DynAppACry · Understanding signaling in photoreceptors involved in the regulation of bacterial photosynthesis genes using serial crystallography and time-resolved spectroscopy.
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2020-09-01 → 2022-10-18
- EU contribution
- €184,708
- Participants
- 1
- Scheme
- MSCA-IF
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Results in brief
Understanding signaling in photoreceptors involved in the regulation of bacterial photosynthesis genes using serial crystallography and time-resolved spectroscopy.
Living systems are fundamentally dependent on the ability of proteins to respond to external stimuli. This response is characterized by time dependent changes in structure that occur on multiple time scales, from subpicosecond to seconds. These signal-transduction events are far from being fully understood in all photoreceptor classes. The aim of the project is to measure the real-time structural evolution during photoreceptor-mediated signal transduction, a fundamental cellular process that enables diverse organisms to adapt to changing environmental light conditions and regulate important processes including vision, circadian rhythms and photomovement. Using state-of-the-art time-resolved structural biology techniques, we have monitored the dynamic behaviour of a blue-light photoreceptor. The acquired knowledge may help in the engineering of photoreceptors that will enhance the optogenetics toolbox. It should be mentioned that optogenetics have a great potential in contributing to improved treatments for many diseases (e.g., Alzheimer, Parkinson’s, stroke) and therefore research in that direction may have in the long term a great impact in the society.
Data: CORDIS, © European Union
Project objective
Photosynthetic organisms need to sense environmental light effectively in order to regulate cellular processes. AppA (Activation of Photopigment and PUC A protein) and CryB (cryptochrome B) are two flavin (FAD) containing photoreceptors found in the facultatively photosynthetic bacterium Rhodobacter sphaeroides and depending on the oxygen levels can regulate the expression of photosynthetic genes by light. Photoexcitation of AppA and CryB is accompanied by changes on their conformation and their affinity to partner binding proteins to initiate signaling transduction processes. The mechanisms by which AppA and CryB regulate downstream signaling events is not known. Thus there is substantial interest in capturing the conformational landscape that lead to the signaling state and in understanding how absorption of light by the flavin is coupled to these conformational changes. The aim of the project is to provide atomic level characterization of the photoactivation mechanism of AppA and structural information on the photocycle of CryB. To achieve our objectives, we will use a combination of biochemical methods, ultrafast transient absorption spectroscopy, QM/MM (hybrid quantum mechanics/molecular mechanisms) calculations and time-resolved structural methods. The latter include TR-serial crystallography (SX) at synchrotrons (SSX) and X-ray free electron lasers (SFX) and TR-solution scattering (small-angle, SAXS and wide-angle X-ray scattering, WAXS). Ultimately, this project will provide a molecular movie of the AppA that features the structural changes occurring upon blue-light illumination and significant information on the photocycle of CryB. The proposed research lies on the implementation of new instrumentation and novel approaches to advance our knowledge on how photoreceptors function in order to engineer novel systems that use light as a tool to achieve noninvasive control of biological processes with high spatiotemporal resolution.
Original text from CORDIS.
Participants
- COMMISSARIAT A L ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES · ParisCoordinatorFrance
Links
Data: CORDIS, © European Union