Curated Optogenetic Publication Database

Abstract: Glycosylation plays a pivotal role in regulating diverse biological processes. However, the lack of tools capable of controlling the spatiotemporal dynamics of glycosylation has largely hindered its functional elucidation. Here, we introduce an optogenetic approach that employs red/far-red light to dynamically and reversibly control the plasma membrane localization of O-linked N-acetylglucosamine transferase (OGT) in living systems. Red-light-induced translocation of OGT suppresses insulin signaling in both cells and mice. Glycoproteomic and phosphoproteomic analyses reveal a global impact of OGT-mediated glycosylation on signal transduction. Moreover, using protein semisynthesis, cell-based assays, and molecular dynamics simulations, we demonstrate that red-light-induced O-GlcNAcylation of WNK1 at S1949 inhibits downstream cell volume response signaling pathways by suppressing WNK1 biomolecular condensate formation. Together, our findings provide a valuable tool to modulate subcellular O-GlcNAcylation and control cellular signaling in living systems, with broad applicability to the study of glycosylation in cells.

Abstract: Optogenetic tools-light-responsive proteins that enable to regulate specific cellular activities, study biological processes, and develop new therapies-are attractive approaches for achieving endogenous gene regulation under minimally invasive conditions. Our first step in constructing an optogenetic system to regulate endogenous Drosophila gene expression was to identify inhibitory anti-CRISPR (Acr) proteins that block CRISPRa-mediated activation. Next, we inserted optogenetic protein LOV2 into these Acrs, tested for their ability to optogenetically modulate endogenous gene upregulation through the CRISPRa-based flySAM system in Drosophila, and found that the photoswitchability of these prototypes was weak. We therefore engineered an optimized Acr-LOV2 fusion module by refining length of intrinsically disordered and ordered regions (IDR and IOR) of Acrs. This optimization yielded a variant with significantly greater sensitivity to blue-light-induced endogenous gene upregulation than the prototypes, leading to new in vivo discoveries. In addition, this work provides insights for in vivo functional characterization of the IDR and the IOR of these small-sized proteins. Together, these findings establish a robust optogenetic toolbox for precise, light-controlled endogenous gene regulation in Drosophila.

Abstract: The mechanisms by which core clock components are spatially organized to ensure robust oscillations in mammals remain unclear. Here, we identify the positive limb factor BMAL1 as a phase-separating protein that forms dynamic biomolecular condensates essential for circadian transcription and behavior. Endogenous BMAL1 forms nuclear puncta that oscillate in sync with the circadian cycle. Deletion analysis and optogenetic clustering identify an N-terminal 90-amino acid intrinsically disordered region whose phosphorylation state tunes BMAL1 phase separation. Besides, BMAL1 condensates behave as multi-molecular assemblies that selectively recruit CLOCK, p300, MED1, and are specifically promoted by E-box DNA. Functionally, an IDR-deleted BMAL1 mutant fails to rescue rhythmic transcription in Bmal1-KO cells and cannot restore locomotor rhythms when reintroduced into SCN-specific Bmal1‑KO mice. These findings establish BMAL1 condensates as dynamic transcriptional hubs that couple phase separation to circadian rhythm in cells and in vivo.

Abstract: Photosensory protein domains, derived from nature, are foundational for optogenetic protein engineering. Tailoring their properties enables their full exploitation for optogenetic regulation in basic research and applied bioengineering applications. Here, we present a simple, yet powerful strategy based on random mutagenesis coupled to high-throughput screening that allowed altering the most fundamental properties of the widely used nMag/pMag photodimerization system: its light sensitivity and activation. Variants were characterized in vivo in bacteria by flow cytometry and during the entire growth curve by spectrofluorometry. We identify mutations that either increase or decrease the light sensitivity at sub-saturating light intensities, while also improving the light activation and dark-to-light fold change. Notably, light sensitivity and activation levels could be changed independently. In addition, we demonstrated that the shapes of the dose-response curves can be finely tuned. This broadens the applicability of the Magnets photosensors for optogenetic regulation strategies.

Abstract: Estrogen receptor (ER)-mediated genomic actions are crucial for maintaining various physiological functions, and their dysfunction is associated with numerous human diseases. Traditional estrogen replacement therapy (ERT) is commonly used to manage estrogen deficiency-related conditions, such as vulvovaginal atrophy during menopause, but its systemic effects pose notable risks. This study introduces OptoER, an optogenetic tool engineered to precisely modulate ER-mediated genomic pathways through light-induced transcription regulation, offering spatial-temporal control over ER-dependent gene expression. Our in vitro studies demonstrate that OptoER significantly enhances ER-specific gene transcription and protein synthesis, leading to improved cell proliferation and migration. In a proof-of-principle study using ovariectomized (OVX) mice, OptoER demonstrated considerable therapeutic potential for vaginal atrophy, with observed improvement in epithelial thickness and keratinization. These findings suggest that OptoER provides a targeted therapeutic strategy for estrogen deficiency conditions, with significant implications for treating vaginal atrophy and promoting regenerative healing in estrogen-deprived tissues.

Abstract: CRISPR-Cas systems enable powerful gene editing and regulation, yet single-modality control often fails to achieve orthogonal, spatiotemporally precise regulation of multiple endogenous genes. We engineered OREC, an orthogonal platform integrating chemogenetic and optogenetic modalities for precise, reversible, multiplex gene control. OREC comprises two components: ORECC regulated by doxycycline (Dox) and ORECo controlled by light. By assembling catalytically dead Cpf1 (dCpf1), gene regulatory elements, and crRNA arrays on single transcripts, OREC enables robust simultaneous manipulation of multiple genes. We demonstrated OREC's therapeutic potential in vitro for osteoblast function modulation and in vivo for osteoporotic fracture repair. OREC effectively activated Bmp2 while inhibiting Dkk1, significantly enhancing bone formation and fracture healing in mouse models. These results establish OREC as a versatile platform for precise multiplex gene regulation, offering significant advancement for CRISPR-based gene therapy applications in complex tissues where coordinated control of multiple therapeutic targets is essential.

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: Inducible translocation to subcellular compartments is a common strategy for protein switches that control a variety of cell behaviors. However, existing switches achieve translocation through induced dimerization, requiring constitutive anchoring of one component into the target compartment and optimization of relative expression levels between the two components. We present a simpler, single-component strategy called Avidity-assisted targeting (Aviatar). Aviatar achieves translocation with only a single protein by converting low-affinity monomers into high-avidity assemblies through inducible clustering. We demonstrated the Aviatar concept and its generality using optogenetic clustering to drive translocation to the plasma membrane, endosomes, golgi, endoplasmic reticulum, and microtubules using binding domains for lipids or endogenous proteins that were specific to those compartments. Aviatar recruitment regulated actin polymerization at the cell periphery and revealed compartment-specific signaling of receptor tyrosine kinase fusions associated with cancer. Finally, GFP-targeting Aviatar probes allowed inducible localization to any GFP-tagged target, including endogenously tagged stress granule proteins. Aviatar is a straightforward platform that can be rapidly adapted to a broad array of targets without the need for their prior modification or disruption.

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: Cells process dynamic signaling inputs to regulate fate decisions during development. While oscillations or waves in key developmental pathways, such as Wnt, have been widely observed, the principles governing how cells decode these signals remain unclear. By leveraging optogenetic control of the Wnt signaling pathway in both HEK293T cells and H9 human embryonic stem cells, we systematically map the relationship between signal frequency and downstream pathway activation. We find that cells exhibit a minimal response to Wnt at certain frequencies, a behavior we term anti-resonance. We developed both detailed biochemical and simplified hidden variable models that explain how anti-resonance emerges from the interplay between fast and slow pathway dynamics. Remarkably, we find that frequency directly influences cell fate decisions involved in human gastrulation; signals delivered at anti-resonant frequencies result in dramatically reduced mesoderm differentiation. Our work reveals a previously unknown mechanism of how cells decode dynamic signals and how anti-resonance may filter against spurious activation. These findings establish new insights into how cells decode dynamic signals with implications for tissue engineering, regenerative medicine, and cancer biology.

Abstract: Despite the therapeutic potential of engineered immune cell therapy against metastases, it faces challenges including cytokine-driven systemic toxicity, off-target biodistribution, and host rejection. Here, we develop red/far-red light-regulated individually encapsulated (RL/FRL-EnE) cells, integrating optogenetics with biomaterial encapsulation for precise immunomodulation. This system uses a phytochrome A-based photoswitch (ΔPhyA-PCB) that enables bidirectional control. RL (660 nanometers) triggers interferon-γ, interleukin-6, and anti-CD47 expression via ΔPhyA-PCB-far-red elongated hypocotyl 1 heterodimerization, while FRL (740 nanometers) rapidly reverses production, minimizing toxicity. Single-cell nanoencapsulation prevents intercellular cross-talk and immune clearance, enabling strict light-dependent regulation and extended tumor residence. In vivo, RL/FRL-EnE cells remodeled the tumor microenvironment, reducing immunosuppressive myeloid cells (1.3- to 1.7-fold), while enhancing dendritic cell (1.4-fold) and CD8+ T cell (2.8-fold) infiltration. Collectively, this work establishes a paradigm for closed-loop cellular immunotherapy, where light-regulated living therapeutics achieve on-demand immune reprogramming.

Abstract: Crafting synthetic in vitro tissues with mammalian cells faces a shortage of methods to define spatial features. Optogenetic tissue engineering can provide the desired spatial and temporal control but requires stable genomic engineering to support long-term cultivation and high response resolution. Here, we developed BlueGENEs, a set of optimized optogenetic gene switches. BlueGENEs support rapid, stable cell line generation, including precision engineering into the human AAVS1 safe harbor locus. By combining a designer endonuclease and a phage integrase, the approach overcomes gene-disruptive effects of random gene delivery and enables reproducible cell line development. BlueGENEs comprise an optogenetic blue light-responsive gene switch, a synthetic response promoter, and selection strategies serving broad use scenarios. We generated various human cell lines for optical control of apoptotic cell fate, 3D tissue formation, and signals promoting cytoskeletal remodeling. Our results demonstrate the integration of optogenetic cells with bioprinting technologies, illustrating the potential of BlueGENEs in advancing the synthesis of de novo or patient-derived in vitro model systems.

Abstract: Neuronal activity robustly engages the extracellular signal-regulated kinase (ERK) signaling pathway through Ca2+-dependent mechanisms; however, whether ERK can acutely and causally modulates ongoing neuronal activity remains unsolved due to complex upstream regulation and diverse subcellular functions. Here, we directly address this question using an optogenetic ERK activator, opto-miniRaf, that enables selective, rapid, graded, and reversible control of ERK signaling. Combining this AAV-compatible system with calcium imaging and electrophysiology, we interrogate ERK functions across biological scales, from cultured neurons, acute brain slices, and the intact brain. Acute optogenetic activation of ERK enhances synchronized network burst activity in cultured rat cortical neurons and increases calcium activity of cortical pyramidal neurons in awake and moving mice following non-invasive light stimulation. Together, these results establish ERK signaling as an acute modulator of neuronal and network activity, positioning opto-miniRaf as a generalizable platform for precise spatiotemporal control of intracellular kinase signaling in complex biological systems.

Abstract: Cellular lipid metabolism is subject to strong homeostatic regulation, but the players involved in and mechanisms underlying these pathways remain largely uncharacterized. Here we develop a 'feeding-fishing' approach coupling membrane editing using optogenetic lipid-modifying enzymes (feeding) with organelle membrane proteomics through proximity labeling (fishing) to elucidate molecular players and pathways involved in the homeostasis of phosphatidic acid (PA), a multifunctional lipid central to glycerolipid metabolism. This approach identified several PA-metabolizing enzymes and lipid transfer proteins enriched in and depleted from PA-fed membranes. Mechanistic analysis revealed that PA homeostasis in the cytosolic leaflets of the plasma membrane and lysosomes is mediated by both local PA metabolism and the action of lipid transfer proteins that carry out interorganelle lipid transport before subsequent metabolism. More broadly, the interfacing of membrane editing to controllably modify membrane lipid composition with organelle membrane proteomics using proximity labeling represents a strategy for revealing mechanisms governing lipid homeostasis.

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: 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: 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: 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: 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: Precise control of covalent protein binding and cleavage in mammalian cells is crucial for manipulating cellular processes but remains challenging due to dark background, poor stability, low efficiency, or requirement of unnatural amino acids in current optogenetic tools. We introduce a photoswitchable intein (PS Intein) engineered by allosterically modulating a small autocatalytic gp41-1 intein with tandem Vivid photoreceptor. PS Intein exhibits superior functionality and low background in cells compared to existing tools. PS Intein-based systems enable light-induced covalent binding, cleavage, and release of proteins for regulating gene expression and cell fate. The high responsiveness and ability to integrate multiple inputs allow for intersectional cell targeting using cancer- and tumor microenvironment-specific promoters. PS Intein tolerates various fusions and insertions, facilitating its application in diverse cellular contexts. This versatile technology offers efficient light-controlled protein manipulation, providing a powerful tool for adding functionalities to proteins and precisely controlling protein networks in living cells.

Abstract: Localized translation broadly enables spatiotemporal control of gene expression. Here, we present LOV-domain-controlled ligase for translation localization (LOCL-TL), an optogenetic approach for monitoring translation with codon resolution at any defined subcellular location under physiological conditions. Application of LOCL-TL to mitochondrially localized translation revealed that ∼20% of human nuclear-encoded mitochondrial genes are translated on the outer mitochondrial membrane (OMM). Mitochondrially translated messages form two classes distinguished by encoded protein length, recruitment mechanism, and cellular function. An evolutionarily ancient mechanism allows nascent chains to drive cotranslational recruitment of long proteins via an unanticipated bipartite targeting signal. Conversely, mRNAs of short proteins, especially eukaryotic-origin electron transport chain (ETC) components, are specifically recruited by the OMM protein A-kinase anchoring protein 1 (AKAP1) in a translation-independent manner that depends on mRNA splicing. AKAP1 loss lowers ETC levels. LOCL-TL thus reveals a hierarchical strategy that enables preferential translation of a subset of proteins on the OMM.

Abstract: The Cre-loxP recombination system enables precise genome engineering; however, existing photoactivatable Cre tools suffer from several limitations, including low DNA recombination efficiency, background activation, slow activation kinetics, and poor tissue penetration. Here, we present REDMAPCre, a red-light-controlled split-Cre system based on the ΔPhyA/FHY1 interaction. REDMAPCre enables rapid activation (1-s illumination) and achieves an 85-fold increase in reporter expression over background levels. We demonstrate its efficient regulation of DNA recombination in mammalian cells and mice, as well as its compatibility with other inducible recombinase systems for Boolean logic-gated DNA recombination. Using a single-vector adeno-associated virus delivery system, we successfully induced REDMAPCre-mediated DNA recombination in mice. Furthermore, we generated a REDMAPCre transgenic mouse line and validated its efficient, light-dependent recombination across multiple organs. To explore its functional applications, REDMAPCre transgenic mice were crossed with isogenic Cre-dependent reporter mice, enabling optogenetic induction of insulin resistance and hepatic lipid accumulation via Cre-dependent overexpression of ubiquitin-like with PHD and RING finger domains 1 (UHRF1), as well as targeted cell ablation through diphtheria toxin fragment A expression. Collectively, REDMAPCre provides a powerful tool for achieving remote control of recombination and facilitating functional genetic studies in living systems.

Abstract: Domain insertion engineering is a powerful approach to juxtapose otherwise separate biological functions, resulting in proteins with new-to-nature activities. A prominent example are switchable protein variants, created by receptor domain insertion into effector proteins. Identifying suitable, allosteric sites for domain insertion, however, typically requires extensive screening and optimization. We present ProDomino, a machine learning pipeline to rationalize domain recombination, trained on a semisynthetic protein sequence dataset derived from naturally occurring intradomain insertion events. ProDomino robustly identifies domain insertion sites in proteins of biotechnological relevance, which we experimentally validated in Escherichia coli and human cells. Finally, we used light- and chemically regulated receptor domains as inserts and demonstrate the rapid, model-guided creation of potent, single-component opto- and chemogenetic protein switches. These include novel CRISPR-Cas9 and -Cas12a variants for inducible genome engineering in human cells. Our work enables one-shot domain insertion engineering and substantially accelerates the design of customized allosteric proteins.

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: 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.