The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform
Donald A. Bryant - One of the best experts on this subject based on the ideXlab platform.
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Characterization of cyanobacterial allophycocyanins absorbing Far-Red Light
Photosynthesis Research, 2020Co-Authors: Nathan Soulier, Tatiana N. Laremore, Donald A. BryantAbstract:Phycobiliproteins (PBPs) are pigment proteins that comprise phycobilisomes (PBS), major Light-harvesting antenna complexes of cyanobacteria and Red algae. PBS core substructures are made up of allophycocyanins (APs), a subfamily of PBPs. Five paralogous AP subunits are encoded by the Far-Red Light Photoacclimation (FarLiP) gene cluster, which is transcriptionally activated in cells grown in Far-Red Light (FRL; λ = 700 to 800 nm). FarLiP gene expression enables some terrestrial cyanobacteria to remodel their PBS and photosystems and perform oxygenic photosynthesis in Far-Red Light (FRL). Paralogous AP genes encoding a putative, FRL-absorbing AP (FRL-AP) are also found in an operon associated with improved low-Light growth (LL;
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characterization of cyanobacterial allophycocyanins absorbing Far Red Light
Photosynthesis Research, 2020Co-Authors: Nathan Soulier, Tatiana N. Laremore, Donald A. BryantAbstract:Phycobiliproteins (PBPs) are pigment proteins that comprise phycobilisomes (PBS), major Light-harvesting antenna complexes of cyanobacteria and Red algae. PBS core substructures are made up of allophycocyanins (APs), a subfamily of PBPs. Five paralogous AP subunits are encoded by the Far-Red Light Photoacclimation (FarLiP) gene cluster, which is transcriptionally activated in cells grown in Far-Red Light (FRL; λ = 700 to 800 nm). FarLiP gene expression enables some terrestrial cyanobacteria to remodel their PBS and photosystems and perform oxygenic photosynthesis in Far-Red Light (FRL). Paralogous AP genes encoding a putative, FRL-absorbing AP (FRL-AP) are also found in an operon associated with improved low-Light growth (LL; < 50 μmol photons m–2 s–1) in some thermophilic Synechococcus spp., a phenomenon termed low-Light photoacclimation (LoLiP). In this study, apc genes from FarLiP and LoLiP gene clusters were heterologously expressed individually and in combinations in Escherichia coli. The resulting novel FRL-APs were characterized and identified as major contributors to the FRL absorbance observed in whole cells after FarLiP and potentially LoLiP. Post-translational modifications of native FRL-APs from FarLiP cyanobacterium, Leptolyngbya sp. strain JSC-1, were analyzed by mass spectrometry. The PBP complexes made in two FarLiP organisms were compaRed, revealing strain-specific diversity in the FarLiP responses of cyanobacteria. Through analyses of native and recombinant proteins, we improved our understanding of how different cyanobacterial strains utilize specialized APs to acclimate to FRL and LL. We discuss some insights into structural changes that may allow these APs to absorb longer Light wavelengths than their visible-Light-absorbing paralogs.
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Far Red Light allophycocyanin subunits play a role in chlorophyll d accumulation in Far Red Light
Photosynthesis Research, 2020Co-Authors: Nathan Soulier, Tatiana N. Laremore, Donald A. Bryant, Gaozhong Shen, Gavin M Turner, Ming Yang HoAbstract:Some terrestrial cyanobacteria acclimate to and utilize Far-Red Light (FRL; λ = 700–800 nm) for oxygenic photosynthesis, a process known as Far-Red Light photoacclimation (FarLiP). A conserved, 20-gene FarLiP cluster encodes core subunits of Photosystem I (PSI) and Photosystem II (PSII), five phycobiliprotein subunits of FRL-bicylindrical cores, and enzymes for synthesis of chlorophyll (Chl) f and possibly Chl d. Deletion mutants for each of the five apc genes of the FarLiP cluster were constructed in Synechococcus sp. PCC 7335, and all had similar phenotypes. When the mutants were grown in white (WL) or Red (RL) Light, the cells closely resembled the wild-type (WT) strain grown under the same conditions. However, the WT and mutant strains were very different when grown under FRL. Mutants grown in FRL were unable to assemble FRL-bicylindrical cores, were essentially devoid of FRL-specific phycobiliproteins, but retained RL-type phycobilisomes and WL-PSII. The transcript levels for genes of the FarLiP cluster in the mutants were similar to those in WT. Surprisingly, the Chl d contents of the mutant strains were greatly Reduced (~ 60–99%) compaRed to WT and so were the levels of FRL-PSII. We infer that Chl d may be essential for the assembly of FRL-PSII, which does not accumulate to normal levels in the mutants. We further infer that the cysteine-rich subunits of FRL allophycocyanin may either directly participate in the synthesis of Chl d or that FRL bicylindrical cores stabilize FRL-PSII to prevent loss of Chl d.
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Far Red Light photoacclimation Farlip in synechococcus sp pcc 7335 ii characterization of phycobiliproteins produced during acclimation to Far Red Light
Photosynthesis Research, 2017Co-Authors: Ming Yang Ho, Donald A. Bryant, Gaozhong ShenAbstract:Phycobilisomes (PBS) are antenna complexes that harvest Light for photosystem (PS) I and PS II in cyanobacteria and some algae. A process known as Far-Red Light photoacclimation (FarLiP) occurs when some cyanobacteria are grown in Far-Red Light (FRL). They synthesize chlorophylls d and f and remodel PS I, PS II, and PBS using subunits paralogous to those produced in white Light. The FarLiP strain, Leptolyngbya sp. JSC-1, replaces hemidiscoidal PBS with pentacylindrical cores, which are produced when cells are grown in Red or white Light, with PBS with bicylindrical cores when cells are grown in FRL. This study shows that the PBS of another FarLiP strain, Synechococcus sp. PCC 7335, are not remodeled in cells grown in FRL. Instead, cells grown in FRL produce bicylindrical cores that uniquely contain the paralogous allophycocyanin subunits encoded in the FarLiP cluster, and these bicylindrical cores coexist with Red-Light-type PBS with tricylindrical cores. The bicylindrical cores have absorption maxima at 650 and 711 nm and a low-temperature fluorescence emission maximum at 730 nm. They contain ApcE2:ApcF:ApcD3:ApcD2:ApcD5:ApcB2 in the approximate ratio 2:2:4:6:12:22, and a structural model is proposed. Time course experiments showed that bicylindrical cores were detectable about 48 h after cells were transferRed from RL to FRL and that synthesis of Red-Light-type PBS continued throughout a 21-day growth period. When consideRed in comparison with results for other FarLiP cyanobacteria, the results here show that acclimation responses to FRL can differ considerably among FarLiP cyanobacteria.
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adaptive and acclimative responses of cyanobacteria to Far Red Light
Environmental Microbiology, 2015Co-Authors: Donald A. BryantAbstract:Summary Cyanobacteria use three major photosynthetic complexes, photosystem (PS) I, PS II and phycobilisomes, to harvest and convert sunLight into chemical energy. Until recently, it was generally thought that cyanobacteria only used Light between 400 nm and 700 nm to perform photosynthesis. However, the discovery of chlorophyll (Chl) d in Acaryochloris marina and Chl f in Halomicronema hongdechloris showed that some cyanobacteria could utilize Far-Red Light. The synthesis of Chl f (and Chl d) is part of an extensive acclimation process, Far-Red Light photoacclimation (FarLiP), which occurs in many cyanobacteria. Organisms performing FarLiP contain a conserved set of 17 genes encoding paralogous subunits of the three major photosynthetic complexes. Far-Red Light photoacclimation leads to substantial remodelling of the photosynthetic apparatus and other changes in cellular metabolism through extensive changes in transcription. Far-Red Light photoacclimation appears to be controlled by a Red/Far-Red photoreceptor, RfpA, as well as two response regulators (RfpB and RfpC), one of which is a DNA-binding protein. The remodelled photosynthetic complexes, including novel phycobiliproteins, absorb Light above 700 nm and enable cells to grow in Far-Red Light. A much simpler acclimation response, low-Light photoacclimation (LoLiP), occurs in some cyanobacteria that contain the apcD4-apcB3-isiX cluster, which allows cells to grow under low Light conditions.
Wilfried Weber - One of the best experts on this subject based on the ideXlab platform.
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control of gene expression using a Red and Far Red Light responsive bi stable toggle switch
Nature Protocols, 2014Co-Authors: Konrad Muller, Matias D Zurbriggen, Wilfried WeberAbstract:Control of gene expression using a Red- and Far-Red Light–responsive bi-stable toggle switch
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Control of gene expression using a Red- and Far-Red Light–responsive bi-stable toggle switch
Nature Protocols, 2014Co-Authors: Konrad Muller, Matias D Zurbriggen, Wilfried WeberAbstract:Control of gene expression using a Red- and Far-Red Light–responsive bi-stable toggle switch
Seraphine V Wegner - One of the best experts on this subject based on the ideXlab platform.
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Red Far Red Light switchable cargo attachment and release in bacteria driven microswimmers
Advanced Healthcare Materials, 2020Co-Authors: Oya Ilke Senturk, Oliver Schauer, Fei Chen, Victor Sourjik, Seraphine V WegnerAbstract:: In bacteria-driven microswimmers, i.e., bacteriabots, artificial cargos are attached to flagellated chemotactic bacteria for active delivery with potential applications in biomedical technology. Controlling when and where bacteria bind and release their cargo is a critical step for bacteriabot fabrication and efficient cargo delivery/deposition at the target site. Toward this goal, photoregulating the cargo integration and release in bacteriabots using Red and Far-Red Light, which are noninvasive stimuli with good tissue penetration and provide high spatiotemporal control, is proposed. In the bacteriabot design, the surfaces of E. coli and microsized model cargo particles with the proteins PhyB and PIF6, which bind to each other under Red Light and dissociate from each other under Far-Red Light are functionalized. Consequently, the engineeRed bacteria adhere and transport the model cargo under Red Light and release it on-demand upon Far-Red Light illumination due to the photoswitchable PhyB-PIF6 protein interaction. Overall, the proof-of-concept for Red/Far-Red Light switchable bacteriabots, which opens new possibilities in the photoregulation in biohybrid systems for bioengineering, targeted drug delivery, and lab-on-a-chip devices, is demonstrated.
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Red/Far‐Red Light Switchable Cargo Attachment and Release in Bacteria‐Driven Microswimmers
Advanced Healthcare Materials, 2019Co-Authors: Oya Ilke Senturk, Oliver Schauer, Fei Chen, Victor Sourjik, Seraphine V WegnerAbstract:: In bacteria-driven microswimmers, i.e., bacteriabots, artificial cargos are attached to flagellated chemotactic bacteria for active delivery with potential applications in biomedical technology. Controlling when and where bacteria bind and release their cargo is a critical step for bacteriabot fabrication and efficient cargo delivery/deposition at the target site. Toward this goal, photoregulating the cargo integration and release in bacteriabots using Red and Far-Red Light, which are noninvasive stimuli with good tissue penetration and provide high spatiotemporal control, is proposed. In the bacteriabot design, the surfaces of E. coli and microsized model cargo particles with the proteins PhyB and PIF6, which bind to each other under Red Light and dissociate from each other under Far-Red Light are functionalized. Consequently, the engineeRed bacteria adhere and transport the model cargo under Red Light and release it on-demand upon Far-Red Light illumination due to the photoswitchable PhyB-PIF6 protein interaction. Overall, the proof-of-concept for Red/Far-Red Light switchable bacteriabots, which opens new possibilities in the photoregulation in biohybrid systems for bioengineering, targeted drug delivery, and lab-on-a-chip devices, is demonstrated.
Konrad Muller - One of the best experts on this subject based on the ideXlab platform.
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control of gene expression using a Red and Far Red Light responsive bi stable toggle switch
Nature Protocols, 2014Co-Authors: Konrad Muller, Matias D Zurbriggen, Wilfried WeberAbstract:Control of gene expression using a Red- and Far-Red Light–responsive bi-stable toggle switch
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Control of gene expression using a Red- and Far-Red Light–responsive bi-stable toggle switch
Nature Protocols, 2014Co-Authors: Konrad Muller, Matias D Zurbriggen, Wilfried WeberAbstract:Control of gene expression using a Red- and Far-Red Light–responsive bi-stable toggle switch
Ming Yang Ho - One of the best experts on this subject based on the ideXlab platform.
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Far Red Light allophycocyanin subunits play a role in chlorophyll d accumulation in Far Red Light
Photosynthesis Research, 2020Co-Authors: Nathan Soulier, Tatiana N. Laremore, Donald A. Bryant, Gaozhong Shen, Gavin M Turner, Ming Yang HoAbstract:Some terrestrial cyanobacteria acclimate to and utilize Far-Red Light (FRL; λ = 700–800 nm) for oxygenic photosynthesis, a process known as Far-Red Light photoacclimation (FarLiP). A conserved, 20-gene FarLiP cluster encodes core subunits of Photosystem I (PSI) and Photosystem II (PSII), five phycobiliprotein subunits of FRL-bicylindrical cores, and enzymes for synthesis of chlorophyll (Chl) f and possibly Chl d. Deletion mutants for each of the five apc genes of the FarLiP cluster were constructed in Synechococcus sp. PCC 7335, and all had similar phenotypes. When the mutants were grown in white (WL) or Red (RL) Light, the cells closely resembled the wild-type (WT) strain grown under the same conditions. However, the WT and mutant strains were very different when grown under FRL. Mutants grown in FRL were unable to assemble FRL-bicylindrical cores, were essentially devoid of FRL-specific phycobiliproteins, but retained RL-type phycobilisomes and WL-PSII. The transcript levels for genes of the FarLiP cluster in the mutants were similar to those in WT. Surprisingly, the Chl d contents of the mutant strains were greatly Reduced (~ 60–99%) compaRed to WT and so were the levels of FRL-PSII. We infer that Chl d may be essential for the assembly of FRL-PSII, which does not accumulate to normal levels in the mutants. We further infer that the cysteine-rich subunits of FRL allophycocyanin may either directly participate in the synthesis of Chl d or that FRL bicylindrical cores stabilize FRL-PSII to prevent loss of Chl d.
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Far Red Light photoacclimation Farlip in synechococcus sp pcc 7335 ii characterization of phycobiliproteins produced during acclimation to Far Red Light
Photosynthesis Research, 2017Co-Authors: Ming Yang Ho, Donald A. Bryant, Gaozhong ShenAbstract:Phycobilisomes (PBS) are antenna complexes that harvest Light for photosystem (PS) I and PS II in cyanobacteria and some algae. A process known as Far-Red Light photoacclimation (FarLiP) occurs when some cyanobacteria are grown in Far-Red Light (FRL). They synthesize chlorophylls d and f and remodel PS I, PS II, and PBS using subunits paralogous to those produced in white Light. The FarLiP strain, Leptolyngbya sp. JSC-1, replaces hemidiscoidal PBS with pentacylindrical cores, which are produced when cells are grown in Red or white Light, with PBS with bicylindrical cores when cells are grown in FRL. This study shows that the PBS of another FarLiP strain, Synechococcus sp. PCC 7335, are not remodeled in cells grown in FRL. Instead, cells grown in FRL produce bicylindrical cores that uniquely contain the paralogous allophycocyanin subunits encoded in the FarLiP cluster, and these bicylindrical cores coexist with Red-Light-type PBS with tricylindrical cores. The bicylindrical cores have absorption maxima at 650 and 711 nm and a low-temperature fluorescence emission maximum at 730 nm. They contain ApcE2:ApcF:ApcD3:ApcD2:ApcD5:ApcB2 in the approximate ratio 2:2:4:6:12:22, and a structural model is proposed. Time course experiments showed that bicylindrical cores were detectable about 48 h after cells were transferRed from RL to FRL and that synthesis of Red-Light-type PBS continued throughout a 21-day growth period. When consideRed in comparison with results for other FarLiP cyanobacteria, the results here show that acclimation responses to FRL can differ considerably among FarLiP cyanobacteria.
