1
|
Yang G, Liu X, Lin L. Detection of UVR8 Homodimers and Monomers by Immunoblotting Analysis in Tomato. Methods Mol Biol 2021; 2297:83-93. [PMID: 33656672 DOI: 10.1007/978-1-0716-1370-2_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The UV RESISTANCE LOCUS 8 (UVR8) is a photoreceptor mediating photomorphogenic responses to UV-B. UVR8 exists as homodimer in plants and UV-B induces dissociation of dimeric UVR8 into monomers to initiate responses. The monomer/dimer status of UVR8 is reversible and a dynamic photo-equilibrium is established in plants according to the ambient light conditions. Here we describe a method to detect UVR8 homodimer and monomer by immunoblotting method from tomato (Solanum lycopersicum) plants. The feature of this method is that protein samples are not boiled prior to loading on an SDS-PAGE gel, which allows the detection of UVR8 homodimer and monomers simultaneously with a single antibody.
Collapse
Affiliation(s)
- Guoqian Yang
- Key Laboratory of Urban Agriculture Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaorui Liu
- Key Laboratory of Urban Agriculture Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Li Lin
- Key Laboratory of Urban Agriculture Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
| |
Collapse
|
2
|
Hepp S, Trauth J, Hasenjäger S, Bezold F, Essen LO, Taxis C. An Optogenetic Tool for Induced Protein Stabilization Based on the Phaeodactylum tricornutum Aureochrome 1a Light-Oxygen-Voltage Domain. J Mol Biol 2020; 432:1880-1900. [PMID: 32105734 DOI: 10.1016/j.jmb.2020.02.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 01/10/2020] [Accepted: 02/14/2020] [Indexed: 01/02/2023]
Abstract
Control of cellular events by optogenetic tools is a powerful approach to manipulate cellular functions in a minimally invasive manner. A common problem posed by the application of optogenetic tools is to tune the activity range to be physiologically relevant. Here, we characterized a photoreceptor of the light-oxygen-voltage (LOV) domain family of Phaeodactylum tricornutum aureochrome 1a (AuLOV) as a tool for increasing protein stability under blue light conditions in budding yeast. Structural studies of AuLOVwt, the variants AuLOVM254, and AuLOVW349 revealed alternative dimer association modes for the dark state, which differ from previously reported AuLOV dark-state structures. Rational design of AuLOV-dimer interface mutations resulted in an optimized optogenetic tool that we fused to the photoactivatable adenylyl cyclase from Beggiatoa sp. This synergistic light-regulation approach using two photoreceptors resulted in an optimized, photoactivatable adenylyl cyclase with a cyclic adenosine monophosphate production activity that matches the physiological range of Saccharomyces cerevisiae. Overall, we enlarged the optogenetic toolbox for yeast and demonstrated the importance of fine-tuning the optogenetic tool activity for successful application in cells.
Collapse
Affiliation(s)
- Sebastian Hepp
- Unit for Structural Biochemistry, Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany; Center of Synthetic Microbiology, Philipps Universität Marburg, Hans-Meerwein- Strasse 4, 35032 Marburg, Germany
| | - Jonathan Trauth
- Unit for Structural Biochemistry, Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany; Center of Synthetic Microbiology, Philipps Universität Marburg, Hans-Meerwein- Strasse 4, 35032 Marburg, Germany; Molecular Genetics, Department of Biology, Philipps Universität Marburg, Karl-von-Frisch-Strasse 8, 35043 Marburg, Germany
| | - Sophia Hasenjäger
- Molecular Genetics, Department of Biology, Philipps Universität Marburg, Karl-von-Frisch-Strasse 8, 35043 Marburg, Germany
| | - Filipp Bezold
- Unit for Structural Biochemistry, Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany; Center of Synthetic Microbiology, Philipps Universität Marburg, Hans-Meerwein- Strasse 4, 35032 Marburg, Germany
| | - Lars-Oliver Essen
- Unit for Structural Biochemistry, Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany; Center of Synthetic Microbiology, Philipps Universität Marburg, Hans-Meerwein- Strasse 4, 35032 Marburg, Germany.
| | - Christof Taxis
- Molecular Genetics, Department of Biology, Philipps Universität Marburg, Karl-von-Frisch-Strasse 8, 35043 Marburg, Germany.
| |
Collapse
|
3
|
Iuliano JN, Gil AA, Laptenok SP, Hall CR, Collado JT, Lukacs A, Hag Ahmed SA, Abyad J, Daryaee T, Greetham GM, Sazanovich IV, Illarionov B, Bacher A, Fischer M, Towrie M, French JB, Meech SR, Tonge PJ. Variation in LOV Photoreceptor Activation Dynamics Probed by Time-Resolved Infrared Spectroscopy. Biochemistry 2018; 57:620-630. [PMID: 29239168 PMCID: PMC5801046 DOI: 10.1021/acs.biochem.7b01040] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The light, oxygen, voltage (LOV) domain proteins are blue light photoreceptors that utilize a noncovalently bound flavin mononucleotide (FMN) cofactor as the chromophore. The modular nature of these proteins has led to their wide adoption in the emerging fields of optogenetics and optobiology, where the LOV domain has been fused to a variety of output domains leading to novel light-controlled applications. In this work, we extend our studies of the subpicosecond to several hundred microsecond transient infrared spectroscopy of the isolated LOV domain AsLOV2 to three full-length photoreceptors in which the LOV domain is fused to an output domain: the LOV-STAS protein, YtvA, the LOV-HTH transcription factor, EL222, and the LOV-histidine kinase, LovK. Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate. However, significant differences are observed in the vibrational spectra and kinetics after adduct formation, which are directly linked to the specific output function of the LOV domain. While the rate of adduct formation varies by only 3.6-fold among the proteins, the subsequent large-scale structural changes in the full-length LOV photoreceptors occur over the micro- to submillisecond time scales and vary by orders of magnitude depending on the different output function of each LOV domain.
Collapse
Affiliation(s)
- James N. Iuliano
- Department of Chemistry, Stony Brook University, New York, 11794, United States
| | - Agnieszka A. Gil
- Department of Chemistry, Stony Brook University, New York, 11794, 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 út 12, 7624 Pecs, Hungary
| | - Safaa A. Hag Ahmed
- Department of Chemistry, Stony Brook University, New York, 11794, United States
| | - Jenna Abyad
- Department of Chemistry, Stony Brook University, New York, 11794, United States
| | - Taraneh Daryaee
- Department of Chemistry, Stony Brook University, New York, 11794, United States
| | - Gregory M. Greetham
- Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, OX11 0QX, U.K
| | - Igor V. Sazanovich
- Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, OX11 0QX, U.K
| | - Boris Illarionov
- Institut für Biochemie und Lebensmittelchemie, Universität Hamburg, Grindelallee 117, D-20146 Hamburg, Germany
| | - Adelbert Bacher
- Department Chemie, Technische Universität München, D-85747 Garching, Germany
| | - Markus Fischer
- Institut für Biochemie und Lebensmittelchemie, Universität Hamburg, Grindelallee 117, D-20146 Hamburg, Germany
| | - Michael Towrie
- Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, OX11 0QX, U.K
| | - Jarrod B. French
- Department of Chemistry, Stony Brook University, New York, 11794, United States
| | - Stephen R. Meech
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, U.K
| | - Peter J. Tonge
- Department of Chemistry, Stony Brook University, New York, 11794, United States
| |
Collapse
|
4
|
Essen LO, Franz S, Banerjee A. Structural and evolutionary aspects of algal blue light receptors of the cryptochrome and aureochrome type. J Plant Physiol 2017; 217:27-37. [PMID: 28756992 DOI: 10.1016/j.jplph.2017.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 07/05/2017] [Accepted: 07/05/2017] [Indexed: 06/07/2023]
Abstract
Blue-light reception plays a pivotal role for algae to adapt to changing environmental conditions. In this review we summarize the current structural and mechanistic knowledge about flavin-dependent algal photoreceptors. We especially focus on the cryptochrome and aureochrome type photoreceptors in the context of their evolutionary divergence. Despite similar photochemical characteristics to orthologous photoreceptors from higher plants and animals the algal blue-light photoreceptors have developed a set of unique structural and mechanistic features that are summarized below.
Collapse
Affiliation(s)
- Lars-Oliver Essen
- Department of Biochemistry, Philipps-University, 35043 Marburg, Germany; LOEWE Center for Synthetic Microbiology, Philipps-University, 35043 Marburg, Germany.
| | - Sophie Franz
- Department of Biochemistry, Philipps-University, 35043 Marburg, Germany
| | - Ankan Banerjee
- Department of Biochemistry, Philipps-University, 35043 Marburg, Germany
| |
Collapse
|
5
|
Fu G, Nagasato C, Yamagishi T, Kawai H, Okuda K, Takao Y, Horiguchi T, Motomura T. Ubiquitous distribution of helmchrome in phototactic swarmers of the stramenopiles. Protoplasma 2016; 253:929-941. [PMID: 26202473 DOI: 10.1007/s00709-015-0857-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 07/13/2015] [Indexed: 12/16/2023]
Abstract
Most swarmers (swimming cells) of the stramenopile group, ranging from unicellular protist to giant kelps (brown algae), have two heterogeneous flagella: a long anterior flagellum (AF) and a relatively shorter posterior flagellum (PF). These flagellated cells often exhibit phototaxis upon light stimulation, although the mechanism by which how the phototactic response is regulated remains largely unknown. A flavoprotein concentrating at the paraflagellar body (PFB) on the basal part of the PF, which can emit green autofluorescence under blue light irradiance, has been proposed as a possible blue light photoreceptor for brown algal phototaxis although the nature of the flavoprotein still remains elusive. Recently, we identified helmchrome as a PF-specific flavoprotein protein in a LC-MS/MS-based proteomics study of brown algal flagella (Fu et al. 2014). To verify the conservation of helmchrome, in the present study, the absence or presence and the localization of helmchrome in swarmers of various algal species were investigated. The results showed that helmchrome was only detected in phototactic swarmers but not the non-phototactic ones of the stramenopile group. Electron microscopy further revealed that the helmchrome detectable swarmers bear a conserved PFB-eyespot complex, which may serve as structural basis for light sensing. It is speculated that all three conserved properties: helmchrome, the PFB structure, and the eyespot apparatus, will be essential parts for phototaxis of stramenopile swarmers.
Collapse
Affiliation(s)
- Gang Fu
- Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran, 051-0013, Japan
| | - Chikako Nagasato
- Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran, 051-0013, Japan
| | - Takahiro Yamagishi
- Research Center for Inland Seas, Kobe University, Rokkodai, Nadaku, Kobe, 657-8501, Japan
| | - Hiroshi Kawai
- Research Center for Inland Seas, Kobe University, Rokkodai, Nadaku, Kobe, 657-8501, Japan
| | - Kazuo Okuda
- Graduate School of Integrated Arts and Sciences, Kochi University, Kochi, 780-8520, Japan
| | - Yoshitake Takao
- Faculty of Marine Bioscience, Fukui Prefectural University, Obama, 917-0003, Japan
| | - Takeo Horiguchi
- Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Taizo Motomura
- Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran, 051-0013, Japan.
| |
Collapse
|
6
|
Glantz ST, Carpenter EJ, Melkonian M, Gardner KH, Boyden ES, Wong GKS, Chow BY. Functional and topological diversity of LOV domain photoreceptors. Proc Natl Acad Sci U S A 2016; 113:E1442-51. [PMID: 26929367 PMCID: PMC4801262 DOI: 10.1073/pnas.1509428113] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Light-oxygen-voltage sensitive (LOV) flavoproteins are ubiquitous photoreceptors that mediate responses to environmental cues. Photosensory inputs are transduced into signaling outputs via structural rearrangements in sensor domains that consequently modulate the activity of an effector domain or multidomain clusters. Establishing the diversity in effector function and sensor-effector topology will inform what signaling mechanisms govern light-responsive behaviors across multiple kingdoms of life and how these signals are transduced. Here, we report the bioinformatics identification of over 6,700 candidate LOV domains (including over 4,000 previously unidentified sequences from plants and protists), and insights from their annotations for ontological function and structural arrangements. Motif analysis identified the sensors from ∼42 million ORFs, with strong statistical separation from other flavoproteins and non-LOV members of the structurally related Per-aryl hydrocarbon receptor nuclear translocator (ARNT)-Sim family. Conserved-domain analysis determined putative light-regulated function and multidomain topologies. We found that for certain effectors, sensor-effector linker length is discretized based on both phylogeny and the preservation of α-helical heptad repeats within an extended coiled-coil linker structure. This finding suggests that preserving sensor-effector orientation is a key determinant of linker length, in addition to ancestry, in LOV signaling structure-function. We found a surprisingly high prevalence of effectors with functions previously thought to be rare among LOV proteins, such as regulators of G protein signaling, and discovered several previously unidentified effectors, such as lipases. This work highlights the value of applying genomic and transcriptomic technologies to diverse organisms to capture the structural and functional variation in photosensory proteins that are vastly important in adaptation, photobiology, and optogenetics.
Collapse
Affiliation(s)
- Spencer T Glantz
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104
| | - Eric J Carpenter
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - Michael Melkonian
- Institute of Botany, Cologne Biocenter, University of Cologne, 50674 Cologne, Germany
| | - Kevin H Gardner
- Structural Biology Initiative, CUNY Advanced Science Research Center, City College of New York, New York, NY 10031; Department of Chemistry and Biochemistry, City College of New York, New York, NY 10031; Biochemistry, Chemistry and Biology Programs, Graduate Center, The City University of New York, New York, NY 10031
| | - Edward S Boyden
- The Media Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139; McGovern Institute for Brain Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Gane Ka-Shu Wong
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9; Department of Medicine, University of Alberta, Edmonton, AB, Canada T6G 2E1; BGI-Shenzhen, Beishan Industrial Zone, Yantian District, Shenzhen 518083, China
| | - Brian Y Chow
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104;
| |
Collapse
|
7
|
Takahashi F. Blue-light-regulated transcription factor, Aureochrome, in photosynthetic stramenopiles. J Plant Res 2016; 129:189-197. [PMID: 26781435 DOI: 10.1007/s10265-016-0784-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 12/23/2015] [Indexed: 06/05/2023]
Abstract
During the course of evolution through various endosymbiotic processes, diverse photosynthetic eukaryotes acquired blue light (BL) responses that do not use photosynthetic pathways. Photosynthetic stramenopiles, which have red algae-derived chloroplasts through secondary symbiosis, are principal primary producers in aquatic environments, and play important roles in ecosystems and aquaculture. Through secondary symbiosis, these taxa acquired BL responses, such as phototropism, chloroplast photo-relocation movement, and photomorphogenesis similar to those which green plants acquired through primary symbiosis. Photosynthetic stramenopile BL receptors were undefined until the discovery in 2007, of a new type of BL receptor, the aureochrome (AUREO), from the photosynthetic stramenopile alga, Vaucheria. AUREO has a bZIP domain and a LOV domain, and thus BL-responsive transcription factor. AUREO orthologs are only conserved in photosynthetic stramenopiles, such as brown algae, diatoms, and red tide algae. Here, a brief review is presented of the role of AUREOs as photoreceptors for these diverse BL responses and their biochemical properties in photosynthetic stramenopiles.
Collapse
Affiliation(s)
- Fumio Takahashi
- College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577, Japan.
| |
Collapse
|
8
|
Abstract
Plant photoreceptors link environmental light cues with physiological responses, determining how individual plants complete their life cycles. Structural and functional evolution of photoreceptors has co-occurred as plants diversified and faced the challenge of new light environments, during the transition of plants to land and as substantial plant canopies evolved. Large-scale comparative sequencing projects allow us for the first time to document photoreceptor evolution in understudied clades, revealing some surprises. Here we review recent progress in evolutionary studies of three photoreceptor families: phytochromes, phototropins and neochromes.
Collapse
Affiliation(s)
- Fay-Wei Li
- Department of Biology, Duke University, Durham, NC, 27708, USA.
- University Herbarium and Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA.
| | - Sarah Mathews
- CSIRO National Research Collections Australia, Australian National Herbarium, Canberra, ACT, 2601, Australia.
| |
Collapse
|
9
|
Abstract
Low doses of UV-B light (280 to 315 nm) elicit photomorphogenic responses in plants that modify biochemical composition, photosynthetic competence, morphogenesis, and defense. UV RESISTANCE LOCUS8 (UVR8) mediates photomorphogenic responses to UV-B by regulating transcription of a set of target genes. UVR8 differs from other known photoreceptors in that it uses specific Trp amino acids instead of a prosthetic chromophore for light absorption during UV-B photoreception. Absorption of UV-B dissociates the UVR8 dimer into monomers, initiating signal transduction through interaction with CONSTITUTIVELY PHOTOMORPHOGENIC1. However, much remains to be learned about the physiological role of UVR8 and its interaction with other signaling pathways, the molecular mechanism of UVR8 photoreception, how the UVR8 protein initiates signaling, how it is regulated, and how UVR8 regulates transcription of its target genes.
Collapse
Affiliation(s)
- Gareth I. Jenkins
- Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| |
Collapse
|
10
|
|
11
|
O’Hara A, Jenkins GI. In vivo function of tryptophans in the Arabidopsis UV-B photoreceptor UVR8. Plant Cell 2012; 24:3755-66. [PMID: 23012433 PMCID: PMC3480300 DOI: 10.1105/tpc.112.101451] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 08/10/2012] [Accepted: 08/23/2012] [Indexed: 05/19/2023]
Abstract
Arabidopsis thaliana UV RESISTANCE LOCUS8 (UVR8) is a photoreceptor specifically for UV-B light that initiates photomorphogenic responses in plants. UV-B exposure causes rapid conversion of UVR8 from dimer to monomer, accumulation in the nucleus, and interaction with CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1), which functions with UVR8 in UV-B responses. Studies in yeast and with purified UVR8 implicate several tryptophan amino acids in UV-B photoreception. However, their roles in UV-B responses in plants, and the functional significance of all 14 UVR8 tryptophans, are not known. Here we report the functions of the UVR8 tryptophans in vivo. Three tryptophans in the β-propeller core are important in maintaining structural stability and function of UVR8. However, mutation of three other core tryptophans and four at the dimeric interface has no apparent effect on function in vivo. Mutation of three tryptophans implicated in UV-B photoreception, W233, W285, and W337, impairs photomorphogenic responses to different extents. W285 is essential for UVR8 function in plants, whereas W233 is important but not essential for function, and W337 has a lesser role. Ala mutants of these tryptophans appear monomeric and constitutively bind COP1 in plants, but their responses indicate that monomer formation and COP1 binding are not sufficient for UVR8 function.
Collapse
|
12
|
|
13
|
Abstract
Ultraviolet-B radiation (UV-B) is a key environmental signal that is specifically perceived by plants to promote UV acclimation and survival in sunlight. Whereas the plant photoreceptors for visible light are rather well characterised, the UV-B photoreceptor UVR8 was only recently described at the molecular level. Here, we review the current understanding of the UVR8 photoreceptor-mediated pathway in the context of UV-B perception mechanism, early signalling components and physiological responses. We further outline the commonalities in UV-B and visible light signalling as well as highlight differences between these pathways.
Collapse
Affiliation(s)
- Marc Heijde
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland
| | | |
Collapse
|
14
|
Abstract
Phytochrome-like proteins have been recently identified in prokaryotes but their features and functions are not clear. We cloned a gene encoding the phytochrome-like protein (XoBphP) in a pathogenic bacteria, Xanthomonas oryzae pv. oryzae (Xoo) and investigated characteristics of the protein using a recombinant XoBphP. The N-terminal region of XoBphP containing the PAS/GAF/PHY domains is highly similar to most bacteriophytochromes, but Cys4, corresponding to Cys24 of DrBphP, isn't involved in chromophore attachment. Recombinant XoBphP could bind a bilin molecule and a differential spectrum from Pr/Pfr shows that XoBphP has similar characteristics of known bacteriophytochromes with shifted absorption maxima of 683 and 757 nm for the Pr and Pfr forms. Unlike other bacteriophytochromes, XoBphP has no histidine kinase domain at C-terminus. The domain was predicted from amino-acid 279 to 342 with less significance than the required threshold. This result suggests that XoBphP probably has different signal transduction mechanisms for its intracellular function.
Collapse
Affiliation(s)
- Man-Ho Cho
- Graduate School of Biotechnology, Kyung Hee University, Yongin 446-701, Korea
| | | | | | | |
Collapse
|
15
|
Liu B, Liu H, Zhong D, Lin C. Searching for a photocycle of the cryptochrome photoreceptors. Curr Opin Plant Biol 2010; 13:578-86. [PMID: 20943427 PMCID: PMC2972227 DOI: 10.1016/j.pbi.2010.09.005] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 09/09/2010] [Accepted: 09/13/2010] [Indexed: 05/20/2023]
Abstract
The initial photochemistry of plant cryptochromes has been extensively investigated in recent years. It is hypothesized that cryptochrome photoexcitation involves a Trp-triad-dependent photoreduction. According to this hypothesis, cryptochromes in the resting state contain oxidized FAD; light triggers a sequential electron transfer from three tryptophan residues to reduce FAD to a neutral semiquinone (FADH*); FADH* is the presumed signaling state and it is re-oxidized to complete the photocycle. However, this photoreduction hypothesis is currently under debate. An alternative model argues that the initial photochemistry of cryptochromes involves a photolyase-like cyclic electron shuttle without a bona fide redox reaction mediated by the Trp-triad residues, leading to conformational changes, signal propagation, and physiological responses.
Collapse
Affiliation(s)
- Bin Liu
- Department of Molecular, Cell & Developmental Biology, University of California, Los Angeles, CA 90095, USA
| | | | | | | |
Collapse
|
16
|
Abstract
Signaling photoreceptors use the information contained in the absorption of a photon to modulate biological activity in plants and a wide range of organisms. The fundamental-and as yet imperfectly answered-question is, how is this achieved at the molecular level? We adopt the perspective of biophysicists interested in light-dependent signal transduction in nature and the three-dimensional structures that underpin signaling. Six classes of photoreceptors are known: light-oxygen-voltage (LOV) sensors, xanthopsins, phytochromes, blue-light sensors using flavin adenine dinucleotide (BLUF), cryptochromes, and rhodopsins. All are water-soluble proteins except rhodopsins, which are integral membrane proteins; all are based on a modular architecture except cryptochromes and rhodopsins; and each displays a distinct, light-dependent chemical process based on the photochemistry of their nonprotein chromophore, such as isomerization about a double bond (xanthopsins, phytochromes, and rhodopsins), formation or rupture of a covalent bond (LOV sensors), or electron transfer (BLUF sensors and cryptochromes).
Collapse
Affiliation(s)
- Andreas Möglich
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637, USA.
| | | | | | | |
Collapse
|