Curated Optogenetic Publication Database

Abstract: The genome folds inside the cell nucleus into hierarchical architectural features, such as chromatin loops and domains. If and how this genome organization influences the regulation of gene expression remains only partially understood. The structure-function relationship of genomes has traditionally been probed by population-wide measurements after mutation of critical DNA elements or by perturbation of chromatin-associated proteins. To circumvent possible pleiotropic effects of such approaches, we have developed OptoLoop, an optogenetic system that allows direct manipulation of chromatin contacts by light in a controlled fashion. OptoLoop is based on the fusion between a nuclease-dead SpCas9 protein and the light-inducible oligomerizing protein CRY2. We demonstrate that OptoLoop can drive the induction of contacts between genomically distant, repetitive DNA loci. As a proof-of-principle application of OptoLoop, we probed the functional role of DNA looping in the regulation of the human telomerase gene TERT by long-range contacts with the telomere. By analyzing the extent of chromatin looping and nascent RNA production at individual alleles, we find evidence for looping-mediated repression of TERT. In sum, OptoLoop represents a novel means for the interrogation of structure-function relationships in the genome at single-allele resolution.

Abstract: Inducible gene expression tools can open novel applications in human health and biotechnology, but current options are often expensive, difficult to reverse, and have undesirable off-target effects. Optogenetic systems use light-responsive proteins to control the activity of regulators such that expression is controlled with the "flip of a switch". This study optimizes a simplified light activated CRISPR effector (2pLACE) system, which provides tunable, reversible, and precise control of mammalian gene expression. The OptoPlate-96 enables high-throughput screening via flow cytometry for single-cell analysis and rapid optimization of 2pLACE. This study demonstrates how to use the 2pLACE system with the OptoPlate-96 in HEK293T cells to identify the optimal component ratios for maximizing dynamic range and to find the blue light intensity response curve. Similar workflows can be developed for other mammalian cells and for other optogenetic systems and wavelengths of light. These advancements enhance the precision, scalability, and adaptability of optogenetic tools for biomanufacturing applications.

Abstract: Microtubules (MTs) form dynamic cytoskeletal scaffolds essential for intracellular transport, organelle positioning, and spatial organization of signaling. Their architecture and function are continuously remodeled through the concerted actions of microtubule-associated proteins (MAPs), post-translational modifications (PTMs), and molecular motors. To precisely interrogate these processes in living systems, we developed a genetically encoded optogenetic toolkit for spatiotemporal control of MT organization and dynamics. By replacing native multimerization motifs with a blue light-responsive oligoermization domain, we have engineered single-component probes, OptoMT and OptoTIP, that reversibly label MT polymers or track plus-ends with tunable kinetics from seconds to minutes. When coupled to enzymatic effectors, these modules enable localized tubulin acetylation or detyrosination, directly linking PTMs to MT stability. We further engineered OptoMotor, a light-activatable kinesin platform that reconstitutes tail-dependent cargo transport along MTs, and OptoSAW, a light-triggered severing actuator for controlled MT disassembly. Using these tools, we reveal how local MT integrity governs lysosomal trafficking and ER-associated signaling dynamics. Collectively, this versatile single-component toolkit bridges molecular design with cytoskeletal function, offering new avenues to illuminate how dynamic cytoskeletal architectures coordinate intracellular organization, transport, and signaling.

Abstract: The response of cell populations to external stimuli plays a central role in biological mechanical processes such as epithelial wound healing and developmental morphogenesis. Wave-like propagation of a signal of ERK MAP kinase has been shown to direct collective migration in one direction; however, the mechanism based on continuum mechanics under a traveling wave is not fully understood. To elucidate how the traveling wave of the ERK kinase signal directs collective migration, we constructed the mechanical model of the epithelial cell monolayer by considering the signal-dependent coordination of contractile stress and cellular orientation. The proposed model was studied by using an optogenetically controlled cell system where we found that local signal activation induces changes in cell density and orientation with the direction of propagation. The net motion of the cell population occurred relative to the wave, and the migration velocity showed a maximum in resonance with the velocity of the ERK signal wave. The presented mechanical model was further validated in an in vitro wound healing process.

Abstract: In adherent cells, actomyosin contractility is regulated mainly by the RhoA signaling pathway, which can be controlled by optogenetics. To model the mechanochemical coupling in such systems, we introduce a finite element framework based on the discontinuous Galerkin method, which allows us to treat cell doublets, chains of cells, and monolayers within the same conceptual framework. While the adherent cell layer is modeled as an actively contracting viscoelastic solid on an elastic foundation, different models are considered for the Rho pathway, starting with a simple linear chain that can be solved analytically and later including direct feedback that can be solved only numerically. Our model predicts signal propagation as a function of coupling strength and viscoelastic timescales and identifies the conditions for optimal cell responses and wave propagation. In general, it provides a systematic understanding of how biochemistry and mechanics simultaneously contribute to the communication of adherent cells.

Abstract: During development, epithelia function as malleable sheets that undergo extensive remodeling to shape developing embryos. Optogenetic control of Rho signaling provides an avenue to investigate mechanisms of epithelial morphogenesis, but transgenic optogenetic tools can be limited by variability in expression levels and deleterious effects of transgenic overexpression on development. Here, we use CRISPR/Cas9 to tag Drosophila RhoGEF2 and Cysts/Dp114RhoGEF with components of the iLID/SspB optogenetic heterodimer, permitting light-dependent control over endogenous protein activities. Using quantitative optogenetic perturbations, we uncover a dose-dependence of tissue furrow depth and bending behavior on RhoGEF recruitment, revealing mechanisms by which developing embryos can shape tissues into particular morphologies. We show that at the onset of gastrulation, furrows formed by cell lateral contraction are oriented and size-constrained by basal actomyosin. Our findings demonstrate the use of quantitative, 3D-patterned perturbations of cell contractility to precisely shape tissue structures and interrogate developmental mechanics.

Abstract: Methods for monitoring physiological changes in cellular Ca2+ levels have been in high demand for their utility in monitoring neuronal signaling. Recently, we introduced SCANR (Split-Tobacco Etch Virus (TEV) protease Calcium-regulated Neuron Recorder), which reports on Ca2+ changes in cells through the binding of calmodulin and M13 to reconstitute an active TEV protease. First-generation SCANR marked all of the Ca2+ spikes that occur throughout the lifetime of the cell, but it did not have a mechanism for controlling the time window in which recording of physiological changes in Ca2+ occurred. Here, we explore both chemical and light-based strategies for controlling the time and place in which Ca2+ recording occurs. We describe the adaptation of six popular chemo- and opto-genetics methods for controlling protein activity and subcellular localization to the SCANR system. We report two successful strategies, one that leverages the LOV-Jα optogenetics system for sterically controlling protein interactions and another that employs chemogenetic manipulation of subcellular protein distribution using the FKBP/FRB rapamycin binding pair.

Abstract: p53 protein, a crucial transcription factor in cellular responses to a wide variety of stress, regulates multiple target genes involved in tumor suppression, senescence induction, and metabolic functions. To characterize the context-dependent roles of p53, it is still needed to develop an experimental system that enables selective activation of p53 in cells and tissues. In this study, we developed an optogenetic tool, Opto-p53, to control p53 signaling by light. Opto-p53 was designed to trigger p53 signaling by reconstituting p53 N-terminal and C-terminal fragments with a light-inducible dimerization (LID) system. Upon light exposure, cells expressing Opto-p53 demonstrated p53 transcriptional activation, resulting in cell death and cell cycle arrest. We further enhanced the efficacy of light-induced p53 activation by introducing specific mutations into Opto-p53 fragments. Our findings unveil the capability of Opto-p53 to serve as a powerful tool for dissecting the complex roles of p53 in cellular processes, thereby contributing to the field of synthetic biology and providing general design principles for optogenetic tools using endogenous transcription factors.Key words: synthetic biology, transcriptional factor, p53, optogenetics.

Abstract: Optogenetic systems use light-responsive proteins to control gene expression, ion channels, protein localization, and signaling with the "flip of a switch". One such tool is the light activated CRISPR effector (LACE) system. Its ability to regulate gene expression in a tunable, reversible, and spatially resolved manner makes it attractive for many applications. However, LACE relies on delivery of four separate components on individual plasmids, which can limit its use. Here, we optimize LACE to reduce the number of plasmids needed to deliver all four components.

Abstract: Lipid droplets (LDs) are dynamic organelles crucial for lipid storage and homeostasis. Despite extensive documentation of their importance, the causal relationship between LD localization and function in health and disease remains inadequately understood. Here, we developed optogenetics-based tools, termed "Opto-LDs," which facilitate the interaction between LDs and motor proteins in a light-dependent manner, enabling precise control of LD localization within cells. Utilizing these optogenetic modules, we demonstrated that light-induced relocation of LDs to the periphery of hepatocytes results in elevated very-low-density lipoprotein (VLDL) secretion, recapturing the beneficial effect of insulin in vitro. Furthermore, our studies in transgenic Drosophila revealed that proper LD localization is critical for embryonic development, with mistargeting of LDs significantly affecting egg hatching success. In summary, our work underscores the great importance of LD localization in lipid metabolism and development, and our developed tools offer valuable insights into the functions of LDs in health and disease.

Abstract: Membrane receptors, particularly G protein-coupled receptors (GPCRs), are integral to numerous physiological processes. Precise control of the receptor endocytosis is essential for understanding cellular signaling pathways. In this study, we present the development of a broadly applicable optogenetic tool for light-inducible receptor internalization. This system, named E-fragment, leverages the CRY2-CIB photodimerization pair to enable blue-light-dependent recruitment of β-arrestin and subsequent receptor internalization. We showed that the E-fragment system is applicable across diverse membrane proteins, including multiple GPCRs. Furthermore, we investigated its impact on intracellular cAMP signaling in cells expressing dopamine receptor D1 and α2-adrenergic receptor. Quantitative analyses revealed that light-induced internalization led to reduced surface receptor expression and attenuated ligand-evoked cAMP responses. These findings demonstrate the versatility of the E-fragment system as a platform for studying membrane receptor function and suggest potential applications in therapeutic strategies targeting receptor trafficking and signaling modulation.

Abstract: Red light, characterized by superior tissue penetration and minimal phototoxicity, represents an ideal wavelength for optogenetic applications. However, the existing tools for reversible protein inhibition by red light remain limited. Here, we introduce R-LARIAT (red light-activated reversible inhibition by assembled trap), a novel optogenetic system enabling precise spatiotemporal control of protein function via 660 nm red-light-induced protein clustering. Our system harnesses the rapid and reversible binding of engineered light-dependent binders (LDBs) to the bacterial phytochrome DrBphP, which utilizes the endogenous mammalian biliverdin chromophore for red light absorption. By fusing LDBs with single-domain antibodies targeting epitope-tagged proteins (e.g., GFP), R-LARIAT enables the rapid sequestration of diverse proteins into light-responsive clusters. This approach demonstrates high light sensitivity, clustering efficiency, and sustained stability. As a proof of concept, R-LARIAT-mediated sequestration of tubulin inhibits cell cycle progression in HeLa cells. This system expands the optogenetic toolbox for studying dynamic biological processes with high spatial and temporal resolution and holds the potential for applications in living tissues.

Abstract: Post-translational modifications (PTMs) are indispensable modulators of protein activity. Most cellular behaviors, from cell division to cytoskeletal organization, are controlled by PTMs, their misregulation being associated with a plethora of human diseases. Traditionally, the role of PTMs has been studied employing biochemical techniques. However, these approaches fall short when studying PTM dynamics in vivo. In recent years, functionalized protein binders have allowed the PTM of endogenous proteins by bringing an enzymatic domain in close proximity to the protein they recognize. To date, most of these methods lack the temporal control necessary to understand the complex effects triggered by PTMs. In this study, we have developed a method to phosphorylate endogenous Myosin in a light-inducible manner. The method relies both on nanobody-targeting and light-inducible activation in order to achieve both tight specificity and temporal control. We demonstrate that this technology is able to disrupt cytoskeletal dynamics during Drosophila embryonic development. Together, our results highlight the potential of combining optogenetics and protein binders for the study of the proteome in multicellular systems.

Abstract: Ferroptosis is a lytic, iron-dependent form of regulated cell death characterized by excessive lipid peroxidation and associated with necrosis spread in diseased tissues through unknown mechanisms. Using a novel optogenetic system for light-driven ferroptosis induction via degradation of the anti-ferroptotic protein GPX4, we show that lipid peroxidation and ferroptotic death can spread to neighboring cells through their closely adjacent plasma membranes. Ferroptosis propagation is dependent on cell distance and completely abolished by disruption of α-catenin-dependent intercellular contacts or by chelation of extracellular iron. Remarkably, bridging cells with a lipid bilayer or increasing contacts between neighboring cells enhances ferroptosis spread. Reconstitution of iron-dependent spread of lipid peroxidation between pure lipid, contacting liposomes provides evidence for the physicochemical mechanism involved. Our findings support a model in which iron-dependent lipid peroxidation propagates across proximal plasma membranes of neighboring cells, thereby promoting the transmission of ferroptotic cell death with consequences for pathological tissue necrosis spread.

Abstract: There is currently a lack of tools capable of perturbing genes in both a precise and a spatiotemporal fashion. The flexibility of CRISPR (clustered regularly interspaced short palindromic repeats), coupled with light's unparalleled spatiotemporal resolution deliverable from a controllable source, makes optogenetic CRISPR a well-suited solution for precise spatiotemporal gene perturbations. Here, we present a new optogenetic CRISPR tool (Blue Light-inducible Universal VPR-Improved Production of RGRs, BLU-VIPR) that diverges from prevailing split-Cas design strategies and instead focuses on optogenetic regulation of guide RNA (gRNA) production. We engineered BLU-VIPR around a new potent blue-light activated transcription factor (VPR-EL222) and ribozyme-flanked gRNA. The BLU-VIPR design is genetically encoded and ensures precise excision of multiple gRNAs from a single messenger RNA transcript. This simplified spatiotemporal gene perturbation and allowed for several types of optogenetic CRISPR, including indels, CRISPRa, and base editing. BLU-VIPR also worked in vivo with cells previously intractable to optogenetic gene editing, achieving optogenetic gene editing in T lymphocytes in vivo.

Abstract: Calcium (Ca2+) release from intracellular stores, Ca2+ entry across the plasma membrane, and their coordination via store-operated Ca2+ entry (SOCE) are critical for receptor-activated Ca2+ oscillations. However, the precise mechanism of Ca2+ oscillations and whether their control loop resides at the plasma membrane or intracellularly remain unresolved. By examining the dynamics of stromal interaction molecule 1 (STIM1), an endoplasmic reticulum (ER)-localized Ca2+ sensor that activates the Orai1 channel on the plasma membrane for SOCE and in mast cells, we found that a significant proportion of cells exhibited STIM1 oscillations with the same periodicity as Ca2+ oscillations. These cortical oscillations, occurring in the cell's cortical region and shared with ER-plasma membrane (ER-PM) contact site proteins, were only detectable using total internal reflection fluorescence microscopy (TIRFM). Notably, STIM1 oscillations could occur independently of Ca2+ oscillations. Simultaneous imaging of cytoplasmic Ca2+ and ER Ca2+ with SEPIA-ER revealed that receptor activation does not deplete ER Ca2+, whereas receptor activation without extracellular Ca2+ influx induces cyclic ER Ca2+ depletion. However, under such nonphysiological conditions, cyclic ER Ca2+ oscillations lead to sustained STIM1 recruitment, indicating that oscillatory Ca2+ release is neither necessary nor sufficient for STIM1 oscillations. Using optogenetic tools to manipulate ER-PM contact site dynamics, we found that persistent ER-PM contact sites reduced the amplitude of Ca2+ oscillations without alteration of oscillation frequency. Together, these findings suggest an active cortical mechanism governs the rapid dissociation of ER-PM contact sites, thereby controlling the amplitude of oscillatory Ca2+ dynamics during receptor-induced Ca2+ oscillations.

Abstract: Talin regulates the adhesion and migration of cells in part by promoting the affinity of integrins for extracellular matrix proteins, a process that in cells such as endothelial cells and platelets requires the direct interaction of talin with both the small GTPase Rap1 bound to GTP (Rap1-GTP) and the integrin β3 cytoplasmic tail. To study this process in more detail, we employed an optogenetic approach in living, immortalized endothelial cells to be able to regulate the interaction of talin with the plasma membrane. Previous studies identified talin as the Rap1-GTP effector for β3 integrin activation. Surprisingly, optogenetic recruitment of talin-1 (TLN1; herein referred to as talin) to the plasma membrane also led to the localized activation of Rap1 itself, apparently by talin competing for Rap1-GTP with SHANK3, a protein known to sequester Rap1-GTP and to block integrin activation. Rap1 activation by talin was localized to the cell periphery in suspension cells and within lamellipodia and pseudopodia in cells adherent to fibronectin. Thus, membrane-associated talin can play a dual role in regulating integrin function in endothelial cells: first, by releasing Rap1-GTP from its sequestration by SHANK3, and second, by serving as the relevant Rap1 effector for integrin activation.

Abstract: G-protein-coupled receptors (GPCRs) are efficient guanine nucleotide exchange factors (GEFs) and exchange GDP to GTP on the Gα subunit of G-protein heterotrimers in response to various extracellular stimuli, including neurotransmitters and light. GPCRs primarily broadcast signals through activated G proteins, GαGTP and free Gβγ and are major disease drivers. Evidence shows that the ambient low threshold signalling required for cells is likely supplemented by signalling regulators such as non-GPCR GEFs and guanine nucleotide dissociation inhibitors (GDIs). Activators of G-protein signalling 3 (AGS3) are recognized as a GDI involved in multiple health and disease-related processes. Nevertheless, understanding of AGS3 is limited, and no significant information is available on its structure-function relationship or signalling regulation in living cells. Here, we employed in silico structure-guided engineering of a novel optogenetic GDI, based on the AGS3's G-protein regulatory motif, to understand its GDI activity and induce standalone Gβγ signalling in living cells on optical command. Our results demonstrate that plasma membrane recruitment of OptoGDI efficiently releases Gβγ, and its subcellular targeting generated localized PIP3 and triggered macrophage migration. Therefore, we propose OptoGDI as a powerful tool for optically dissecting GDI-mediated signalling pathways and triggering GPCR-independent Gβγ signalling in cells and in vivo.

Abstract: The regulation of PKC epsilon (PKCε) and its downstream effects is still not fully understood, making it challenging to develop targeted therapies or interventions. A more precise tool that enables spatiotemporal control of PKCε activity is thus required. Here, we describe a photo-activatable optogenetic PKCε probe (Opto-PKCε) consisting of an engineered PKCε catalytic domain and a blue-light inducible dimerization domain. Molecular dynamics and AlphaFold simulations enable rationalization of the dark-light activity of the optogenetic probe. We first characterize the binding partners of Opto-PKCε, which are similar to those of PKCε. Subsequent validation of the Opto-PKCε tool is performed with phosphoproteome analysis, which reveals that only PKCε substrates are phosphorylated upon light activation. Opto-PKCε could be engineered for recruitment to specific subcellular locations. Activation of Opto-PKCε in isolated hepatocytes reveals its sustained activation at the plasma membrane is required for its phosphorylation of the insulin receptor at Thr1160. In addition, Opto-PKCε recruitment to the mitochondria results in its lowering of the spare respiratory capacity through phosphorylation of complex I NDUFS4. These results demonstrate that Opto-PKCε may have broad applications for the studies of PKCε signaling with high specificity and spatiotemporal resolution.

Abstract: The balance of mitochondrial fission and fusion plays an important role in maintaining the stability of cellular homeostasis. Abnormal mitochondrial fission and fragmentation have been shown to be associated with oxidative stress, which causes a variety of human diseases from neurodegeneration disease to cancer. Therefore, the induction of mitochondrial aggregation and fusion may provide an alternative approach to alleviate these conditions. Here, an optogenetic-based mitochondrial aggregation system (Opto-MitoA) developed, which is based on the CRY2clust/CIBN light-sensitive module. Upon blue light illumination, CRY2clust relocates from the cytosol to mitochondria where it induces mitochondrial aggregation by CRY2clust homo-oligomerization and CRY2clust-CIBN hetero-dimerization. Our functional experiments demonstrate that Opto-MitoA-induced mitochondrial aggregation potently alleviates niclosamide-caused cell dysfunction in ATP production. This study establishes a novel optogenetic-based strategy to regulate mitochondrial dynamics in cells, which may provide a potential therapy for treating mitochondrial-related diseases.

Abstract: Most bacteria lack membrane-enclosed organelles and rely on macromolecular scaffolds at different subcellular locations to recruit proteins for specific functions. Here, we demonstrate that the optogenetic CRY2-CIB1 system from Arabidopsis thaliana can be used to rapidly direct proteins to different subcellular locations with varying efficiencies in live Escherichia coli cells, including the nucleoid, the cell pole, the membrane, and the midcell division plane. Such light-induced re-localization can be used to rapidly inhibit cytokinesis in actively dividing E. coli cells. We further show that CRY2-CIBN binding kinetics can be modulated by green light, adding a new dimension of control to the system. Finally, we test this optogenetic system in three additional bacterial species, Bacillus subtilis, Caulobacter crescentus, and Streptococcus pneumoniae, providing important considerations for this system's applicability in bacterial cell biology.

Abstract: Starvation, which is associated with inactivation of the growth-promoting TOR complex 1 (TORC1), is a strong environmental signal for cell differentiation. In the fission yeast Schizosaccharomyces pombe, nitrogen starvation has distinct physiological consequences depending on the presence of mating partners. In their absence, cells enter quiescence, and TORC1 inactivation prolongs their life. In presence of compatible mates, TORC1 inactivation is essential for sexual differentiation. Gametes engage in paracrine pheromone signaling, grow towards each other, fuse to form the diploid zygote, and form resistant, haploid spore progenies. To understand the signaling changes in the proteome and phospho-proteome during sexual reproduction, we developed cell synchronization strategies and present (phospho-)proteomic data sets that dissect pheromone from starvation signals over the sexual differentiation and cell–cell fusion processes. Unexpectedly, these data sets reveal phosphorylation of ribosomal protein S6 during sexual development, which we establish requires TORC1 activity. We demonstrate that TORC1 is re-activated by pheromone signaling, in a manner that does not require autophagy. Mutants with low TORC1 re-activation exhibit compromised mating and poorly viable spores. Thus, while inactivated to initiate the mating process, TORC1 is reactivated by pheromone signaling in starved cells to support sexual reproduction.

Abstract: Collective cell migration is key during development, wound healing, and metastasis and relies on coordinated cell behaviors at the group level. Src kinase is a key signalling protein for the physiological functions of epithelia, as it regulates many cellular processes, including adhesion, motility, and mechanotransduction. Its overactivation is associated with cancer aggressiveness. Here, we take advantage of optogenetics to precisely control Src activation in time and show that its pathological-like activation slows the collective rotation of epithelial cells confined into circular adhesive patches. We interpret velocity, force, and stress data during period of non-activation and period of activation of Src thanks to a hydrodynamic description of the cell assembly as a polar active fluid. Src activation leads to a 2-fold decrease in the ratio of polar angle to friction, which could result from increased adhesiveness at the cell-substrate interface. Measuring internal stress allows us to show that active stresses are subdominant compared to traction forces. Our work reveals the importance of fine-tuning the level of Src activity for coordinated collective behaviors.

Abstract: The post-translational modification of intracellular proteins through O-linked β-N-acetylglucosamine (O-GlcNAc) is a conserved regulatory mechanism in multicellular organisms. Catalyzed by O-GlcNAc transferase (OGT), this dynamic modification has an essential role in signal transduction, gene expression, organelle function and systemic physiology. Here, we present Opto-OGT, an optogenetic probe that allows for precise spatiotemporal control of OGT activity through light stimulation. By fusing a photosensitive cryptochrome protein to OGT, Opto-OGT can be robustly and reversibly activated with high temporal resolution by blue light and exhibits minimal background activity without illumination. Transient activation of Opto-OGT results in mTORC activation and AMPK suppression, which recapitulate nutrient-sensing signaling. Furthermore, Opto-OGT can be customized to localize to specific subcellular sites. By targeting OGT to the plasma membrane, we demonstrate the downregulation of site-specific AKT phosphorylation and signaling outputs in response to insulin stimulation. Thus, Opto-OGT is a powerful tool for defining the role of O-GlcNAcylation in cell signaling and physiology.

Abstract: Intracellular trafficking, an extremely complex network, dynamically orchestrates nearly all cellular activities. A versatile method that enables the manipulation of target transport pathways with high spatiotemporal accuracy in vitro and in vivo is required to study how this network coordinates its functions. Here, a new method called RIVET (Rapid Immobilization of target Vesicles on Engaged Tracks) is presented. Utilizing inducible dimerization between target vesicles and selective cytoskeletons, RIVET can spatiotemporally halt numerous intracellular trafficking pathways within seconds in a reversible manner. Its highly specific perturbations allow for the real-time dissection of the dynamic relationships among different trafficking pathways. Moreover, RIVET is capable of inhibiting receptor-mediated endocytosis. This versatile system can be applied from the cellular level to whole organisms. RIVET opens up new avenues for studying intracellular trafficking under various physiological and pathological conditions and offers potential strategies for treating trafficking-related disorders.