Curated Optogenetic Publication Database

Abstract: Light-induced membrane fusion has become a pivotal technique for constructing and functionalizing synthetic cells by enabling precise control over membrane merging events. Traditional fusion approaches that rely on chemical, physical, and mechanical stimuli frequently lack both specificity and reversibility, limiting their utility in mimicking dynamic cellular processes. Here, we review advances employing photosensitive molecules and optogenetic tools that facilitate spatiotemporally controlled fusion of lipid and polymer vesicles, enabling dynamic content exchange and membrane remodeling. These approaches have enhanced synthetic cell assembly, molecular transport, and signal transduction, with applications extending to drug delivery and biosensing. Despite challenges in efficiency and biocompatibility, ongoing innovations in photosensitizer design and light activation strategies promise to expand the capabilities of synthetic biology platforms. This work underscores the potential of light-induced fusion to advance the development of intelligent nanomaterials and functional synthetic cellular systems.

Abstract: The light-mediated, specific, and precise control of cell functions enabled by optogenetics has become a versatile method for investigating and combatting cancer. An increasing set of optogenetic tools enables tightly controlled regulation of ion flux across biological membranes, gene expression, gene editing, and protein-protein interactions and is being used to interrogate hallmark traits of cancer at the cellular, subcellular, and organismic level. This enables, on the one hand, the identification of critical signaling circuits required for cancer development and progression in vitro and in animal models and can flag potential intervention points for pharmacologic interference. On the other hand, optogenetics can improve the level of control in cell-based therapeutics. The current article provides a review of optogenetic tools and approaches used in the cancer research field and their multiple applications for improving our understanding of signal transduction pathways, modulating immune functions in the tumor microenvironment, facilitating drug screening, or directly attacking cancer cells. Key advantages and achievements of optogenetics in the cancer research field and remaining barriers for clinical applications are discussed.

Abstract: Endoplasmic reticulum-plasma membrane (ER-PM) contact sites are essential signaling hubs that regulate lipid transport, calcium homeostasis, and spatially organized signal transduction. Emerging evidence indicates that not only the presence but also the dynamics, stability, and geometry of ER-PM contacts critically shape cellular functions; however, tools that enable simultaneous high-fidelity visualization and reversible, quantitative control of these contacts in living cells remain limited. Here, we introduce a modular toolkit for inducible ER-PM contact-site reconstitution based on complementary chemical and optical dimerization strategies. We develop a nontoxic and reversible abscisic acid (ABA)-inducible system using the plant-derived ABIcs/PYLcs pair, and a rapidly reversible optogenetic system based on the iLID/SspB module, both of which allow robust visualization and dose-dependent control over contact-site formation kinetics, increasing contact-site density and total area fraction per cell without altering the size of individual contacts. In contrast, systematic variation of rigid α-helical linker length or inducible tether abundance selectively tunes the lateral growth, stability, and lifetime of individual contact sites, without changing their density. By combining these two orthogonal strategies, we achieve independent control of both individual contact-site size and overall contact-site density, providing complementary mechanisms to adjust total contact area per cell. This versatile platform enables quantitative dissection of ER-PM contact site structure-function relationships and offers broad utility in studies of lipid exchange, calcium signaling, membrane repair, metabolic regulation, and disease-relevant dysregulation.

Abstract: Notch signalling is a critical regulator of multiple developmental processes through its ability to control gene expression and thereby influence cell fate specification and cell proliferation through direct cell-cell communication. Although Notch signalling has been implicated in myogenesis during late embryogenesis, its role in early mesoderm development has been largely unexplored. Endocytosis of the Notch ligand Delta and the Notch receptor extracellular domain, a critical step in Notch pathway activation, has been extensively observed in the ventral mesoderm of the early Drosophila embryo, indicating a potential for Notch signalling activity in this early germ layer. Here, we present evidence that genes critical to mesoderm development require and are responsive to Notch signalling activity. Using a novel light-inducible Optogenetic variant of the Notch intracellular domain (OptoNotch), which affords precise spatial and temporal control over ectopic activation of Notch signalling, in combination with high-resolution fluorescent RNA in situ hybridization and qPCR, we identified a set of mesodermal genes whose expression is directly regulated by Notch signalling. We also provide evidence that Notch signalling indirectly regulates the dorsal-ventral patterning program mediated by the Toll signalling pathway through the Dorsal/Twist/Snail gene network. Our findings demonstrate that Notch signalling regulates ventral mesoderm patterning and is critical for establishing the mesoderm-mesectoderm-ectoderm boundary by regulating gene expression patterns and providing negative feedback on the upstream patterning network.

Abstract: Various blue-light photoreceptor proteins have photo-responsive domains known as light, oxygen, voltage (LOV) domains, which are extensively distributed in plants, algae, fungi, and bacteria. When exposed to blue light, the flavin chromophore and a highly conserved cysteine residue form a covalent adduct on a microsecond time scale. LOV domains are common photosensory modules that can be applied to optogenetics, regulated synthesis of reactive oxygen species, and fluorescence microscopy. This review explores the photocycle kinetics and applications of various LOV domains, which have been explored for confocal microscopy, two-photon microscopy, and super-resolution microscopy. Many LOV domains have been derived and modulated for use in different types of microscopic applications. Molecular understanding, diversity of LOV domains, and versatile photo-physical characteristics of these proteins have immense potential for the development of useful probes for various microscopy tools. There is a great demand for perspective research on LOV domain proteins for harnessing their possible optobiotechnological applications.

Abstract: Cancer is known to be a disease of altered cellular signaling; however, the relationship between mutation-specific changes to signal transduction and the phenotypic consequences produced remains poorly understood. Here, we investigate two common breast cancer driver mutations, the PIK3CAH1047R mutation and the ErbB2 amplification, both of which activate the PI3K-Akt pathway but paradoxically drive distinct cellular outcomes. Indeed, in nontransformed mammary epithelial cells, PI3KH1047R expression induced features of epithelial-mesenchymal transition (EMT), while ErbB2amp cells exhibited a hyperproliferative phenotype. Characterization of PI3K axis signaling revealed that ErbB2amp cells display prolonged, stimulus-dependent PI3K activation, whereas PI3KH1047R cells show constitutive, ligand-independent signaling. To test whether these distinct dynamics contribute to the phenotypic responses, we employed an iLID-based optogenetic system that enables precise, tunable control of endogenous PI3K activity. Using this tool to mimic the mutation-specific dynamics in MCF10A mammary epithelial cells, we found that PI3K signaling patterns alone were sufficient to reproduce key features of the PIK3CA H1047R-associated EMT phenotype but not the ErbB2-associated proliferative phenotype. These findings suggest that the temporal encoding of pathway activity, not merely its magnitude, can drive some phenotypic changes in oncogenic progression, explain how distinct mutations within a common signaling pathway can produce divergent cellular phenotypes, and provide a workflow for interrogating the functional consequences of changes in signaling dynamics.

Abstract: RNA-binding proteins (RBPs) with prion-like domains (PrLDs), such as FUS and TDP-43, condense into functional liquids, which can transform into pathological fibrils that underpin fatal neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD). Here, we define short RNAs that prevent FUS fibrillization by promoting liquid phases and distinct short RNAs that prevent and reverse FUS condensation and fibrillization. These activities require interactions with multiple RNA-binding domains of FUS and are encoded by RNA sequence, length, and structure. We define a short RNA that dissolves cytoplasmic FUS aggregates, restores nuclear FUS, and mitigates FUS toxicity in optogenetic models and ALS patient-derived motor neurons. Another short RNA dissolves cytoplasmic TDP-43 aggregates, restores nuclear TDP-43, and mitigates TDP-43 toxicity. Since short RNAs can be effectively delivered to the human brain, these oligonucleotides could have utility for ALS/FTD and related disorders.

Abstract: Mitochondria besides being the powerhouse of the cell are also involved in performing a multitude of critical cellular functions. Any failure in maintenance of these organelles is implicated in multiple human pathologies, including neurodegenerative disorders. Over the past two decades, significant efforts have been made to investigate the pharmacodynamic propensity of various potential compounds, which could be engaged as efficient therapeutic approach in modulating mitochondrial dynamics during neuronal dysfunctions.

Abstract: CRISPR/Cas9 is a powerful tool for targeted genome editing experiments. Using CRISPR/Cas9, genes can be deleted or modified by inserting specific DNA sequences, encoding for fluorescent proteins, small peptide tags, or other modifications. Such experiments are essential for detailed gene and protein characterization. However, designing and cloning the corresponding constructs can be repetitive, time-consuming, and laborious. To assist users in CRISPR/Cas9-based genome engineering, we developed CrisprBuildr, an open-source, web-based application for designing modifications to their target genes. CrisprBuildr guides users through creating guide RNAs and repair template vectors to generate cloning maps. The application is designed for the Drosophila melanogaster genome but can serve as a template for other available genomes. We also created new tagging vectors using EGFP and mCherry combined with the small peptide SspB-Q73R for use in iLID-based optogenetic experiments.

Abstract: How do cells maintain robust, yet flexible polarization for directed motion? Recent optogenetic experiments by Town and Weiner on neutrophil-like HL-60 cells strongly point to the essential role of a Rac-inhibitor (downstream of the small GTPase Rac) in shaping requisite negative feedback that allows cells to respond to rapidly changing directional cues. Here we adapt a previous mathematical model for cell polarity to model interactions of Rac, its putative inhibitor, and upstream PIP3 (a product of the optogenetically stimulated PI3K). We fit parameters in our partial differential equation (PDE) model to temporal and spatial experimental data. Cell shapes, motility, and stimulus responses are modeled in 2D simulations, with PDEs solved along the cell edge. We show that the Rac-inhibitor-PIP3 circuit accounts for the optogenetic data (including exotic cell trajectories), that it is the minimal circuit to do so, and that it improves gradient sensing under noisy or dynamic conditions.

Abstract: Molecular biology has benefited enormously from repurposed tools-many enzymes and antibodies evolved for other functions but are now essential for interrogating biological function by manipulating proteins or nucleic acids. In contrast, lipids have remained technically difficult to visualize or manipulate in cells. This review introduces tools that bring lipid biology into reach for molecular cell biologists, using familiar experimental approaches. We first describe adaptations of immunofluorescence and live-cell imaging of fluorescent molecules to track lipids. Then, we discuss tools for manipulating lipid levels, including pharmacologic inhibitors, synthetic biology platforms for inducible lipid generation or degradation, and optogenetic systems for precise temporal control. While some methods remain technically demanding, most tools are now broadly accessible. Our goal is to offer a practical framework for integrating lipid biology into mainstream cell biology experiments.

Abstract: Primordial germ cells (PGCs) are the first cells specified in the Drosophila embryo and serve as precursors to the germline. Their formation requires suppression of somatic fates, a process achieved by excluding the receptor tyrosine kinase Torso from the posterior pole through degradation mediated by the ubiquitin ligase adaptor Germ Cell-Less (GCL). Although Torso is known to antagonize PGC formation, the underlying mechanism has remained unclear. Here, we combine optogenetic Ras activation and Ras effector loop mutants to show that Ras signaling suppresses PGC formation independently of the canonical Raf/MEK/ERK pathway. We identify an unexpected early role for Torso in activating phosphoinositide 3-kinase (PI3K), generating posterior membrane domains enriched in phosphatidylinositol (3,4,5)-trisphosphate (PIP3). Elevated PI3K activity disrupts PGC formation, while reduced PI3K activity leads to ectopic PGCs. We further demonstrate that GCL remodels the posterior pole membrane by suppressing Torso-dependent PI3K activation. Clearing PIP3 enables Myosin II enrichment, thereby constricting the pole bud for PGC formation. Together, our findings reveal how antagonistic Torso and GCL activities establish the soma-germline boundary by regulating cortical lipid organization.

Abstract: Precise regulation of protein abundance is essential for understanding dynamic cellular processes and for advancing therapeutic development. However, existing approaches lack the spatiotemporal resolution required to these cellular processes. Recent advances in optogenetics have enabled the design of optogenetic targeted protein degradation systems (Opto-TPD) allowing reversible and non-invasive control of protein stability with high spatiotemporal precision. In this review, we systematically summarize the design principles of Opto-TPD tools, including those based on light-oxygen-voltage (LOV)-domain conformational systems, light-inducible dimerization systems, and light-controlled degradation tool expression systems. We further highlight their applications in probing protein function, modulating signaling pathways, and therapeutic translations. By comparing the mechanistic features, performance, and limitations of each platform, we aim to provide a comprehensive resource for guiding future tool optimization. Altogether, these Opto-TPD tools represent a powerful and versatile complement to existing protein manipulation technologies, expanding the toolbox for precise control of protein homeostasis in living systems.

Abstract: Smart microscopy is transforming biological imaging by integrating real-time analysis with adaptive acquisition to enhance imaging efficiency. Whereas many emerging implementations are event-driven and focus on on-demand data acquisition to reduce phototoxicity, we here present 'outcome-driven' microscopy, a framework combining smart microscopy with optogenetics to control cell biological processes and achieve predefined outcomes. We validate this approach using light-based control of cell migration and nucleocytoplasmic transport, demonstrating robust spatiotemporal control of cellular behaviour in single cells and in cell populations.

Abstract: Light-sensitive proteins allow organisms to perceive and respond to their environment, and have diversified over billions of years. Among these, Light-Oxygen-Voltage (LOV) domains are widespread photosensors that control diverse physiological processes and are increasingly used in optogenetics. Yet, the evolutionary constraints that shaped their protein dynamics and thereby their functional diversity remain poorly resolved. Here we systematically characterize the dynamics of 21 natural LOV core domains, significantly extending the spectroscopically resolved catalog through the addition of 18 previously unstudied variants. Using time-resolved spectroscopy, we uncover an exceptional kinetic diversity spanning from picoseconds to days and identify distinct functional clusters within the LOV family. These clusters reflect evolutionary branching, including a divergence of ≈1.0 billion years between investigatedLOV variants from plants and ≈0.4 billion years of separation within one of these functional clusters. Individual variants with extreme photocycles emerge as promising anchor points for optogenetic applications, ranging from highly efficient adduct formation to ultrafast recovery. Beyond natural diversity, we introduce a LOV domain generated by artificial intelligence-guided protein design. Despite being sequentially remote from its maternal template, this variant retains core photocycle function while exhibiting unique biophysical properties, thereby occupying a new region on the biophysical landscape. Our work emphasizes how billions of years of evolution defined LOV protein dynamics, and how protein design can expand this repertoire, engineering next-generation optogenetic tools.

Abstract: Cellular receptors serve as central hubs that translate external signals into intracellular programs governing cell fate, function and behavior. Achieving precise and reversible control over receptor activity has long been a major challenge in both fundamental biology and translational medicine. Optogenetic receptor engineering provides a transformative solution by integrating photosensitive domains into natural receptor frameworks. This strategy enables light-dependent modulation of signaling with high spatial and temporal precision while maintaining minimal disturbance to endogenous pathways. Unlike chemogenetic systems or classical photoreceptive ion channels, this approach preserves endogenous ligand specificity and avoids slow ligand diffusion/clearance-associated artifacts. Through such systems, researchers can dissect causal relationships in dynamic signaling events, finely manipulate neuromodulatory and immune circuits and program cellular activities involved in development and tissue regeneration. The approach also allows quantitative control of signaling intensity and duration, offering new opportunities for linking molecular design to physiological outcomes. By combining optogenetic principles with advances in materials science and bioelectronics, future designs may achieve improved optical fidelity, enhanced light penetration and better signal amplification within complex biological environments. Integration with AI-guided protein engineering may also accelerate the discovery of optimized photosensory-receptor pairings. Together, these developments point to an emerging field where light-responsive receptors function as programmable interfaces between photonic control and cellular computation. In summary, the engineering of optogenetic receptors establishes a conceptual and technological framework for reversible, accurate and tunable regulation of cellular communication. This review summarizes current progress, outlines key design principles and provides conceptual guidelines for advancing next-generation light-responsive receptors and their biomedical applications. However, key translational challenges-including immunogenicity of non-human photoreceptors, limited gene-delivery efficiency and long-term biosafety-remain to be addressed through nonviral delivery strategies, autologous cell engineering and de-immunized or humanized photoreceptor design.

Abstract: Microtubules are crucial regulators of plant development and are organized by a suite of microtubule-associated proteins (MAPs) that can rapidly remodel the array in response to various cues. This complexity has inspired countless studies into microtubule function from the subcellular to tissue scale, revealing an ever-increasing number of microtubule-dependent processes. Developing a comprehensive understanding of how local microtubule configuration, dynamicity, and remodeling drive developmental progression requires new approaches to capture and alter microtubule behavior. In this review, we will introduce the technological advancements we believe are poised to transform the study of microtubules in plant cells. In particular, we focus on (1) advanced imaging and analysis methods to quantify microtubule organization and behavior, and (2) novel tools to target specific microtubule populations in vivo. By showcasing innovative methodologies developed in non-plant systems, we hope to motivate their increased adoption and raise awareness of possible means of adapting them for studying microtubules in plants.

Abstract: Cellular signaling cascades rely on transfer of information from one protein to another or within a single protein. To facilitate signal integration, specific structural motifs evolved that allow signal processing and also enable modular downstream response integration, facilitating sophisticated regulatory mechanisms. On a structural level, especially coiled-coil helices are frequently observed as signaling motifs. In diguanylate cyclases (DGCs) featuring GGDEF domains, N-terminal coiled-coils frequently activate systems by rearrangements of the interdimer active site. The variety of sensory domains that modulate this structural equilibrium in response to different stimuli highlights the importance of DGCs in bacterial adaptation. One interesting example of sensor DGCs is blue light-activated light-oxygen-voltage (LOV)-GGDEF couples. Here, we describe molecular details of a two-stage mechanism that allows tight dark-state inhibition while enabling high enzymatic activities upon illumination, achieving fold changes exceeding 10,000-fold. Using an in vivo activity assay, we screened amino acid substitutions at the inhibitory interface and the sensor-effector linker region to identify variants that promote enzymatic activity in the dark. In combination with chimeras of LOV and GGDEF domains preventing inhibitory interface formation, we successfully stabilized elongated active-state conformations and confirmed the role of the inhibitory interface between sensor and effector in the tight dark-state inhibition. Interestingly, the initially generated chimeras are still light regulatable as long as the linker sequence is not stabilized in either inhibiting or stimulating coiled-coil register. Our results offer valuable insights for potential optogenetic applications but also demonstrate inherent challenges associated with Methylotenera sp. LOV-activated DGCs.

Abstract: Multimerization and phase separation represent two paradigms for organizing receptor tyrosine kinases (RTKs). However, their functional distinctions from the perspective of biomolecular organization remain unclear. Here, we present CORdensate, a light-controllable condensation system combining two synergistic photoactuators: oligomeric Cry2 and heterodimeric LOVpep/ePDZ. Engineering single-chain photoswitches, we achieve four biomolecular organization patterns ranging from monomerization to phase separation. CORdensate exhibits constant assembly and disassembly kinetics. Applying CORdensate to mimic pathogenic RTK granules establishes the role of phase separation in activating ALK and RET. Moreover, assembling ALK and RET through varying organization patterns, we highlight the superior organizational ability of phase separation over multimerization. Additionally, CORdensate-based RTK granules suggest that phase separation broadly and robustly activates RTKs. This study introduces a optogenetic tool for investigating biomolecular condensation.

Abstract: The modification of key enzymes for chemical production plays a crucial role in enhancing the yield of targeted products. However, manipulating key nodes in specific signalling pathways remains constrained by traditional gene overexpression or knockout strategies. Discovering and designing optogenetic tools enable us to regulate enzymatic activity or gene expression at key nodes in a spatiotemporal manner, rather than relying solely on chemical induction throughout production processes. In this review, we discuss the recent applications of optogenetic tools in the regulation of microbial metabolites, plant sciences and disease therapies. We categorize optogenetic tools into five classes based on their distinct applications. First, light-induced gene expression schedules can balance the trade-off between chemical production and cell growth phases. Second, light-triggered liquid-liquid phase separation (LLPS) modules provide opportunities to co-localize and condense key enzymes for enhancing catalytic efficiency. Third, light-induced subcellular localized photoreceptors enable the relocation of protein of interest across various subcellular compartments, allowing for the investigation of their dynamic regulatory processes. Fourth, light-regulated enzymes can dynamically regulate production of cyclic nucleotides or investigate endogenous components similar with conditional depletion or recovery function of protein of interest. Fifth, light-gated ion channels and pumps can be utilized to investigate dynamic ion signalling cascades in both animals and plants, or to boost ATP accumulation for enhancing biomass or bioproduct yields in microorganisms. Overall, this review aims to provide a comprehensive overview of optogenetic strategies that have the potential to advance both basic research and bioindustry within the field of synthetic biology.

Abstract: Intracellular optogenetics represents a rapidly advancing biotechnology that enables precise, reversible control of protein activity, signaling dynamics, and cellular behaviours using genetically encoded, light-responsive systems. Originally pioneered in neuroscience through channelrhodopsins to manipulate neuronal excitability, the field has since expanded into diverse intracellular applications with broad implications for medicine, agriculture, and biomanufacturing. Key to these advances are photoreceptors such as cryptochrome 2 (CRY2), light-oxygen-voltage (LOV) domains, and phytochromes, which undergo conformational changes upon illumination to trigger conditional protein-protein interactions, localization shifts, or phase transitions. Recent engineering breakthroughs-including the creation of red-light responsive systems such as MagRed that exploit endogenous biliverdin-have enhanced tissue penetration, minimized phototoxicity, and expanded applicability to complex biological systems. This review provides an overarching synthesis of the molecular principles underlying intracellular optogenetic actuators, including the photophysical basis of light-induced conformational changes, oligomerization, and signaling control. We highlight strategies that employ domain fusions, rational mutagenesis, and synthetic circuits to extend their utility across biological and industrial contexts. We also critically assess current limitations, such as chromophore dependence, light delivery challenges, and safety considerations, so as to frame realistic paths towards translation. Looking ahead, future opportunities include multi-colour and multiplexed systems, integration with high-throughput omics and artificial intelligence, and development of non-invasive modalities suited for in vivo and industrial applications. Intracellular optogenetics is thus emerging as a versatile platform technology, with the potential to reshape how we interrogate biology and engineer cells for therapeutic, agricultural, and environmental solutions.

Abstract: Small GTPases are critical regulators of cellular processes, such as cell migration, and comprise a family of over 167 proteins in the human genome. Importantly, the location-dependent regulation of small GTPase activity is integral to coordinating cellular signaling. Currently, there are no generalizable methods for directly controlling the activity of these signaling enzymes with subcellular precision. To address this issue, we introduce a modular, optogenetic platform for the spatial control of small GTPase activity within living cells, termed spLIT-small GTPases. This platform enabled spatially precise control of cytoskeletal dynamics such as filopodia formation (spLIT-Cdc42) and directed cell migration (spLIT-Rac1). Furthermore, a spLIT-RhoA system uncovered previously unreported long-range RhoA signaling in HeLa cells, resulting in bipolar membrane retraction. These results establish spLIT-small GTPases as a versatile platform for the direct, spatial control of small GTPase signaling and demonstrate the ability to uncover spatially defined aspects of small GTPase signaling.

Abstract: Phospholipase C-γ1 (PLC-γ1) signaling is required for mesenchymal chemotaxis, but is it sufficient to bias motility? PLC-γ1 enzyme activity is basally autoinhibited, and light-controlled membrane recruitment of wild-type (WT) PLC-γ1 (OptoPLC-γ1) in Plcg1-null fibroblasts does not trigger lipid hydrolysis, complicating efforts to isolate its contribution. Utilizing cancer-associated mutations to investigate the regulatory logic of PLC-γ1, we demonstrate that the canonical hallmark of enzyme activity, phosphorylated Tyr783 (pTyr783), is not a proxy for activity level, but is rather a marker of dysregulated autoinhibition. Accordingly, OptoPLC-γ1 with a deregulating mutation (P867R, S345F, or D1165H) exhibits elevated phosphorylation, and membrane localization of such is sufficient to activate substrate hydrolysis and concomitant motility responses. In particular, local recruitment of OptoPLC-γ1 S345F polarizes cell motility on demand. This response is spatially dose-sensitive and only partially reduced by blocking canonical PLC-γ1 signaling yet is lipase-dependent. Our findings reframe the interpretation of PLC-γ1 regulation and demonstrate that local activation of PLC-γ1 is sufficient to direct cell motility.

Abstract: Cellular immunotherapy has transformed cancer treatment by harnessing T cells to target malignant cells. However, its broader adoption is hindered by challenges such as efficacy loss, limited persistence, tumor heterogeneity, an immunosuppressive tumor microenvironment (TME), and safety concerns related to systemic adverse effects. Optogenetics, a technology that uses light-sensitive proteins to regulate cellular functions with high spatial and temporal accuracy, offers a potential solution to overcome these issues. By enabling targeted modulation of T cell receptor signaling, ion channels, transcriptional programming, and antigen recognition, optogenetics provides dynamic control over T cell activation, cytokine production, and cytotoxic responses. Moreover, optogenetic strategies can be applied to remodel the TME by selectively activating immune responses or inducing targeted immune cell depletion, thereby enhancing T cell infiltration and immune surveillance. However, practical hurdles such as limited tissue penetration of visible light and the need for cell- or tissue-specific gene delivery must be addressed for clinical translation. Emerging solutions, including upconversion nanoparticles, are being explored to improve light delivery to deeper tissues. Future integration of optogenetics with existing immunotherapies, such as checkpoint blockade and adoptive T cell therapies, could improve treatment specificity, minimize adverse effects, and provide real-time control over immune responses. By refining the precision and adaptability of immunotherapy, optogenetics promises to further enhance both the safety and efficacy of cancer immunotherapy.

Abstract: Over the past two decades, optogenetics has evolved from a conceptual framework into a powerful and versatile technology for controlling cellular processes with light. Rooted in the discovery and characterization of natural photoreceptors, the field has advanced through the development of genetically encoded, light-sensitive proteins that enable precise spatiotemporal control of ion flux, intracellular signaling, gene expression, and protein interactions. This review traces key milestones in the emergence of optogenetics and highlights the development of major optogenetic tools. From the perspective of genetic tool innovation, the focus is on how these tools have been engineered and optimized for novel or enhanced functions, altered spectral properties, improved light sensitivity, subcellular targeting, and beyond. Their broadening applications are also explored across neuroscience, cardiovascular biology, hematology, plant sciences, and other emerging fields. In addition, current trends such as all-optical approaches, multiplexed control, and clinical translation, particularly in vision restoration are discussed. Finally, ongoing challenges are addressed and outline future directions in optogenetic tool development and in vivo applications, positioning optogenetics as a transformative platform for basic research and therapeutic advancement.