatile toolbox for developing biosensors for optogenetic applications. These molecular tools get activated upon illumination of blue light, which in turn offers a non-invasive method for gaining high spatiotemporal resolution and precise control of cellular signal transduction. The Light-Oxygen-Voltage (LOV) domain family of proteins is a well-recognized system for constructing optogenetic devices. Translation of these proteins into efficient cellular sensors is possible by tuning their photochemistry lifetime. However, the bottleneck is the need for more understanding of the relationship between the protein environment and photocycle kinetics. Significantly, the effect of the local environment also modulates the electronic structure of chromophore, which perturbs the electrostatic and hydrophobic interaction within the binding site. This work highlights the critical factors hidden in the protein networks, linking with their experimental photocycle kinetics. It presents an opportunity to quantitatively examine the alternation in chromophore's equilibrium geometry and identify details which have substantial implications in designing synthetic LOV constructs with desirable photocycle efficiency.
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Affiliation(s)
- Rishab Panda
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Pritam K Panda
- Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20, Uppsala, Sweden; Division of Immunology and Chronic Disease, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | | | - Rajiv K Kar
- Jyoti and Bhupat Mehta School of Health Sciences and Technology, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
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9
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Jain A, Dokholyan NV, Lee AL. Allosteric inactivation of an engineered optogenetic GTPase. Proc Natl Acad Sci U S A 2023; 120:e2219254120. [PMID: 36972433 PMCID: PMC10083549 DOI: 10.1073/pnas.2219254120] [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: 12/02/2022] [Accepted: 02/14/2023] [Indexed: 03/29/2023] Open
Abstract
Optogenetics is a technique for establishing direct spatiotemporal control over molecular function within living cells using light. Light application induces conformational changes within targeted proteins that produce changes in function. One of the applications of optogenetic tools is an allosteric control of proteins via light-sensing domain (LOV2), which allows direct and robust control of protein function. Computational studies supported by cellular imaging demonstrated that application of light allosterically inhibited signaling proteins Vav2, ITSN, and Rac1, but the structural and dynamic basis of such control has yet to be elucidated by experiment. Here, using NMR spectroscopy, we discover principles of action of allosteric control of cell division control protein 42 (CDC42), a small GTPase involved in cell signaling. Both LOV2 and Cdc42 employ flexibility in their function to switch between "dark"/"lit" or active/inactive states, respectively. By conjoining Cdc42 and phototropin1 LOV2 domains into the bi-switchable fusion Cdc42Lov, application of light-or alternatively, mutation in LOV2 to mimic light absorption-allosterically inhibits Cdc42 downstream signaling. The flow and patterning of allosteric transduction in this flexible system are well suited to observation by NMR. Close monitoring of the structural and dynamic properties of dark versus "lit" states of Cdc42Lov revealed lit-induced allosteric perturbations that extend to Cdc42's downstream effector binding site. Chemical shift perturbations for lit mimic, I539E, have distinct regions of sensitivity, and both the domains are coupled together, leading to bidirectional interdomain signaling. Insights gained from this optoallosteric design will increase our ability to control response sensitivity in future designs.
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Affiliation(s)
- Abha Jain
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC27599
| | - Nikolay V. Dokholyan
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA17033
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Hershey, PA17033
| | - Andrew L. Lee
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC27599
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10
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Maity S, Price BD, Wilson CB, Mukherjee A, Starck M, Parker D, Wilson MZ, Lovett JE, Han S, Sherwin MS. Triggered Functional Dynamics of AsLOV2 by Time-Resolved Electron Paramagnetic Resonance at High Magnetic Fields. Angew Chem Int Ed Engl 2023; 62:e202212832. [PMID: 36638360 DOI: 10.1002/anie.202212832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 01/06/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023]
Abstract
We present time-resolved Gd-Gd electron paramagnetic resonance (TiGGER) at 240 GHz for tracking inter-residue distances during a protein's mechanical cycle in the solution state. TiGGER makes use of Gd-sTPATCN spin labels, whose favorable qualities include a spin-7/2 EPR-active center, short linker, narrow intrinsic linewidth, and virtually no anisotropy at high fields (8.6 T) when compared to nitroxide spin labels. Using TiGGER, we determined that upon light activation, the C-terminus and N-terminus of AsLOV2 separate in less than 1 s and relax back to equilibrium with a time constant of approximately 60 s. TiGGER revealed that the light-activated long-range mechanical motion is slowed in the Q513A variant of AsLOV2 and is correlated to the similarly slowed relaxation of the optically excited chromophore as described in recent literature. TiGGER has the potential to valuably complement existing methods for the study of triggered functional dynamics in proteins.
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Affiliation(s)
- Shiny Maity
- Dept. of Chemistry and Biochemistry, Univ. of California, Santa Barbara, CA 93106, USA
| | - Brad D Price
- Dept. of Physics, Univ. of California, Santa Barbara, CA 93106, USA
| | - C Blake Wilson
- Dept. of Physics, Univ. of California, Santa Barbara, CA 93106, USA.,Laboratory of Chemical Physics, Nat. Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892-0520, USA
| | - Arnab Mukherjee
- Dept. of Chemical Engineering, Univ. of California, Santa Barbara, CA 93106, USA
| | | | - David Parker
- Dept. of Chemistry, Univ. of Durham, Durham, DH1 3LE, UK
| | - Maxwell Z Wilson
- Dept. of Molecular, Cellular, and Developmental Biology, Univ. of California, Santa Barbara, CA 93106, USA
| | - Janet E Lovett
- School of Physics and Astronomy and the Biomedical Sciences Research Complex, Univ. of St. Andrews, St. Andrews, KY16 9SS, UK
| | - Songi Han
- Dept. of Chemistry and Biochemistry, Univ. of California, Santa Barbara, CA 93106, USA
| | - Mark S Sherwin
- Dept. of Physics, Univ. of California, Santa Barbara, CA 93106, USA
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11
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Zhang N, Yang Y, Li W, Zhou S, Li W, Peng Y, Zheng J. Asparagine and Glutamine Residues Participate in Protein Covalent Binding by Epoxide Metabolite of 8-Epidiosbulbin E Acetate In Vitro and In Vivo. Chem Res Toxicol 2022; 35:1821-1830. [PMID: 35839447 DOI: 10.1021/acs.chemrestox.2c00130] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dioscorea Bulbifera L. (DBL), an effective traditional Chinese medicine, has been restricted because of multiple reports that it can cause severe hepatotoxicity. 8-Epidiosbulbin E acetate (EEA), one of the main components of DBL, can induce severe liver injury. It has been reported that EEA can be metabolized by CYP3A to the corresponding cis-enedial intermediate which alkylates the lysine residues of proteins to form pyrroline derivatives. The present study unexpectedly found that the reactive intermediate reacted with the amide groups of asparagine (Asn) and glutamine (Gln) residues of hepatic proteins of mice treated with EEA. The amide-derived protein modification increased with the increase in the dose administered. Like the adduction of the primary amine of lysine residues, the electrophilic metabolite reacted with the amide groups of Asn and Gln residues to offer the corresponding pyrrolines. The structures of the pyrrolines were confirmed by mass spectrometry and nuclear magnetic resonance spectroscopy.
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Affiliation(s)
- Na Zhang
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, Liaoning 110016, PR China
| | - Yi Yang
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, Liaoning 110016, PR China
| | - Wei Li
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, Liaoning 110016, PR China
| | - Shenzhi Zhou
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, Liaoning 110016, PR China
| | - Weiwei Li
- State Key Laboratory of Functions and Applications of Medicinal Plants, Key Laboratory of Pharmaceutics of Guizhou Province, Guizhou Medical University, Guiyang, Guizhou 550025, PR China
| | - Ying Peng
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, Liaoning 110016, PR China
| | - Jiang Zheng
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, Liaoning 110016, PR China.,State Key Laboratory of Functions and Applications of Medicinal Plants, Key Laboratory of Pharmaceutics of Guizhou Province, Guizhou Medical University, Guiyang, Guizhou 550025, PR China
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12
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Dietler J, Gelfert R, Kaiser J, Borin V, Renzl C, Pilsl S, Ranzani AT, García de Fuentes A, Gleichmann T, Diensthuber RP, Weyand M, Mayer G, Schapiro I, Möglich A. Signal transduction in light-oxygen-voltage receptors lacking the active-site glutamine. Nat Commun 2022; 13:2618. [PMID: 35552382 PMCID: PMC9098866 DOI: 10.1038/s41467-022-30252-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 04/22/2022] [Indexed: 11/12/2022] Open
Abstract
In nature as in biotechnology, light-oxygen-voltage photoreceptors perceive blue light to elicit spatiotemporally defined cellular responses. Photon absorption drives thioadduct formation between a conserved cysteine and the flavin chromophore. An equally conserved, proximal glutamine processes the resultant flavin protonation into downstream hydrogen-bond rearrangements. Here, we report that this glutamine, long deemed essential, is generally dispensable. In its absence, several light-oxygen-voltage receptors invariably retained productive, if often attenuated, signaling responses. Structures of a light-oxygen-voltage paradigm at around 1 Å resolution revealed highly similar light-induced conformational changes, irrespective of whether the glutamine is present. Naturally occurring, glutamine-deficient light-oxygen-voltage receptors likely serve as bona fide photoreceptors, as we showcase for a diguanylate cyclase. We propose that without the glutamine, water molecules transiently approach the chromophore and thus propagate flavin protonation downstream. Signaling without glutamine appears intrinsic to light-oxygen-voltage receptors, which pertains to biotechnological applications and suggests evolutionary descendance from redox-active flavoproteins. Light-oxygen-voltage (LOV) photoreceptors perceive blue light to elicit spatio-temporally defined cellular responses, and their signalling process has been extensively characterized. Here the authors report that the light signal is still transduced in the absence of a conserved Gln residue, thought to be key.
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Affiliation(s)
- Julia Dietler
- Department of Biochemistry, University of Bayreuth, 95447, Bayreuth, Germany
| | - Renate Gelfert
- Department of Biochemistry, University of Bayreuth, 95447, Bayreuth, Germany
| | - Jennifer Kaiser
- Department of Biochemistry, University of Bayreuth, 95447, Bayreuth, Germany
| | - Veniamin Borin
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Christian Renzl
- Life and Medical Sciences (LIMES), University of Bonn, 53121, Bonn, Germany
| | - Sebastian Pilsl
- Life and Medical Sciences (LIMES), University of Bonn, 53121, Bonn, Germany
| | | | | | - Tobias Gleichmann
- Biophysical Chemistry, Humboldt-University Berlin, 10115, Berlin, Germany
| | | | - Michael Weyand
- Department of Biochemistry, University of Bayreuth, 95447, Bayreuth, Germany
| | - Günter Mayer
- Life and Medical Sciences (LIMES), University of Bonn, 53121, Bonn, Germany.,Center of Aptamer Research & Development, University of Bonn, 53121, Bonn, Germany
| | - Igor Schapiro
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Andreas Möglich
- Department of Biochemistry, University of Bayreuth, 95447, Bayreuth, Germany. .,Biophysical Chemistry, Humboldt-University Berlin, 10115, Berlin, Germany. .,Bayreuth Center for Biochemistry & Molecular Biology, Universität Bayreuth, 95447, Bayreuth, Germany. .,North-Bavarian NMR Center, Universität Bayreuth, 95447, Bayreuth, Germany.
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13
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Ibrahim MT, Trozzi F, Tao P. Dynamics of hydrogen bonds in the secondary structures of allosteric protein Avena Sativa phototropin 1. Comput Struct Biotechnol J 2022; 20:50-64. [PMID: 34976311 PMCID: PMC8671528 DOI: 10.1016/j.csbj.2021.11.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 11/28/2021] [Accepted: 11/28/2021] [Indexed: 11/06/2022] Open
Abstract
The Light-Oxygen-Voltage 2 (LOV2) domain of Avena Sativa phototropin 1 (AsLOV2) protein is one of the most studied domains in the field of designing photoswitches. This is due to the several unique features in the AsLOV2, such as the monomeric structure of the protein in both light and dark states and the relatively short transition time between the two states. Despite that, not many studies focus on the effect of the secondary structures on the drastic conformational change between the light and dark states. In this study, we focus on the role of A’α helix as a key player in the transition between both states using various computational tools as: 1.5 μs molecular dynamics simulations for each configuration, Markov state model, different machine learning techniques, and community analysis. The impact of the A’α helix was studied on the atomistic level by introducing two groups of mutations, helicity enhancing mutations (T406A and T407A) and helicity disrupting mutations (L408D and R410P), as well as on the overall secondary structure by using the community analysis. Maintaining the N-terminal hydrogen bond network was found to be essential for the transition between the two states. Via in-depth hydrogen bonding and contact analysis we were able to identify key residues (Thr407 and Arg410) involved in the functional conformational switch and their impact on the overall protein dynamics. Moreover, the community analysis highlighted the significant role of the β sheets in the overall protein allosteric process.
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Affiliation(s)
- Mayar Tarek Ibrahim
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, United States
| | - Francesco Trozzi
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, United States
| | - Peng Tao
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, United States
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14
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Trozzi F, Wang F, Verkhivker G, Zoltowski BD, Tao P. Dimeric allostery mechanism of the plant circadian clock photoreceptor ZEITLUPE. PLoS Comput Biol 2021; 17:e1009168. [PMID: 34310591 PMCID: PMC8341706 DOI: 10.1371/journal.pcbi.1009168] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 08/05/2021] [Accepted: 06/10/2021] [Indexed: 11/19/2022] Open
Abstract
In Arabidopsis thaliana, the Light-Oxygen-Voltage (LOV) domain containing protein ZEITLUPE (ZTL) integrates light quality, intensity, and duration into regulation of the circadian clock. Recent structural and biochemical studies of ZTL indicate that the protein diverges from other members of the LOV superfamily in its allosteric mechanism, and that the divergent allosteric mechanism hinges upon conservation of two signaling residues G46 and V48 that alter dynamic motions of a Gln residue implicated in signal transduction in all LOV proteins. Here, we delineate the allosteric mechanism of ZTL via an integrated computational approach that employs atomistic simulations of wild type and allosteric variants of ZTL in the functional dark and light states, together with Markov state and supervised machine learning classification models. This approach has unveiled key factors of the ZTL allosteric mechanisms, and identified specific interactions and residues implicated in functional allosteric changes. The final results reveal atomic level insights into allosteric mechanisms of ZTL function that operate via a non-trivial combination of population-shift and dynamics-driven allosteric pathways.
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Affiliation(s)
- Francesco Trozzi
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, United States of America
| | - Feng Wang
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, United States of America
| | - Gennady Verkhivker
- Graduate Program in Computational and Data Sciences, Schmid College of Science and Technology, Chapman University, Orange, California, United States of America
- Chapman University School of Pharmacy, Irvine, California, United States of America
| | - Brian D. Zoltowski
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, United States of America
| | - Peng Tao
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, Texas, United States of America
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15
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Andrikopoulos PC, Chaudhari AS, Liu Y, Konold PE, Kennis JTM, Schneider B, Fuertes G. QM calculations predict the energetics and infrared spectra of transient glutamine isomers in LOV photoreceptors. Phys Chem Chem Phys 2021; 23:13934-13950. [PMID: 34142688 PMCID: PMC8246142 DOI: 10.1039/d1cp00447f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 06/04/2021] [Indexed: 11/21/2022]
Abstract
Photosensory receptors containing the flavin-binding light-oxygen-voltage (LOV) domain are modular proteins that fulfil a variety of biological functions ranging from gene expression to phototropism. The LOV photocycle is initiated by blue-light and involves a cascade of intermediate species, including an electronically excited triplet state, that leads to covalent bond formation between the flavin mononucleotide (FMN) chromophore and a nearby cysteine residue. Subsequent conformational changes in the polypeptide chain arise due to the remodelling of the hydrogen bond network in the cofactor binding pocket, whereby a conserved glutamine residue plays a key role in coupling FMN photochemistry with LOV photobiology. Although the dark-to-light transition of LOV photosensors has been previously addressed by spectroscopy and computational approaches, the mechanistic basis of the underlying reactions is still not well understood. Here we present a detailed computational study of three distinct LOV domains: EL222 from Erythrobacter litoralis, AsLOV2 from the second LOV domain of Avena sativa phototropin 1, and RsLOV from Rhodobacter sphaeroides LOV protein. Extended protein-chromophore models containing all known crucial residues involved in the initial steps (femtosecond-to-microsecond) of the photocycle were employed. Energies and rotational barriers were calculated for possible rotamers and tautomers of the critical glutamine side chain, which allowed us to postulate the most energetically favoured glutamine orientation for each LOV domain along the assumed reaction path. In turn, for each evolving species, infrared difference spectra were constructed and compared to experimental EL222 and AsLOV2 transient infrared spectra, the former from original work presented here and the latter from the literature. The good agreement between theory and experiment permitted the assignment of the majority of observed bands, notably the ∼1635 cm-1 transient of the adduct state to the carbonyl of the glutamine side chain after rotation. Moreover, both the energetic and spectroscopic approaches converge in suggesting a facile glutamine flip at the adduct intermediate for EL222 and more so for AsLOV2, while for RsLOV the glutamine keeps its initial configuration. Additionally, the computed infrared shifts of the glutamine and interacting residues could guide experimental research addressing early events of signal transduction in LOV proteins.
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Affiliation(s)
- Prokopis C Andrikopoulos
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Průmyslová 595, CZ-252 50 Vestec, Czechia.
| | - Aditya S Chaudhari
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Průmyslová 595, CZ-252 50 Vestec, Czechia.
| | - Yingliang Liu
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Průmyslová 595, CZ-252 50 Vestec, Czechia.
| | - Patrick E Konold
- Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, 1081 De Boelelaan, 1081HV Amsterdam, The Netherlands
| | - John T M Kennis
- Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, 1081 De Boelelaan, 1081HV Amsterdam, The Netherlands
| | - Bohdan Schneider
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Průmyslová 595, CZ-252 50 Vestec, Czechia.
| | - Gustavo Fuertes
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Průmyslová 595, CZ-252 50 Vestec, Czechia.
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16
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Remeeva A, Nazarenko VV, Kovalev K, Goncharov IM, Yudenko A, Astashkin R, Gordeliy V, Gushchin I. Insights into the mechanisms of light-oxygen-voltage domain color tuning from a set of high-resolution X-ray structures. Proteins 2021; 89:1005-1016. [PMID: 33774867 DOI: 10.1002/prot.26078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 03/16/2021] [Indexed: 01/01/2023]
Abstract
Light-oxygen-voltage (LOV) domains are widespread photosensory modules that can be used in fluorescence microscopy, optogenetics and controlled production of reactive oxygen species. All of the currently known LOV domains have absorption maxima in the range of ~440 to ~450 nm, and it is not clear whether they can be shifted significantly using mutations. Here, we have generated a panel of LOV domain variants by mutating the key chromophore-proximal glutamine aminoacid of a thermostable flavin based fluorescent protein CagFbFP (Gln148) to asparagine, aspartate, glutamate, histidine, lysine and arginine. Absorption spectra of all of the mutants are blue-shifted, with the maximal shift of 8 nm observed for the Q148H variant. While CagFbFP and its Q148N/D/E variants are not sensitive to pH, Q148H/K/R reveal a moderate red shift induced byacidic pH. To gain further insight, we determined high resolution crystal structures of all of the mutants studied at the resolutions from 1.07 Å for Q148D to 1.63 Å for Q148R. Whereas in some of the variants, the aminoacid 148 remains in the vicinity of the flavin, in Q148K, Q148R and partially Q148D, the C-terminus of the protein unlatches and the side chain of the residue 148 is reoriented away from the chromophore. Our results explain the absence of color shifts from replacing Gln148 with charged aminoacids and pave the way for rational design of color-shifted flavin based fluorescent proteins.
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Affiliation(s)
- Alina Remeeva
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Vera V Nazarenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Kirill Kovalev
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, Grenoble, France
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
- Institute of Crystallography, RWTH Aachen University, Aachen, Germany
| | - Ivan M Goncharov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Anna Yudenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Roman Astashkin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, Grenoble, France
| | - Valentin Gordeliy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, Grenoble, France
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
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17
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Zhao Y, Zhang Y, Sun M, Zheng Q. A theoretical study on the signal transduction process of bacterial photoreceptor PpSB1 based on the Markov state model. Phys Chem Chem Phys 2021; 23:2398-2405. [PMID: 33458728 DOI: 10.1039/d0cp05532h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Light-oxygen-voltage (LOV) domains are blue light sensors and play an important role in signal transduction in many organisms. Generally, LOV domains use chromophores to absorb photons, and then photochemical reactions will occur to convert light energy into chemical energy and transduce it to the main chain of proteins. These reactions can cause conformational rearrangement of proteins, and thus leading to signal transduction. Therefore, it is important to study the signal transduction process of LOV domains for understanding the control mechanism of cellular functions. However, how small photochemical changes in the active sites of the LOV domains lead to large conformational rearrangements of proteins, which in turn lead to signal transduction, has been puzzling us for a long time. Currently, the LOV domains are mainly studied in plants. The signal transduction mechanism of LOV domains in bacteria is still unclear. In this work, the Markov state model (MSM) combined with molecular dynamics (MD) simulations was applied to investigate the signal transduction process of the LOV protein from pseudomonas putida (PpSB1-LOV). The present work will play an important role in understanding the signal transduction mechanism of PpSB1-LOV domains, which may provide theoretical basis for the design and improvement of LOV-based optogenetic tools.
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Affiliation(s)
- Yajie Zhao
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Jilin University, Changchun 130023, People's Republic of China.
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18
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Pudasaini A, Green R, Song YH, Blumenfeld A, Karki N, Imaizumi T, Zoltowski BD. Steric and Electronic Interactions at Gln154 in ZEITLUPE Induce Reorganization of the LOV Domain Dimer Interface. Biochemistry 2021; 60:95-103. [PMID: 33337855 PMCID: PMC8211391 DOI: 10.1021/acs.biochem.0c00819] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Plants measure light quality, intensity, and duration to coordinate growth and development with daily and seasonal changes in environmental conditions; however, the molecular details linking photochemistry to signal transduction remain incomplete. Two closely related light, oxygen, or voltage (LOV) domain-containing photoreceptor proteins, ZEITLUPE (ZTL) and FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 (FKF1), divergently regulate the protein stability of circadian clock and photoperiodic flowering components to mediate daily and seasonal development. Using structural approaches, we identified that mutations at the Gly46 position led to global rearrangements of the ZTL dimer interface in the isolated ZTL-LOV domain. Specifically, G46S and G46A variants induce a 180° rotation about the ZTL-LOV dimer interface that is coupled to ordering of N- and C-terminal signaling elements. These conformational changes hinge upon rotation of a C-terminal Gln residue (Gln154) analogous to that present in light-state structures of ZTL. In contrast to other LOV proteins, a Q154L variant retains light-state interactions with GIGANTEA (GI), thereby indicating N5 protonation is not required for ZTL signaling. The results presented herein confirm a divergent signaling mechanism within ZTL, whereby steric and electronic effects following adduct formation can be sufficient for signal propagation in LOV proteins containing a Gly residue at position 46. Examination of bacterial LOV structures with Gly residues at the equivalent position suggests that mechanisms of signal transduction in LOV proteins may be fluid across the LOV protein family.
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Affiliation(s)
- Ashutosh Pudasaini
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275, USA Center for Drug Discovery, Design and Delivery, Southern Methodist University
| | - Robert Green
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275, USA Center for Drug Discovery, Design and Delivery, Southern Methodist University
| | - Young Hun Song
- Department of Agricultural Biotechnology, Seoul National University, Seoul, 08826, Korea
| | - Abby Blumenfeld
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275, USA Center for Drug Discovery, Design and Delivery, Southern Methodist University
| | - Nischal Karki
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275, USA Center for Drug Discovery, Design and Delivery, Southern Methodist University
| | - Takato Imaizumi
- Department of Biology, University of Washington, Seattle, WA, 98195-1800, USA
| | - Brian D. Zoltowski
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275, USA Center for Drug Discovery, Design and Delivery, Southern Methodist University,corresponding author: Brian D. Zoltowski, Associate Professor, Department of Chemistry, Southern Methodist University, Dallas, TX 75275-0314, t. 214-768-2640, f. 214-768-4089,
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19
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Hart JE, Gardner KH. Lighting the way: Recent insights into the structure and regulation of phototropin blue light receptors. J Biol Chem 2021; 296:100594. [PMID: 33781746 PMCID: PMC8086140 DOI: 10.1016/j.jbc.2021.100594] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 02/06/2023] Open
Abstract
The phototropins (phots) are light-activated kinases that are critical for plant physiology and the many diverse optogenetic tools that they have inspired. Phototropins combine two blue-light-sensing Light-Oxygen-Voltage (LOV) domains (LOV1 and LOV2) and a C-terminal serine/threonine kinase domain, using the LOV domains to control the catalytic activity of the kinase. While much is known about the structure and photochemistry of the light-perceiving LOV domains, particularly in how activation of the LOV2 domain triggers the unfolding of alpha helices that communicate the light signal to the kinase domain, many questions about phot structure and mechanism remain. Recent studies have made progress addressing these questions by utilizing small-angle X-ray scattering (SAXS) and other biophysical approaches to study multidomain phots from Chlamydomonas and Arabidopsis, leading to models where the domains have an extended linear arrangement, with the regulatory LOV2 domain contacting the kinase domain N-lobe. We discuss this and other advances that have improved structural and mechanistic understanding of phot regulation in this review, along with the challenges that will have to be overcome to obtain high-resolution structural information on these exciting photoreceptors. Such information will be essential to advancing fundamental understanding of plant physiology while enabling engineering efforts at both the whole plant and molecular levels.
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Affiliation(s)
- Jaynee E Hart
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, New York, USA
| | - Kevin H Gardner
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, New York, USA; Department of Chemistry and Biochemistry, City College of New York, New York, USA; PhD Programs in Biochemistry, Chemistry, and Biology, Graduate Center, City University of New York, New York, USA.
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20
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Iuliano JN, Collado JT, Gil AA, Ravindran PT, Lukacs A, Shin S, Woroniecka HA, Adamczyk K, Aramini JM, Edupuganti UR, Hall CR, Greetham GM, Sazanovich IV, Clark IP, Daryaee T, Toettcher JE, French JB, Gardner KH, Simmerling CL, Meech SR, Tonge PJ. Unraveling the Mechanism of a LOV Domain Optogenetic Sensor: A Glutamine Lever Induces Unfolding of the Jα Helix. ACS Chem Biol 2020; 15:2752-2765. [PMID: 32880430 DOI: 10.1021/acschembio.0c00543] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Light-activated protein domains provide a convenient, modular, and genetically encodable sensor for optogenetics and optobiology. Although these domains have now been deployed in numerous systems, the precise mechanism of photoactivation and the accompanying structural dynamics that modulate output domain activity remain to be fully elucidated. In the C-terminal light-oxygen-voltage (LOV) domain of plant phototropins (LOV2), blue light activation leads to formation of an adduct between a conserved Cys residue and the embedded FMN chromophore, rotation of a conserved Gln (Q513), and unfolding of a helix (Jα-helix) which is coupled to the output domain. In the present work, we focus on the allosteric pathways leading to Jα helix unfolding in Avena sativa LOV2 (AsLOV2) using an interdisciplinary approach involving molecular dynamics simulations extending to 7 μs, time-resolved infrared spectroscopy, solution NMR spectroscopy, and in-cell optogenetic experiments. In the dark state, the side chain of N414 is hydrogen bonded to the backbone N-H of Q513. The simulations predict a lever-like motion of Q513 after Cys adduct formation resulting in a loss of the interaction between the side chain of N414 and the backbone C═O of Q513, and formation of a transient hydrogen bond between the Q513 and N414 side chains. The central role of N414 in signal transduction was evaluated by site-directed mutagenesis supporting a direct link between Jα helix unfolding dynamics and the cellular function of the Zdk2-AsLOV2 optogenetic construct. Through this multifaceted approach, we show that Q513 and N414 are critical mediators of protein structural dynamics, linking the ultrafast (sub-ps) excitation of the FMN chromophore to the microsecond conformational changes that result in photoreceptor activation and biological function.
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Affiliation(s)
- James N. Iuliano
- Department of Chemistry, Stony Brook University, New York, 11794, United States
| | | | - Agnieszka A. Gil
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, United States
| | - Pavithran T. Ravindran
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, United States
| | - Andras Lukacs
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
- Department of Biophysics, Medical School, University of Pecs, Szigeti út 12, 7624 Pecs, Hungary
| | - SeungYoun Shin
- Department of Chemistry, Stony Brook University, New York, 11794, United States
| | | | - Katrin Adamczyk
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
| | - James M. Aramini
- Structural Biology Initiative, CUNY Advanced Science Research Center, 85 St. Nicholas Terrace, New York, New York 10031, United States
| | - Uthama R. Edupuganti
- Structural Biology Initiative, CUNY Advanced Science Research Center, 85 St. Nicholas Terrace, New York, New York 10031, United States
- Ph.D. Program in Biochemistry, CUNY Graduate Center, New York, New York, United States
| | - Christopher R. Hall
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
| | - Gregory M. Greetham
- Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, OX11 0QX, United Kingdom
| | - Igor V. Sazanovich
- Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, OX11 0QX, United Kingdom
| | - Ian P. Clark
- Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, OX11 0QX, United Kingdom
| | - Taraneh Daryaee
- Department of Chemistry, Stony Brook University, New York, 11794, United States
| | - Jared E. Toettcher
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, United States
| | - Jarrod B. French
- Department of Chemistry, Stony Brook University, New York, 11794, United States
- Hormel Institute, University of Minnesota, Austin, Minnesota 55912, United States
| | - Kevin H. Gardner
- Structural Biology Initiative, CUNY Advanced Science Research Center, 85 St. Nicholas Terrace, New York, New York 10031, United States
- Ph.D. Programs in Biochemistry, Biology, and Chemistry, CUNY Graduate Center, New York, New York, United States
- Department of Chemistry and Biochemistry, City College of New York, New York, New York, United States
| | | | - Stephen R. Meech
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
| | - Peter J. Tonge
- Department of Chemistry, Stony Brook University, New York, 11794, United States
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21
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Lu X, Shen Y, Campbell RE. Engineering Photosensory Modules of Non-Opsin-Based Optogenetic Actuators. Int J Mol Sci 2020; 21:E6522. [PMID: 32906617 PMCID: PMC7555876 DOI: 10.3390/ijms21186522] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/03/2020] [Accepted: 09/04/2020] [Indexed: 11/17/2022] Open
Abstract
Optogenetic (photo-responsive) actuators engineered from photoreceptors are widely used in various applications to study cell biology and tissue physiology. In the toolkit of optogenetic actuators, the key building blocks are genetically encodable light-sensitive proteins. Currently, most optogenetic photosensory modules are engineered from naturally-occurring photoreceptor proteins from bacteria, fungi, and plants. There is a growing demand for novel photosensory domains with improved optical properties and light-induced responses to satisfy the needs of a wider variety of studies in biological sciences. In this review, we focus on progress towards engineering of non-opsin-based photosensory domains, and their representative applications in cell biology and physiology. We summarize current knowledge of engineering of light-sensitive proteins including light-oxygen-voltage-sensing domain (LOV), cryptochrome (CRY2), phytochrome (PhyB and BphP), and fluorescent protein (FP)-based photosensitive domains (Dronpa and PhoCl).
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Affiliation(s)
- Xiaocen Lu
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada; (X.L.); (Y.S.)
| | - Yi Shen
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada; (X.L.); (Y.S.)
| | - Robert E. Campbell
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada; (X.L.); (Y.S.)
- Department of Chemistry, The University of Tokyo, Tokyo 113-0033, Japan
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22
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Henry L, Berntsson O, Panman MR, Cellini A, Hughes AJ, Kosheleva I, Henning R, Westenhoff S. New Light on the Mechanism of Phototransduction in Phototropin. Biochemistry 2020; 59:3206-3215. [PMID: 32786255 DOI: 10.1021/acs.biochem.0c00324] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Phototropins are photoreceptor proteins that regulate blue light-dependent biological processes for efficient photosynthesis in plants and algae. The proteins consist of a photosensory domain that responds to the ambient light and an output module that triggers cellular responses. The photosensory domain of phototropin from Chlamydomonas reinhardtii contains two conserved LOV (light-oxygen-voltage) domains with flavin chromophores. Blue light triggers the formation of a covalent cysteine-flavin adduct and upregulates the phototropin kinase activity. Little is known about the structural mechanism that leads to kinase activation and how the two LOV domains contribute to this. Here, we investigate the role of the LOV1 domain from C. reinhardtii phototropin by characterizing the structural changes occurring after blue light illumination with nano- to millisecond time-resolved X-ray solution scattering. By structurally fitting the data with atomic models generated by molecular dynamics simulations, we find that adduct formation induces a rearrangement of the hydrogen bond network from the buried chromophore to the protein surface. In particular, the change in conformation and the associated hydrogen bonding of the conserved glutamine 120 induce a global movement of the β-sheet, ultimately driving a change in the electrostatic potential on the protein surface. On the basis of the change in the electrostatics, we propose a structural model of how LOV1 and LOV2 domains interact and regulate the full-length phototropin from C. reinhardtii. This provides a rationale for how LOV photosensor proteins function and contributes to the optimal design of optogenetic tools based on LOV domains.
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Affiliation(s)
- L Henry
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - O Berntsson
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden.,MAX IV Laboratory, Lund University, P.O. Box 118, 221 00 Lund, Sweden
| | - M R Panman
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - A Cellini
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - A J Hughes
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - I Kosheleva
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois 60637, United States
| | - R Henning
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois 60637, United States
| | - S Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
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23
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Kobayashi I, Nakajima H, Hisatomi O. Molecular Mechanism of Light-Induced Conformational Switching of the LOV Domain in Aureochrome-1. Biochemistry 2020; 59:2592-2601. [PMID: 32567839 DOI: 10.1021/acs.biochem.0c00271] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Light oxygen voltage-sensing (LOV) domains are widely found in photoreceptor proteins of plants, algae, fungi, and bacteria. Structural studies of LOV domains suggest that Phe and Gln residues located in the proximity of the chromophore undergo conformational changes upon illumination; however, the molecular mechanism associated with activation of the effector domain remains to be elucidated. Photozipper (PZ) protein is an N-terminally truncated aureochrome-1 comprising a LOV domain and a basic leucine zipper domain. Blue light (BL) induces PZ dimerization and subsequently increases its affinity for target DNA. In this study, we prepared PZ mutants with substitutions of F298 and Q317 and performed quantitative analyses in dark and light states. Substitutions of Q317 significantly reduced the light-induced changes in PZ affinity for the target DNA, especially in the case of the high affinities observed in the dark state. Upon illumination, all PZ mutants showed increased affinity for the target sequence, which demonstrated a clear correlation with the dimer fraction of each PZ mutant. These results suggest the existence of a conformational equilibrium and that its shift by a synergistic interaction between the chromophore and protein moiety probably enables BL-regulated switching of aureochrome-1.
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Affiliation(s)
- Itsuki Kobayashi
- Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Hiroto Nakajima
- Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Osamu Hisatomi
- Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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24
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Polverini E, Schackert FK, Losi A. Interplay among the “flipping” glutamine, a conserved phenylalanine, water and hydrogen bonds within a blue-light sensing LOV domain. Photochem Photobiol Sci 2020; 19:892-904. [DOI: 10.1039/d0pp00082e] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A combined photoacoustics and molecular dynamics approach highlights the crucial role of a conserved phenyalanine in photosensing LOV domains.
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Affiliation(s)
- Eugenia Polverini
- Department of Mathematical
- Physical and Computer Sciences
- University of Parma
- 43124 Parma
- Italy
| | - Florian Karl Schackert
- Department of Mathematical
- Physical and Computer Sciences
- University of Parma
- 43124 Parma
- Italy
| | - Aba Losi
- Department of Mathematical
- Physical and Computer Sciences
- University of Parma
- 43124 Parma
- Italy
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25
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Engineering the phototropin photocycle improves photoreceptor performance and plant biomass production. Proc Natl Acad Sci U S A 2019; 116:12550-12557. [PMID: 31160455 PMCID: PMC6589663 DOI: 10.1073/pnas.1902915116] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A key challenge for plant molecular biologists is to increase plant yield by altering photosynthetic productivity to secure food, energy, and environmental sustainability. In the model plant Arabidopsis thaliana, the plasma-membrane–associated phototropin kinases, phot1 and phot2, are activated by blue light and play important roles in regulating several responses that optimize photosynthetic efficiency. However, little effort has been made to target these pathways to increase plant growth. Here, we demonstrate that modifying the photocycle of phot1 and phot2 increases their sensitivity to light. Plants with these engineered phototropins exhibit more rapid and robust chloroplast movement responses and improved leaf positioning and expansion, leading to improved biomass accumulation under light-limiting conditions. The ability to enhance photosynthetic capacity remains a recognized bottleneck to improving plant productivity. Phototropin blue light receptors (phot1 and phot2) optimize photosynthetic efficiency in Arabidopsis thaliana by coordinating multiple light-capturing processes. In this study, we explore the potential of using protein engineering to improve photoreceptor performance and thereby plant growth. We demonstrate that targeted mutagenesis can decrease or increase the photocycle lifetime of Arabidopsis phototropins in vitro and show that these variants can be used to reduce or extend the duration of photoreceptor activation in planta. Our findings show that slowing the phototropin photocycle enhanced several light-capturing responses, while accelerating it reduced phototropin’s sensitivity for chloroplast accumulation movement. Moreover, plants engineered to have a slow-photocycling variant of phot1 or phot2 displayed increased biomass production under low-light conditions as a consequence of their improved sensitivity. Together, these findings demonstrate the feasibility of engineering photoreceptors to manipulate plant growth and offer additional opportunities to enhance photosynthetic competence, particularly under suboptimal light regimes.
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26
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Kalvaitis ME, Johnson LA, Mart RJ, Rizkallah P, Allemann RK. A Noncanonical Chromophore Reveals Structural Rearrangements of the Light-Oxygen-Voltage Domain upon Photoactivation. Biochemistry 2019; 58:2608-2616. [PMID: 31082213 PMCID: PMC7007005 DOI: 10.1021/acs.biochem.9b00255] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
![]()
Light-oxygen-voltage
(LOV) domains are increasingly used to engineer
photoresponsive biological systems. While the photochemical cycle
is well documented, the allosteric mechanism by which formation of
a cysteinyl-flavin adduct leads to activation is unclear. Via replacement
of flavin mononucleotide (FMN) with 5-deazaflavin mononucleotide (5dFMN)
in the Aureochrome1a (Au1a) transcription factor from Ochromonas
danica, a thermally stable cysteinyl-5dFMN adduct was generated.
High-resolution crystal structures (<2 Å) under different
illumination conditions with either FMN or 5dFMN chromophores reveal
three conformations of the highly conserved glutamine 293. An allosteric
hydrogen bond network linking the chromophore via Gln293 to the auxiliary
A′α helix is observed. With FMN, a “flip”
of the Gln293 side chain occurs between dark and lit states. 5dFMN
cannot hydrogen bond through the C5 position and proved to be unable
to support Au1a domain dimerization. Under blue light, the Gln293
side chain instead “swings” away in a conformation distal
to the chromophore and not previously observed in existing LOV domain
structures. Together, the multiple side chain conformations of Gln293
and functional analysis of 5dFMN provide new insight into the structural
requirements for LOV domain activation.
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Affiliation(s)
- Mindaugas E Kalvaitis
- School of Chemistry , Cardiff University , Park Place , Cardiff CF10 3AT , United Kingdom
| | - Luke A Johnson
- School of Chemistry , Cardiff University , Park Place , Cardiff CF10 3AT , United Kingdom
| | - Robert J Mart
- School of Chemistry , Cardiff University , Park Place , Cardiff CF10 3AT , United Kingdom
| | - Pierre Rizkallah
- School of Medicine , University Hospital Wales , Main Building, Heath Park , Cardiff CF14 4XN , United Kingdom
| | - Rudolf K Allemann
- School of Chemistry , Cardiff University , Park Place , Cardiff CF10 3AT , United Kingdom
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27
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Glantz ST, Berlew EE, Chow BY. Synthetic cell-like membrane interfaces for probing dynamic protein-lipid interactions. Methods Enzymol 2019; 622:249-270. [PMID: 31155055 DOI: 10.1016/bs.mie.2019.02.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The ability to rapidly screen interactions between proteins and membrane-like interfaces would aid in establishing the structure-function of protein-lipid interactions, provide a platform for engineering lipid-interacting protein tools, and potentially inform the signaling mechanisms and dynamics of membrane-associated proteins. Here, we describe the preparation and application of water-in-oil (w/o) emulsions with lipid-stabilized droplet interfaces that emulate the plasma membrane inner leaflet with tunable composition. Fluorescently labeled proteins are easily visualized in these synthetic cell-like droplets on an automated inverted fluorescence microscope, thus allowing for both rapid screening of relative binding and spatiotemporally resolved analyses of for example, protein-interface association and dissociation dynamics and competitive interactions, using commonplace instrumentation. We provide protocols for droplet formation, automated imaging assays and analysis, and the production of the positive control protein BcLOV4, a natural photoreceptor with a directly light-regulated interaction with anionic membrane phospholipids that is useful for optogenetic membrane recruitment.
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Affiliation(s)
- Spencer T Glantz
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Erin E Berlew
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Brian Y Chow
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States.
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28
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Optogenetic Navigation of Routes Leading to Protein Amyloidogenesis in Bacteria. J Mol Biol 2019; 431:1186-1202. [PMID: 30721672 DOI: 10.1016/j.jmb.2019.01.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/24/2019] [Accepted: 01/28/2019] [Indexed: 01/10/2023]
Abstract
Modulation of liquid-liquid and liquid-hydrogel phase transitions is central to avoid the cytotoxic aggregation of proteins in eukaryotic cells, but knowledge on its relevance in bacteria is limited. Here the power of optogenetics to engineer proteins as light-responsive switches has been used to control the balance between solubility and aggregation for LOV2-WH1, a chimera between the plant blue light-responsive domain LOV2 and the bacterial prion-like protein RepA-WH1. These proteins were first linked by fusing, as a continuous α-helix, the C-terminal photo-transducer Jα helix in LOV2 with the N-terminal domain-closure α1 helix in RepA-WH1, and then improved for light-responsiveness by including mutations in the Jα moiety. In the darkness and in a crowded solution in vitro, LOV2-WH1 nucleates the irreversible assembly of amyloid fibers into a hydrogel. However, under blue light illumination, LOV2-WH1 assembles as soluble oligomers. When expressed in Escherichia coli, LOV2-WH1 forms in the darkness large intracellular amyloid inclusions compatible with bacterial proliferation. Strikingly, under blue light, LOV2-WH1 aggregates decrease in size, while they become detrimental for bacterial growth. LOV2-WH1 optogenetics governs the assembly of mutually exclusive inert amyloid fibers or cytotoxic oligomers, thus enabling the navigation of the conformational landscape of protein amyloidogenesis to generate potential photo-activated anti-bacterial devices (optobiotics).
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29
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Zayner JP, Mathes T, Sosnick TR, Kennis JTM. Helical Contributions Mediate Light-Activated Conformational Change in the LOV2 Domain of Avena sativa Phototropin 1. ACS OMEGA 2019; 4:1238-1243. [PMID: 31459397 PMCID: PMC6648828 DOI: 10.1021/acsomega.8b02872] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 01/02/2019] [Indexed: 06/10/2023]
Abstract
Algae, plants, bacteria, and fungi contain flavin-binding light-oxygen-voltage (LOV) domains that function as blue light sensors to control cellular responses to light. In the second LOV domain of phototropins, called LOV2 domains, blue light illumination leads to covalent bond formation between protein and flavin that induces the dissociation and unfolding of a C-terminally attached α helix (Jα) and the N-terminal helix (A'α). To date, the majority of studies on these domains have focused on versions that contain truncations in the termini, which creates difficulties when extrapolating to the much larger proteins that contain these domains. Here, we study the influence of deletions and extensions of the A'α helix of the LOV2 domain of Avena sativa phototropin 1 (AsLOV2) on the light-triggered structural response of the protein by Fourier-transform infrared difference spectroscopy. Deletion of the A'α helix abolishes the light-induced unfolding of Jα, whereas extensions of the A'α helix lead to an attenuated structural change of Jα. These results are different from shorter constructs, indicating that the conformational changes in full-length phototropin LOV domains might not be as large as previously assumed, and that the well-characterized full unfolding of the Jα helix in AsLOV2 with short A'α helices may be considered a truncation artifact. It also suggests that the N- and C-terminal helices of phot-LOV2 domains are necessary for allosteric regulation of the phototropin kinase domain and may provide a basis for signal integration of LOV1 and LOV2 domains in phototropins.
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Affiliation(s)
- Josiah P. Zayner
- Department of Biochemistry
and Molecular Biology, The University of
Chicago, Chicago 60637, United States
| | - Tilo Mathes
- Biophysics
Section, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Tobin R. Sosnick
- Department of Biochemistry
and Molecular Biology, The University of
Chicago, Chicago 60637, United States
- Institute
for Biophysical Dynamics, The University
of Chicago, Chicago, Illinois 60637 United States
| | - John T. M. Kennis
- Biophysics
Section, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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30
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de Mena L, Rizk P, Rincon-Limas DE. Bringing Light to Transcription: The Optogenetics Repertoire. Front Genet 2018; 9:518. [PMID: 30450113 PMCID: PMC6224442 DOI: 10.3389/fgene.2018.00518] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 10/15/2018] [Indexed: 11/13/2022] Open
Abstract
The ability to manipulate expression of exogenous genes in particular regions of living organisms has profoundly transformed the way we study biomolecular processes involved in both normal development and disease. Unfortunately, most of the classical inducible systems lack fine spatial and temporal accuracy, thereby limiting the study of molecular events that strongly depend on time, duration of activation, or cellular localization. By exploiting genetically engineered photo sensing proteins that respond to specific wavelengths, we can now provide acute control of numerous molecular activities with unprecedented precision. In this review, we present a comprehensive breakdown of all of the current optogenetic systems adapted to regulate gene expression in both unicellular and multicellular organisms. We focus on the advantages and disadvantages of these different tools and discuss current and future challenges in the successful translation to more complex organisms.
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Affiliation(s)
- Lorena de Mena
- Department of Neurology, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Patrick Rizk
- Department of Neurology, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Diego E Rincon-Limas
- Department of Neurology, McKnight Brain Institute, University of Florida, Gainesville, FL, United States.,Department of Neuroscience, Genetics Institute, Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, United States
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31
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Nguyen NT, Ma G, Lin E, D'Souza B, Jing J, He L, Huang Y, Zhou Y. CRAC channel-based optogenetics. Cell Calcium 2018; 75:79-88. [PMID: 30199756 DOI: 10.1016/j.ceca.2018.08.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 08/31/2018] [Indexed: 01/28/2023]
Abstract
Store-operated Ca²+ entry (SOCE) constitutes a major Ca2+ influx pathway in mammals to regulate a myriad of physiological processes, including muscle contraction, synaptic transmission, gene expression, and metabolism. In non-excitable cells, the Ca²+ release-activated Ca²+ (CRAC) channel, composed of ORAI and stromal interaction molecules (STIM), constitutes a prototypical example of SOCE to mediate Ca2+ entry at specialized membrane contact sites (MCSs) between the endoplasmic reticulum (ER) and the plasma membrane (PM). The key steps of SOCE activation include the oligomerization of the luminal domain of the ER-resident Ca2+ sensor STIM1 upon Ca²+ store depletion, subsequent signal propagation toward the cytoplasmic domain to trigger a conformational switch and overcome the intramolecular autoinhibition, and ultimate exposure of the minimal ORAI-activating domain to directly engage and gate ORAI channels in the plasma membrane. This exquisitely coordinated cellular event is also facilitated by the C-terminal polybasic domain of STIM1, which physically associates with negatively charged phosphoinositides embedded in the inner leaflet of the PM to enable efficient translocation of STIM1 into ER-PM MCSs. Here, we present recent progress in recapitulating STIM1-mediated SOCE activation by engineering CRAC channels with optogenetic approaches. These STIM1-based optogenetic tools make it possible to not only mechanistically recapture the key molecular steps of SOCE activation, but also remotely and reversibly control Ca²+-dependent cellular processes, inter-organellar tethering at MCSs, and transcriptional reprogramming when combined with CRISPR/Cas9-based genome-editing tools.
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Affiliation(s)
- Nhung Thi Nguyen
- Center for Translational Cancer Research, Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX 77030, USA
| | - Guolin Ma
- Center for Translational Cancer Research, Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX 77030, USA
| | - Eena Lin
- Center for Translational Cancer Research, Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX 77030, USA
| | - Brendan D'Souza
- Center for Translational Cancer Research, Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX 77030, USA
| | - Ji Jing
- Center for Translational Cancer Research, Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX 77030, USA
| | - Lian He
- Center for Translational Cancer Research, Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX 77030, USA
| | - Yun Huang
- Center for Epigenetics and Disease Prevention, Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX 77030, USA; Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University, College Station, TX 77843, USA
| | - Yubin Zhou
- Center for Translational Cancer Research, Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX 77030, USA; Department of Medical Physiology, College of Medicine, Texas A&M University, Temple, TX 76504, USA.
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32
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Directly light-regulated binding of RGS-LOV photoreceptors to anionic membrane phospholipids. Proc Natl Acad Sci U S A 2018; 115:E7720-E7727. [PMID: 30065115 PMCID: PMC6099885 DOI: 10.1073/pnas.1802832115] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Light–oxygen–voltage (LOV) domain photoreceptors are found ubiquitously in nature and possess highly diverse signaling roles and mechanisms. Here, we show that a class of fungal LOV proteins dynamically associates with anionic plasma membrane phospholipids by a blue light-switched electrostatic interaction. This reversible association is rapidly triggered by blue light and ceases within seconds when illumination ceases. Within the native host, we predict that these proteins regulate G-protein signaling by the controlled recruitment of fused regulator of G-protein signaling (RGS) domains; in applied contexts, we anticipate that engineered chimeric versions of such proteins will be useful for rapid optogenetic membrane localization of fused proteins through direct interaction with the membrane itself, without requiring additional components to direct subcellular localization. We report natural light–oxygen–voltage (LOV) photoreceptors with a blue light-switched, high-affinity (KD ∼ 10−7 M), and direct electrostatic interaction with anionic phospholipids. Membrane localization of one such photoreceptor, BcLOV4 from Botrytis cinerea, is directly coupled to its flavin photocycle, and is mediated by a polybasic amphipathic helix in the linker region between the LOV sensor and its C-terminal domain of unknown function (DUF), as revealed through a combination of bioinformatics, computational protein modeling, structure–function studies, and optogenetic assays in yeast and mammalian cell line expression systems. In model systems, BcLOV4 rapidly translocates from the cytosol to plasma membrane (∼1 second). The reversible electrostatic interaction is nonselective among anionic phospholipids, exhibiting binding strengths dependent on the total anionic content of the membrane without preference for a specific headgroup. The in vitro and cellular responses were also observed with a BcLOV4 homolog and thus are likely to be general across the dikarya LOV class, whose members are associated with regulator of G-protein signaling (RGS) domains. Natural photoreceptors are not previously known to directly associate with membrane phospholipids in a light-dependent manner, and thus this work establishes both a photosensory signal transmission mode and a single-component optogenetic tool with rapid membrane localization kinetics that approaches the diffusion limit.
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33
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Abstract
The first stage in biological signaling is based on changes in the functional state of a receptor protein triggered by interaction of the receptor with its ligand(s). The light-triggered nature of photoreceptors allows studies on the mechanism of such changes in receptor proteins using a wide range of biophysical methods and with superb time resolution. Here, we critically evaluate current understanding of proton and electron transfer in photosensory proteins and their involvement both in primary photochemistry and subsequent processes that lead to the formation of the signaling state. An insight emerging from multiple families of photoreceptors is that ultrafast primary photochemistry is followed by slower proton transfer steps that contribute to triggering large protein conformational changes during signaling state formation. We discuss themes and principles for light sensing shared by the six photoreceptor families: rhodopsins, phytochromes, photoactive yellow proteins, light-oxygen-voltage proteins, blue-light sensors using flavin, and cryptochromes.
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Affiliation(s)
- Tilman Kottke
- Department of Chemistry, Bielefeld University, 33615 Bielefeld, Germany
| | - Aihua Xie
- Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078, USA
| | - Delmar S. Larsen
- Department of Chemistry, University of California, Davis, California 95616, USA
| | - Wouter D. Hoff
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma 74078, USA
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, USA
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34
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Petersen J, Inoue SI, Kelly SM, Sullivan S, Kinoshita T, Christie JM. Functional characterization of a constitutively active kinase variant of Arabidopsis phototropin 1. J Biol Chem 2017; 292:13843-13852. [PMID: 28663371 PMCID: PMC5566536 DOI: 10.1074/jbc.m117.799643] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 06/21/2017] [Indexed: 01/14/2023] Open
Abstract
Phototropins (phots) are plasma membrane–associated serine/threonine kinases that coordinate a range of processes linked to optimizing photosynthetic efficiency in plants. These photoreceptors contain two light-, oxygen-, or voltage-sensing (LOV) domains within their N terminus, with each binding one molecule of flavin mononucleotide as a UV/blue light–absorbing chromophore. Although phots contain two LOV domains, light-induced activation of the C-terminal kinase domain and subsequent receptor autophosphorylation is controlled primarily by the A′α-LOV2-Jα photosensory module. Mutations that disrupt interactions between the LOV2 core and its flanking helical segments can uncouple this mode of light regulation. However, the impact of these mutations on phot function in Arabidopsis has not been explored. Here we report that histidine substitution of Arg-472 located within the A′α-helix of Arabidopsis phot1 constitutively activates phot1 kinase activity in vitro without affecting LOV2 photochemistry. Expression analysis of phot1 R472H in the phot-deficient mutant confirmed that it is autophosphorylated in darkness in vivo but unable to initiate phot1 signaling in the absence of light. Instead, we found that phot1 R472H is poorly functional under low-light conditions but can restore phototropism, chloroplast accumulation, stomatal opening, and leaf positioning and expansion at higher light intensities. Our findings suggest that Arabidopsis can adapt to the elevated phosphorylation status of the phot1 R472H mutant in part by reducing its stability, whereas the activity of the mutant under high-light conditions can be attributed to additional increases in LOV2-mediated photoreceptor autophosphorylation.
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Affiliation(s)
- Jan Petersen
- From the Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Bower Building, Glasgow G12 8QQ, United Kingdom
| | | | - Sharon M Kelly
- From the Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Bower Building, Glasgow G12 8QQ, United Kingdom
| | - Stuart Sullivan
- From the Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Bower Building, Glasgow G12 8QQ, United Kingdom
| | - Toshinori Kinoshita
- the Division of Biological Science, Graduate School of Science and.,Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya 464-8602, Japan
| | - John M Christie
- From the Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Bower Building, Glasgow G12 8QQ, United Kingdom,
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35
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Ganguly A, Thiel W, Crane BR. Glutamine Amide Flip Elicits Long Distance Allosteric Responses in the LOV Protein Vivid. J Am Chem Soc 2017; 139:2972-2980. [PMID: 28145707 PMCID: PMC5902025 DOI: 10.1021/jacs.6b10701] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Light-oxygen-voltage (LOV) domains sense blue light through the photochemical formation of a cysteinyl-flavin covalent adduct. Concurrent protonation at the flavin N5 position alters the hydrogen bonding interactions of an invariant Gln residue that has been proposed to flip its amide side chain as a critical step in the propagation of conformational change. Traditional molecular dynamics (MD) and replica-exchange MD (REMD) simulations of the well-characterized LOV protein Vivid (VVD) demonstrate that the Gln182 amide indeed reorients by ∼180° in response to either adduct formation or reduction of the isoalloxazine ring to the neutral semiquinone, both of which involve N5 protonation. Free energy simulations reveal that the relative free energies of the flipped Gln conformation and the flipping barrier are significantly lower in the light-adapted state. The Gln182 flip stabilizes an important hinge-bβ region between the PAS β-sheet and the N-terminal cap helix that in turn destabilizes an N-terminal latch region against the PAS core. Release of the latch, observed both experimentally and in the simulations, is known to mediate light-induced VVD dimerization. This computational study of a LOV protein, unprecedented in its agreement with experiment, provides an atomistic view of long-range allosteric coupling in a photoreceptor.
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Affiliation(s)
- Abir Ganguly
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1. 45470 Mülheim an der Ruhr, Germany
| | - Walter Thiel
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1. 45470 Mülheim an der Ruhr, Germany
| | - Brian R. Crane
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
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36
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Pudasaini A, Shim JS, Song YH, Shi H, Kiba T, Somers DE, Imaizumi T, Zoltowski BD. Kinetics of the LOV domain of ZEITLUPE determine its circadian function in Arabidopsis. eLife 2017; 6. [PMID: 28244872 PMCID: PMC5370183 DOI: 10.7554/elife.21646] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 02/26/2017] [Indexed: 11/13/2022] Open
Abstract
A LOV (Light, Oxygen, or Voltage) domain containing blue-light photoreceptor ZEITLUPE (ZTL) directs circadian timing by degrading clock proteins in plants. Functions hinge upon allosteric differences coupled to the ZTL photocycle; however, structural and kinetic information was unavailable. Herein, we tune the ZTL photocycle over two orders of magnitude. These variants reveal that ZTL complexes with targets independent of light, but dictates enhanced protein degradation in the dark. In vivo experiments definitively show photocycle kinetics dictate the rate of clock component degradation, thereby impacting circadian period. Structural studies demonstrate that photocycle dependent activation of ZTL depends on an unusual dark-state conformation of ZTL. Crystal structures of ZTL LOV domain confirm delineation of structural and kinetic mechanisms and identify an evolutionarily selected allosteric hinge differentiating modes of PAS/LOV signal transduction. The combined biochemical, genetic and structural studies provide new mechanisms indicating how PAS/LOV proteins integrate environmental variables in complex networks.
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Affiliation(s)
- Ashutosh Pudasaini
- Department of Chemistry, Southern Methodist University, Dallas, United States.,Center for Drug Discovery, Design and Delivery, Southern Methodist University, Dallas, United States
| | - Jae Sung Shim
- Department of Biology, University of Washington, Seattle, United States
| | - Young Hun Song
- Department of Biology, University of Washington, Seattle, United States.,Department of Life Sciences, Ajou University, Suwon, Korea
| | - Hua Shi
- Department of Molecular Genetics, Ohio State University, Columbus, United States
| | - Takatoshi Kiba
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - David E Somers
- Department of Molecular Genetics, Ohio State University, Columbus, United States
| | - Takato Imaizumi
- Department of Biology, University of Washington, Seattle, United States
| | - Brian D Zoltowski
- Department of Chemistry, Southern Methodist University, Dallas, United States.,Center for Drug Discovery, Design and Delivery, Southern Methodist University, Dallas, United States
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37
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Gil AA, Laptenok SP, French JB, Iuliano JN, Lukacs A, Hall CR, Sazanovich IV, Greetham GM, Bacher A, Illarionov B, Fischer M, Tonge PJ, Meech SR. Femtosecond to Millisecond Dynamics of Light Induced Allostery in the Avena sativa LOV Domain. J Phys Chem B 2017; 121:1010-1019. [PMID: 28068090 DOI: 10.1021/acs.jpcb.7b00088] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The rational engineering of photosensor proteins underpins the field of optogenetics, in which light is used for spatiotemporal control of cell signaling. Optogenetic elements function by converting electronic excitation of an embedded chromophore into structural changes on the microseconds to seconds time scale, which then modulate the activity of output domains responsible for biological signaling. Using time-resolved vibrational spectroscopy coupled with isotope labeling, we have mapped the structural evolution of the LOV2 domain of the flavin binding phototropin Avena sativa (AsLOV2) over 10 decades of time, reporting structural dynamics between 100 fs and 1 ms after optical excitation. The transient vibrational spectra contain contributions from both the flavin chromophore and the surrounding protein matrix. These contributions are resolved and assigned through the study of four different isotopically labeled samples. High signal-to-noise data permit the detailed analysis of kinetics associated with the light activated structural evolution. A pathway for the photocycle consistent with the data is proposed. The earliest events occur in the flavin binding pocket, where a subpicosecond perturbation of the protein matrix occurs. In this perturbed environment, the previously characterized reaction between triplet state isoalloxazine and an adjacent cysteine leads to formation of the adduct state; this step is shown to exhibit dispersive kinetics. This reaction promotes coupling of the optical excitation to successive time-dependent structural changes, initially in the β-sheet and then α-helix regions of the AsLOV2 domain, which ultimately gives rise to Jα-helix unfolding, yielding the signaling state. This model is tested through point mutagenesis, elucidating in particular the key mediating role played by Q513.
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Affiliation(s)
- Agnieszka A Gil
- Department of Chemistry, Stony Brook University , New York 11794-3400, United States
| | - Sergey P Laptenok
- School of Chemistry, University of East Anglia , Norwich, NR4 7TJ, U.K
| | - Jarrod B French
- Department of Chemistry, Stony Brook University , New York 11794-3400, United States
| | - James N Iuliano
- Department of Chemistry, Stony Brook University , New York 11794-3400, United States
| | - Andras Lukacs
- School of Chemistry, University of East Anglia , Norwich, NR4 7TJ, U.K.,Department of Biophysics, Medical School, University of Pecs , Szigeti ut 12, 7624 Pecs, Hungary
| | | | - Igor V Sazanovich
- Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory , Didcot, Oxon OX11 0QX, U.K
| | - Gregory M Greetham
- Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory , Didcot, Oxon OX11 0QX, U.K
| | - Adelbert Bacher
- Department Chemie, Technische Universität München , D-85747 Garching, Germany
| | - Boris Illarionov
- Institut für Biochemie und Lebensmittelchemie, Universität Hamburg , Grindelallee 117, D-20146 Hamburg, Germany
| | - Markus Fischer
- Institut für Biochemie und Lebensmittelchemie, Universität Hamburg , Grindelallee 117, D-20146 Hamburg, Germany
| | - Peter J Tonge
- Department of Chemistry, Stony Brook University , New York 11794-3400, United States
| | - Stephen R Meech
- School of Chemistry, University of East Anglia , Norwich, NR4 7TJ, U.K
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38
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Losi A, Gärtner W. Solving Blue Light Riddles: New Lessons from Flavin-binding LOV Photoreceptors. Photochem Photobiol 2017; 93:141-158. [PMID: 27861974 DOI: 10.1111/php.12674] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 10/22/2016] [Indexed: 12/15/2022]
Abstract
Detection of blue light (BL) via flavin-binding photoreceptors (Fl-Blues) has evolved throughout all three domains of life. Although the main BL players, that is light, oxygen and voltage (LOV), blue light sensing using flavins (BLUF) and Cry (cryptochrome) proteins, have been characterized in great detail with respect to structure and function, still several unresolved issues at different levels of complexity remain and novel unexpected findings were reported. Here, we review the most prevailing riddles of LOV-based photoreceptors, for example: the relevance of water and/or small metabolites for the dynamics of the photocycle; molecular details of light-to-signal transduction events; the interplay of BL sensing by LOV domains with other environmental stimuli, such as BL plus oxygen-mediating photodamage and its impact on microbial lifestyles; the importance of the cell or chromophore redox state in determining the fate of BL-driven reactions; the evolutionary pathways of LOV-based BL sensing and associated functions through the diverse phyla. We will discuss major novelties emerged during the last few years on these intriguing aspects of LOV proteins by presenting paradigmatic examples from prokaryotic photosensors that exhibit the largest complexity and richness in associated functions.
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Affiliation(s)
- Aba Losi
- Department of Physics and Earth Sciences, University of Parma, Parma, Italy
| | - Wolfgang Gärtner
- Max-Planck-Institute for Chemical Energy Conversion, Mülheim, Germany
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39
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Abstract
Cellular optogenetic switches, a novel class of biological tools, have improved our understanding of biological phenomena that were previously intractable. While the design and engineering of these proteins has historically varied, they are all based on borrowed elements from plant and bacterial photoreceptors. In general terms, each of the optogenetic switches designed to date exploits the endogenous light-induced change in photoreceptor conformation while repurposing its effect to target a different biological phenomenon. We focus on the well-characterized light-oxygen-voltage 2 (LOV2) domain from Avena sativa phototropin 1 as our cornerstone for design. While the function of the LOV2 domain in the context of the phototropin protein is not fully elucidated, its thorough biophysical characterization as an isolated domain has created a strong foundation for engineering of photoswitches. In this chapter, we examine the biophysical characteristics of the LOV2 domain that may be exploited to produce an optogenetic switch and summarize previous design efforts to provide guidelines for an effective design. Furthermore, we provide protocols for assays including fluorescence polarization, phage display, and microscopy that are optimized for validating, improving, and using newly designed photoswitches.
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Affiliation(s)
- S P Zimmerman
- University of North Carolina Chapel Hill, Chapel Hill, NC, United States
| | - B Kuhlman
- University of North Carolina Chapel Hill, Chapel Hill, NC, United States.
| | - H Yumerefendi
- University of North Carolina Chapel Hill, Chapel Hill, NC, United States.
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40
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Tanwar M, Nahar S, Gulati S, Veetil SK, Kateriya S. Molecular determinant modulates thermal recovery kinetics and structural integrity of the bacterial BLUF photoreceptor. FEBS Lett 2016; 590:2146-57. [DOI: 10.1002/1873-3468.12227] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 05/12/2016] [Accepted: 05/25/2016] [Indexed: 01/20/2023]
Affiliation(s)
- Meenakshi Tanwar
- Department of Biochemistry; University of Delhi; New Delhi India
| | - Smita Nahar
- Department of Biochemistry; University of Delhi; New Delhi India
| | - Sahil Gulati
- Department of Biochemistry; University of Delhi; New Delhi India
| | | | - Suneel Kateriya
- Department of Biochemistry; University of Delhi; New Delhi India
- School of Biotechnology; Jawaharlal Nehru University; New Delhi India
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41
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Lokhandwala J, Silverman Y de la Vega RI, Hopkins HC, Britton CW, Rodriguez-Iglesias A, Bogomolni R, Schmoll M, Zoltowski BD. A Native Threonine Coordinates Ordered Water to Tune Light-Oxygen-Voltage (LOV) Domain Photocycle Kinetics and Osmotic Stress Signaling in Trichoderma reesei ENVOY. J Biol Chem 2016; 291:14839-50. [PMID: 27226624 DOI: 10.1074/jbc.m116.731448] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Indexed: 01/24/2023] Open
Abstract
Light-oxygen-voltage (LOV) domain-containing proteins function as small light-activated modules capable of imparting blue light control of biological processes. Their small modular nature has made them model proteins for allosteric signal transduction and optogenetic devices. Despite intense research, key aspects of their signal transduction mechanisms and photochemistry remain poorly understood. In particular, ordered water has been identified as a possible key mediator of photocycle kinetics, despite the lack of ordered water in the LOV active site. Herein, we use recent crystal structures of a fungal LOV protein ENVOY to interrogate the role of Thr(101) in recruiting water to the flavin active site where it can function as an intrinsic base to accelerate photocycle kinetics. Kinetic and molecular dynamic simulations confirm a role in solvent recruitment to the active site and identify structural changes that correlate with solvent recruitment. In vivo analysis of T101I indicates a direct role of the Thr(101) position in mediating adaptation to osmotic stress, thereby verifying biological relevance of ordered water in LOV signaling. The combined studies identify position 101 as a mediator of both allostery and photocycle catalysis that can impact organism physiology.
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Affiliation(s)
- Jameela Lokhandwala
- From the Department of Chemistry, Southern Methodist University, Dallas, Texas 75275
| | | | - Hilary C Hopkins
- From the Department of Chemistry, Southern Methodist University, Dallas, Texas 75275
| | - Collin W Britton
- From the Department of Chemistry, Southern Methodist University, Dallas, Texas 75275
| | - Aroa Rodriguez-Iglesias
- the Department of Health and Environment, Austrian Institute of Technology, Bioresources, 3430 Tulln, Austria
| | - Roberto Bogomolni
- the Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064, and
| | - Monika Schmoll
- the Department of Health and Environment, Austrian Institute of Technology, Bioresources, 3430 Tulln, Austria
| | - Brian D Zoltowski
- From the Department of Chemistry, Southern Methodist University, Dallas, Texas 75275,
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42
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Okajima K. Molecular mechanism of phototropin light signaling. JOURNAL OF PLANT RESEARCH 2016; 129:149-157. [PMID: 26815763 DOI: 10.1007/s10265-016-0783-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 12/24/2015] [Indexed: 06/05/2023]
Abstract
Phototropin (phot) is a blue light (BL) receptor kinase involved in the BL responses of several species, ranging from green algae to higher plants. Phot converts BL signals from the environment into biochemical signals that trigger cellular responses. In phot, the LOV1 and LOV2 domains of the N-terminal region utilize BL for cyclic photoreactions and regulate C-terminal serine/threonine kinase (STK) activity. LOV2-STK peptides are the smallest functional unit of phot and are useful for understanding regulation mechanisms. The combined analysis of spectroscopy and STK activity assay in Arabidopsis phots suggests that the decay speed of the photo-intermediate S390 in LOV2 is one of the factors contributing to light sensitive kinase activity. LOV2 and STK are thought to be adjacent to each other in LOV2-STK with small angle scattering (SAXS). BL irradiation induces LOV2-STK elongation, resulting in LOV2 shifting away from STK. The N- and C-terminal lateral regions of LOV2, A'α-helix, Jα-helix, and A'α/Aβ gap are responsible for the propagation of the BL signal to STK via conformational changes. The comparison between LOV2-STK and full-length phot from Chlamydomonas suggests that LOV1 is directly adjacent to LOV2 in LOV2-STK; therefore, LOV1 may indirectly regulate STK. The molecular mechanism of phot is discussed.
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Affiliation(s)
- Koji Okajima
- Department of Physics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama, Kanagawa, 223-8522, Japan.
- RIKEN Harima Institute, Spring-8, 1-1-1 Kouto, Sayo, Sayo, Hyogo, 679-5148, Japan.
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43
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Abstract
The discovery of light-gated ion channels and their application to controlling neural activities have had a transformative impact on the field of neuroscience. In recent years, the concept of using light-activated proteins to control biological processes has greatly diversified into other fields, driven by the natural diversity of photoreceptors and decades of knowledge obtained from their biophysical characterization. In this chapter, we will briefly discuss the origin and development of optogenetics and highlight the basic concepts that make it such a powerful technology. We will review how these enabling concepts have developed over the past decade, and discuss future perspectives.
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Affiliation(s)
- Yong Ku Cho
- Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT, USA. .,Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA.
| | - Dan Li
- Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT, USA
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44
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Peter EK, Shea JE, Pivkin IV. Coarse kMC-based replica exchange algorithms for the accelerated simulation of protein folding in explicit solvent. Phys Chem Chem Phys 2016; 18:13052-65. [DOI: 10.1039/c5cp06867c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In this paper, we present a coarse replica exchange molecular dynamics (REMD) approach, based on kinetic Monte Carlo (kMC).
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Affiliation(s)
- Emanuel K. Peter
- Institute of Computational Science
- Faculty of Informatics
- University of Lugano
- Switzerland
| | - Joan-Emma Shea
- Department of Chemistry and Biochemistry
- Department of Physics
- University of California
- Santa Barbara
- USA
| | - Igor V. Pivkin
- Institute of Computational Science
- Faculty of Informatics
- University of Lugano
- Switzerland
- Swiss Institute of Bioinformatics
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45
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Kashojiya S, Yoshihara S, Okajima K, Tokutomi S. The linker between LOV2-Jα and STK plays an essential role in the kinase activation by blue light in Arabidopsis phototropin1, a plant blue light receptor. FEBS Lett 2015; 590:139-47. [PMID: 26763121 DOI: 10.1002/1873-3468.12028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 11/25/2015] [Accepted: 11/26/2015] [Indexed: 11/07/2022]
Abstract
Phototropin (phot), a blue light receptor in plants, is composed of several domains: LOV1, LOV2, and a serine/threonine kinase (STK). LOV2 is the main regulator of light activation of STK. However, the detailed mechanism remains unclear. In this report, we focused on the linker region between LOV2 and STK excluding the Jα-helix. Spectroscopy and a kinase assay for the substituents in the linker region of Arabidopsis phot1 LOV2-STK indicated that the linker is involved in the activation of STK. A putative module in the middle of the linker would be critical for intramolecular signaling and/or regulation of STK.
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Affiliation(s)
- Sachiko Kashojiya
- Department of Biological Science, Osaka Prefecture University, Sakai, Osaka, Japan
| | - Shizue Yoshihara
- Department of Biological Science, Osaka Prefecture University, Sakai, Osaka, Japan
| | - Koji Okajima
- Department of Biological Science, Osaka Prefecture University, Sakai, Osaka, Japan
| | - Satoru Tokutomi
- Department of Biological Science, Osaka Prefecture University, Sakai, Osaka, Japan
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46
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Bocola M, Schwaneberg U, Jaeger KE, Krauss U. Light-induced structural changes in a short light, oxygen, voltage (LOV) protein revealed by molecular dynamics simulations-implications for the understanding of LOV photoactivation. Front Mol Biosci 2015; 2:55. [PMID: 26484348 PMCID: PMC4589677 DOI: 10.3389/fmolb.2015.00055] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 09/05/2015] [Indexed: 02/06/2023] Open
Abstract
The modularity of light, oxygen, voltage (LOV) blue-light photoreceptors has recently been exploited for the design of LOV-based optogenetic tools, which allow the light-dependent control of biological functions. For the understanding of LOV sensory function and hence the optimal design of LOV-based optogentic tools it is essential to gain an in depth atomic-level understanding of the underlying photoactivation and intramolecular signal-relay mechanisms. To address this question we performed molecular dynamics simulations on both the dark- and light-adapted state of PpSB1-LOV, a short dimeric bacterial LOV-photoreceptor protein, recently crystallized under constant illumination. While LOV dimers remained globally stable during the light-state simulation with regard to the Jα coiled-coil, distinct conformational changes for a glutamine in the vicinity of the FMN chromophore are observed. In contrast, multiple Jα-helix conformations are sampled in the dark-state. These changes coincide with a displacement of the Iβ and Hβ strands relative to the light-state structure and result in a correlated rotation of both LOV core domains in the dimer. These global changes are most likely initiated by the reorientation of the conserved glutamine Q116, whose side chain flips between the Aβ (dark state) and Hβ strand (light state), while maintaining two potential hydrogen bonds to FMN-N5 and FMN-O4, respectively. This local Q116-FMN reorientation impacts on an inter-subunit salt-bridge (K117-E96), which is stabilized in the light state, hence accounting for the observed decreased mobility. Based on these findings we propose an alternative mechanism for dimeric LOV photoactivation and intramolecular signal-relay, assigning a distinct structural role for the conserved “flipping” glutamine. The proposed mechanism is discussed in light of universal applicability and its implications for the understanding of LOV-based optogenetic tools.
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Affiliation(s)
- Marco Bocola
- Lehrstuhl für Biotechnologie, RWTH Aachen University Aachen, Germany
| | | | - Karl-Erich Jaeger
- Forschungszentrum Jülich, Institut für Molekulare Enzymtechnologie, Heinrich Heine University Düsseldorf Jülich, Germany ; Forschungszentrum Jülich, Institut für Bio- und Geowissenschaften, IBG-1: Biotechnologie Jülich, Germany
| | - Ulrich Krauss
- Forschungszentrum Jülich, Institut für Molekulare Enzymtechnologie, Heinrich Heine University Düsseldorf Jülich, Germany
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47
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Kanegae T, Kimura I. A phytochrome/phototropin chimeric photoreceptor of fern functions as a blue/far-red light-dependent photoreceptor for phototropism in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 83:480-8. [PMID: 26095327 DOI: 10.1111/tpj.12903] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 05/27/2015] [Accepted: 06/01/2015] [Indexed: 05/07/2023]
Abstract
In the fern Adiantum capillus-veneris, the phototropic response of the protonemal cells is induced by blue light and partially inhibited by subsequent irradiation with far-red light. This observation strongly suggests the existence of a phytochrome that mediates this blue/far-red reversible response; however, the phytochrome responsible for this response has not been identified. PHY3/NEO1, one of the three phytochrome genes identified in Adiantum, encodes a chimeric photoreceptor composed of both a phytochrome and a phototropin domain. It was demonstrated that phy3 mediates the red light-dependent phototropic response of Adiantum, and that phy3 potentially functions as a phototropin. These findings suggest that phy3 is the phytochrome that mediates the blue/far-red response in Adiantum protonemata. In the present study, we expressed Adiantum phy3 in a phot1 phot2 phototropin-deficient Arabidopsis line, and investigated the ability of phy3 to induce phototropic responses under various light conditions. Blue light irradiation clearly induced a phototropic response in the phy3-expressing transgenic seedlings, and this effect was fully inhibited by simultaneous irradiation with far-red light. In addition, experiments using amino acid-substituted phy3 indicated that FMN-cysteinyl adduct formation in the light, oxygen, voltage (LOV) domain was not necessary for the induction of blue light-dependent phototropism by phy3. We thus demonstrate that phy3 is the phytochrome that mediates the blue/far-red reversible phototropic response in Adiantum. Furthermore, our results imply that phy3 can function as a phototropin, but that it acts principally as a phytochrome that mediates both the red/far-red and blue/far-red light responses.
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Affiliation(s)
- Takeshi Kanegae
- Department of Biological Sciences, Graduate School of Science and Technology, Tokyo Metropolitan University, Minami Osawa, Hachioji, Tokyo, 192-0397, Japan
| | - Izumi Kimura
- Department of Biological Sciences, Graduate School of Science and Technology, Tokyo Metropolitan University, Minami Osawa, Hachioji, Tokyo, 192-0397, Japan
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48
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Fraikin GY, Strakhovskaya MG, Belenikina NS, Rubin AB. Bacterial photosensory proteins: Regulatory functions and optogenetic applications. Microbiology (Reading) 2015. [DOI: 10.1134/s0026261715040086] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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49
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Kaur Grewal R, Mitra D, Roy S. Mapping networks of light-dark transition in LOV photoreceptors. Bioinformatics 2015. [PMID: 26209799 DOI: 10.1093/bioinformatics/btv429] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
MOTIVATION In optogenetics, designing modules of long or short signaling state lifetime is necessary for control over precise cellular events. A critical parameter for designing artificial or synthetic photoreceptors is the signaling state lifetime of photosensor modules. Design and engineering of biologically relevant artificial photoreceptors is based on signaling mechanisms characteristic of naturally occurring photoreceptors. Therefore identifying residues important for light-dark transition is a definite first step towards rational design of synthetic photoreceptors. A thorough grasp of detailed mechanisms of photo induced signaling process would be immensely helpful in understanding the behaviour of organisms. RESULTS Herein, we introduce the technique of differential networks. We identify key biological interactions, using light-oxygen-voltage domains of all organisms whose dark and light state crystal structures are simultaneously available. Even though structural differences between dark and light states are subtle (other than the covalent bond formation between flavin chromophore and active site Cysteine), our results successfully capture functionally relevant residues and are in complete agreement with experimental findings from literature. Additionally, using sequence-structure alignments, we predict functional significance of interactions found to be important from network perspective yet awaiting experimental validation. Our approach would not only help in minimizing extensive photo-cycle kinetics procedure but is also helpful in providing first-hand information on the fundamentals of photo-adaptation and rational design of synthetic photoreceptors in optogenetics. CONTACT devrani.dbs@presiuniv.ac.in or soumen@jcbose.ac.in SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
| | - Devrani Mitra
- Department of Biological Sciences, Presidency University, Kolkata 700 073, India
| | - Soumen Roy
- Bose Institute, Kolkata 700 009, India and
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Pudasaini A, El-Arab KK, Zoltowski BD. LOV-based optogenetic devices: light-driven modules to impart photoregulated control of cellular signaling. Front Mol Biosci 2015; 2:18. [PMID: 25988185 PMCID: PMC4428443 DOI: 10.3389/fmolb.2015.00018] [Citation(s) in RCA: 141] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 04/27/2015] [Indexed: 12/31/2022] Open
Abstract
The Light-Oxygen-Voltage domain family of proteins is widespread in biology where they impart sensory responses to signal transduction domains. The small, light responsive LOV modules offer a novel platform for the construction of optogenetic tools. Currently, the design and implementation of these devices is partially hindered by a lack of understanding of how light drives allosteric changes in protein conformation to activate diverse signal transduction domains. Further, divergent photocycle properties amongst LOV family members complicate construction of highly sensitive devices with fast on/off kinetics. In the present review we discuss the history of LOV domain research with primary emphasis on tuning LOV domain chemistry and signal transduction to allow for improved optogenetic tools.
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Affiliation(s)
- Ashutosh Pudasaini
- Department of Chemistry, Center for Drug Discovery, Design and Delivery at Dedman College, Southern Methodist University Dallas, TX, USA
| | - Kaley K El-Arab
- Department of Chemistry, Center for Drug Discovery, Design and Delivery at Dedman College, Southern Methodist University Dallas, TX, USA
| | - Brian D Zoltowski
- Department of Chemistry, Center for Drug Discovery, Design and Delivery at Dedman College, Southern Methodist University Dallas, TX, USA
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