The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform
Alex R Jones - One of the best experts on this subject based on the ideXlab platform.
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Native mass spectrometry reveals the conformational diversity of the UVR8 Photoreceptor
Proceedings of the National Academy of Sciences of the United States of America, 2019Co-Authors: Ines Cortes Eusebio Camacho, Bruno Bellina, Linus O Johannissen, Alina Theisen, L. Aranzazú Díaz-ramos, John M. Christie, Gareth I. Jenkins, Perdita E. Barran, Alex R JonesAbstract:UVR8 is a plant Photoreceptor Protein that regulates photomorphogenic and protective responses to UV light. The inactive, homodimeric state absorbs UV-B light, resulting in dissociation into monomers, which are considered to be the active state and comprise a β-propeller core domain and intrinsically disordered N- and C-terminal tails. The C terminus is required for functional binding to signaling partner COP1. To date, however, structural studies have only been conducted with the core domain where the terminal tails have been truncated. Here, we report structural investigations of full-length UVR8 using native ion mobility mass spectrometry adapted for photoactivation. We show that, while truncated UVR8 photoconverts from a single conformation of dimers to a single monomer conformation, the full-length Protein exists in numerous conformational families. The full-length dimer adopts both a compact state and an extended state where the C terminus is primed for activation. In the monomer the extended C terminus destabilizes the core domain to produce highly extended yet stable conformations, which we propose are the fully active states that bind COP1. Our results reveal the conformational diversity of full-length UVR8. We also demonstrate the potential power of native mass spectrometry to probe functionally important structural dynamics of Photoreceptor Proteins throughout nature.
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Native Mass Spectrometry Reveals the Conformational Diversity of the UVR8 Photoreceptor
bioRxiv, 2018Co-Authors: Ines Cortes Eusebio Camacho, Bruno Bellina, Linus O Johannissen, Alina Theisen, L. Aranzazú Díaz-ramos, John M. Christie, Gareth I. Jenkins, Perdita E. Barran, Alex R JonesAbstract:UVR8 is a plant Photoreceptor Protein that regulates photomorphogenic and protective responses to UV light. The inactive, homodimeric state absorbs UV-B light resulting in dissociation into monomers, which are considered to be the active state and comprise a β-propeller core domain and intrinsically disordered N- and C-terminal tails. The C-terminus is required for functional binding to signalling partner COP1. To date, however, structural studies have only been conducted with the core domain where the terminal tails have been truncated. Here, we report structural investigations of full-length UVR8 using native ion mobility mass spectrometry adapted for photo-activation. We show that, whilst truncated UVR8 photoconverts from a single conformation of dimers to a single monomer conformation, the full-length Protein exist in numerous conformational families. The full-length dimer adopts both a compact state and an extended state where the C-terminus is primed for activation. In the monomer the extended C-terminus destabilises the core domain to produce highly extended yet stable conformations, which we propose are the fully active states that bind COP1. Our results reveal the conformational diversity of full-length UVR8. We also demonstrate the potential power of native mass spectrometry to probe functionally important structural dynamics of Photoreceptor Proteins throughout nature.
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The photochemical mechanism of a B12-dependent Photoreceptor Protein.
Nature communications, 2015Co-Authors: Roger J Kutta, Juan Manuel Ortiz-Guerrero, Montserrat ElÃÂas-Arnanz, Perdita Barran, Sowmya Padmanabhan, Samantha J. O. Hardman, Bruno Bellina, Linus O Johannissen, Nigel S Scrutton, Hanan L Messiha, Alex R JonesAbstract:The coenzyme B12-dependent Photoreceptor Protein, CarH, is a bacterial transcriptional regulator that controls the biosynthesis of carotenoids in response to light. On binding of coenzyme B12 the monomeric apoProtein forms tetramers in the dark, which bind operator DNA thus blocking transcription. Under illumination the CarH tetramer dissociates, weakening its affinity for DNA and allowing transcription. The mechanism by which this occurs is unknown. Here we describe the photochemistry in CarH that ultimately triggers tetramer dissociation; it proceeds via a cob(III)alamin intermediate, which then forms a stable adduct with the Protein. This pathway is without precedent and our data suggest it is independent of the radical chemistry common to both coenzyme B12 enzymology and its known photochemistry. It provides a mechanistic foundation for the emerging field of B12 photobiology and will serve to inform the development of a new class of optogenetic tool for the control of gene expression.
Klaus Schulten - One of the best experts on this subject based on the ideXlab platform.
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Decrypting Cryptochrome: Revealing the Molecular Identity of the Photoactivation Reaction
Journal of the American Chemical Society, 2012Co-Authors: Ilia A. Solov’yov, Tatiana Domratcheva, Abdul Rehaman Moughal Shahi, Klaus SchultenAbstract:Migrating birds fly thousands of miles or more, often without visual cues and in treacherous winds, yet keep direction. They employ for this purpose, apparently as a powerful navigational tool, the Photoreceptor Protein cryptochrome to sense the geomagnetic field. The unique biological function of cryptochrome supposedly arises from a photoactivation reaction involving radical pair formation through electron transfer. Radical pairs, indeed, can act as a magnetic compass; however, the cryptochrome photoreaction pathway is not fully resolved yet. To reveal this pathway and underlying photochemical mechanisms, we carried out a combination of quantum chemical calculations and molecular dynamics simulations on plant (Arabidopsis thaliana) cryptochrome. The results demonstrate that after photoexcitation a radical pair forms, becomes stabilized through proton transfer, and decays back to the Protein’s resting state on time scales allowing the Protein, in principle, to act as a radical pair-based magnetic sensor....
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Decrypting cryptochrome: Revealing the molecular identity of the photoactivation reaction
Journal of the American Chemical Society, 2012Co-Authors: Ilia A. Solov'yov, Abdul Rehaman Moughal Shahi, Tatiana Domratcheva, Klaus SchultenAbstract:Migrating birds fly thousands of miles or more, often without visual cues and in treacherous winds, yet keep direction. They employ for this purpose, apparently as a powerful navigational tool, the Photoreceptor Protein cryptochrome to sense the geomagnetic field. The unique biological function of cryptochrome supposedly arises from a photoactivation reaction involving radical pair formation through electron transfer. Radical pairs, indeed, can act as a magnetic compass; however, the cryptochrome photoreaction pathway is not fully resolved yet. To reveal this pathway and underlying photochemical mechanisms, we carried out a combination of quantum chemical calculations and molecular dynamics simulations on plant ( Arabidopsis thaliana ) cryptochrome. The results demonstrate that after photoexcitation a radical pair forms, becomes stabilized through proton transfer, and decays back to the Protein's resting state on time scales allowing the Protein, in principle, to act as a radical pair-based magnetic sensor. We briefly relate our findings on A. thaliana cryptochrome to photoreaction pathways in animal cryptochromes.
Dorothy Trump - One of the best experts on this subject based on the ideXlab platform.
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retinoschisin the x linked retinoschisis Protein is a secreted Photoreceptor Protein and is expressed and released by weri rb1 cells
Human Molecular Genetics, 2000Co-Authors: Celene Grayson, Silvia N M Reid, Juliet A Ellis, Adam Rutherford, Jane C Sowden, John R W Yates, Debora B Farber, Dorothy TrumpAbstract:X-linked retinoschisis is characterized by microcystic-like changes of the macular region and schisis within the inner retinal layers, leading to visual deterioration in males. Many missense and Protein-truncating mutations of the causative gene RS1 have now been identified and are thought to be inactivating. RS1 encodes a 224 amino acid Protein, retinoschisin, which contains a discoidin domain but is of unknown function. We have generated a polyclonal antibody against a peptide from a unique region within retinoschisin, which detects a Protein of similar to 28 kDa in retinal samples reduced with dithiothreitol, but multimers sized >40 kDa under non-reducing conditions. A screen of human tissues with this antibody reveals retinoschisin to be retina specific and the antibody detects a Protein of similar size in bovine and murine retinae. We investigated the expression pattern in the retina of both RSI mRNA (using in situ hybridization with riboprobes) and retinoschisin (using immunohistochemistry), The antisense riboprobe detected RSI mRNA only in the Photoreceptor layer but the Protein product of the gene was present both in the Photoreceptors and within the inner portions of the retina. Furthermore, differentiated retinoblastoma cells (Weri-Rb1 cells) were found to express RSI mRNA and to release retinoschisin, These results suggest that retinoschisin is released by Photoreceptors and has functions within the inner retinal layers. Thus, X-linked retinoschisis is caused by abnormalities in a putative secreted Photoreceptor Protein and is the first example of a secreted Photoreceptor Protein associated with a retinal dystrophy.
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Retinoschisin, the X-linked retinoschisis Protein, is a secreted Photoreceptor Protein, and is expressed and released by Weri–Rb1 cells
Human Molecular Genetics, 2000Co-Authors: Celene Grayson, Silvia N M Reid, Juliet A Ellis, Adam Rutherford, Jane C Sowden, John R W Yates, Debora B Farber, Dorothy TrumpAbstract:X-linked retinoschisis is characterized by microcystic-like changes of the macular region and schisis within the inner retinal layers, leading to visual deterioration in males. Many missense and Protein-truncating mutations of the causative gene RS1 have now been identified and are thought to be inactivating. RS1 encodes a 224 amino acid Protein, retinoschisin, which contains a discoidin domain but is of unknown function. We have generated a polyclonal antibody against a peptide from a unique region within retinoschisin, which detects a Protein of similar to 28 kDa in retinal samples reduced with dithiothreitol, but multimers sized >40 kDa under non-reducing conditions. A screen of human tissues with this antibody reveals retinoschisin to be retina specific and the antibody detects a Protein of similar size in bovine and murine retinae. We investigated the expression pattern in the retina of both RSI mRNA (using in situ hybridization with riboprobes) and retinoschisin (using immunohistochemistry), The antisense riboprobe detected RSI mRNA only in the Photoreceptor layer but the Protein product of the gene was present both in the Photoreceptors and within the inner portions of the retina. Furthermore, differentiated retinoblastoma cells (Weri-Rb1 cells) were found to express RSI mRNA and to release retinoschisin, These results suggest that retinoschisin is released by Photoreceptors and has functions within the inner retinal layers. Thus, X-linked retinoschisis is caused by abnormalities in a putative secreted Photoreceptor Protein and is the first example of a secreted Photoreceptor Protein associated with a retinal dystrophy.
Linus O Johannissen - One of the best experts on this subject based on the ideXlab platform.
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Native mass spectrometry reveals the conformational diversity of the UVR8 Photoreceptor
Proceedings of the National Academy of Sciences of the United States of America, 2019Co-Authors: Ines Cortes Eusebio Camacho, Bruno Bellina, Linus O Johannissen, Alina Theisen, L. Aranzazú Díaz-ramos, John M. Christie, Gareth I. Jenkins, Perdita E. Barran, Alex R JonesAbstract:UVR8 is a plant Photoreceptor Protein that regulates photomorphogenic and protective responses to UV light. The inactive, homodimeric state absorbs UV-B light, resulting in dissociation into monomers, which are considered to be the active state and comprise a β-propeller core domain and intrinsically disordered N- and C-terminal tails. The C terminus is required for functional binding to signaling partner COP1. To date, however, structural studies have only been conducted with the core domain where the terminal tails have been truncated. Here, we report structural investigations of full-length UVR8 using native ion mobility mass spectrometry adapted for photoactivation. We show that, while truncated UVR8 photoconverts from a single conformation of dimers to a single monomer conformation, the full-length Protein exists in numerous conformational families. The full-length dimer adopts both a compact state and an extended state where the C terminus is primed for activation. In the monomer the extended C terminus destabilizes the core domain to produce highly extended yet stable conformations, which we propose are the fully active states that bind COP1. Our results reveal the conformational diversity of full-length UVR8. We also demonstrate the potential power of native mass spectrometry to probe functionally important structural dynamics of Photoreceptor Proteins throughout nature.
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Native Mass Spectrometry Reveals the Conformational Diversity of the UVR8 Photoreceptor
bioRxiv, 2018Co-Authors: Ines Cortes Eusebio Camacho, Bruno Bellina, Linus O Johannissen, Alina Theisen, L. Aranzazú Díaz-ramos, John M. Christie, Gareth I. Jenkins, Perdita E. Barran, Alex R JonesAbstract:UVR8 is a plant Photoreceptor Protein that regulates photomorphogenic and protective responses to UV light. The inactive, homodimeric state absorbs UV-B light resulting in dissociation into monomers, which are considered to be the active state and comprise a β-propeller core domain and intrinsically disordered N- and C-terminal tails. The C-terminus is required for functional binding to signalling partner COP1. To date, however, structural studies have only been conducted with the core domain where the terminal tails have been truncated. Here, we report structural investigations of full-length UVR8 using native ion mobility mass spectrometry adapted for photo-activation. We show that, whilst truncated UVR8 photoconverts from a single conformation of dimers to a single monomer conformation, the full-length Protein exist in numerous conformational families. The full-length dimer adopts both a compact state and an extended state where the C-terminus is primed for activation. In the monomer the extended C-terminus destabilises the core domain to produce highly extended yet stable conformations, which we propose are the fully active states that bind COP1. Our results reveal the conformational diversity of full-length UVR8. We also demonstrate the potential power of native mass spectrometry to probe functionally important structural dynamics of Photoreceptor Proteins throughout nature.
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The photochemical mechanism of a B12-dependent Photoreceptor Protein.
Nature communications, 2015Co-Authors: Roger J Kutta, Juan Manuel Ortiz-Guerrero, Montserrat ElÃÂas-Arnanz, Perdita Barran, Sowmya Padmanabhan, Samantha J. O. Hardman, Bruno Bellina, Linus O Johannissen, Nigel S Scrutton, Hanan L Messiha, Alex R JonesAbstract:The coenzyme B12-dependent Photoreceptor Protein, CarH, is a bacterial transcriptional regulator that controls the biosynthesis of carotenoids in response to light. On binding of coenzyme B12 the monomeric apoProtein forms tetramers in the dark, which bind operator DNA thus blocking transcription. Under illumination the CarH tetramer dissociates, weakening its affinity for DNA and allowing transcription. The mechanism by which this occurs is unknown. Here we describe the photochemistry in CarH that ultimately triggers tetramer dissociation; it proceeds via a cob(III)alamin intermediate, which then forms a stable adduct with the Protein. This pathway is without precedent and our data suggest it is independent of the radical chemistry common to both coenzyme B12 enzymology and its known photochemistry. It provides a mechanistic foundation for the emerging field of B12 photobiology and will serve to inform the development of a new class of optogenetic tool for the control of gene expression.
Bruno Bellina - One of the best experts on this subject based on the ideXlab platform.
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Native mass spectrometry reveals the conformational diversity of the UVR8 Photoreceptor
Proceedings of the National Academy of Sciences of the United States of America, 2019Co-Authors: Ines Cortes Eusebio Camacho, Bruno Bellina, Linus O Johannissen, Alina Theisen, L. Aranzazú Díaz-ramos, John M. Christie, Gareth I. Jenkins, Perdita E. Barran, Alex R JonesAbstract:UVR8 is a plant Photoreceptor Protein that regulates photomorphogenic and protective responses to UV light. The inactive, homodimeric state absorbs UV-B light, resulting in dissociation into monomers, which are considered to be the active state and comprise a β-propeller core domain and intrinsically disordered N- and C-terminal tails. The C terminus is required for functional binding to signaling partner COP1. To date, however, structural studies have only been conducted with the core domain where the terminal tails have been truncated. Here, we report structural investigations of full-length UVR8 using native ion mobility mass spectrometry adapted for photoactivation. We show that, while truncated UVR8 photoconverts from a single conformation of dimers to a single monomer conformation, the full-length Protein exists in numerous conformational families. The full-length dimer adopts both a compact state and an extended state where the C terminus is primed for activation. In the monomer the extended C terminus destabilizes the core domain to produce highly extended yet stable conformations, which we propose are the fully active states that bind COP1. Our results reveal the conformational diversity of full-length UVR8. We also demonstrate the potential power of native mass spectrometry to probe functionally important structural dynamics of Photoreceptor Proteins throughout nature.
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Native Mass Spectrometry Reveals the Conformational Diversity of the UVR8 Photoreceptor
bioRxiv, 2018Co-Authors: Ines Cortes Eusebio Camacho, Bruno Bellina, Linus O Johannissen, Alina Theisen, L. Aranzazú Díaz-ramos, John M. Christie, Gareth I. Jenkins, Perdita E. Barran, Alex R JonesAbstract:UVR8 is a plant Photoreceptor Protein that regulates photomorphogenic and protective responses to UV light. The inactive, homodimeric state absorbs UV-B light resulting in dissociation into monomers, which are considered to be the active state and comprise a β-propeller core domain and intrinsically disordered N- and C-terminal tails. The C-terminus is required for functional binding to signalling partner COP1. To date, however, structural studies have only been conducted with the core domain where the terminal tails have been truncated. Here, we report structural investigations of full-length UVR8 using native ion mobility mass spectrometry adapted for photo-activation. We show that, whilst truncated UVR8 photoconverts from a single conformation of dimers to a single monomer conformation, the full-length Protein exist in numerous conformational families. The full-length dimer adopts both a compact state and an extended state where the C-terminus is primed for activation. In the monomer the extended C-terminus destabilises the core domain to produce highly extended yet stable conformations, which we propose are the fully active states that bind COP1. Our results reveal the conformational diversity of full-length UVR8. We also demonstrate the potential power of native mass spectrometry to probe functionally important structural dynamics of Photoreceptor Proteins throughout nature.
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The photochemical mechanism of a B12-dependent Photoreceptor Protein.
Nature communications, 2015Co-Authors: Roger J Kutta, Juan Manuel Ortiz-Guerrero, Montserrat ElÃÂas-Arnanz, Perdita Barran, Sowmya Padmanabhan, Samantha J. O. Hardman, Bruno Bellina, Linus O Johannissen, Nigel S Scrutton, Hanan L Messiha, Alex R JonesAbstract:The coenzyme B12-dependent Photoreceptor Protein, CarH, is a bacterial transcriptional regulator that controls the biosynthesis of carotenoids in response to light. On binding of coenzyme B12 the monomeric apoProtein forms tetramers in the dark, which bind operator DNA thus blocking transcription. Under illumination the CarH tetramer dissociates, weakening its affinity for DNA and allowing transcription. The mechanism by which this occurs is unknown. Here we describe the photochemistry in CarH that ultimately triggers tetramer dissociation; it proceeds via a cob(III)alamin intermediate, which then forms a stable adduct with the Protein. This pathway is without precedent and our data suggest it is independent of the radical chemistry common to both coenzyme B12 enzymology and its known photochemistry. It provides a mechanistic foundation for the emerging field of B12 photobiology and will serve to inform the development of a new class of optogenetic tool for the control of gene expression.