Long-Distance Protonation-Conformation Coupling in Phytochrome Species
Phytochromes are biological red/far-red light sensors found in many organisms. The connection between photoconversion and the cellular output signal involves light-mediated global structural changes in the interaction between the photosensory module (PAS-GAF-PHY, PGP) and the C-terminal transmitter...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-12-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/27/23/8395 |
| _version_ | 1797462656684130304 |
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| author | Maryam Sadeghi Jens Balke Timm Rafaluk-Mohr Ulrike Alexiev |
| author_facet | Maryam Sadeghi Jens Balke Timm Rafaluk-Mohr Ulrike Alexiev |
| author_sort | Maryam Sadeghi |
| collection | DOAJ |
| description | Phytochromes are biological red/far-red light sensors found in many organisms. The connection between photoconversion and the cellular output signal involves light-mediated global structural changes in the interaction between the photosensory module (PAS-GAF-PHY, PGP) and the C-terminal transmitter (output) module. We recently showed a direct correlation of chromophore deprotonation with pH-dependent conformational changes in the various domains of the prototypical phytochrome Cph1 PGP. These results suggested that the transient phycocyanobilin (PCB) chromophore deprotonation is closely associated with a higher protein mobility both in proximal and distal protein sites, implying a causal relationship that might be important for the global large-scale protein rearrangements. Here, we investigate the prototypical biliverdin (BV)-binding phytochrome Agp1. The structural changes at various positions in Agp1 PGP were investigated as a function of pH using picosecond time-resolved fluorescence anisotropy and site-directed fluorescence labeling of cysteine variants of Agp1 PGP. We show that the direct correlation of chromophore deprotonation with pH-dependent conformational changes does not occur in Agp1. Together with the absence of long-range effects between the PHY domain and chromophore p<i>K</i><sub>a</sub>, in contrast to the findings in Cph1, our results imply phytochrome species-specific correlations between transient chromophore deprotonation and intramolecular signal transduction. |
| first_indexed | 2024-03-09T17:39:43Z |
| format | Article |
| id | doaj.art-7e0a051e34a747de87a66404a1484d78 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-09T17:39:43Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-7e0a051e34a747de87a66404a1484d782023-11-24T11:41:31ZengMDPI AGMolecules1420-30492022-12-012723839510.3390/molecules27238395Long-Distance Protonation-Conformation Coupling in Phytochrome SpeciesMaryam Sadeghi0Jens Balke1Timm Rafaluk-Mohr2Ulrike Alexiev3Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, GermanyDepartment of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, GermanyDepartment of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, GermanyDepartment of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, GermanyPhytochromes are biological red/far-red light sensors found in many organisms. The connection between photoconversion and the cellular output signal involves light-mediated global structural changes in the interaction between the photosensory module (PAS-GAF-PHY, PGP) and the C-terminal transmitter (output) module. We recently showed a direct correlation of chromophore deprotonation with pH-dependent conformational changes in the various domains of the prototypical phytochrome Cph1 PGP. These results suggested that the transient phycocyanobilin (PCB) chromophore deprotonation is closely associated with a higher protein mobility both in proximal and distal protein sites, implying a causal relationship that might be important for the global large-scale protein rearrangements. Here, we investigate the prototypical biliverdin (BV)-binding phytochrome Agp1. The structural changes at various positions in Agp1 PGP were investigated as a function of pH using picosecond time-resolved fluorescence anisotropy and site-directed fluorescence labeling of cysteine variants of Agp1 PGP. We show that the direct correlation of chromophore deprotonation with pH-dependent conformational changes does not occur in Agp1. Together with the absence of long-range effects between the PHY domain and chromophore p<i>K</i><sub>a</sub>, in contrast to the findings in Cph1, our results imply phytochrome species-specific correlations between transient chromophore deprotonation and intramolecular signal transduction.https://www.mdpi.com/1420-3049/27/23/8395phytochromeAgp1Cph1biliverdinchromophore protonationconformational coupling |
| spellingShingle | Maryam Sadeghi Jens Balke Timm Rafaluk-Mohr Ulrike Alexiev Long-Distance Protonation-Conformation Coupling in Phytochrome Species Molecules phytochrome Agp1 Cph1 biliverdin chromophore protonation conformational coupling |
| title | Long-Distance Protonation-Conformation Coupling in Phytochrome Species |
| title_full | Long-Distance Protonation-Conformation Coupling in Phytochrome Species |
| title_fullStr | Long-Distance Protonation-Conformation Coupling in Phytochrome Species |
| title_full_unstemmed | Long-Distance Protonation-Conformation Coupling in Phytochrome Species |
| title_short | Long-Distance Protonation-Conformation Coupling in Phytochrome Species |
| title_sort | long distance protonation conformation coupling in phytochrome species |
| topic | phytochrome Agp1 Cph1 biliverdin chromophore protonation conformational coupling |
| url | https://www.mdpi.com/1420-3049/27/23/8395 |
| work_keys_str_mv | AT maryamsadeghi longdistanceprotonationconformationcouplinginphytochromespecies AT jensbalke longdistanceprotonationconformationcouplinginphytochromespecies AT timmrafalukmohr longdistanceprotonationconformationcouplinginphytochromespecies AT ulrikealexiev longdistanceprotonationconformationcouplinginphytochromespecies |