Curated Optogenetic Publication Database

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: Protein homeostasis, or proteostasis, is essential for cellular proteins to function properly. The buildup of abnormal proteins (such as damaged, misfolded, or aggregated proteins) is associated with many diseases, including cancer. Therefore, maintaining proteostasis is critical for cellular health. Currently, genetic methods for modulating proteostasis, such as RNA interference and CRISPR knockout, lack spatial and temporal precision. They are also not suitable for depleting already-synthesized proteins. Similarly, molecular tools like PROTACs and molecular glue face challenges in drug design and discovery. To directly control targeted protein degradation within cells, we introduce an intrabody-based optogenetic toolbox named Flash-Away. Flash-Away integrates the light-responsive ubiquitination activity of the RING domain of TRIM21 for protein degradation, coupled with specific intrabodies for precise targeting. Upon exposure to blue light, Flash-Away enables rapid and targeted degradation of selected proteins. This versatility is demonstrated through successful application to diverse protein targets, including actin, MLKL, and ALFA-tag fused proteins. This innovative light-inducible protein degradation system offers a powerful approach to investigate the functions of specific proteins within physiological contexts. Moreover, Flash-Away presents potential opportunities for clinical translational research and precise medical interventions, advancing the prospects of precision medicine.

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: Cancer can result from abnormal regulation of cells by their environment, potentially because cancer cells may misperceive environmental cues. However, the magnitude to which the oncogenic state alters cellular information processing has not been quantified. Here, we apply pseudorandom pulsatile optogenetic stimulation, live-cell imaging, and information theory to compare the information capacity of receptor tyrosine kinase (RTK) signaling pathways in EML4-ALK-driven lung cancer (STE-1) and in non-transformed (BEAS-2B) cells. The average information rate through RTK/ERK signaling in STE-1 cells was less than 0.5 bit/hour, compared to 7 bit/hour in BEAS-2B cells, but increased to 3 bit/hour after oncogene inhibition. Information was transmitted by 50-70% of cells, whose channel capacity (maximum information rate) was estimated through in silico protocol optimization. In BEAS-2B cells, channel capacity of the parallel RTK/calcineurin pathway surpassed that of the RTK/ERK pathway. This study highlights information capacity as a sensitive metric for identifying disease-associated dysfunction and evaluating the effects of targeted interventions.

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: Cells constantly encounter environmental and physiological fluctuations that challenge homeostasis and threaten viability. In response to these cues, specific proteins and nucleic acids engage in multivalent interactions and undergo phase separation to form membraneless assemblies known as biomolecular condensates. Nuclear condensates include paraspeckles, nuclear speckles, and Cajal bodies, while cytoplasmic condensates include stress granules, processing bodies, RNA transport granules, U-bodies, and Balbiani bodies. These assemblies regulate transcription, splicing fidelity, RNA stability, translational reprogramming, and integration of signaling pathways, thereby serving as dynamic platforms for metabolic regulation and physiological adaptation. However, dysregulation of these condensates has been increasingly recognized as a central pathogenic mechanism in neurodegenerative diseases, cancers, and viral infections, contributing to toxic protein aggregation, nucleic acid dysregulation, and aberrant cell survival signaling. This review provides a comprehensive synthesis of the molecular mechanisms governing condensation, delineates the diverse types and functions of major biomolecular condensates, and examines therapeutic approaches based on their pathophysiological relevance to disease development and progression. Furthermore, we highlight the cutting-edge technologies, including CRISPR/Cas-based imaging, optogenetic manipulation, and AI-driven phase separation prediction tools, which enable the real-time monitoring and precision targeting of cytoplasmic biomolecular condensates. These insights underscore the emerging potential of biomolecular condensates as both biomarkers and therapeutic targets, paving the way for precision medicine approaches in condensate-associated diseases.

Abstract: Human topoisomerase IIβ binding protein 1 (TopBP1) is a scaffold protein involved in DNA replication initiation, DNA repair, transcription regulation, and checkpoint activation. TopBP1 forms nuclear condensates that act as a molecular switch to amplify ATR activity and promote the activation of the checkpoint effector kinase Chk1. In cancer cells, ATR activity is crucial to tolerate the intrinsically high level of DNA lesions and obstacles that block replication fork progression. Thus, ATR inhibitors are currently tested in clinical trials, often in combination with chemotherapy drugs. However, resistance and toxicity are still major issues. The weak interactions that hold TopBP1 condensates together are highly sensitive to changes in the cellular milieu, suggesting that small molecules may alter the formation of TopBP1 condensates. Here, we developed a high-throughput screening system to identify TopBP1 condensation modulators. This system allowed us to identify FDA-approved drugs, including thimerosal and quinacrine, that inhibit TopBP1 condensation and block the activation of ATR/Chk1 signaling. Mechanistically, quinacrine impaired TopBP1's ability to associate with chromatin, thereby interfering with its capacity to form condensates. Furthermore, quinacrine enhanced the therapeutic efficacy of 5-fluorouracil and irinotecan, components of the clinically used FOLFIRI regimen in a mouse model of peritoneal carcinomatosis from colorectal cancer.

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: Mitochondrial membrane potential (MMP) is essential for mitochondrial functions, yet current methods for modulating MMP lack precise spatial and temporal control. Here, we present an optogenetic system that enables reversible formation of inter-mitochondrial contacts (mito-contacts) with high spatiotemporal precision. Blue light stimulation induces rapid formation of mito-contacts, which fully dissipate upon cessation of illumination. These light-induced mito-contacts can enhance MMP, leading to increased ATP production under stress conditions. Moreover, in human retinal cells and C. elegans, high MMP induced by mito-contacts alleviates the deleterious effects of prolonged blue light exposure, restoring energy metabolism and extending organismal lifespan. This optogenetic approach provides a powerful tool for modulating MMP and offers potential therapeutic applications for diseases linked to mitochondrial dysfunction.

Abstract: Oligomerization of photoactivatable proteins underlies many optogenetic strategies, yet their assembly states remain difficult to quantify in living cells. Here, we applied photon counting histogram analysis to directly measure the oligomerization of widely used optogenetic modules, Vaucheria frigida Aureochrome light-oxygen-voltage (VfAuLOV) and Arabidopsis thaliana cryptochrome 2 (AtCRY2), in living HEK293T cells. Oligomerization of both photoactivatable protein variants is concentration-dependent in cells. VfAuLOV primarily forms dimers, whereas AtCRY2 transitions into tetramers at concentrations above 1,000 nM, consistent with cryoEM structures. Human CRY2 exhibits light-independent oligomerization, while inactive AtCRY2 mutants (D387A and R439L) remain monomeric in light or darkness. Surprisingly, the constitutively active AtCRY2(W374) mutant still undergoes light-mediated oligomerization. The extent of light-induced lytic cell death correlates with the oligomerization state of these proteins when fused to receptor-interacting serine/threonine protein kinase 3. This study establishes a quantitative framework to resolve protein assembly dynamics in living cells, advancing mechanistic understanding of optogenetic tools and broadening their applications in cell signaling research.

Abstract: Since its discovery, the cyclic GMP-AMP synthase (cGAS)-stimulator of the interferon gene (STING) signaling pathway has been considered a pivotal component of innate immunity and a promising target for cancer immunotherapy. Beyond its canonical role in pathogen defense, accumulating evidence has demonstrated that the cGAS-STING pathway critically regulates diverse cellular processes, including cellular senescence, autophagy, cell death, and tumor immunosurveillance; therefore, dysregulation of this pathway correlates with the pathogenesis and progression of various human diseases, ranging from autoimmune and inflammatory disorders to cancer. Herein, we reviewed the regulatory mechanisms and cellular functions of the cGAS-STING pathway, highlighting its essential role in maintaining immune homeostasis. We systematically discussed the dual roles of the cGAS-STING pathway in cancer immunity, in which it triggers both antitumor and immunosuppressive effects. Finally, we summarized the recent advances and challenges in therapeutic strategies targeting the cGAS-STING pathway and discussed the next generation of therapies, including nanomaterials, antibody-drug conjugates, engineered bacteria, alternative strategies, optogenetic approaches, and combination strategies. We hope that our efforts will advance the understanding of the fundamental principles of innate immune recognition and response, and provide novel directions for improving the clinical outcomes of cGAS-STING-targeted therapies.

Abstract: Optogenetics, a modern tool to control cellular excitability in a non-invasive way, has widely been used in neuroscience. Recently, optogenetic approaches begin to be applied to studies of other biological phenomena including muscle functions. For these analyses, chicken embryos serve as an excellent model animal since they are highly amenable to site-specific manipulations with genes of optogenetics such as Channelrhodopsins, and its following targeted light irradiation. We here overview recent progresses in optogenetics using chicken embryos with a highlight on the studies of axon pathfinding, gut peristalsis, and feather morphogenesis.

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: Oncolytic virus (OVs) therapy has emerged as a promising modality in cancer immunotherapy, attracting growing attention for its multifaceted mechanisms of tumor elimination. However, its efficacy as a monotherapy remains constrained by physiological barriers, limited delivery routes, and suboptimal immune activation. Phototherapy, an innovative and rapidly advancing cancer treatment technology, can mitigate these limitations when used in conjunction with OVs, enhancing viral delivery, amplifying tumor destruction, and boosting antitumor immune responses. This review provides the first comprehensive analysis of synergistic integration of OVs with both photodynamic therapy (PDT) and photothermal therapy (PTT). It also explores their applications in optical imaging-guided diagnosis and optogenetically controlled delivery. Furthermore, it discusses emerging strategies involving biomimetic virus or viroid-based vectors in conjunction with phototherapy, and delves into the immunomodulatory mechanisms of this combinatorial approach. While promising in preclinical models, these combined strategies are still largely in early-stage research. Challenges such as limited light penetration, delivery efficiency, and safety concerns remain to be addressed for clinical translation. Consequently, the integration of OV therapy and phototherapy represents a compelling strategy in cancer treatment, offering significant promise for advancing precision oncology and next-generation immunotherapies.

Abstract: Organ-on-a-chip platforms have emerged as promising human tissue models for drug screening and mechanistic studies, offering alternatives to traditional animal models. Integration of vascular structures into these platforms is pivotal for creating physiologically faithful models of individual organs and studying interorgan crosstalk. However, most vascular structures grown in vitro do not account for organ-specific endothelial permeability or its modulation in response to disease. Here, we present optoBarrier, an optogenetic organ-on-a-chip platform designed to modulate endothelial barrier permeability through light stimulation. By optically activating RhoA signaling in engineered optogenetic endothelial cells, we demonstrate the formation of stress fibers, disruption of vascular endothelial cadherin (VE-cadherin) and increased barrier permeability. We further show that permeability is tunable in a reversible and dose-dependent manner in response to light. We therefore propose that optoBarrier offers a user-defined, controlled and simple method to manipulate endothelial permeability for in vitro studies of human vasculature.

Abstract: Nuclear factor kappa B (NF-κB) has been extensively investigated for approximately four decades. Throughout this timeframe, significant progress has been accomplished in determining the structure, function, and regulation of NF-κB; however, some nuanced complexities of this fundamental signaling pathway remain underexplored. A notable gap exists in the spatiotemporal regulation and molecular dynamics of NF-κB nucleocytoplasmic shuttling, which significantly impacts the complex function and behavior, yet lacks comprehensive characterization. The nucleocytoplasmic shuttling process is also related to resistance mechanisms that evolved following the application of NF-κB or proteasomal inhibitors. Furthermore, the NF-κB complex has a stochastic variability in its trafficking that contributes to heterogeneous cellular responses at the single-cell level and lacks a well-defined druggable pocket, making its complete suppression in cancer cells challenging and uncertain. Engineering synthetic gene circuits and utilizing optogenetic tools can pave the way for precise control of the NF-κB complex, enabling advanced investigations into NF-κB regulation and post-therapeutic behavior implicated in cancer resistance. This approach also permits tumor microenvironment (TME)-immune modulation by synthetic gene circuits that reactivate immune cells within the TME. In this review, we discussed the structure and function of NF-κB, the molecular dynamics of NF-κB nucleocytoplasmic shuttling based on established findings, NF-κB engineering via synthetic biology tools, and critically deciphered the post-therapeutic behavior of NF-κB in cancer, supported by potential therapeutic targets to abrogate resistance.

Abstract: Molecular optogenetics allows the control of molecular signaling pathways in response to light. This enables the analysis of the kinetics of signal activation and propagation in a spatially and temporally resolved manner. A key strategy for such control is the light-inducible clustering of signaling molecules, which leads to their activation and subsequent downstream signaling. In this work, an optogenetic approach is developed for inducing graded clustering of different proteins that are fused to eGFP, a widely used protein tag. To this aim, an eGFP-specific nanobody is fused to Cryptochrome 2 variants engineered for different orders of cluster formation. This is exemplified by clustering eGFP-IKKα and eGFP-IKKβ, thereby achieving potent and reversible activation of NF-κB signaling. It is demonstrated that this approach can activate downstream signaling via the endogenous NF-κB pathway and is thereby capable of activating both an NF-κB-responsive reporter construct as well as endogenous NF-κB-responsive target genes as analyzed by RNA sequencing. The generic design of this system is likely transferable to other signaling pathways to analyze the kinetics of signal activation and propagation.

Abstract: Clustered regularly interspaced short palindromic repeats (CRISPR) technology represents a landmark advance in the field of gene editing. However, conventional CRISPR/Cas systems are limited by inadequate temporal and spatial control. In recent years, the development of optically controlled CRISPR (Opto-CRISPR) technology has offered a novel solution to this issue. As a combination of optogenetics and the CRISPR technology, the Opto-CRISPR technology enables dynamic space-time-specific gene editing and regulation in cells and organisms. In this review, we concisely introduce the basic principles of Opto-CRISPR, summarize its operational mechanisms, and discuss its applications and recent advances across various research fields. In addition, this review analyzes the limitations of Opto-CRISPR, aiming to provide a reference for the development of this emerging field.

Abstract: Optogenetic bacterial technology is a cutting-edge approach that combines optogenetics and microbiology, offering a transformative strategy for disease diagnosis and therapy. This synergistic merger transcends the limitations of traditional diagnostic and therapeutic methodologies in a highly controllable, accurate and non-invasive manner. In this review, we introduce the optogenetic systems developed for microbial engineering and summarize fundamental in vitro design principles underlying light-responsive signal transduction in bacteria, as well as the optogenetic regulation of bacterial behaviors. We address multidisciplinary solutions to the challenges in the in vivo applications of light-controlled bacteria, such as limited light excitation, suboptimal delivery and targeting, and difficulties in signal tracking and management. Furthermore, we comprehensively highlight the recent progress in photo-responsive bacteria for disease diagnosis and therapy, and discuss how to accelerate translational applications.

Abstract: In cancer cells, lipid droplets (LDs) establish extensive membrane contact sites (MCSs) with mitochondria to facilitate fatty acid transfer and sustain energy production, thus enabling cancer cell survival, in nutrient-deprived tumor microenvironments. However, effective strategies to disrupt these LD-mitochondria interactions remain unavailable. We engineered an optogenetic system to control LD intracellular organization through clustering. Upon blue light stimulation, the system induces LDs to undergo spatial reorganization and form clusters, thereby restricting LD accessibility by reducing the available surface area for mitochondrial interaction. Consequently, this clustering significantly diminishes the number of LD-mitochondria MCSs, suppresses fatty acid transport from LDs to mitochondria during starvation, and ultimately leads to cancer cell death in vitro and tumor growth inhibition in vivo. Collectively, our results demonstrate that optogenetically controlled LD clustering offers a novel approach to impede tumor progression by blocking nutrient flow from LDs to mitochondria.

Abstract: Neurodegenerative diseases involve toxic protein aggregation. Recent evidence suggests that biomolecular phase separation, a process in which proteins and nucleic acids form dynamic, liquid-like condensates, plays a key role in this aggregation. Optogenetics, originally developed to control neuronal activity with light, has emerged as a powerful tool to investigate phase separation in living systems. This is achieved by fusing disease-associated proteins to light-sensitive oligomerization domains, enabling researchers to induce or reverse condensate formation with precise spatial and temporal control. This review highlights how optogenetic systems such as OptoDroplet are being used to dissect the mechanisms of neurodegenerative disease. We examine how these tools have been applied in models of neurodegenerative diseases, such as amyotrophic lateral sclerosis, Alzheimer's, Parkinson's, and Huntington's disease. These studies implicate small oligomeric aggregates as key drivers of toxicity and highlight new opportunities for therapeutic screening. Finally, we discuss advances in light-controlled dissolution of condensates and future directions for applying optogenetics to combat neurodegeneration. By enabling precise, dynamic control of protein phase behavior in living systems, optogenetic approaches provide a powerful framework for elucidating disease mechanisms and informing the development of targeted therapies.

Abstract: Many animals can regenerate tissues after injury. While the initiation of regeneration has been studied extensively, how the damage response ends and normal gene expression returns is unclear. We found that in Drosophila wing imaginal discs, the pioneer transcription factor Zelda controls the exit from regeneration and return to normal gene expression. Optogenetic inactivation of Zelda during regeneration disrupted patterning, induced cell fate errors, and caused morphological defects yet had no effect on normal wing development. Using Cleavage Under Targets & Release Using Nuclease, we identified targets of Zelda important for the end of regeneration, including genes that control wing margin and vein specification, compartment identity, and cell adhesion. We also found that GAGA factor and Fork head similarly coordinate patterning after regeneration and that chromatin regions bound by Zelda increase in accessibility during regeneration. Thus, Zelda orchestrates the transition from regeneration to normal gene expression, highlighting a fundamental difference between developmental and regeneration patterning in the wing disc.

Abstract: During mitosis, the microtubule depolymerase KIF2C, the tumor suppressor BRCA2, and the kinase PLK1 contribute to the control of kinetochore-microtubule attachments. Both KIF2C and BRCA2 are phosphorylated by PLK1, and BRCA2 phosphorylated at T207 (BRCA2-pT207) serves as a docking site for PLK1. Reducing this interaction results in unstable microtubule-kinetochore attachments. Here we identified that KIF2C also directly interacts with BRCA2-pT207. Indeed, the N-terminal domain of KIF2C adopts a Tudor/PWWP/MBT fold that unexpectedly binds to phosphorylated motifs. Using an optogenetic platform, we found that KIF2C forms membrane-less organelles that assemble through interactions mediated by this phospho-binding domain. KIF2C condensation does not depend on BRCA2-pT207 but requires active Aurora B and PLK1 kinases. Moreover, it concentrates PLK1 and BRCA2-pT207 in an Aurora B-dependent manner. Finally, KIF2C depolymerase activity promotes the formation of KIF2C condensates, but strikingly, KIF2C condensates exclude tubulin: they are located on microtubules, especially at their extremities. Altogether, our results suggest that, during the attachment of kinetochores to microtubules, the assembly of KIF2C condensates amplifies PLK1 and KIF2C catalytic activities and spatially concentrates BRCA2-pT207 at the extremities of microtubules. We propose that this novel and highly regulated mechanism contributes to the control of microtubule-kinetochore attachments, chromosome alignment, and stability.

Abstract: The Arabidopsis blue light photoreceptor cryptochrome 2 (CRY2) responds to blue light to initiate a variety of plant light-based behaviors and has been widely used for optogenetic engineering. Despite these important biological functions, the precise photoactivation mechanism of CRY2 remains incompletely understood. In light, CRY2 undergoes tetramerization and binds to partner proteins, including the transcription factor CIB1. Here we used yeast-two hybrid screening and deep mutational scanning to identify CRY2 amino acid changes that result in constitutive interaction with CIB1 in dark. The majority of CRY2 variants show constitutive CIB1 interaction mapped to two regions, one near the FAD chromophore and a second region located near the ATP binding site. Further testing of CRY2 variants from each region revealed three mapping near to the FAD binding pocket (D393S, D393A, and M378R) that also form constitutive CRY2-CRY2 homomers in dark, suggesting they adopt global conformational changes that mimic the photoactive state. Characterization of D393S in the homolog pCRY from Chlamydomonas reinhardtii using time-resolved UV-vis spectroscopy revealed that the FAD chromophore fails to form the neutral radical as signaling state upon illumination. Size exclusion chromatography of D393S shows the presence of homomers instead of a monomer in the dark, providing support for a hyperactive variant decoupled from the FAD. Our work provides new insight into photoactivation mechanisms of plant cryptochromes relevant for physiology and optogenetic application by revealing and localizing distinct activation pathways for light-driven CRY2-CIB1 and CRY2-CRY2 interactions.