Qr: switch:"LOV domains"
Showing 1 - 25 of 1143 results
1.
Gene expression in synthetic biology: Going with the light.
Abstract:
Inducible expression of endogenous and foreign genes has been a pivotal driving force behind a lot many seminal breakthroughs in biotechnology. Synthetic biology, a very promising field, largely relies on transgene expression platforms which facilitate convenient and conditional regulation. Optogenetic approaches that exploit light to steer biological events, e.g., gene expression, with excellent spatiotemporal control, are often more precise compared to chemical induction. Light being an omnipresent environmental stimulus, serves as the ideal cue, and enables high spatiotemporal accuracy with respect to gene expression. In this review, we focus on different elements relevant to light-inducible gene expression - light-responsive promoters, light-regulated transcription factors, and photocaged inducers. Using light as a binary input function, we explore the essence of logic gates towards the development of gene expression circuits - thereby understanding the entanglement between optogenetics and synthetic biology. We primarily focus on prokaryotes, but also draw comparisons with analogous eukaryotic gene expression systems.
2.
Long-range mutual activation establishes Rho and Rac polarity during cell migration.
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De Belly, H
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Gallén, AF
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Strickland, E
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Estrada, DC
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Godinez, DS
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Neiva, E
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Zager, PJ
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Nagy, TL
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Burkhardt, JK
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Turlier, H
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Weiner, OD
Abstract:
In migrating cells, the GTPase Rac organizes a protrusive front, whereas Rho organizes a contractile back. How these GTPases are positioned at opposite poles remains unclear. We leverage optogenetics, mechanical perturbations, and mathematical modelling to reveal a surprising mechanochemical long-range mutual activation between front and back polarity programmes that complements their well-known local mutual inhibition. Rac-based protrusions elevate membrane tension, stimulating an mTORC2-dependent activation of Rho at the opposite side of the cell. Conversely, Rho-mediated contractility induces cortical-flow-based regulation of phosphoinositide signalling that triggers Rac activation distally. We develop a minimal mechanochemical model to explain how long-range facilitation, together with local inhibition, enables robust Rho and Rac partitioning. Our findings demonstrate how the actin cortex and plasma membrane interact as an integrated mechanochemical system for long-range Rac-Rho patterning. This circuit is required for efficient polarity and migration in primary human T cells and is conserved in epithelial cells, highlighting the generality of this mechanism.
3.
The regulatory logic of a dose-dependent developmental fate decision.
Abstract:
In canonical developmental patterning, the embryo is exposed to gradients of signaling activators that elicit different cellular responses depending on the activator's concentration. Recent optogenetic studies of terminal ERK signaling downstream of Torso receptor tyrosine kinase in the early Drosophila embryo reveal that even a brief, 5-minute ERK stimulus is sufficient to rescue the development of larval "tail" structures. Here, we reveal components of the molecular network that defines this sensitive developmental fate response. We find that low ERK doses produce sustained Abdominal-B ( Abd-B ) expression comparable to that of wild-type embryos. Abd-B expression is adjacent to, but non-overlapping with, two other transcriptional repressors: the ERK effector Tailless (Tll) and the gap gene Giant (Gt). Analysis of gene expression patterns in response to optogenetic perturbations suggests that the Tll-dependent repression of gt constitutes the sensitive ERK-responsive step: even low tll expression leads to potent repression of gt in nearby regions, with Abd-B expression arising in a stripe between the tll and gt domains. Our work suggests that the spectrum of phenotypes produced through optogenetic manipulation can be used to define how robust patterning can arise from low doses of inductive signals.
4.
Inducible CRISPR/Cas systems in precision oncology: Current applications and future perspectives.
Abstract:
Inducible CRISPR/Cas systems enable spatiotemporal control of genome editing in response to chemical, optical, biological, or physical stimuli. By restricting genome-editing activity to defined conditions, these systems may reduce off-target exposure and immune burden while improving tumor-selective control, making them attractive tools for precision oncology.
5.
Advanced strategies to enhance the safety, persistence, and efficacy of CAR-T cells in solid tumors.
Abstract:
Chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of hematologic cancers but encounters challenges, including severe treatment-related toxicities, a highly suppressive tumor microenvironment (TME), limited long-term persistence, and poor trafficking/infiltration into solid tumors. This review outlines recent genetic engineering strategies to address these issues and enhance the safety, durability, and efficacy of CAR-T cell therapy. To reduce cytokine release syndrome and neurotoxicity, methods such as affinity-tuned and humanized scFvs, hinge/TM optimization, and ITAM calibration have been developed, along with programmable "switch-off" and "switch-on" systems that include suicide genes, antibody-bridging switches, and optogenetic or hypoxia-gated circuits. TME remodeling strategies utilize nanomaterials for targeted cytokine delivery, cell-surface "backpack" systems, and engineered oncolytic viruses that release cytokines or checkpoint-blocking agents. For durability and resistance to exhaustion, precise genome engineering techniques, including CRISPR-based editing and multiplexed shRNA platforms, were employed to target inhibitory receptors and exhaustion-driving transcriptional programs. Additionally, chemokine-receptor engineering and local biomaterial-based delivery systems are discussed as ways to enhance CAR-T trafficking and intratumoral persistence. These innovations collectively point toward integrated, patient-specific CAR-T platforms that incorporate safety controls, metabolic and transcriptional flexibility, and enhanced trafficking through the TME to broaden clinical use.
6.
Engineering an Optogenetic pH-Modulator in Bacteria.
Abstract:
Cells in many naturally occurring organisms routinely cooperate to control their extracellular pH in a dynamic and reversible manner, but this capability has been underexplored in synthetic biology. Here, we sought to engineer a microbial system that switches between two states -high and low extracellular pH- with minimal human intervention. We accomplished this by combining: (1) a genetic circuit that produces recombinant urease under the control of a light-inducible promoter; (2) a degradation tag on urease to accelerate the high-to-low pH transition; and (3) optimization of several environmental factors, including media composition, replenishment rate, and light exposure patterns. The system raises the pH when urease is produced and hydrolyzes urea in the media to produce ammonia; it lowers the pH as a byproduct of the cell's native metabolism when urease production ceases. We demonstrate that the optimized system cycles continuously for up to 14 days with minimal performance loss. Overall, our system demonstrates synthetic pH control in an engineered living system and highlights challenges and potential solutions for using such systems outside of the context of typical laboratory manipulation.
7.
Optimized optogenetic anti-CRISPR for endogenous gene regulation in Drosophila.
Abstract:
Optogenetic tools-light-responsive proteins that enable to regulate specific cellular activities, study biological processes, and develop new therapies-are attractive approaches for achieving endogenous gene regulation under minimally invasive conditions. Our first step in constructing an optogenetic system to regulate endogenous Drosophila gene expression was to identify inhibitory anti-CRISPR (Acr) proteins that block CRISPRa-mediated activation. Next, we inserted optogenetic protein LOV2 into these Acrs, tested for their ability to optogenetically modulate endogenous gene upregulation through the CRISPRa-based flySAM system in Drosophila, and found that the photoswitchability of these prototypes was weak. We therefore engineered an optimized Acr-LOV2 fusion module by refining length of intrinsically disordered and ordered regions (IDR and IOR) of Acrs. This optimization yielded a variant with significantly greater sensitivity to blue-light-induced endogenous gene upregulation than the prototypes, leading to new in vivo discoveries. In addition, this work provides insights for in vivo functional characterization of the IDR and the IOR of these small-sized proteins. Together, these findings establish a robust optogenetic toolbox for precise, light-controlled endogenous gene regulation in Drosophila.
8.
Illuminating cancer therapy: The translational path of optogenetics.
Abstract:
Tumor recurrence, metastasis, and therapeutic resistance remain major challenges in oncology, driving the need for advanced therapeutic strategies with improved precision and controllability. Optogenetics, which enables light-mediated regulation of cellular functions, has emerged as a promising modality for cancer therapy by offering unparalleled spatiotemporal precision. This capability allows dynamic control of intracellular signaling and transgene expression, enabling selective targeting of malignant cells while minimizing damage to surrounding tissues. However, clinical translation is hindered by key challenges, including inefficient in vivo delivery of optogenetic components, limited tissue penetration of activating light, and suboptimal performance of existing tools. Addressing these barriers requires a convergence of molecular engineering and materials science, wherein advanced biomaterials play a critical role in enabling gene delivery and overcoming tissue-penetration limitations in complex tumor environments. In this review, we provide a comprehensive oriented overview of optogenetics in oncology. We first analyze the molecular mechanisms and engineering principles of representative optogenetic tools, with a focus on LOV- and CRY2-based systems. We then highlight recent advances in biomaterial-assisted optogene delivery and light delivery strategies, emphasizing their material-dependent mechanisms that enable precise spatiotemporal control in vivo. Furthermore, we summarize emerging preclinical applications in cancer immunotherapy, gene regulation, and intracellular signaling control. Finally, we discuss key challenges in biosafety, kinetic optimization, and clinical scalability, and outline future directions that integrate optogenetics with functional materials and intelligent design to realize clinically viable platforms. This review aims to provide a framework for the development of clinically viable optogenetic platforms for next-generation cancer therapy.
9.
Optical Control of Actin Network Assembly on the Supported Lipid Bilayer.
Abstract:
The spatiotemporal dynamics and density of actin networks are key determinants of actin cytoskeleton-mediated cellular functions. In vitro reconstitution systems have been widely used to study actin cytoskeletal dynamics; however, many existing approaches offer limited flexibility in controlling the geometry, thickness, and density of the assembled actin networks. Here, we present an in vitro optogenetic protocol that enables precise control of actin network assembly on supported lipid bilayers using an improved light-induced dimer (iLID)-SspB-based light-inducible dimerization system. In this system, His-mEGFP-iLID is anchored to a Ni-NTA-containing lipid bilayer, while SspB-mScarlet-I-VCA, a nucleation-promoting factor fused with SspB, together with other actin cytoskeletal proteins, is supplied in bulk solution. Upon blue light illumination, SspB-mScarlet-I-VCA is recruited to the membrane in a spatially and temporally defined manner, inducing localized actin polymerization. By tuning illumination patterns and duration, actin networks with defined density, thickness, and geometry can be generated, and polymerization can be rapidly halted by stopping illumination. This protocol provides a versatile platform for reconstructing actin networks with controlled spatial organization and density, enabling quantitative analysis of density-dependent interactions between actin networks and actin-binding proteins. Key features • Actin networks with varying densities and arbitrary shapes can be formed on the same supported lipid bilayer by controlling blue light illumination through the objective lens. • Actin polymerization can be stopped simply by turning off blue light illumination, enabling the formation of actin networks with defined thicknesses. • This protocol requires purified actin and actin-binding proteins.
10.
Phage-assisted evolution of allosteric protein switches.
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Southern, NT
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von Bachmann, A
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Hovsepyan, A
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Griebl, M
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Wolf, B
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Lemmen, N
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Kroell, AS
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Westermann, S
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Mathony, J
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Niopek, D
Abstract:
Allostery, the transmission of locally induced conformational changes to distant functional sites, is a key mechanism for protein regulation. Artificial allosteric effectors enable remote manipulation of cell function; their engineering, however, is hampered by our limited understanding of allosteric residue networks. Here, we introduce a phage-assisted evolution platform for in vivo optimization of allosteric proteins. It applies opposing selection pressures to enhance activity and switchability of phage-encoded effectors and leverages retron-based recombineering to broadly explore fitness landscapes, introducing point mutations, insertions, and deletions. Applying this framework to the transcription factor AraC yielded near-binary optogenetic switches, with light-controlled activity spanning ~1000-fold dynamic range. Long-read sequencing across selection cycles enabled high-resolution tracking of evolving variant pools, revealing adaptive trajectories and context-dependent residue interactions. Mechanistically, we find that linker mutations promoting α-helix extension at the sensor-effector junction enhance conformational coupling between LOV2 and AraC. These variants emerge consistently across independently evolved pools, underscoring their functional relevance. Together, we develop a framework for the directed evolution of programmable allosteric switches in vivo. By coupling dynamic selection with deep mutational scanning and temporal sequencing, it enables both functional optimization and mechanistic insight into allosteric networks.
11.
Optogenetic Tools for Spatiotemporal Interrogation of Cytoskeletal Dynamics.
Abstract:
The cytoskeleton is a dynamic intracellular network that governs cell shape, migration, division, and mechanotransduction. Precise spatiotemporal control of cytoskeletal regulation is essential for understanding how these processes are coordinated in physiology and disease, yet conventional pharmacological and genetic approaches often lack sufficient resolution or reversibility. Optogenetic technologies provide a powerful alternative by enabling light-controlled, noninvasive manipulation of cytoskeletal regulators with high temporal precision and subcellular specificity. This review summarizes recent advances in genetically encoded optogenetic tools for interrogating cytoskeletal dynamics. We discuss core design strategies, including allosteric regulation, light-induced oligomerization, heterodimerization, and dissociation, and highlight representative applications targeting actin filaments, microtubules, and upstream signaling pathways such as Rho family GTPases. We conclude by outlining current limitations and emerging directions, including improved tissue penetration, reduced phototoxicity, and multiplexed optical control, which are expected to further expand the utility of optogenetics in cytoskeleton research.
12.
Local RhoA activation induces anillin-independent septin recruitment in interphase cells.
Abstract:
The regulation of the actin cytoskeleton is key to controlling cell shape and structure. While the Rho GTPase RhoA is well known to regulate the actomyosin cytoskeleton, its function in controlling the septin cytoskeleton remains unclear. As RhoA interactions can vary in both time and space, they can be challenging to discern from traditional bulk biochemical assays. Here, we use multiple optogenetic tools to spatially and temporally increase myosin localization, stimulate contractile force, and activate RhoA to investigate how RhoA and its downstream effector myosin impact the septin cytoskeleton. We find that neither local accumulation of myosin nor increased activity of myosin is sufficient to alter septin architecture. Local activation of RhoA, however, results in a local increase in septin accumulation. Importantly, this septin increase is independent of the scaffolding protein anillin, which can directly bind both septin and RhoA. Together, these data expand the potential role of septins in mediating RhoA signaling by stimulating the remodeling of the septin cytoskeleton.
13.
OptoTAT reveals microtubule acetylation as a rapid trigger for GEF-H1-mediated cell migration.
Abstract:
Microtubule acetylation is implicated in regulating cell motility, yet its physiological role in directional migration and the underlying molecular mechanisms have remained unclear. This knowledge gap has persisted primarily due to a lack of tools capable of rapidly manipulating microtubule acetylation in actively migrating cells. To overcome this limitation and elucidate the causal relationship between microtubule acetylation and cell migration, we developed a novel optogenetic actuator, optoTAT, which enables precise induction of microtubule acetylation within minutes in live cells. Implementing optoTAT in migration assays, we observed striking and rapid responses at both molecular and cellular levels. First, microtubule acetylation triggers release of the RhoA activator GEF-H1 from sequestration on microtubules. This release subsequently enhances actomyosin contractility and drives focal adhesion maturation. These subcellular processes collectively promote sustained directional migration. Our findings position GEF-H1 as a critical molecular responder to microtubule acetylation, enabling a dynamic crosstalk between the actin and microtubule cytoskeletal networks in the coordination of cellular motility.
14.
Enhancing the performance of Magnets photosensors.
Abstract:
Photosensory protein domains, derived from nature, are foundational for optogenetic protein engineering. Tailoring their properties enables their full exploitation for optogenetic regulation in basic research and applied bioengineering applications. Here, we present a simple, yet powerful strategy based on random mutagenesis coupled to high-throughput screening that allowed altering the most fundamental properties of the widely used nMag/pMag photodimerization system: its light sensitivity and activation. Variants were characterized in vivo in bacteria by flow cytometry and during the entire growth curve by spectrofluorometry. We identify mutations that either increase or decrease the light sensitivity at sub-saturating light intensities, while also improving the light activation and dark-to-light fold change. Notably, light sensitivity and activation levels could be changed independently. In addition, we demonstrated that the shapes of the dose-response curves can be finely tuned. This broadens the applicability of the Magnets photosensors for optogenetic regulation strategies.
15.
Actin-membrane interface stress regulates Arp2/3-branched actin density during lamellipodial protrusion.
Abstract:
Motile cells can sense and exert forces on the extracellular environment through dynamic actin networks. Increased stress against the polymerizing barbed ends of branched actin networks has been shown to lead to an increase in the density of these networks through a force feedback mechanism, though this phenomenon has not been explored through the examination of real-time responses of endogenous actin networks in cells. Here, we utilize mouse embryonic fibroblast CRISPR knock-in lines with labeled ARP2/3 complex to identify cellular and extracellular conditions that regulate branched actin density and enrichment at the leading edge of lamellipodial protrusions. A common theme shared among all branched actin density-increasing conditions is higher levels of interface stress between the plasma membrane and the barbed ends of the lamellipodial actin network. Among these conditions, we find that ARP2/3 is specifically required for robust spreading and protrusion in response to increased extracellular viscosity. Interestingly, time-lapse traction force microscopy of ARP2/3-dependent viscosity responses show significantly reduced changes in strain energy applied to the substrate when compared to spreading and motility through cell-matrix adhesion. In addition, we find that increased extracellular viscosity can bypass the need for extracellular matrix proteins to support lamellipodial protrusion driven by optogenetic Rac activation. Our studies provide strong support for in vitro models of branched actin force feedback responses and further characterize an essential role for branched actin in mediating dramatic cell shape changes in response to increased extracellular viscosity.
16.
Zebrafish as a Model for Cardiovascular Disease Using Nanotechnology and Emerging Optogenetic Tools.
Abstract:
Recent advances in experimental model systems have improved our ability to study cardiovascular development, function, and disease with high spatial and temporal resolution. The zebrafish (Danio rerio) has emerged as a powerful vertebrate model for cardiovascular research due to its transparency, genetic tractability, and conserved cardiac physiology, similar to humans. These features allow real-time in vivo imaging, the functional assessment of cardiac performance, and the tracking of signaling pathways that are fundamental in cardiovascular development and disease. Recent advances in nanotechnology and optogenetics have introduced complementary tools for probing and manipulating cardiovascular systems with high spatial and temporal precision. Nanoparticle-based platforms enable the tunable delivery of drugs, nucleic acids, and imaging agents, while optogenetic systems allow the light-mediated control of gene expression, signaling pathways, and cardiac electrophysiology. In this review, we summarize recent progress in the application of nanoparticle-based technologies and the emerging optogenetic tools in zebrafish cardiovascular research, including the optical control of cardiac signaling and electrophysiology. We briefly discuss emerging complementary efforts toward nanoparticle and optogenetic approaches, how to overcome key technical limitations, such as light penetration and gene delivery, and how to facilitate the development of fully optical platforms for cardiovascular disease modeling and drug screening.
17.
Light-directed evolution of dynamic, multi-state, and computational protein functionalities.
Abstract:
Evolving dynamic, multi-state, and computational protein functionalities is challenging because it requires selection pressure on all the states of a protein of interest (POI) and the transitions between them. To create a continuous directed evolution paradigm for such properties, we genetically engineered budding yeast for optogenetic input to switch a POI "on" and "off," which, in turn, controls a Cdk1 cyclin that is essential for one cell-cycle stage but detrimental for another. The method, "optovolution," generates dynamic selection pressure on POI cycling at the timescale of tens of minutes. We used it to evolve 19 new variants of the LOV transcription factor El222, including in vivo green-light-responsive variants allowing LOV color-multiplexing. Evolving the PhyB-Pif3 optogenetic system, we discovered that loss of YOR1 makes supplementing phycocyanobilin (PCB) unnecessary. Finally, we demonstrated the generality of the method by evolving a non-light-responsive AND gate (PEST-rtTA). Optovolution makes difficult-to-engineer protein functionalities continuously evolvable.
18.
Red/far-red light optogenetics: technological principles and biomedical applications.
Abstract:
As an interdisciplinary frontier integrating optical technologies and genetic principles, optogenetics enables precise spatiotemporal control of gene expression and neuronal activity via light-sensitive molecular assemblies, thereby driving transformative advancements in biomedical fields. Red/far-red light optogenetic tools, by virtue of the advantages of long wavelengths, have emerged as powerful platforms for deep-tissue manipulations for both basic researches and clinical applications. Although a number of in-depth studies on various red/far-red light optogenetic tools and their biomedical applications have been published, there has not yet been a comprehensive review that systematically summarizes the advancements of diverse researches on this type of optogenetics. This article systematically delineates the technology of red/far-red light optogenetics, focusing on the molecular mechanisms and biomedical applications of two core photoreceptor protein families: phytochromes and channelrhodopsins. Phytochromes distributed in plants, bacteria and fungi undergo reversible red/far-red light-driven conformational conversion, initiating downstream signaling cascades that support various optogenetic technologies. Channelrhodopsins, originally microalgal blue-light-gated cation channels, are engineered into red-shifted variants, enabling rapid and non-invasive red/far-red light-controlled neuronal excitability manipulation at precise spatiotemporal resolution. The representative case studies of applications of phytochromes-based optogenetic tools in gene editing, transcriptional regulation, light-gated drug delivery and deep tissue imaging and diagnosis; as well as applications of red-shifted channelrhodopsins-based optogenetic tools in spatiotemporally precise neuromodulation are discussed in detail. Moreover, the main technical challenges in the utilization of red/far-red light optogenetic tools are analyzed. With continuous advancements of wavelength-optimized actuators and closed-loop control architectures, red/far-red light optogenetic techniques are poised to drive multidisciplinary convergence, offering unprecedented tools for decoding cellular dynamics and accelerating therapeutic discoveries.
19.
Magneto-Photonic Gene Circuit for Minimally Invasive Control of Gene Expression in Mammalian Cells.
Abstract:
Precise control of gene expression is one of the fundamental goals of synthetic biology. Whether the objective is to modify endogenous cellular function or induce the expression of molecules for diagnostic and therapeutic purposes, gene regulation remains a key aspect of biological systems. Over time, advances in protein engineering and molecular biology have led to the creation of gene circuits capable of inducing the expression of specific proteins in response to external stimulus such as light. These optogenetic, or light-activated circuits hold significant potential for gene therapy as a tool for regulating the expression of therapeutic genes within cells. However, the applications of optogenetic systems can be limited by the lack of efficient ways to deliver light into cells or tissue. Our approach to address this challenge is to harness the power of bioluminescence to produce light directly inside cells using a luminescent enzyme. Combined with a photosensitive transcription factor, we report the development of a genetically encoded optogenetic circuit for the control of gene expression. Furthermore, we utilized a magneto-sensitive protein to engineer a split-protein version of this luminescent enzyme, where its reconstitution is driven by a 50 mT magnetic stimulus. Thus, resulting in a gene circuit activated by a combination of light and magnetic stimulus. We expect this work to advance the implementation of light-controlled systems without the need of external light sources, as well as serve as a basis for the development of future magneto-sensitive tools.
20.
The dynamic response of the bacterial flagellar motor to its direct intracellular input signal.
Abstract:
The bacterial flagellar motor drives bacterial swimming and chemotaxis by rotating helical flagellar filaments. When Escherichia coli navigates chemical gradients, the motor switches from counterclockwise (CCW) during forward swimming to clockwise (CW) during direction-changing tumbles. The motor responds indirectly to extracellular chemosensory input to membrane-bound chemoreceptors using an intervening intracellular signaling pathway. How the motor responds to its direct input signal-the diffusible messenger phosphorylated CheY (CheY-P)-remains poorly understood. Steady-state motor measurements have been modeled as an allosteric switch between CCW/CW states that depends on mean CheY-P levels. Allosteric models have suggested that as many as 20 CheY-P molecules can be bound to the motor when it switches rotational direction. But steady-state models cannot predict the sensitivity of the motor to dynamic changes in CheY-P that essentially modulate chemotactic behavior. We present an optogenetic reagent that precisely controls the direct dynamical input signal to the motor. We designed a "caged" molecule, Opto-CheY, that is transiently activated by photon absorption. We find that activation and binding of one to three additional CheY-P molecules is sufficient to switch the motor from the CCW to CW state. The sensitivity of the motor to small changes in CheY-P occupancy helps resolve a long-standing paradox about the high sensitivity of the chemotactic response to external sensory input. Optogenetic biochemistry by light-activated uncaging of signal molecules is a new strategy to dissect information-processing in the living cell.
21.
Advances in mechanistic understanding of light signal transduction derived from plant structural biology.
Abstract:
Light is a pivotal environmental signal regulating diverse plant developmental and physiological processes, including seed germination, hypocotyl elongation, phototropism, metabolite biosynthesis, stress resistance, temperature response, and circadian rhythms. Multiple signal transduction pathways of ultraviolet, blue light, and red/far-red light as well as related protein interaction networks in plants have been identified. Deciphering the mechanisms of light perception and signal transduction is of great significance to crop breeding and optogenetic manipulation. Structural biology has profoundly advanced the studies of light signal transduction by elucidating high-resolution three-dimensional (3D) structures of photoreceptors and their downstream signaling components. These studies uncover the molecular basis underlying perception and transduction of different light signals by plants. This review summarizes key structural findings of plant light signal transduction, highlighting the architectures and molecular functions of photoreceptors and associated signaling factors. We also outline the mechanisms underlying photoreceptor activation, inhibition, and regulatory interactions within light signaling networks and discuss the challenges in this field.
22.
ShineGAL4 drivers for tissue and cell-type specific optogenetics in Drosophila.
Abstract:
An optogenetic split-GAL4 system, ShineGAL4, allows genes to be manipulated with unprecedented spatiotemporal precision. Here, we convert a panel of 14 GAL4 drivers widely used in Drosophila research into their ShineGAL4 counterparts. Homology assisted CRISPR knock-in (HACK) is used to replace GAL4 with the GAL4 DNA binding domain fused to a Magnet photoswitch. We show that the resulting ShineGAL4 drivers enable gene expression to be rapidly induced by light specifically in fat body, muscles, enterocytes, oenocytes, Malpighian tubules, neurons, neuroblast lineages, glial subtypes or in all glia. We also develop an optogenetic cassette for photoactivation of GAL4 in 'silent' FLP-out clones. This panel of optogenetic tools will enable precise spatiotemporal control of gene expression in a wide range of different Drosophila tissues and cell-types.
23.
Single-cell characterization of bacterial optogenetic Cre recombinases.
Abstract:
Microbial optogenetic tools can regulate gene expression with spatial and temporal precision, offering excellent potential for single-cell resolution studies. However, bacterial optogenetic systems have primarily been deployed for population-level experiments. It is not always clear how these tools perform in single cells, where stochastic effects can be substantial. In this study, we focus on optogenetic Cre recombinase and compare the performance of three variants (OptoCre-REDMAP, OptoCre-Vvd, and PA-Cre) for their population-level and single-cell activity. We quantify recombination efficiency, expression variability, and activation dynamics using reporters which produce changes in fluorescence or antibiotic resistance following light-induced Cre activity. We find that optogenetic recombinase performance can be reporter-dependent. Further, single-cell analysis reveals highly heterogeneous activity, with substantial variation in the efficiency and timing of recombinase activity from cell to cell. These findings suggest important criteria for selecting optogenetic recombinases and indicate areas for optimization to improve single-cell capabilities of bacterial optogenetic tools.
24.
Optogenetic manipulation of estrogen receptor signaling to improve estrogen deficiency.
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Liu, J
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Xie, L
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Wang, J
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Chen, Q
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Zhu, M
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Zhang, L
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Xie, S
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Lu, B
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Chen, X
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Xu, Y
Abstract:
Estrogen receptor (ER)-mediated genomic actions are crucial for maintaining various physiological functions, and their dysfunction is associated with numerous human diseases. Traditional estrogen replacement therapy (ERT) is commonly used to manage estrogen deficiency-related conditions, such as vulvovaginal atrophy during menopause, but its systemic effects pose notable risks. This study introduces OptoER, an optogenetic tool engineered to precisely modulate ER-mediated genomic pathways through light-induced transcription regulation, offering spatial-temporal control over ER-dependent gene expression. Our in vitro studies demonstrate that OptoER significantly enhances ER-specific gene transcription and protein synthesis, leading to improved cell proliferation and migration. In a proof-of-principle study using ovariectomized (OVX) mice, OptoER demonstrated considerable therapeutic potential for vaginal atrophy, with observed improvement in epithelial thickness and keratinization. These findings suggest that OptoER provides a targeted therapeutic strategy for estrogen deficiency conditions, with significant implications for treating vaginal atrophy and promoting regenerative healing in estrogen-deprived tissues.
25.
Engineering microbial consortia for biosynthesis: Construction, regulation, and applications.
Abstract:
Synthetic microbial consortia (SMCs) represent a paradigm shift from monocultures to multi-strain systems that leverage ecological interactions for enhanced environmental adaptation and bioproduction. This review systematically sorts out engineering strategies for constructing stable SMCs, focusing on three core principles regarding host selection based on obligate mutualism (e.g., auxotrophs), pathway modularization to resolve metabolic conflicts, and dynamic regulation using tools like quorum sensing and optogenetics. We demonstrate the efficacy of SMCs in diverse applications including high-value compound synthesis and lignocellulosic biomass conversion through consolidated bioprocessing and inhibitor mitigation. SMCs enabling advanced functions in engineered living materials, environmental remediation, and biomedical innovation via division of labor are also described. Despite such progress, challenges in scalability and real-time control of SMCs under industrial conditions remain. We conclude that SMCs serve to bridge evolutionary ecology and biotechnology, offering robust solutions for sustainable biomanufacturing and beyond.