Curated Optogenetic Publication Database

Abstract: Autophagy, a conserved recycling process, manages intracellular quality control to mitigate stress. To determine the rapid effects of autophagy perturbation, we developed the first optogenetic tool to rapidly inhibit autophagy, termed ASAP. Our approach selectively inhibits autophagy within 5 minutes, providing a precise and dynamic approach to study autophagy regulation. Proteomic profiling with ASAP revealed the most tightly regulated autophagy substrates along with novel, previously unidentified substrates, including nuclear pore complex (NPC) proteins. Interestingly, autophagy regulates quality control of incomplete NPCs still in the cytoplasm via specific LC3-interacting regions (LIRs), sparing NPCs embedded in the nuclear envelope. Upon rapid autophagy inhibition, incomplete NPCs accumulate and instead of undergoing autophagic degradation, cytoplasmic NPCs aggregate in processing bodies. Using ASAP, we demonstrate rapid and specific inhibition of autophagy, revealing that the nuclear pore complex is a tightly regulated autophagy substrate.

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: Single-cell resolution studies have transformed our understanding of microbial systems, revealing substantial cell-to-cell heterogeneity and complex dynamic behaviors. This review describes recent advances in using optogenetics, where light-sensitive proteins control cellular processes, to investigate microbial behavior at the individual cell level. We discuss studies where optogenetic approaches have enabled high-resolution analysis of properties such as relative cell positioning, subcellular localization, morphology, and gene expression dynamics. In addition, we highlight emerging feedback and event-driven control methods that dynamically modulate cellular states using light signals. By leveraging light's unique capabilities for spatial and temporal manipulation, researchers can now probe cellular characteristics with unprecedented precision. We anticipate significant advances as researchers introduce more sophisticated dynamically patterned light signals for single-cell microbial research.

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: During vertebrate development, the segmentation clock drives oscillatory gene expression in the presomitic mesoderm (PSM), leading to the periodic formation of somites. Oscillatory gene expression is synchronized at the cell population level; inhibition of Delta-Notch signaling results in the loss of synchrony and the fusion of somites. However, it remains unclear how cell-cell signaling couples oscillatory gene expression and controls synchronization. Here, we report that synthetic cell-cell signaling using designed ligand-receptor pairs can induce synchronized oscillations in PSM organoids. Optogenetic assays uncovered that the intracellular domains of synthetic ligands play key roles in dynamic cell-cell communication. Oscillatory coupling using synthetic cell-cell signaling recovered the synchronized oscillation in PSM cells deficient for Delta-Notch signaling; nonoscillatory coupling did not induce recovery. This study reveals the mechanism by which ligand-receptor molecules coordinate the synchronization of the segmentation clock and provides a way to program temporal gene expression in organoids and artificial tissues.

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: Outer mitochondrial membranes (OMM) function as dynamic hubs for inter-organelle communication, integrating bidirectional signals, and coordinating organelle behavior in a context-dependent manner. However, tools for mapping mitochondrial surface proteomes with high spatial and temporal resolution remain limited. Here, we introduce an optogenetic proximity labeling strategy using LOV-Turbo, a light-activated biotin ligase, to profile mitochondrial surface proteomes with improved precision, temporal control, and reduced background. By fusing LOV-Turbo to a panel of variants of an OMM-anchored protein, Miro1, we generate spatially distinct baits that resolve modular architectures and regulatory states of the OMM proteomes across diverse conditions, a database we name MitoSurf. Building on this proteomic map, we present RiboLOOM, a platform that defines LOV-Turbo labeled ribosomes and their bound mRNAs at the mitochondrial surface. MitoSurf and RiboLOOM uncover a spatially distinct ribosome pool at the OMM that is maintained by Miro1, enabling local mRNA engagement and translation of mitochondria-related proteins. These findings establish Miro1 as a key organizer of mitochondrial protein biogenesis through spatial confinement of surface-associated ribosomes. Our platform reveals an uncharted layer of mitochondrial surface biology and provides a generalizable strategy to dissect dynamic RNA-protein-organelle interfaces in living cells.

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: 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: The CRISPR-Cas9 system has been proven to be a powerful tool for gene editing in living cells and shows great potential in genetic disease treatment. Anti-CRISPR (Acr)-based optogenetic tools could spatiotemporally regulate the activity of CRISPR-Cas9, thereby improving the precision and safety of gene editing. However, these tools could only regulate a certain Cas9 protein because of the high specificity of Acr used, limiting their further application. In this study, we developed a new optogenetic tool named CASANOVA-A5 (CRISPR-Cas9 activity switching via a novel optogenetic variant of AcrIIA5) by inserting the blue light sensor AsLOV2 into AcrIIA5 with a broad inhibition spectrum. We proved that the CASANOVA-A5 could regulate the gene editing activity of SpCas9, SaCas9, NmeCas9, and St1Cas9 in a blue light-dependent manner. Additionally, we engineered AcrIIA5-LOV9 by integrating the blue light-dependent degron module LOV9, showing obvious optical regulation for SpCas9. Together, our work demonstrates two feasible methods to engineer the Acrs to potent optogenetic tools and suggests systematic strategies for further optimization.

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: Tumor initiation remains one of the least understood events in cancer biology, largely due to the challenge of dissecting the intricacy of the tumorigenic process in laboratory settings. The insufficient biological complexity of conventional in vitro systems makes animal models the primary experimental approach to study tumorigenesis. Despite providing valuable insights, these in vivo models function as experimental black boxes with limited spatiotemporal resolution of cellular dynamics during oncogenesis. In addition, their use raises ethical concerns, further underscoring the need for alternative ex vivo systems. Here we provide a detailed protocol to integrate state-of-the-art microfabrication, tissue engineering and optogenetic approaches to generate topobiologically complex miniature colons ('mini-colons') capable of undergoing tumorigenesis in vitro. We describe the key methodology for the generation of blue light-inducible oncogenic cells, the establishment of hydrogel-based mini-colon scaffolds within microfluidic devices, the development of mini-colons and the induction of spatiotemporally controlled tumorigenesis. This protocol enables the formation and long-term culture of complex cancerous tissues that capture in vivo-like tumoral biology while offering real-time and single-cell resolution analyses. It can be implemented in 4-6 weeks by researchers with prior experience in 3D cell culture techniques. We anticipate that these methodological guidelines will have a broad impact on the cancer research community by opening new avenues for tumorigenesis studies.

Abstract: Light Oxygen Voltage (LOV) domains are important widespread receptors of blue light that also found applications in optogenetics and imaging. While LOV domains from mesophiles are relatively well characterized, their counterparts from thermophilic microorganisms remain understudied. Here, we express two constructs of a LOV domain belonging to a histidine kinase from Meiothermus ruber, MrLOV and MrLOVe, and show that they are photoactive, with recovery time values of 21 and 27 min, respectively, and thermostable. Crystal structures reveal that MrLOV, which lacks helices A'α and Jα, forms a parallel dimer, whereas MrLOVe is a tetramer organized as an antiparallel dimer of two parallel dimers interacting via helices Jα. One MrLOVe dimer is symmetric, and the other is asymmetric, with conformational differences mirroring activation-related changes in other LOV domains. Our data provide the structural basis for understanding and engineering of thermophilic LOVs and pave the way for development of thermostable and photostable LOV-derived optogenetic tools and flavin-based fluorescent proteins.

Abstract: Saccharomyces cerevisiae is a widely used chassis in metabolic engineering. Due to the Crabtree effect, it preferentially produces ethanol under high-glucose conditions, limiting the synthesis of other valuable metabolites. Conventional metabolic engineering approaches typically rely on irreversible genetic modifications, making it insufficient for dynamic metabolic control. In contrast, optogenetics offers a reversible and tunable method for regulating cellular metabolism with high temporal precision. In this study, we engineered the pyruvate decarboxylase isozyme 1 (Pdc1) by inserting the photosensory modules (AsLOV2 and cpLOV2 domains) into rationally selected positions within the enzyme. Through a growth phenotype-based screening system, we identified two blue light-responsive variants, OptoPdc1D1 and OptoPdc1D2, which enable light-dependent control of enzymatic activity. Leveraging these OptoPdc1 variants, we developed opto-S. cerevisiae strains, MLy-9 and MLy-10, which demonstrated high efficiency in modulating both cell growth and ethanol production. These strains allow reliable regulation of ethanol biosynthesis in response to blue light, achieving a dynamic control range of approximately 20- to 120-fold. The opto-S. cerevisiae strains exhibited dose-dependent production in response to blue light intensity and pulse patterns, confirming their potential for precise metabolic control. This work establishes a novel protein-level strategy for regulating metabolic pathways in S. cerevisiae and introduces an effective method for controlling ethanol metabolism via optogenetic regulation.

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 efficacy of antitumor immunotherapy is closely associated with the expansion of tumor-infiltrating CD8+ T cells. However, within the tumor microenvironment, CD8+ T cells often exhibit reduced proliferation due to persistent exposure to tumor antigens. The cytokine IL-2 is a potent growth factor that can drive the expansion of tumor-infiltrating lymphocytes. While its clinical application has been severely limited by systemic toxicity and in vivo instability. To address these challenges, we have developed a dual-responsive system (EcNIL-2@UCNP/Gel-CTX) leveraging the hypoxic tropisms of E. coli Nissle 1917(EcN). This system is capable of producing IL-2 in situ upon near-infrared (NIR) irradiation and releasing low-dose cyclophosphamide (CTX) in response to matrix metalloproteinase-2 (MMP-2) in the tumor microenvironment. The EcNIL-2@UCNP/Gel-CTX system not only drives the expansion of CD8+ T cells and boost the activity of NK cells but also reduces Treg cell populations, thereby remodeling the immune microenvironment and eliciting robust tumor-specific immune responses in H22 subcutaneous tumors in mice and confers long-term protection against tumor rechallenge by promoting the generation of durable memory T cells. Our findings provide an both light and tumor microenvironment responsive platform for enhanced cancer immunotherapy.

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: Coenzyme Q10 biosynthesis in Escherichia coli is constrained by kinetic mismatches between precursor synthesis and methylation, alongside bioenergetic uncoupling. We implemented an optogenetic phase-control strategy integrating dynamic light induction, ribosome binding site (RBS) engineering, and real-time membrane potential (ΔΨ) feedback. Temporal coordination of 1-deoxy-D-xylulose-5-phosphate synthase (DXS) and UbiG methyltransferase (UbiG) via a 6-h phase delay reduced methylglyoxal shunt flux by 41 ± 3% (p < 0.01) through enhanced precursor channeling. Membrane hyperpolarization to - 90 ± 2 mV (relative to - 70 mV in controls) triggered voltage-gated UbiG membrane localization (62 ± 3%) and ATP-driven S-adenosylmethionine regeneration, increasing methylation efficiency 2.3-fold. Multivariate modeling identified ΔΨ and acetate as critical control parameters, enabling optimized fermentation (dissolved oxygen (DO) 15-20%, pH 6.7-6.9). The engineered strain achieved 0.63 ± 0.07 g/L CoQ10 in 5-L bioreactors-a 4.3-fold improvement over the static control strain (0.15 ± 0.02 g/L)-with 82.5% carbon efficiency and 25.8% glycerol-to-product yield. This work establishes bioenergetically coupled temporal control as a scalable paradigm for membrane-bound isoprenoid biomanufacturing. KEY POINTS: • Phase-driven enzyme synchronization via optogenetics resolves kinetic mismatch. • Membrane hyperpolarization gates enzyme localization and ATP regeneration. • Model-integrated bioenergetic-process control enhances CoQ10 production efficiency.

Abstract: The soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein syntaxin mediates neuronal exocytosis and self-assembles into large clusters in the plasma membrane. The formation and function of these clusters, and whether they promote or inhibit synaptic-vesicle fusion, remain unclear. Here using optogenetic control of syntaxin clustering in vitro and in vivo, as a light-inducible gain-of-function assay, we show that light-enhanced clustering reduces both spontaneous and triggered vesicle fusion, and this impairs mouse hunting behavior. Cluster formation is induced by liquid-liquid phase separation (LLPS) of the SNARE domain of syntaxin. For the regulatory mechanism, Munc18, which is known to alter syntaxin conformation, acts to reduce LLPS for cluster formation, thereby promoting active syntaxin. These results suggest that exocytosis regulation involves LLPS-induced syntaxin clusters that serve as a syntaxin reservoir from which Munc18 captures syntaxin monomers to form a syntaxin-Munc18 complex, setting the stage for efficient fusion.

Abstract: Precise control of gene expression is one of the fundamental goals of synthetic biology. Whether the objective is to modify endogenous cellular function or induce the expression of molecules for diagnostic and therapeutic purposes, gene regulation remains a key aspect of biological systems. Over time, advances in protein engineering and molecular biology have led to the creation of gene circuits capable of inducing the expression of specific proteins in response to external stimulus such as light. These optogenetic, or light-activated circuits hold significant potential for gene therapy as a tool for regulating the expression of therapeutic genes within cells. However, the applications of optogenetic systems can be limited by the lack of efficient ways for light delivery inside cells or tissue. Our approach to address this challenge is to harness the power of bioluminescence to produce light directly inside cells using a luminescent enzyme. Combined with a photosensitive transcription factor, we report the development of a fully genetically encoded optogenetic circuit for control of gene expression. Furthermore, we utilized a magneto sensitive protein to engineer a split protein version of this luminescent enzyme, where its reconstitution is driven by a 50mT magnetic stimulus. Thus, resulting in a first-of-its-kind gene circuit activated by a combination of light and magnetic stimulus. We expect this work to advance the implementation of light-controlled systems without the need of external light sources, as well as serve as a basis for the development of future magneto-sensitive tools.