Pulsatile illumination for photobiology and optogenetics

Dietler, Julia; Stabel, Robert; Möglich, Andreas

doi:10.1016/bs.mie.2019.04.005

Cited by 7 publications

(3 citation statements)

References 46 publications

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“…Upon hundredfold dilution of the cultures in 20 mL LB/Kan medium, 200-µL aliquots were dispensed into 64 wells of clear-bottom, black-walled microtiter plates (MTP) (µClear, Greiner BioOne, Frickenhausen, Germany). The MTPs were sealed with a gas-permeable membrane (BF-410400-S, Corning, New York, USA) and illuminated from below with an 8 × 8 array of light-emitting diodes (LED) with a peak wavelength of (624 ± 8) nm for the red emission channel 35 , 64 . Light intensities were calibrated with a power meter (model 842-PE equipped with a 918D-UV-OD3 silicon detector, Newport, Darmstadt, Germany).…”

Section: Methodsmentioning

confidence: 99%

Leveraging the histidine kinase-phosphatase duality to sculpt two-component signaling

Meier,

Multamäki,

Ranzani

et al. 2024

Nat Commun

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Bacteria must constantly probe their environment for rapid adaptation, a crucial need most frequently served by two-component systems (TCS). As one component, sensor histidine kinases (SHK) control the phosphorylation of the second component, the response regulator (RR). Downstream responses hinge on RR phosphorylation and can be highly stringent, acute, and sensitive because SHKs commonly exert both kinase and phosphatase activity. With a bacteriophytochrome TCS as a paradigm, we here interrogate how this catalytic duality underlies signal responses. Derivative systems exhibit tenfold higher red-light sensitivity, owing to an altered kinase-phosphatase balance. Modifications of the linker intervening the SHK sensor and catalytic entities likewise tilt this balance and provide TCSs with inverted output that increases under red light. These TCSs expand synthetic biology and showcase how deliberate perturbations of the kinase-phosphatase duality unlock altered signal-response regimes. Arguably, these aspects equally pertain to the engineering and the natural evolution of TCSs.

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Section: Methodsmentioning

confidence: 99%

Leveraging the histidine kinase-phosphatase duality to sculpt two-component signaling

Meier,

Multamäki,

Ranzani

et al. 2024

Nat Commun

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“…Following 100-fold dilution in fresh LB/Kan medium, 200 μL of each of the cell suspension was dispensed into individual wells of 96-well clear-bottom, black-walled microtiter plates (μClear plates, Greiner BioOne, Frickenhausen, Germany). Plates were sealed with a gas-permeable film (BF-410400-S, Corning, New York, USA) and placed on top of a programmable matrix equipped with an 8 × 8 array of three-color LEDs at emission wavelengths of (463 ± 12) nm, (521 ± 14) nm, and (624 ± 8) nm. , To assess the influence of simultaneously applied or interleaved red/far-red light, a custom-made LED array configured with (660 ± 10) nm and (850 ± 21) nm LEDs was used instead . In either case, using an Arduino microcontroller, the illumination intensity and timing can be configured for each of 8 × 8 wells individually.…”

Section: Methodsmentioning

confidence: 99%

Optogenetic Control of Bacterial Expression by Red Light

et al. 2022

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In optogenetics, as in nature, sensory photoreceptors serve to control cellular processes by light. Bacteriophytochrome (BphP) photoreceptors sense red and farred light via a biliverdin chromophore and, in response, cycle between the spectroscopically, structurally, and functionally distinct Pr and Pfr states. BphPs commonly belong to two-component systems that control the phosphorylation of cognate response regulators and downstream gene expression through histidine kinase modules. We recently demonstrated that the paradigm BphP from Deinococcus radiodurans exclusively acts as a phosphatase but that its photosensory module can control the histidine kinase activity of homologous receptors. Here, we apply this insight to reprogram two widely used setups for bacterial gene expression from blue-light to red-light control. The resultant pREDusk and pREDawn systems allow gene expression to be regulated down and up, respectively, uniformly under red light by 100-fold or more. Both setups are realized as portable, single plasmids that encode all necessary components including the biliverdin-producing machinery. The triggering by red light affords high spatial resolution down to the single-cell level. As pREDusk and pREDawn respond sensitively to red light, they support multiplexing with optogenetic systems sensitive to other light colors. Owing to the superior tissue penetration of red light, the pREDawn system can be triggered at therapeutically safe light intensities through material layers, replicating the optical properties of the skin and skull. Given these advantages, pREDusk and pREDawn enable red-light-regulated expression for diverse use cases in bacteria.

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“…328 In a follow-up approach, Moglich and co-workers further developed their hardware tools, by generating a programmable switchboard that allows continuous or pulsed illumination with LEDs at several wavelengths. 329 In this manuscript, the authors also provide a detailed building plan and several fully automated protocols for pulsed or continuous illumination. Their setup was built using their former devices for blue light illumination, now including several applications of phytochromes.…”

Section: Website Platforms Modeling and Relatedmentioning

confidence: 99%

The Red Edge: Bilin-Binding Photoreceptors as Optogenetic Tools and Fluorescence Reporters

et al. 2021

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This review adds the bilin-binding phytochromes to the Chemical Reviews thematic issue “Optogenetics and Photopharmacology”. The work is structured into two parts. We first outline the photochemistry of the covalently bound tetrapyrrole chromophore and summarize relevant spectroscopic, kinetic, biochemical, and physiological properties of the different families of phytochromes. Based on this knowledge, we then describe the engineering of phytochromes to further improve these chromoproteins as photoswitches and review their employment in an ever-growing number of different optogenetic applications. Most applications rely on the light-controlled complex formation between the plant photoreceptor PhyB and phytochrome-interacting factors (PIFs) or C-terminal light-regulated domains with enzymatic functions present in many bacterial and algal phytochromes. Phytochrome-based optogenetic tools are currently implemented in bacteria, yeast, plants, and animals to achieve light control of a wide range of biological activities. These cover the regulation of gene expression, protein transport into cell organelles, and the recruitment of phytochrome- or PIF-tagged proteins to membranes and other cellular compartments. This compilation illustrates the intrinsic advantages of phytochromes compared to other photoreceptor classes, e.g., their bidirectional dual-wavelength control enabling instant ON and OFF regulation. In particular, the long wavelength range of absorption and fluorescence within the “transparent window” makes phytochromes attractive for complex applications requiring deep tissue penetration or dual-wavelength control in combination with blue and UV light-sensing photoreceptors. In addition to the wide variability of applications employing natural and engineered phytochromes, we also discuss recent progress in the development of bilin-based fluorescent proteins.

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Pulsatile illumination for photobiology and optogenetics

Cited by 7 publications

References 46 publications

Leveraging the histidine kinase-phosphatase duality to sculpt two-component signaling

Leveraging the histidine kinase-phosphatase duality to sculpt two-component signaling

Optogenetic Control of Bacterial Expression by Red Light

The Red Edge: Bilin-Binding Photoreceptors as Optogenetic Tools and Fluorescence Reporters

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