Curated Optogenetic Publication Database

Abstract: Optogenetics involves the use of light to control cellular functions and has become increasingly popular in various areas of research, especially in the precise control of gene expression. While this technology is already well established in neurobiology and basic research, its use in bioprocess development is still emerging. Some optogenetic switches have been implemented in yeasts for different purposes, taking advantage of a wide repertoire of biological parts and relatively easy genetic manipulation. In this review, we cover the current strategies used for the construction of yeast strains to be used in optogenetically controlled protein or metabolite production, as well as the operational aspects to be considered for the scale-up of this type of process. Finally, we discuss the main applications of optogenetic switches in yeast systems and highlight the main advantages and challenges of bioprocess development considering future directions for this field.

Abstract: The field of optogenetics is rapidly growing in relevance and number of developed tools. Amongst other things, the optogenetic repertoire includes light-responsive ion channels and methods for gene regulation. This review will be confined to the optogenetic control of gene expression in mammalian cells as suitable models for clinical applications. Here optogenetic gene regulation might offer an excellent method for spatially and timely regulated gene and protein expression in cell therapeutic approaches. Well-known systems for gene regulation, such as the LOV-, CRY2/CIB-, PhyB/PIF-systems, as well as other, in mammalian cells not yet fully established systems will be described. Advantages and disadvantages with regard to clinical applications are outlined in detail. Among the many unanswered questions concerning the application of optogenetics, we discuss items such as the use of exogenous chromophores and their effects on the biology of the cells and methods for a gentle, but effective gene transfection method for optogenetic tools for in vivo applications. This article is protected by copyright. All rights reserved.

Abstract: Materials in nature have fascinating properties that serve as a continuous source of inspiration for materials scientists. Accordingly, bio-mimetic and bio-inspired approaches have yielded remarkable structural and functional materials for a plethora of applications. Despite these advances, many properties of natural materials remain challenging or yet impossible to incorporate into synthetic materials. Natural materials are produced by living cells, which sense and process environmental cues and conditions by means of signaling and genetic programs, thereby controlling the biosynthesis, remodeling, functionalization, or degradation of the natural material. In this context, synthetic biology offers unique opportunities in materials sciences by providing direct access to the rational engineering of how a cell senses and processes environmental information and translates them into the properties and functions of materials. Here, we identify and review two main directions by which synthetic biology can be harnessed to provide new impulses for the biologization of the materials sciences: first, the engineering of cells to produce precursors for the subsequent synthesis of materials. This includes materials that are otherwise produced from petrochemical resources, but also materials where the bio-produced substances contribute unique properties and functions not existing in traditional materials. Second, engineered living materials that are formed or assembled by cells or in which cells contribute specific functions while remaining an integral part of the living composite material. We finally provide a perspective of future scientific directions of this promising area of research and discuss science policy that would be required to support research and development in this field.

Abstract: Decades of genetic, molecular and biochemical studies in plants have provided foundational knowledge about light sensory proteins and led to their application in synthetic biology. Optogenetic tools take advantage of the light switchable activity of plant photoreceptors to control intracellular signaling pathways. The recent discovery of the UV-B photoreceptor UV RESISTANCE LOCUS 8 in the model plant Arabidopsis thaliana opens up new avenues for light-controllable methodologies. In this review, we discuss current developments in optogenetic control by UV-B light and its signaling components, as well as rational considerations in the design and applications of UV-B-based optogenetic tools.

Abstract: Cells receive enormous amounts of information from their environment. How they act on this information-by migrating, expressing genes, or relaying signals to other cells-comprises much of the regulatory and self-organizational complexity found across biology. The "parts list" involved in cell signaling is generally well established, but how do these parts work together to decode signals and produce appropriate responses? This fundamental question is increasingly being addressed with optogenetic tools: light-sensitive proteins that enable biologists to manipulate the interaction, localization, and activity state of proteins with high spatial and temporal precision. In this review, we summarize how optogenetics is being used in the pursuit of an answer to this question, outlining the current suite of optogenetic tools available to the researcher and calling attention to studies that increase our understanding of and improve our ability to engineer biology. Expected final online publication date for the Annual Review of Biomedical Engineering, Volume 23 is June 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Abstract: Site-specific recombinases (SSRs) are invaluable genome engineering tools that have enormously boosted our understanding of gene functions and cell lineage relationships in developmental biology, stem cell biology, regenerative medicine, and multiple diseases. However, the ever-increasing complexity of biomedical research requires the development of novel site-specific genetic recombination technologies that can manipulate genomic DNA with high efficiency and fine spatiotemporal control. Here, we review the latest innovative strategies of the commonly used Cre-loxP recombination system and its combinatorial strategies with other SSR systems. We also highlight recent progress with a focus on the new generation of chemical- and light-inducible genetic systems and discuss the merits and limitations of each new and established system. Finally, we provide the future perspectives of combining various recombination systems or improving well-established site-specific genetic tools to achieve more efficient and precise spatiotemporal genetic manipulation.

Abstract: Light has become established as a tool not only to visualize and investigate but also to steer biological systems. This review starts by discussing the unique features that make light such an effective control input in biology. It then gives an overview of how light‐control came to progress, starting with photoactivatable compounds and leading up to current genetic implementations using optogenetic approaches. The review then zooms in on optogenetics, focusing on photosensitive proteins, which form the basis for optogenetic engineering using synthetic biological approaches. As the regulation of transcription provides a highly versatile means for steering diverse biological functions, the focus of this review then shifts to transcriptional light regulators, which are presented in the biotechnologically highly relevant model organism Escherichia coli.

Abstract: Optogenetics utilizes photosensitive proteins to manipulate the localization and interaction of molecules in living cells. Because light can be rapidly switched and conveniently confined to the sub‐micrometer scale, optogenetics allows for controlling cellular events with an unprecedented resolution in time and space. The past decade has witnessed an enormous progress in the field of optogenetics within the biological sciences. The ever‐increasing amount of optogenetic tools, however, can overwhelm the selection of appropriate optogenetic strategies. Considering that each optogenetic tool may have a distinct mode of action, a comparative analysis of the current optogenetic toolbox can promote the further use of optogenetics, especially by researchers new to this field. This review provides such a compilation that highlights the spatiotemporal accuracy of current optogenetic systems. Recent advances of optogenetics in live cells and animal models are summarized, the emerging work that interlinks optogenetics with other research fields is presented, and exciting clinical and industrial efforts to employ optogenetic strategy toward disease intervention are reported.

Abstract: Progress in metabolic engineering and synthetic and systems biology has made bioproduction an increasingly attractive and competitive strategy for synthesizing biomolecules, recombinant proteins and biofuels from renewable feedstocks. Yet, due to poor productivity, it remains difficult to make a bioproduction process economically viable at large scale. Achieving dynamic control of cellular processes could lead to even better yields by balancing the two characteristic phases of bioproduction, namely, growth versus production, which lie at the heart of a trade-off that substantially impacts productivity. The versatility and controllability offered by light will be a key element in attaining the level of control desired. The popularity of light-mediated control is increasing, with an expanding repertoire of optogenetic systems for novel applications, and many optogenetic devices have been designed to test optogenetic strains at various culture scales for bioproduction objectives. In this review, we aim to highlight the most important advances in this direction. We discuss how optogenetics is currently applied to control metabolism in the context of bioproduction, describe the optogenetic instruments and devices used at the laboratory scale for strain development, and explore how current industrial-scale bioproduction processes could be adapted for optogenetics or could benefit from existing photobioreactor designs. We then draw attention to the steps that must be undertaken to further optimize the control of biological systems in order to take full advantage of the potential offered by microbial factories.

Abstract: Optogenetics refers to the control of biological processes with light. The activation of cellular phenomena by defined wavelengths has several advantages compared to traditional chemically-inducible systems, such as spatiotemporal resolution, dose-response regulation, low cost and moderate toxic effects. Optogenetics has been successfully implemented in yeast, a remarkable biological platform that is not only a model organism for cellular and molecular biology studies, but also a microorganism with diverse biotechnological applications. In this review, we summarize the main optogenetic systems implemented in the budding yeast Saccharomyces cerevisiae, which allow orthogonal control (by light) of gene expression, protein subcellular localization, reconstitution of protein activity, or protein sequestration by oligomerization. Furthermore, we review the application of optogenetic systems in the control of metabolic pathways, heterologous protein production and flocculation. We then revise an example of a previously described yeast optogenetic switch, named FUN-LOV, which allows precise and strong activation of the target gene. Finally, we describe optogenetic systems that have not yet been implemented in yeast, which could therefore be used to expand the panel of available tools in this biological chassis. In conclusion, a wide repertoire of optogenetic systems can be used to address fundamental biological questions and broaden the biotechnological toolkit in yeast.

Abstract: The last two decades have witnessed the emergence of optogenetics; a field that has given researchers the ability to use light to control biological processes at high spatio-temporal and quantitative resolution, in a reversible manner with minimal side effects. Optogenetics has revolutionised the neurosciences, increased our understanding of cellular signalling and metabolic networks and resulted in variety of applications in biotechnology and biomedicine. However, implementing optogenetics in plants has been less straight forward given their dependency on light for their life cycle. Here, we highlight some of the widely used technologies in microorganisms and animal systems derived from plant photoreceptor proteins and discuss strategies recently implemented to overcome the challenges for using optogenetics in plants.

Abstract: Cybergenetic systems use computer interfaces to enable feed-back controls over biological processes in real time. The complex and dynamic nature of cellular metabolism makes cybergenetics attractive for controlling engineered metabolic pathways in microbial fermentations. Cybergenetics would not only create new avenues of research into cellular metabolism, it would also enable unprecedented strategies for pathway optimization and bioreactor operation and automation. Implementation of metabolic cybergenetics, however, will require new capabilities from actuators, biosensors, and control algorithms. The recent application of optogenetics in metabolic engineering, the expanding role of genetically encoded biosensors in strain development, and continued progress in control algorithms for biological processes suggest that this technology will become available in the not so distant future.

Abstract: Since the neurobiological inception of optogenetics, light-controlled molecular perturbations have been applied in many scientific disciplines to both manipulate and observe cellular function. Proteins exhibiting light-sensitive conformational changes provide researchers with avenues for spatiotemporal control over the cellular environment and serve as valuable alternatives to chemically inducible systems. Optogenetic approaches have been developed to target proteins to specific subcellular compartments, allowing for the manipulation of nuclear translocation and plasma membrane morphology. Additionally, these tools have been harnessed for molecular interrogation of organelle function, location, and dynamics. Optogenetic approaches offer novel ways to answer fundamental biological questions and to improve the efficiency of bioengineered cell factories by controlling the assembly of synthetic organelles. This review first provides a summary of available optogenetic systems with an emphasis on their organelle-specific utility. It then explores the strategies employed for organelle targeting and concludes by discussing our perspective on the future of optogenetics to control subcellular structure and organization. This article is categorized under: Laboratory Methods and Technologies > Genetic/Genomic Methods Physiology > Physiology of Model Organisms Biological Mechanisms > Regulatory Biology Models of Systems Properties and Processes > Cellular Models.

Abstract: G protein-coupled receptors (GPCRs) form the largest class of membrane receptors in the mammalian genome with nearly 800 human genes encoding for unique subtypes. Accordingly, GPCR signaling is implicated in nearly all physiological processes. However, GPCRs have been difficult to study due in part to the complexity of their function which can lead to a plethora of converging or diverging downstream effects over different time and length scales. Classic techniques such as pharmacological control, genetic knockout and biochemical assays often lack the precision required to probe the functions of specific GPCR subtypes. Here we describe the rapidly growing set of optogenetic tools, ranging from methods for optical control of the receptor itself to optical sensing and manipulation of downstream effectors. These tools permit the quantitative measurements of GPCRs and their downstream signaling with high specificity and spatiotemporal precision.

Abstract: Cells rely on a complex network of spatiotemporally regulated signaling activities to effectively transduce information from extracellular cues to intracellular machinery. To probe this activity architecture, researchers have developed an extensive molecular tool kit of fluorescent biosensors and optogenetic actuators capable of monitoring and manipulating various signaling activities with high spatiotemporal precision. The goal of this review is to provide readers with an overview of basic concepts and recent advances in the development and application of genetically encodable biosensors and optogenetic tools for understanding signaling activity.

Abstract: In multicellular organisms, living cells cooperate with each other to exert coordinated complex functions by responding to extracellular chemical or physical stimuli via proteins on the plasma membrane. Conventionally, chemical signal transduction or mechano-transduction has been investigated by chemical, genetic, or physical perturbation; however, these methods cannot manipulate biomolecular reactions at high spatiotemporal resolution. In contrast, recent advances in optogenetic perturbation approaches have succeeded in controlling signal transduction with external light. The methods have enabled spatiotemporal perturbation of the signaling, providing functional roles of the specific proteins. In this chapter, we summarize recent advances in the optogenetic tools that modulate the function of a receptor protein. While most optogenetic systems have been devised for controlling ion channel conductivities, the present review focuses on the other membrane proteins involved in chemical transduction or mechano-transduction. We describe the properties of natural or artificial photoreceptor proteins used in optogenetic systems. Then, we discuss the strategies for controlling the receptor protein functions by external light. Future prospects of optogenetic tool development are discussed.

Abstract: Cells respond to a wide range of extracellular stimuli, and process the input information through an intracellular signaling system comprised of biochemical and biophysical reactions, including enzymatic and protein-protein interactions. It is essential to understand the molecular mechanisms underlying intracellular signal transduction in order to clarify not only physiological cellular functions but also pathological processes such as tumorigenesis. Fluorescent proteins have revolutionized the field of life science, and brought the study of intracellular signaling to the single-cell and subcellular levels. Much effort has been devoted to developing genetically encoded fluorescent biosensors based on fluorescent proteins, which enable us to visualize the spatiotemporal dynamics of cell signaling. In addition, optogenetic techniques for controlling intracellular signal transduction systems have been developed and applied in recent years by regulating intracellular signaling in a light-dependent manner. Here, we outline the principles of biosensors for probing intracellular signaling and the optogenetic tools for manipulating them.

Abstract: Embryogenesis is coordinated by signaling pathways that pattern the developing organism. Many aspects of this process are not fully understood, including how signaling molecules spread through embryonic tissues, how signaling amplitude and dynamics are decoded, and how multiple signaling pathways cooperate to pattern the body plan. Optogenetic approaches can be used to address these questions by providing precise experimental control over a variety of biological processes. Here, we review how these strategies have provided new insights into developmental signaling and discuss how they could contribute to future investigations.

Abstract: In optogenetics, light-sensitive proteins are specifically expressed in target cells and light is used to precisely control the activity of these proteins at high spatiotemporal resolution. Optogenetics initially used naturally occurring photoreceptors to control neural circuits, but has expanded to include carefully designed and engineered photoreceptors. Several optogenetic constructs are based on plant photoreceptors, but their application to plant systems has been limited. Here, we present perspectives on the development of plant optogenetics, considering different levels of design complexity. We discuss how general principles of light-driven signal transduction can be coupled with approaches for engineering protein folding to develop novel optogenetic tools. Finally, we explore how the use of computation, networks, circular permutation, and directed evolution could enrich optogenetics.

Abstract: Molecular motors are diverse enzymes that transduce chemical energy into mechanical work and, in doing so, perform critical cellular functions such as DNA replication and transcription, DNA supercoiling, intracellular transport, and ATP synthesis. Single-molecule techniques have been extensively used to identify structural intermediates in the reaction cycles of molecular motors and to understand how substeps in energy consumption drive transitions between the intermediates. Here, we review a broad spectrum of single-molecule tools and techniques such as optical and magnetic tweezers, atomic force microscopy (AFM), single-molecule fluorescence resonance energy transfer (smFRET), nanopore tweezers, and hybrid techniques that increase the number of observables. These methods enable the manipulation of individual biomolecules via the application of forces and torques and the observation of dynamic conformational changes in single motor complexes. We also review how these techniques have been applied to study various motors such as helicases, DNA and RNA polymerases, topoisomerases, nucleosome remodelers, and motors involved in the condensation, segregation, and digestion of DNA. In-depth analysis of mechanochemical coupling in molecular motors has made the development of artificially engineered motors possible. We review techniques such as mutagenesis, chemical modifications, and optogenetics that have been used to re-engineer existing molecular motors to have, for instance, altered speed, processivity, or functionality. We also discuss how single-molecule analysis of engineered motors allows us to challenge our fundamental understanding of how molecular motors transduce energy.

Abstract: Optogenetics has demonstrated great potential in the fields of tissue engineering and regenerative medicine, from basic research to clinical applications. Spatiotemporal encoding during individual development has been widely identified and is considered a novel strategy for regeneration. A as a noninvasive method with high spatiotemporal resolution, optogenetics are suitable for this strategy. In this review, we discuss roles of dynamic signal coding in cell physiology and embryonic development. Several optogenetic systems are introduced as ideal optogenetic tools, and their features are compared. In addition, potential applications of optogenetics for tissue engineering are discussed, including light-controlled genetic engineering and regulation of signaling pathways. Furthermore, we present how emerging biomaterials and photoelectric technologies have greatly promoted the clinical application of optogenetics and inspired new concepts for optically controlled therapies. Our summation of currently available data conclusively demonstrates that optogenetic tools are a promising method for elucidating and simulating developmental processes, thus providing vast prospects for tissue engineering and regenerative medicine applications.

Abstract: Light-inducible approaches provide means to control biological systems with spatial and temporal resolution that is unmatched by traditional genetic perturbations. Recent developments of optogenetic and chemo-optogenetic systems for induced proximity in cells facilitate rapid and reversible manipulation of highly dynamic cellular processes and have become valuable tools in diverse biological applications. The new expansions of the toolbox facilitate control of signal transduction, genome editing, 'painting' patterns of active molecules onto cellular membranes and light-induced cell cycle control. A combination of light- and chemically induced dimerization approaches has also seen interesting progress. Here we provide an overview of the optogenetic systems and the emerging chemo-optogenetic systems, and discuss recent applications in tackling complex biological problems.

Abstract: In order to study the role of signaling proteins, such as kinases and GTPases, in brain functions it is necessary to control their activity at the appropriate spatiotemporal resolution and to examine the cellular and behavioral effects of such changes in activity. Reduced spatiotemporal resolution in the regulation of these proteins activity will impede the ability to understand the proteins normal functions as longer modification of their activity in non-normal locations could lead to effects different from their natural functions. To control intracellular signaling proteins at the highest temporal resolution recent innovative optogenetic approaches were developed to allow the control of photoactivable signaling proteins activity by light. These photoactivatable proteins can be activated in selected cell population in brain and in specific subcellular compartments. Minimal-invasive tools are being developed to photoactivate these proteins for study and therapy. Together these techniques afford an unprecedented spatiotemporal control of signaling proteins activity to unveil the function of brain proteins with high accuracy in behaving animals. As dysfunctional signaling proteins are involved in brain diseases, the optogenetic technique has also the potential to be used as a tool to treat brain diseases.

Abstract: Optogenetic dimerizers are modular domains that can be utilized in a variety of versatile ways to modulate cellular biochemistry. Because of their modularity, many applications using these tools can be easily transferred to new targets without extensive engineering. While a number of photodimerizer systems are currently available, the field remains nascent, with new optimizations for existing systems and new approaches to regulating biological function continuing to be introduced at a steady pace.

Abstract: Synthetic biology is an established but ever-growing interdisciplinary field of research currently revolutionizing biomedicine studies and the biotech industry. The engineering of synthetic circuitry in bacterial, yeast, and animal systems prompted considerable advances for the understanding and manipulation of genetic and metabolic networks; however, their implementation in the plant field lags behind. Here, we review theoretical-experimental approaches to the engineering of synthetic chemical- and light-regulated (optogenetic) switches for the targeted interrogation and control of cellular processes, including existing applications in the plant field. We highlight the strategies for the modular assembly of genetic parts into synthetic circuits of different complexity, ranging from Boolean logic gates and oscillatory devices up to semi- and fully synthetic open- and closed-loop molecular and cellular circuits. Finally, we explore potential applications of these approaches for the engineering of novel functionalities in plants, including understanding complex signaling networks, improving crop productivity, and the production of biopharmaceuticals.