Heterodimerization

AQTrip is an engineered EL222 variant carrying V41I, L52I, A79Q, and V121I substitutions in the blue-light-responsive LOV–HTH transcription factor. It stabilizes the photoactivated state and, in the reported study, oligomerizes without DNA and forms an EL222 dimer–DNA complex in the presence of DNA substrates.

BcLOV4-ARHGEF11 is a single-transgene optogenetic fusion in which the upstream RhoA activator ARHGEF11 is fused to BcLOV4. It enables light-inducible, spatiotemporally precise control of RhoA signaling through dynamic membrane localization without requiring a separate protein binding partner.

The BcLOV4-RhoA optogenetic fusion is a single-transgene light-responsive construct in which RhoA GTPase, or its upstream activator ARHGEF11, is fused to BcLOV4. It enables spatiotemporally precise optical control of RhoA signaling and associated cytoskeletal and mechanotransductive responses without requiring a separate protein binding partner for dynamic membrane localization.

BcWCL1 PASΔ is a PAS-domain-deleted variant of the Botrytis cinerea blue-light photoreceptor BcWCL1 that functions in yeast as a blue-light-activated transcription switch. The reported activity depends on the BcWCL1 N-terminal region, which supports light-stimulated self-dimerization and contains a functional 9aaTAD-family transcriptional activation domain.

Biofunctional nanodot arrays (bNDAs) are nanoscale surface-patterned delivery harnesses designed to spatially control dimerization and clustering of cell-surface receptors. In live cells, they were used to capture extracellularly GFP-tagged Lrp6 and drive assembly of active Wnt signalosomes at the plasma membrane.

The blue light-inducible cryptochrome-based dimerization system is a light-responsive multi-component switch that uses blue light to induce protein dimerization. The cited evidence supports its use for spatiotemporally precise control of signaling or cytoskeletal events.

The blue light-inducible LOV domain-based dimerization system is a light-responsive multi-component switch in which blue light induces dimerization to control intracellular signaling or cytoskeletal events. The cited literature describes this class of systems as providing spatiotemporally precise perturbation of cell behavior.

The C120 promoter is a TAEL-responsive regulatory element used in the zebrafish TAEL optogenetic transcription system. Blue light induces TAEL transcription factor dimerization, which activates transcription from the C120 promoter.

Cry2-Cib is a light-responsive photodimerizing protein pair used as a multi-component optogenetic switch. In the cited application, light stimulation drives translocation of a low-constitutive-activity protein kinase A catalytic subunit to a subcellular region containing Cib, thereby restoring kinase activity.

The CRY2-CIB1 interaction system is a blue-light-responsive optogenetic multi-component switch built from the light-inducible CRY2-CIB1 interaction system in mammalian cells. Photoexcited CRY2 supports inducible CRY2-CIB1 heterodimerization and can also undergo concomitant CRY2-CRY2 homo-oligomerization, enabling light-controlled manipulation of signaling pathways and cellular processes with high spatiotemporal precision.

Cry2/CIB is a genetically encoded blue-light-activated protein dimerization module derived from Arabidopsis thaliana. It is used to optically induce protein-protein interactions and has been applied to control transcription, protein localization, protein secretion, and, when coupled to BAX, light-triggered apoptosis.

The CRY2/CIBN light-gated dimerizer system is an optogenetic multi-component switch used to control subcellular RhoA activation through light-dependent recruitment of a CRY2-fused RhoA activator. In the cited implementation, the ARHGEF11 DHPH catalytic domain is fused to CRY2-mCherry to drive light-gated relocalization and thereby modulate force-related cellular phenotypes.

The cryptochrome 2-mediated optogenetic C-RAF activation tool is a mammalian-cell optogenetic system in which Arabidopsis thaliana cryptochrome 2 drives blue light-dependent dimerization to activate the protein kinase C-RAF. It enables reversible optical control of C-RAF signaling outputs, including ERK1/2 phosphorylation and serum response factor-mediated gene expression.

De novo tripeptides composed of glycine, tyrosine, and lysine were reported to generate cyan fluorescence in vitro. The same study further indicates that amino acid identity and residue order modulate the fluorescent output, and that these peptides form robust dimer structures under moderate oxidizing conditions.

Drug-inducible lentiviral and transposon vectors were used to deliver the PhyB-PIF light-inducible dimerization system together with the synPCB phycocyanobilin synthesis module. In the cited study, doxycycline treatment induced PCB synthesis and enabled PhyB-PIF light-inducible dimerization function.

FerriTag is a genetically encoded, chemically inducible tag for correlative light-electron microscopy built as a fluorescent, electron-dense ferritin particle. It labels target proteins through induced heterodimerization and enables nanoscale localization in electron micrographs.

The FKF1/GIGANTEA light-inducible transcription system is an optogenetic multi-component switch for mammalian cells built from the Arabidopsis photoreceptor FKF1 and its binding partner GIGANTEA. In an optimized split FKF1/GI dimerized Gal4-VP16 configuration, light induces transcriptional activation by reconstituting a functional transcriptional regulator.

Galpha(15i3) is a G protein chimera reported in HEK293 cells as a pathway-linking component that couples the sweet taste receptor heterodimer TAS1R2/TAS1R3 to an InsP3-dependent Ca2+ release pathway. It is described together with Galpha(16gust44) in receptor signaling assays.

Galpha(16gust44) is a G protein chimera used in HEK293 cells as part of a multi-component signaling switch. It couples the sweet taste receptor heterodimer TAS1R2/TAS1R3 to an InsP3-dependent intracellular Ca2+ release pathway.

The genetically encodable, light activatable heterodimerizer system is an optogenetic multi-component switch that places a protein cargo within a genetically encoded, light-responsive heterodimerization framework. In the cited application, incorporation of cofilin enabled illumination-dependent remodeling of the F-actin network and consequent changes in cell motility.

The genetically encoded PhyB–PIF light-inducible dimerization system is an optogenetic multi-component switch that uses a PhyB-based light-induced dimerization interaction to control signal transduction. The cited chapter describes a genetically encoded implementation enabled by efficient phycocyanobilin synthesis in cultured mammalian cells and reports applications in cultured cells and animals.

The iLID N414L variant is a modified iLID light-inducible dimerization system in which an N414L point mutation in the LOV domain lengthens the reversion half-life. In combination with SspB binding partners, it supports blue-light-dependent control of protein colocalization and has been used in reengineered iLID-SspB systems for processes including transmembrane protein localization.

iLID-antiGFP-nanobody is a multi-component optogenetic recruitment system in which iLID is fused to an antiGFP nanobody to target existing GFP-tagged proteins. Under blue-light illumination, iLID heterodimerizes with SspB, enabling light-dependent recruitment to locations defined by GFP fusions.

iLID-nano is a multi-component optogenetic switch built from an improved light-induced dimerization pair comprising LOV2-SsrA and SspB. It has been used to control talin-mediated cell spreading and migration and has been physically characterized for force-coupled regulation in mechanotransduction contexts.

iLID-RTK is a blue-light-controlled, multi-component receptor tyrosine kinase switch built from the iLID and tdnano system. In darkness it is cytosolic, monomeric, and inactive, while blue light recruits two iLID-RTK molecules to tdnano to drive RTK dimerization and activation.

The iLID-SspB A58V variant is a blue-light-inducible heterodimerization system in which SspB carries a single A58V substitution. It was reengineered to tune iLID-SspB binding for improved light-controlled protein colocalization, including transmembrane protein localization in neurons.

iLID/SspB is a blue-light-inducible heterodimerization system built from an engineered iLID module and the SspB binding partner. It is used to reversibly recruit proteins in cells for control of localization and signaling, including membrane recruitment, neurotrophin receptor construction, microtubule plus-end targeting, and perturbation of small GTPase pathways.

LADL (light-activated dynamic looping system) is a multi-component optogenetic genome-engineering platform that targets two genomic anchors with CRISPR guide RNAs and promotes their spatial co-localization through light-induced heterodimerization between CRY2 and dCas9-CIBN. In the cited 2018 study, this engineered looping altered endogenous gene expression, including increased nascent Zfp462 transcription and increased synchronous Sox2 expression.

Light Activated BioID (LAB) is an optically controlled proximity-labeling system in which the two halves of split-TurboID are fused to the photodimerizing proteins CRY2 and CIB1. Blue light induces CRY2–CIB1 association, reconstituting split-TurboID and enabling proximity-dependent biotinylation of nearby proteins.

Light inducible dimer pairs are multicomponent optogenetic switches derived from cyanobacteriochrome photoswitchable proteins. They enable light-dependent heterodimerization and were developed to support orthogonal control of biological processes with red, green, and blue light.

Light-activated neurotrophin receptors are engineered optogenetic multi-component receptor systems built using the improved light-induced dimerizer (iLID). The available evidence indicates that they use light-controlled iLID interactions to drive neurotrophin receptor assembly or activation.

Opto-RGS2 is an optogenetic multi-component switch that uses a light-induced heterodimerization system to recruit the RGS2 domain to the plasma membrane, where it interacts with its cognate G protein. It was developed to enable optical control of Gq-protein signaling and associated calcium oscillation dynamics.

LINTAD is a multi-component light-inducible nuclear translocation and dimerization system developed for gene regulation. In the cited study, it was used to control chimeric antigen receptor (CAR) T-cell activation, and pulsed light stimulation activated LINTAD-engineered CAR T cells to produce strong cytotoxicity against target cancer cells in vitro and in vivo.

The light-inducible split Cre recombinase is an optogenetic multi-component switch in which split Cre recombinase fragments are coupled to light-inducible dimerization modules to achieve inducible post-translational control of Cre activity. It was characterized by comprehensive screening of split sites across the Cre protein using a pooled, sequencing-based domain insertion profiling approach.

LOVpep/ePDZb is a blue-light-inducible heterodimerization system examined as one of three optogenetic dimer variants in a comparative cellular optogenetics study. It mediates light-dependent protein association that was used to control cellular localization and activity in assays including transcription, intracellular localization, and GTPase signaling.

Magnets are engineered pairs of distinct light-responsive protein modules derived from the Neurospora crassa photoreceptor Vivid. They act as a multi-component optogenetic switch by converting a native Vivid homodimerization interface into complementary light-dependent heterodimers for protein interaction and recruitment in subcellular volumes.

Membrane-tethered CRY2 is a CRY2/CIB optical dimerization configuration in which CRY2 is localized at a membrane to control recruitment of CIB-linked partners with light. The reported application demonstrates that this arrangement is functional and may provide improved local control of protein interactions.

mOptoT7 is a mammalian optogenetic transcription system composed of a split T7 RNA polymerase fused to the blue-light-inducible nMag/pMag Magnets photodimerization system. Blue light drives reconstitution of the split polymerase to activate transcription from orthogonal T7 promoters in mammalian cells, and the system has been used to produce protein-coding mRNA, shRNA, and the Pepper RNA aptamer.

The near-infrared light activatable chemically induced split-Cas9/dCas9 system is a multi-component CRISPR switch in which split Cas9 or dCas9 is activated through a near-infrared photocleavable dimerization complex. It is intended to provide near-infrared light-gated control of CRISPR genome editing-related activity.

The near-infrared light-activated DNA agonist nanodevice (NIR-DA) is a multicomponent, nongenetic system for remote optical control of receptor tyrosine kinase signaling in live cells and animals. Upon near-infrared illumination, an active DNA agonist is released and dimerizes DNA-modified chimeric or native receptor tyrosine kinases at the cell surface, triggering downstream signaling.

The NIR light-activated CRISPR-dCas9/Cas9 system is a multi-component optogenetic platform that controls CRISPR-dCas9/Cas9 gene regulation and editing with near-infrared light. It uses a chemically cleavable rapamycin dimer to confer precise and rapid light-dependent activity in living organisms.

Optical dimerizers are genetically encoded actuators that use light to control protein-protein interactions. The cited examples are the CRY2/CIB and UVR8/UVR8 systems, which have been applied to light-regulated transcription, protein localization, and protein secretion.

The optimized Enhanced Magnet transcription factor is a light-responsive split transcription factor developed in Saccharomyces cerevisiae using Enhanced Magnet dimerization modules. It was rationally designed and tested to improve light-sensitive gene expression.

opto-Dab1 is a single-component, photoactivatable version of Disabled-1 (Dab1) created by exploiting the blue light-sensitive dimerization/oligomerization properties of Arabidopsis thaliana Cryptochrome 2 (Cry2). Upon blue light illumination, it enables rapid, local, and reversible activation of Dab1 downstream signaling.

opto-iTrkB, also called iLID opto-iTrkB, is a blue-light-activated TrkB receptor tyrosine kinase construct built on the improved Light-Induced Dimerizer system. In the reported design, cytosolic inactive iLID-RTK is recruited to tdnano under blue light, which drives receptor dimerization and activates downstream ERK and Akt signaling.

Optogenetic protein kinase A is a light-controlled multi-component switch for probing localized protein kinase A signaling. It uses the Cry2-Cib photodimerizing pair to translocate a low-constitutive-activity protein kinase A catalytic subunit to a Cib-defined subcellular site, where kinase activity is restored.

Optogenetic split transcription factors are multi-component light-responsive transcriptional regulators developed in Saccharomyces cerevisiae. In the cited yeast toolkit, split transcription factor designs incorporated cryptochrome and Enhanced Magnet light-sensitive dimerizers, and an optimized Enhanced Magnet variant improved light-sensitive gene expression.

OptoMYPT is a blue-light-controlled multi-component optogenetic switch that couples the PP1c-binding domain of MYPT1 to an optogenetic dimerizer to recruit endogenous protein phosphatase 1c to the plasma membrane. This recruitment induces dephosphorylation of myosin regulatory light chains and reduces actomyosin contractile force.

optoRAF is an optogenetic multi-component switch for light-controlled clustering and activation of RAF proteins. It was described as mimicking naturally occurring RAS-mediated RAF dimerization and was used to probe BRAF and CRAF responses to kinase inhibitors.

OptoRAF1 is a blue light-responsive optogenetic RAF1 system built on the CRY2/CIB1 dimerizer pair. It reversibly activates the RAF/MEK/ERK pathway by recruiting RAF1 to the plasma membrane.

PA-Cre2.0 is a photoactivatable split Cre recombinase in which Cre activity is reconstituted by light-induced CRY2-CIB1 dimerization. It enables light-dependent control of Cre-mediated recombination and has been functionally characterized in mammalian cells and rodent brain.

Photoactivatable Cre recombinase is a light-controlled recombination tool reported in a 2016 Nature Chemical Biology study. The available evidence links it to optimized second-generation CRY2–CIB dimerizers and indicates that it enables light regulation of Cre-mediated recombination.

PhyB/PIF is a genetically encoded red/far-red light-inducible dimerization system built from phytochrome B and phytochrome-interacting factor. It enables reversible light-controlled protein association and dissociation on the second time scale and has been applied to gene regulation, protein transport, and subcellular recruitment.

phyB/PIF3 is a red-light-regulated multi-component optical dimerizer system benchmarked in a yeast transcriptional assay. It uses light-controlled heterodimerization between phyB and PIF3 to regulate transcriptional output.

phyB/PIF6 is a red-light-regulated optical dimerizer system composed of phyB and PIF6. In a yeast transcriptional assay, it supported light-dependent regulation and was benchmarked against phyB/PIF3, CRY2/CIB1, and TULIPs, with significant differences reported between phyB/PIF6 and phyB/PIF3 in light sensitivity and fold activation.

Single-component optogenetic tools were created to control RhoA GTPase signaling with light. The reported system does not require protein binding partners and enables inducible RhoA-mediated cytoskeletal activation with downstream YAP nuclear localization and YAP-TEAD mechanotranscription.

Single-construct optogenetic talin is an engineered light-responsive talin system in which pdDronpa1.2 enables light-inducible C-terminal talin homodimerization. In the cited study, this induced talin recruitment to adhesion sites, promoted adhesion formation, engaged actin retrograde flow, and activated downstream mechanosignaling.

The split synthetic zinc-finger transcription factor is a light-controlled transcriptional switch developed for Saccharomyces cerevisiae. Its activity is reconstituted from split components through CRY2- and CIB1-mediated light-induced dimerization, enabling optical control of gene expression.

The split transcriptional activator based gluconate switch is a multi-component mammalian gene-control system derived from the Escherichia coli gluconate-responsive regulator GntR. It uses gluconate-induced GntR dimerization to reconstitute a split transcriptional activator and activate transgene expression.

The SspB A58V iLID dimer variant is a blue-light-inducible, multi-component protein interaction system in which a single A58V substitution in SspB tunes binding to iLID. It mediates light-gated heterodimerization and was reported to enable light-activated colocalization of transmembrane proteins in neurons.

synPCB is a genetically encoded phycocyanobilin synthesis system that supplies the chromophore required for PhyB-PIF phytochrome-based optogenetics. The improved synPCB version increased PCB production by approximately 4-fold and was incorporated with PhyB-PIF into doxycycline-inducible lentiviral and transposon vectors to support light-inducible dimerization system expression or function.

TAEL 2.0 is a modified version of the TAEL/C120 optogenetic transcription system in which both the TAEL transcriptional activator and the C120 regulatory element were altered. In zebrafish embryos, blue light induces TAEL dimerization, binding to the C120 element, and transcriptional activation to drive light-inducible gene expression.

tdnano is a constructed tandem-dimer of the iLID binding partner nano used as the second component of a blue-light-responsive iLID system. In the reported opto-receptor tyrosine kinase designs, blue light drives recruitment of two iLID-fused RTK molecules to tdnano, enabling receptor dimerization and activation.

TULIPs is an optical dimerizer system benchmarked as a multi-component light-controlled switch for regulating protein interactions in yeast. In the cited comparison, it produced a transcriptional response similar to CRY2/CIB1 and was evaluated in assays relevant to transcription and MAPK signaling control.

This tool is a two-photon-sensitive chemical caging group applied to gibberellic acid 3 (GA3) to permit infrared-light-triggered release of active GA3 in living cells. The uncaged GA3 is used to induce protein dimerization.

UVR8 is an Arabidopsis thaliana UV-B photoreceptor that senses solar UV-B light in the 280-315 nm range. It functions as a light-responsive multi-component switch through UV-B-induced dissociation of a UVR8 dimer.

UVR8/UVR8 is a light-controlled protein interaction system described as one of two optical dimerizer platforms in a protocol-focused study. It is presented for regulating cellular processes including transcription, protein localization, and protein secretion using light.

Venus iLID is an optogenetic improved Light Inducer Dimer system used to impose light-controlled protein proximity. In the cited application, a Venus iLID-based strategy was developed to bring αvβ3 integrin and ALK3 into proximity, and this was sufficient to induce cell spreading on a soft substrate.

WCC, the white collar complex, is a light-responsive heterodimeric complex in Neurospora composed of the PAS-domain-containing proteins WC-1 and WC-2. The available evidence identifies it as a major photoreceptor and suggests a role in transcriptional regulation through zinc-finger-containing subunits.

The yeast optogenetic toolkit (yOTK) is a modular construct system for light-controlled gene expression in Saccharomyces cerevisiae. It integrates optogenetic parts into an existing yeast toolkit and supports rapid assembly of light-controlled circuits, including split transcription factors built from cryptochrome and Enhanced Magnet dimerizers.

The Aer PAS domain is the FAD-binding sensory domain from the dimeric Escherichia coli aerotaxis receptor Aer. It monitors cellular respiration through a redox-sensitive flavin cofactor and is structurally characterized in the Aer-PAS-GVV variant at 2.4 Å resolution.

The antiGFP nanobody is used as a targeting domain in an iLID fusion to localize the light-inducible iLID module to GFP-tagged proteins. In this configuration, blue-light illumination induces iLID-SspB heterodimerization while recruitment remains efficient at the GFP-labeled target.

Arabidopsis thaliana cryptochrome 2 (CRY2) is a plant photoreceptor protein domain used as an optogenetic module. In the supplied evidence, CRY2 mediates blue light-dependent dimerization to activate C-RAF in mammalian cells.

The aureochrome 1 LOV-domain-based optical TrkB activation approach is an optogenetic TrkB activation strategy built around the light-oxygen-voltage domain of aureochrome 1 from Vaucheria frigida. It was presented as a demonstration that optical TrkB activation can be implemented with an optical homo-dimerizer other than CRY2.

The CIB1 N-terminal CRY2-binding region is a protein domain derived from the N terminus of calcium and integrin-binding protein 1 (CIB1). It serves as the CIB1 partner in blue light-activated CRY2-CIB1 optogenetic dimerization systems.

Cyanobacteriochromes are photoswitchable protein domains from cyanobacteria that sense light across a broad spectral range from the UV to the near infra-red. In the cited 2022 work, they were engineered into light-inducible dimer pairs that support orthogonal control with red, green, and blue light.

The dimerization/histidine phosphotransfer-like (DHpL) domain is a regulatory domain element within the blue-light-responsive histidine kinase EL346. Structural evidence indicates that, in the dark, interactions involving the LOV sensor domain and the DHpL domain stabilize an inhibited kinase conformation and suppress dimerization, while photoactivation weakens these contacts to promote activation.

The Drosophila PERIOD PAS domain fragment is a dPER protein segment comprising the PAS-A and PAS-B domains. Structural and functional analyses indicate that this fragment participates in PAS-mediated protein interactions, with the PAS-B beta-sheet surface mediating heterodimer formation with Drosophila TIMELESS (dTIM).

The Drosophila PERIOD PAS-B beta-sheet surface is a protein interaction interface within dPER that mediates binding to the clock protein TIMELESS (dTIM). Comparative analysis further indicates that this PAS-B beta-sheet surface is a reusable interaction site within PERIOD-family proteins, supporting dPER-dTIM heterodimer formation in Drosophila and mPER2 homodimerization in mammals.

Enhanced Magnets (eMags) are Vivid-derived light-sensitive protein dimerization domains used in optogenetic split transcription factors and subcellular recruitment systems. In Saccharomyces cerevisiae, optimized eMag-based transcription factor designs improved light-sensitive gene expression, and eMags were also validated for rapid, reversible protein recruitment to subcellular organelles.

The integrin αIIb cytoplasmic domain is a platelet integrin tail segment that functions as a specific binding partner for the calcium- and integrin-binding protein CIB1. Solution structural analysis indicates that this interaction involves EF-hand III of CIB1 and is associated with a CIB1 conformational response distinct from that of related EF-hand proteins.

Light-harvesting complex II (LHCII) is the major chlorophyll a/b-binding photosynthetic antenna complex of plants that has been studied in isolated native and recombinant forms. The cited literature indicates that light induces reversible conformational changes in LHCII that expose its N-terminal phosphorylation site and can also promote formation of dimeric LHCII states with distinct chlorophyll excitation-quenching properties.

The light-oxygen-voltage (LOV) sensor domain is a light-responsive regulatory protein domain characterized in the monomeric histidine kinase EL346. Structural evidence indicates that it binds one side of the DHpL domain to control kinase output, prevent dimerization, and release the catalytic apparatus from an inhibited conformation upon photoactivation.

The light-oxygen-voltage sensing (LOV) domain is a blue light-responsive protein domain used in optogenetic constructs to confer light-dependent control over coupled signaling effectors. The supplied evidence specifically describes it as a blue light homodimerizing LOV domain.

nano is the wild-type SspB protein used as the binding partner for iLID in a blue-light-responsive dimerization system. In the cited work, the iLID–nano pair is used to control protein interactions and localization with light.

The nMag/pMag photodimerization system, also called Magnets photosensors, is a light-controlled protein-domain pair that mediates heterodimerization. Reported engineering work altered its light sensitivity and tuned its light-activity dose-response behavior through directed evolution and high-throughput screening.

Optogenetic RGS2 (opto-RGS2) is an engineered light-responsive RGS2-based protein tool created to study calcium encoding in Gq-protein signaling. It uses light-induced heterodimerization to recruit an RGS2 domain to the membrane, where it interacts with its cognate G protein and modulates calcium oscillatory behavior.

pdDronpa1.2 is a protein domain used in a single-construct optogenetic talin system to enable light-inducible C-terminal homodimerization. In the cited 2025 study, this light-triggered talin dimerization was sufficient to drive talin recruitment to adhesion sites, adhesion formation, coupling to actin retrograde flow, and downstream mechanosignaling.

The Arabidopsis thaliana phototropin 1 LOV2 domain is a blue-light-sensing protein domain from phototropin 1 whose dark-adapted crystal structure has been determined. In this state, the domain is dimeric and contains an N-terminal A'α helix and a C-terminal Jα helix that contribute to coiled-coil-mediated dimerization.

Q-PAS1 is an engineered single-domain binding partner for the bacterial phytochrome BphP1 that enables near-infrared-light-inducible protein interactions. It was developed as a smaller, non-oligomerizing alternative to the natural BphP1 partner PpsR2 and has been applied to transcription regulation, chromatin state modification, and spectral multiplexing.

The Rel/NF-κB family is a mammalian set of transcription factors comprising RelA, c-Rel, RelB, NF-κB1 (p50 and precursor p105), and NF-κB2 (p52 and precursor p100). These factors are differentially activated as NF-κB heterodimers by signals from antigen receptors, pattern-recognition receptors, and receptors for TNF and IL-1 family cytokines to regulate transcription.

The Rhodobacter sphaeroides light-oxygen-voltage domain (RsLOV) is a homodimeric LOV photosensory protein domain from Rhodobacter sphaeroides. Reported engineering results indicate that fusion of RsLOV to Cas9-derived effector variants can confer light sensitivity, and the same domain also imparted strong temperature sensitivity in that study.

The SMN tudor domain is a globular protein domain from SMN that is sufficient for dimerization-induced condensation in vivo. Its condensate-forming activity requires binding to dimethylarginine, supporting its use as a chemical-input interaction module for specifying membraneless organelle assembly.

split-TurboID is a split proximity-labeling enzyme used in the Light Activated BioID (LAB) system, where its two halves are fused to the photodimeric proteins CRY2 and CIB1. Blue light induces CRY2–CIB1 association, reconstitutes split-TurboID, and triggers proximity-dependent biotinylation.

SspB is the binding partner used in the iLID blue-light-inducible dimerization system. Upon blue-light activation of iLID, the exposed SsrA peptide binds SspB, enabling light-controlled recruitment and localization of SspB-fused cargo proteins.

TAEL is an engineered optogenetic transcription factor optimized for zebrafish in which blue light induces TAEL dimerization, binding to the C120 promoter element, and activation of downstream transcription. TAEL 2.0 is an improved transgenic implementation that enables inducible expression at late embryonic and larval stages and produces faster, higher reporter expression than the original system.

The TRIM21 RING domain is a catalytic protein domain whose ubiquitination activity is activated by substrate-induced clustering that promotes intermolecular RING dimerization. In the cited 2020 study, this activation mechanism underlies TRIM21-dependent antiviral responses and Trim-Away-mediated protein degradation.

Vivid (VVD) is a blue-light-sensing light-oxygen-voltage (LOV) protein from the filamentous fungus Neurospora crassa. Upon illumination, its flavin cofactor forms a photoadduct that creates a stable light state, while VVD also exhibits light-dependent dimer-associated aggregation behavior and photosensitized self-oxidation.

YtvA is a blue-light-sensing LOV-STAS photoreceptor from Bacillus subtilis whose LOV domain has been structurally analyzed for LOV-LOV dimerization and interdomain interactions. Homologous mutations in a conserved LOV hydrophobic pocket alter activation-state kinetics, supporting YtvA as a tunable LOV sensor domain relevant to optogenetic design.

YtvA from Bacillus subtilis is a LOV-domain photoswitch reported in this evidence set as a homodimeric light-responsive protein domain. It was highlighted in an optogenetics context because its relaxation half-life is longer than that of Avena sativa LOV2, suggesting potential utility as a light-controlled module.