Qr: switch:"VVD"
Showing 26 - 50 of 258 results
26.
AlphaFold3-guided optimization of a photoactivatable endonuclease for top-down genome engineering.
Abstract:
Recent advances in protein structure prediction by artificial intelligence have enabled the rational design of engineered enzymes with enhanced activity and precise regulatory features. Here, we report the AlphaFold3-guided enhancement of MagMboI, a photoactivatable restriction enzyme designed for light-controlled top-down genome engineering. MagMboI is derived from the type II restriction enzyme MboI and functions through a split-protein strategy in which its N- and C-terminal fragments are fused to light-inducible dimerization modules. Upon exposure to blue light, these domains heterodimerize, restoring nuclease activity in a controlled manner. Using AlphaFold3, we modeled the structure of the MagMboI-DNA complex and gained structural insights into the interaction between MagMboI and its target DNA recognition sequence (5'-GATC-3') required for Mg2+-dependent DNA cleavage. Comparing neighboring split-site variants, we identified an alternative split that increases the MagMboI-DNA interface area and enhances complex stability relative to the original construct. This redesigned variant (designated MagMboI-plus) preserves α-helical integrity while strengthening protein-DNA contacts. Although MagMboI-plus, when introduced in Saccharomyces cerevisiae cells, exhibited slightly increased DNA-cleavage activity in vivo upon blue light activation, it was found to induce more pronounced genomic rearrangements compared to the original MagMboI construct. These findings demonstrate that AlphaFold3-based prediction can accelerate functional improvements in engineered enzymes, providing a strategy for developing light-controlled genome engineering tools.
27.
Photoswitchable intein for light control of covalent protein binding and cleavage.
Abstract:
Precise control of covalent protein binding and cleavage in mammalian cells is crucial for manipulating cellular processes but remains challenging due to dark background, poor stability, low efficiency, or requirement of unnatural amino acids in current optogenetic tools. We introduce a photoswitchable intein (PS Intein) engineered by allosterically modulating a small autocatalytic gp41-1 intein with tandem Vivid photoreceptor. PS Intein exhibits superior functionality and low background in cells compared to existing tools. PS Intein-based systems enable light-induced covalent binding, cleavage, and release of proteins for regulating gene expression and cell fate. The high responsiveness and ability to integrate multiple inputs allow for intersectional cell targeting using cancer- and tumor microenvironment-specific promoters. PS Intein tolerates various fusions and insertions, facilitating its application in diverse cellular contexts. This versatile technology offers efficient light-controlled protein manipulation, providing a powerful tool for adding functionalities to proteins and precisely controlling protein networks in living cells.
28.
Investigating morphogen and patterning dynamics with optogenetic control of morphogen production.
Abstract:
Morphogen gradients provide the patterning cues that instruct cell fate decisions during development. Here, we establish an optogenetic system for the precise spatiotemporal control in vitro of Sonic hedgehog (Shh) morphogen production. Using a tunable light-inducible gene expression system, we generate long-range Shh gradients that pattern mouse neural progenitors into spatially distinct domains, mimicking neural tube development. We investigate how biochemical features of Shh and Shh-interacting proteins affect patterning length scales. By measuring clearance rates, we determine that Shh has an extracellular half-life below 1.5 h, substantially shorter than downstream gene expression dynamics, indicating gradients are continually renewed during patterning. We provide evidence that progenitor identity acquisition and maintenance depend on both Shh concentration and exposure duration. Together, this approach provides a quantitative framework for investigating morphogen patterning, enabling reproducible control of morphogen dynamics to dissect the interplay between biochemical cues, gradient formation biophysics, and transcriptional programs underlying developmental patterning.
29.
Multimodal Key Anti-Oncolytic Therapeutics Are Effective In Cancer Treatment?
Abstract:
Oncolytic virus (OVs) therapy has emerged as a promising modality in cancer immunotherapy, attracting growing attention for its multifaceted mechanisms of tumor elimination. However, its efficacy as a monotherapy remains constrained by physiological barriers, limited delivery routes, and suboptimal immune activation. Phototherapy, an innovative and rapidly advancing cancer treatment technology, can mitigate these limitations when used in conjunction with OVs, enhancing viral delivery, amplifying tumor destruction, and boosting antitumor immune responses. This review provides the first comprehensive analysis of synergistic integration of OVs with both photodynamic therapy (PDT) and photothermal therapy (PTT). It also explores their applications in optical imaging-guided diagnosis and optogenetically controlled delivery. Furthermore, it discusses emerging strategies involving biomimetic virus or viroid-based vectors in conjunction with phototherapy, and delves into the immunomodulatory mechanisms of this combinatorial approach. While promising in preclinical models, these combined strategies are still largely in early-stage research. Challenges such as limited light penetration, delivery efficiency, and safety concerns remain to be addressed for clinical translation. Consequently, the integration of OV therapy and phototherapy represents a compelling strategy in cancer treatment, offering significant promise for advancing precision oncology and next-generation immunotherapies.
30.
Optogenetic enzymes: A deep dive into design and impact.
Abstract:
Optogenetically regulated enzymes offer unprecedented spatiotemporal control over protein activity, intermolecular interactions, and intracellular signaling. Many design strategies have been developed for their fabrication based on the principles of intrinsic allostery, oligomerization or 'split' status, intracellular compartmentalization, and steric hindrance. In addition to employing photosensory domains as part of the traditional optogenetic toolset, the specificity of effector domains has also been leveraged for endogenous applications. Here, we discuss the dynamics of light activation while providing a bird's eye view of the crafting approaches, targets, and impact of optogenetic enzymes in orchestrating cellular functions, as well as the bottlenecks and an outlook into the future.
31.
Opto-CRISPR: new prospects for gene editing and regulation.
Abstract:
Clustered regularly interspaced short palindromic repeats (CRISPR) technology represents a landmark advance in the field of gene editing. However, conventional CRISPR/Cas systems are limited by inadequate temporal and spatial control. In recent years, the development of optically controlled CRISPR (Opto-CRISPR) technology has offered a novel solution to this issue. As a combination of optogenetics and the CRISPR technology, the Opto-CRISPR technology enables dynamic space-time-specific gene editing and regulation in cells and organisms. In this review, we concisely introduce the basic principles of Opto-CRISPR, summarize its operational mechanisms, and discuss its applications and recent advances across various research fields. In addition, this review analyzes the limitations of Opto-CRISPR, aiming to provide a reference for the development of this emerging field.
32.
Advances in optogenetically engineered bacteria in disease diagnosis and therapy.
Abstract:
Optogenetic bacterial technology is a cutting-edge approach that combines optogenetics and microbiology, offering a transformative strategy for disease diagnosis and therapy. This synergistic merger transcends the limitations of traditional diagnostic and therapeutic methodologies in a highly controllable, accurate and non-invasive manner. In this review, we introduce the optogenetic systems developed for microbial engineering and summarize fundamental in vitro design principles underlying light-responsive signal transduction in bacteria, as well as the optogenetic regulation of bacterial behaviors. We address multidisciplinary solutions to the challenges in the in vivo applications of light-controlled bacteria, such as limited light excitation, suboptimal delivery and targeting, and difficulties in signal tracking and management. Furthermore, we comprehensively highlight the recent progress in photo-responsive bacteria for disease diagnosis and therapy, and discuss how to accelerate translational applications.
33.
Shaping viral immunotherapy towards cancer-targeted immunological cell death.
Abstract:
Oncolytic viruses (OVs) have the ability to efficiently enter, replicate within, and destroy cancer cells. This capacity to selectively target cancer cells while inducing long-term anti-tumor immune responses, makes OVs a promising tool for next-generation cancer therapy. Immunogenic cell death (ICD) induced by OVs initiates the cancer-immunity cycle (CIC) and plays a critical role in activating and reshaping anti-cancer immunity. Genetic engineering, including arming OVs with cancer cell-specific binders and immunostimulatory molecules, further enhances immune responses at various stages of the CIC, improving the specificity and safety of virotherapy.The aim of this study is to update current knowledge in immunotherapy using OVs and to highlight the remarkable plasticity of viruses in shaping the tumor immune microenvironment, which may facilitate anti-cancer treatment through various approaches.
34.
zHORSE as an optogenetic zebrafish strain for precise spatiotemporal control over gene expression during development.
Abstract:
Proper vertebrate development is dependent on tightly regulated expression of genes at the correct time and place. To identify normal but also dysregulated development leading to disease, in vivo interrogation methods with high spatiotemporal resolution are required. Recently, optogenetic tools to manipulate gene expression with spatiotemporal control have emerged, but their in vivo applications remain challenging. Here, we present a transgenic zebrafish strain termed zebrafish for heat-shock-inducible optogenetic recombinase expression (zHORSE) with inducible expression of a light-activatable Cre recombinase. We demonstrate that zHORSE endows robust spatiotemporal control over gene expression down to single-cell level at different developmental stages. We apply zHORSE for lineage tracing to identify caudal fin progenitors and for targeted expression of oncogenes. Surprisingly, one oncogene, EWS::FLI1, can cause ectopic fin formation when induced in permissive environments. zHORSE is compatible with existing loxP zebrafish effector strains and will enable many applications ranging from dissecting and precisely manipulating development to clonal cancer modeling.
35.
Optogenetics to biomolecular phase separation in neurodegenerative diseases.
Abstract:
Neurodegenerative diseases involve toxic protein aggregation. Recent evidence suggests that biomolecular phase separation, a process in which proteins and nucleic acids form dynamic, liquid-like condensates, plays a key role in this aggregation. Optogenetics, originally developed to control neuronal activity with light, has emerged as a powerful tool to investigate phase separation in living systems. This is achieved by fusing disease-associated proteins to light-sensitive oligomerization domains, enabling researchers to induce or reverse condensate formation with precise spatial and temporal control. This review highlights how optogenetic systems such as OptoDroplet are being used to dissect the mechanisms of neurodegenerative disease. We examine how these tools have been applied in models of neurodegenerative diseases, such as amyotrophic lateral sclerosis, Alzheimer's, Parkinson's, and Huntington's disease. These studies implicate small oligomeric aggregates as key drivers of toxicity and highlight new opportunities for therapeutic screening. Finally, we discuss advances in light-controlled dissolution of condensates and future directions for applying optogenetics to combat neurodegeneration. By enabling precise, dynamic control of protein phase behavior in living systems, optogenetic approaches provide a powerful framework for elucidating disease mechanisms and informing the development of targeted therapies.
36.
Potent optogenetic regulation of gene expression in mammalian cells for bioproduction and basic research.
Abstract:
Precise temporal and spatial control of gene expression greatly benefits the study of specific cellular circuits and activities. Compared to chemical inducers, light-dependent control of gene expression by optogenetics achieves a higher spatial and temporal resolution. Beyond basic research, this could also prove decisive for manufacturing difficult-to-express proteins in pharmaceutical bioproduction. However, current optogenetic gene-expression systems limit this application in mammalian cells, as expression levels and the degree of induction upon light stimulation are insufficient. To overcome this limitation, we designed a photoswitch by fusing the blue light-activated light-oxygen-voltage receptor EL222 from Erythrobacter litoralis to the three transcriptional activator domains VP64, p65, and Rta in tandem. The resultant photoswitch, dubbed DEL-VPR, allows up to a 570-fold induction of target gene expression by blue light, thereby achieving expression levels of strong constitutive promoters. Here, we used DEL-VPR to enable light-induced expression of complex monoclonal and bispecific antibodies with reduced byproduct expression and increased yield of functional protein complexes. Our approach offers temporally controlled yet strong gene expression and applies to academic and industrial settings.
37.
Single-cell characterization of bacterial optogenetic Cre recombinases.
Abstract:
Microbial optogenetic tools can regulate gene expression with high 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 systematically 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. Our results indicate that optogenetic recombinase performance can be reporter-dependent, suggesting that this is an important consideration in system design. Further, our single-cell analysis reveals highly heterogeneous activity across cells. Although general trends match expectations for mean levels of light-dependent recombination, we found substantial variation in this behavior across individual cells. In addition, our results show that the timing of recombinase activity is highly variable from cell to cell. These findings suggest critical criteria for selecting appropriate optogenetic recombinase systems and indicate areas for optimization to improve the single-cell capabilities of bacterial optogenetic tools.
38.
Empowering bacteria with light: Optogenetically engineered bacteria for light-controlled disease theranostics and regulation.
Abstract:
Bacterial therapy has emerged as a promising approach for disease treatment due to its environmental sensitivity, immunogenicity, and modifiability. However, the clinical application of engineered bacteria is limited by differences of expression levels in patients and possible off-targeting. Optogenetics, which combines optics and genetics, offers key advantages such as remote controllability, non-invasiveness, and precise spatiotemporal control. By utilizing optogenetic tools, the behavior of engineered bacteria can be finely regulated, enabling on-demand control of the dosage and location of their therapeutic products. In this review, we highlight the latest advancements in the optogenetic engineering of bacteria for light-controlled disease theranostics and therapeutic regulation. By constructing a three-dimensional analytical framework of “sense-produce-apply”, we begin by discussing the key components of bacterial optogenetic systems, categorizing them based on their photosensitive protein response to blue, green, and red light. Next, we introduce innovative light-producing tools that extend beyond traditional light sources. Then, special emphasis is placed on the biomedical applications of optogenetically engineered bacteria in treating diseases such as cancer, intestinal inflammation and systemic disease regulation. Finally, we address the challenges and future prospects of bacterial optogenetics, outlining potential directions for enhancing the safety and efficacy of light-controlled bacterial therapies. This review aims to provide insights and strategies for researchers working to advance the application of optogenetically engineered bacteria in drug delivery, precision medicine and therapeutic regulation.
39.
Insight into Optogenetics for Diabetes Management.
Abstract:
Optogenetics is an interdisciplinary field wherein optical and genetic engineering methods are employed together to impart photounresponsive cells (usually of higher animals) the ability to respond to light through expression of light-sensitive proteins sourced generally from algae or bacteria. It enables precise spatiotemporal control of various cellular activities through light stimulation. Recently, emerging as a synthetic biology-based approach for diabetes management, optogenetics can provide user-control of hormonal secretion by photoactivation of a suitably modified cell. For around a decade, studies have been performed on the applicability of various light-sensitive proteins and their incorporation into pancreatic and nonpancreatic cells for photoinduced insulin secretion. Further, in vivo studies demonstrated amelioration of diabetes in mouse models through photoactivation of the implanted engineered cells. Here, we attempt to highlight the various optogenetic approaches explored in terms of influencing the insulin secretion pathway at different points in light of the natural insulin secretion pathway in pancreatic β cells. We also discuss how transgenic cells of both pancreatic as well as nonpancreatic origin are exploited for photoinduced secretion of insulin. Recent advances on integration of “smart” technologies for remote control of light irradiation and thereby insulin secretion from implanted engineered cells in preclinical models are also described. Additionally, the need for further comprehensive studies on irradiation parameters, red-shifted opsins, and host–cell interaction is stressed to realize the full potential of optogenetics as a clinically applicable modality providing user-controlled “on demand” hormonal secretion for better management of diabetes.
40.
Protein design accelerates the development and application of optogenetic tools.
Abstract:
Optogenetics has substantially enhanced our understanding of biological processes by enabling high-precision tracking and manipulation of individual cells. It relies on photosensitive proteins to monitor and control cellular activities, thereby paving the way for significant advancements in complex system research. Photosensitive proteins play a vital role in the development of optogenetics, facilitating the establishment of cutting-edge methods. Recent breakthroughs in protein design have opened up opportunities to develop protein-based tools that can precisely manipulate and monitor cellular activities. These advancements will significantly accelerate the development and application of optogenetic tools. This article emphasizes the pivotal role of protein design in the development of optogenetic tools, offering insights into potential future directions. We begin by providing an introduction to the historical development and fundamental principles of optogenetics, followed by an exploration of the operational mechanisms of key photosensitive domains, which includes clarifying the conformational changes they undergo in response to light, such as allosteric modulation and dimerization processes. Building on this foundation, we reveal the development of protein design tools that will enable the creation of even more sophisticated optogenetic techniques.
41.
Optogenetic Modification of Glycerol Production in Wine Yeast.
Abstract:
The wine strains of Saccharomyces cerevisiae transform glucose into ethanol and other byproducts such as glycerol and acetate. The balance of these metabolites is important during the fermentation process, which impacts the organoleptic properties of wines. Ethanol and glycerol productions are mainly controlled by the ADH1 and GPD1 genes, which encode for the alcohol dehydrogenase and glycerol-3-phosphate-dehydrogenase enzymes, respectively. Genetic modification of these genes can thus be used to alter the levels of the corresponding metabolites and to reroute fermentation. In this work, we used an optogenetic system named FUN-LOV (FUNgal-Light Oxygen Voltage) to regulate the expression of ADH1 and GPD1 in a wine yeast strain using light. Initially, we confirmed the light-controlled expression of GPD1 and ADH1 in the engineered strains via RT-qPCR and a translational reporter, respectively. To characterize the generated yeast strains, we performed growth curve assays and laboratory-scale fermentations, observing phenotypic differences between illumination conditions that confirm the optogenetic control of the target genes. We also monitored glucose consumption and ethanol and glycerol productions during a fermentation time course, observing that the optogenetic control of GPD1 increased glycerol production under constant illumination without affecting ethanol production. Interestingly, the optogenetic control of ADH1 showed an inverted phenotype, where glycerol production increased under constant darkness conditions. Altogether, our results highlight the feasibility of using optogenetic tools to control yeast fermentation in a wine yeast strain, which allows changing the balance of metabolic products of interest in a light-dependent manner.
42.
A new flavor of synthetic yeast communities sees the light.
Abstract:
No organism is an island: organisms of varying taxonomic complexity, including genetic variants of a single species, can coexist in particular niches, cooperating for survival while simultaneously competing for environmental resources. In recent years, synthetic biology strategies have witnessed a surge of efforts focused on creating artificial microbial communities to tackle pressing questions about the complexity of natural systems and the interactions that underpin them. These engineered ecosystems depend on the number and nature of their members, allowing complex cell communication designs to recreate and create diverse interactions of interest. Due to its experimental simplicity, the budding yeast Saccharomyces cerevisiae has been harnessed to establish a mixture of varied cell populations with the potential to explore synthetic ecology, metabolic bioprocessing, biosensing, and pattern formation. Indeed, engineered yeast communities enable advanced molecule detection dynamics and logic operations. Here, we present a concise overview of the state-of-the-art, highlighting examples that exploit optogenetics to manipulate, through light stimulation, key yeast phenotypes at the community level, with unprecedented spatial and temporal regulation. Hence, we envision a bright future where the application of optogenetic approaches in synthetic communities (optoecology) illuminates the intricate dynamics of complex ecosystems and drives innovations in metabolic engineering strategies.
43.
Lighting up yeast: overview of optogenetics in yeast and their applications to yeast biotechnology.
Abstract:
Optogenetics is an empowering technology that uses light-responsive proteins to control biological processes. Because of its genetic tractability, abundance of genetic tools, and robust culturing conditions, Saccharomyces cerevisiae has served for many years as an ideal platform in which to study, develop, and apply a wide range of optogenetic systems. In many instances, yeast has been used as a steppingstone in which to characterize and optimize optogenetic tools to later be deployed in higher eukaryotes. More recently, however, optogenetic tools have been developed and deployed in yeast specifically for biotechnological applications, including in nonconventional yeasts. In this review, we summarize various optogenetic systems responding to different wavelengths of light that have been demonstrated in diverse yeast species. We then describe various applications of these optogenetic tools in yeast, particularly in metabolic engineering and recombinant protein production. Finally, we discuss emerging applications in yeast cybergenetics-the interfacing of yeast and computers for closed-loop controls of yeast bioprocesses-and the potential impact of optogenetics in other future biotechnological applications.
44.
Spatiotemporal dissection of collective cell migration and tissue morphogenesis during development by optogenetics.
Abstract:
Collective cell migration and tissue morphogenesis play a variety of important roles in the development of many species. Tissue morphogenesis often generates mechanical forces that alter cell shapes and arrangements, resembling collective cell migration-like behaviors. Genetic methods have been widely used to study collective cell migration and its like behavior, advancing our understanding of these processes during development. However, a growing body of research shows that collective cell migration during development is not a simple behavior but is often combined with other cellular and tissue processes. In addition, different surrounding environments can also influence migrating cells, further complicating collective cell migration during development. Due to the complexity of developmental processes and tissues, traditional genetic approaches often encounter challenges and limitations. Thus, some methods with spatiotemporal control become urgent in dissecting collective cell migration and tissue morphogenesis during development. Optogenetics is a method that combines optics and genetics, providing a perfect strategy for spatiotemporally controlling corresponding protein activity in subcellular, cellular or tissue levels. In this review, we introduce the basic mechanisms underlying different optogenetic tools. Then, we demonstrate how optogenetic methods have been applied in vivo to dissect collective cell migration and tissue morphogenesis during development. Additionally, we describe some promising optogenetic approaches for advancing this field. Together, this review will guide and facilitate future studies of collective cell migration in vivo and tissue morphogenesis by optogenetics.
45.
Recent advances in spatiotemporal control of the CRISPR/Cas9 system.
Abstract:
The CRISPR/Cas9 gene-editing technology, derived from the adaptive immune mechanisms of bacteria, has demonstrated remarkable advantages in fields such as gene function research and the treatment of genetic diseases due to its simplicity in design, precise targeting, and ease of use. Despite challenges such as off-target effects and cytotoxicity, effective spatiotemporal control strategies have been achieved for the CRISPR/Cas9 system through precise regulation of Cas9 protein activity as well as engineering of guide RNAs (gRNAs). This review provides a comprehensive analysis of the core components and functional mechanisms underlying the CRISPR/Cas9 system, highlights recent advancements in spatiotemporal control strategies, and discusses future directions for development.
46.
Environment signal dependent biocontainment systems for engineered organisms: Leveraging triggered responses and combinatorial systems.
Abstract:
As synthetic biology advances, the necessity for robust biocontainment strategies for genetically engineered organisms (GEOs) grows increasingly critical to mitigate biosafety risks related to their potential environmental release. This paper aims to evaluate environment signal-dependent biocontainment systems for engineered organisms, focusing specifically on leveraging triggered responses and combinatorial systems. There are different types of triggers—chemical, light, temperature, and pH—this review illustrates how these systems can be designed to respond to environmental signals, ensuring a higher safety profile. It also focuses on combinatorial biocontainment to avoid consequences of unintended GEO release into an external environment. Case studies are discussed to demonstrate the practical applications of these systems in real-world scenarios.
47.
Illuminating the future of food microbial control: From optical tools to Optogenetic tools.
Abstract:
Light as an environmental signal can effectively regulate various biological processes in microbial systems. Optical and optogenetic tools are able to utilize light for precise control methods with minimal interference. Recently, research on these tools has extended to the field of microbiology. Distinguishing from existing reviews, this review narrows the scope of application into food sector, focusing on advances in optical and optogenetic tools for microbial control, including optical tools targeting pathogenic or probiotic bacteria for non-thermal sterilization, antimicrobial photodynamic therapy, or photobiomodulation, combined with nanomaterials as photosensors for food analysis. As well as using optogenetic tools for more convenient and precise control in food production processes, covering reversible induction, metabolic flux regulation, biofilm formation, and inhibition. These tools offer new solutions to goals that cannot be achieved by traditional methods, and they are still maturing to explore other uses in the food field.
48.
Optogenetic control of Corynebacterium glutamicum gene expression.
Abstract:
Corynebacterium glutamicum is a key industrial workhorse for producing amino acids and high-value chemicals. Balancing metabolic flow between cell growth and product synthesis is crucial for enhancing production efficiency. Developing dynamic, broadly applicable, and minimally toxic gene regulation tools for C. glutamicum remains challenging, as optogenetic tools ideal for dynamic regulatory strategies have not yet been developed. This study introduces an advanced light-controlled gene expression system using light-controlled RNA-binding proteins (RBP), a first for Corynebacterium glutamicum. We established a gene expression regulation system, 'LightOnC.glu', utilizing the light-controlled RBP to construct light-controlled transcription factors in C. glutamicum. Simultaneously, we developed a high-performance light-controlled gene interference system using CRISPR/Cpf1 tools. The metabolic flow in the synthesis network was designed to enable the production of chitin oligosaccharides (CHOSs) and chondroitin sulphate oligosaccharides A (CSA) for the first time in C. glutamicum. Additionally, a light-controlled bioreactor was constructed, achieving a CHOSs production concentration of 6.2 g/L, the highest titer recorded for CHOSs biosynthesis to date. Herein, we have established a programmable light-responsive genetic circuit in C. glutamicum, advancing the theory of dynamic regulation based on light signaling. This breakthrough has potential applications in optimizing metabolic modules in other chassis cells and synthesizing other compounds.
49.
Engineering of LOV-domains for their use as protein tags.
Abstract:
Light-Oxygen-Voltage (LOV) domains are the protein-based light switches used in nature to trigger and regulate various processes. They allow light signals to be converted into metabolic signaling cascades. Various LOV-domain proteins have been characterized in the last few decades and have been used to develop light-sensitive tools in cell biology research. LOV-based applications exploit the light-driven regulation of effector elements to activate signaling pathways, activate genes, or locate proteins within cells. A relatively new application of an engineered small LOV-domain protein called miniSOG (mini singlet oxygen generator) is based on the light-induced formation of reactive oxygen species (ROS). The first miniSOG was engineered from a LOV domain from Arabidopsis thaliana. This engineered 14 kDa light-responsive flavin-containing protein can be exploited as protein tag for the light-triggered localized production of ROS. Such tunable ROS production by miniSOG or similarly redesigned LOV-domains can be of use in studies focused on subcellular phenomena but may also allow new light-fueled catalytic processes. This review provides an overview of the discovery of LOV domains and their development into tools for cell biology. It also highlights recent advancements in engineering LOV domains for various biotechnological applications and cell biology studies.
50.
Red Light Responsive Cre Recombinase for Bacterial Optogenetics.
Abstract:
Optogenetic tools have been used in a wide range of microbial engineering applications that benefit from the tunable, spatiotemporal control that light affords. However, the majority of current optogenetic constructs for bacteria respond to blue light, limiting the potential for multichromatic control. In addition, other wavelengths offer potential benefits over blue light, including improved penetration of dense cultures and reduced potential for toxicity. In this study, we introduce OptoCre-REDMAP, a red light inducible Cre recombinase system in Escherichia coli. This system harnesses the plant photoreceptors PhyA and FHY1 and a split version of Cre recombinase to achieve precise control over gene expression and DNA excision. We optimized the design by modifying the start codon of Cre and characterized the impact of different levels of induction to find conditions that produced minimal basal expression in the dark and induced full activation within 4 h of red light exposure. We characterized the system's sensitivity to ambient light, red light intensity, and exposure time, finding OptoCre-REDMAP to be reliable and flexible across a range of conditions. In coculture experiments with OptoCre-REDMAP and the blue light responsive OptoCre-VVD, we found that the systems responded orthogonally to red and blue light inputs. Direct comparisons between red and blue light induction with OptoCre-REDMAP and OptoCre-VVD demonstrated the superior penetration properties of red light. OptoCre-REDMAP's robust and selective response to red light makes it suitable for advanced synthetic biology applications, particularly those requiring precise multichromatic control.