Source 1primary paper2018Proceedings of the National Academy of Sciences
Toolkit/BcLOV4
BcLOV4
Taxonomy: Mechanism Branch / Architecture. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
BcLOV4 is a blue-light-responsive photoreceptor from Botrytis cinerea that functions as a single-component optogenetic module for rapid plasma membrane recruitment. Illumination drives cytosol-to-membrane translocation through direct protein-lipid electrostatic interaction, and fused cargo such as RhoA GTPase or RhoA-activating GEFs can be relocalized to the membrane with light.
Usefulness & Problems
Why this is useful
BcLOV4 enables optical control of subcellular localization without requiring a second binding partner, which simplifies construct design for membrane recruitment experiments. Its rapid light-triggered membrane association has been used to control signaling proteins including RhoA and upstream RhoA GEF effectors.
Source:
RhoA GTPase, or its upstream activating GEF effectors, were fused to BcLOV4, a photoreceptor that can be dynamically recruited to the plasma membrane by a light-regulated protein-lipid electrostatic interaction with the inner leaflet.
Source:
this work establishes both a photosensory signal transmission mode and a single-component optogenetic tool with rapid membrane localization kinetics that approaches the diffusion limit
Problem solved
This tool addresses the need for a single-component optogenetic system that can rapidly and reversibly recruit proteins from the cytosol to the plasma membrane. It specifically solves the challenge of inducing membrane-localized signaling, such as RhoA pathway activation, without heterodimeric optogenetic pairs.
Published Workflows
Objective: Engineer a BcLOV4-derived optogenetic clustering module that retains light-induced clustering while eliminating plasma membrane association and improving kinetic performance for cytoplasmic applications in mammalian cells.
Why it works: The abstract states that key amino acids coupling BcLOV4 clustering to membrane binding were identified and altered, enabling engineering of a variant that preserves light-induced clustering while removing membrane association. The resulting construct was then benchmarked and tuned through fusion design choices to optimize clustering behavior and application scope.
light-induced protein clusteringdecoupling clustering from membrane bindingtemperature-sensitive cluster dissolutionmultiplexed control of independent condensatesamino-acid-level engineering of a photoreceptor variantcomparative benchmarking against Cry2fusion-based tuning with FUS intrinsically disordered regionfusion-partner selection using fluorescent proteins
Taxonomy & Function
Primary hierarchy
Mechanism Branch
Architecture: A composed arrangement of multiple parts that instantiates one or more mechanisms.
Mechanisms
anionic phospholipid bindingflavin-photocycle-coupled switchinglight-induced clusteringlight-regulated plasma membrane recruitmentMembrane Recruitmentprotein-lipid electrostatic interaction with the inner leafletTechniques
No technique tags yet.
Target processes
localizationsignalingInput: Light
Implementation Constraints
BcLOV4 is implemented as a fusion module, with reported cargoes including RhoA GTPase and upstream activating GEF effectors for light-regulated plasma membrane recruitment. Its activity is linked to the LOV-domain flavin photocycle and to a polybasic amphipathic helix in the linker between the LOV sensor and the C-terminal DUF. Reported observations include mammalian-cell clustering behavior and rapid membrane translocation in model systems under blue light.
Membrane association is nonselective among anionic phospholipids and depends on total membrane anionic content rather than a specific phospholipid headgroup, which may limit lipid-specific targeting. Blue-light-induced clustering has been reported to coincide with membrane translocation, and an engineered variant instead clusters in the cytoplasm without membrane association, indicating that localization behavior can vary by construct. Evidence here does not define performance across many cargo classes or biological contexts beyond the reported model systems and mammalian-cell observations.
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Supporting Sources
Source 2primary paper2023
Source 3primary paper2021
Source 4primary paper2021Advanced Biology
Ranked Claims
A BcLOV4 variant was engineered that clusters in the cytoplasm and does not associate with the membrane in response to blue light.
allowing us to engineer a variant of BcLOV4 that clusters in the cytoplasm and does not associate with the membrane in response to blue light
BcLOV4 can be dynamically recruited to the plasma membrane by a light-regulated protein-lipid electrostatic interaction with the inner leaflet.
BcLOV4, a photoreceptor that can be dynamically recruited to the plasma membrane by a light-regulated protein-lipid electrostatic interaction with the inner leaflet
RhoA GTPase or its upstream activating GEF effectors can be fused to BcLOV4 for light-regulated plasma membrane recruitment.
RhoA GTPase, or its upstream activating GEF effectors, were fused to BcLOV4, a photoreceptor that can be dynamically recruited to the plasma membrane by a light-regulated protein-lipid electrostatic interaction with the inner leaflet.
BcLOV4 electrostatic interaction is nonselective among anionic phospholipids and depends on total membrane anionic content rather than a specific headgroup.
The reversible electrostatic interaction is nonselective among anionic phospholipids, exhibiting binding strengths dependent on the total anionic content of the membrane without preference for a specific headgroup.
Similar in vitro and cellular responses were observed with a BcLOV4 homolog, suggesting the property may be general across the dikarya LOV class associated with RGS domains.
The in vitro and cellular responses were also observed with a BcLOV4 homolog and thus are likely to be general across the dikarya LOV class, whose members are associated with regulator of G-protein signaling (RGS) domains.
In model systems, BcLOV4 rapidly translocates from the cytosol to the plasma membrane in about 1 second.
In model systems, BcLOV4 rapidly translocates from the cytosol to plasma membrane (∼1 second).
translocation time 1 second
BcLOV4 membrane localization is directly coupled to its flavin photocycle and is mediated by a polybasic amphipathic helix in the linker region between the LOV sensor and the C-terminal DUF.
Membrane localization of one such photoreceptor, BcLOV4 from Botrytis cinerea, is directly coupled to its flavin photocycle, and is mediated by a polybasic amphipathic helix in the linker region between the LOV sensor and its C-terminal domain of unknown function (DUF)
This work establishes a single-component optogenetic tool with rapid membrane localization kinetics.
this work establishes both a photosensory signal transmission mode and a single-component optogenetic tool with rapid membrane localization kinetics that approaches the diffusion limit
Approval Evidence
5 sources8 linked approval claimsfirst-pass slug bclov4
Optogenetic clustering and membrane translocation of the BcLOV4 photoreceptor ... Relevant because the anchor review emphasizes comparing underlying photoreceptors and selecting among actuator behaviors beyond canonical CRY2 systems.
Source:
Recently, the photoreceptor BcLOV4 was found to form protein clusters in mammalian cells in response to blue light, although clustering coincided with its translocation to the plasma membrane.
Source:
BcLOV4, a photoreceptor that can be dynamically recruited to the plasma membrane by a light-regulated protein-lipid electrostatic interaction with the inner leaflet
Source:
BcLOV4, a photoreceptor that can be dynamically recruited to the plasma membrane by a light-regulated protein-lipid electrostatic interaction with the inner leaflet
Source:
Membrane localization of one such photoreceptor, BcLOV4 from Botrytis cinerea
Source:
engineering resultsupports
A BcLOV4 variant was engineered that clusters in the cytoplasm and does not associate with the membrane in response to blue light.
allowing us to engineer a variant of BcLOV4 that clusters in the cytoplasm and does not associate with the membrane in response to blue light
Source:
mechanismsupports
BcLOV4 can be dynamically recruited to the plasma membrane by a light-regulated protein-lipid electrostatic interaction with the inner leaflet.
BcLOV4, a photoreceptor that can be dynamically recruited to the plasma membrane by a light-regulated protein-lipid electrostatic interaction with the inner leaflet
Source:
tool mechanismsupports
RhoA GTPase or its upstream activating GEF effectors can be fused to BcLOV4 for light-regulated plasma membrane recruitment.
RhoA GTPase, or its upstream activating GEF effectors, were fused to BcLOV4, a photoreceptor that can be dynamically recruited to the plasma membrane by a light-regulated protein-lipid electrostatic interaction with the inner leaflet.
Source:
binding specificitysupports
BcLOV4 electrostatic interaction is nonselective among anionic phospholipids and depends on total membrane anionic content rather than a specific headgroup.
The reversible electrostatic interaction is nonselective among anionic phospholipids, exhibiting binding strengths dependent on the total anionic content of the membrane without preference for a specific headgroup.
Source:
class generalizationsupports
Similar in vitro and cellular responses were observed with a BcLOV4 homolog, suggesting the property may be general across the dikarya LOV class associated with RGS domains.
The in vitro and cellular responses were also observed with a BcLOV4 homolog and thus are likely to be general across the dikarya LOV class, whose members are associated with regulator of G-protein signaling (RGS) domains.
Source:
localization kineticssupports
In model systems, BcLOV4 rapidly translocates from the cytosol to the plasma membrane in about 1 second.
In model systems, BcLOV4 rapidly translocates from the cytosol to plasma membrane (∼1 second).
Source:
mechanismsupports
BcLOV4 membrane localization is directly coupled to its flavin photocycle and is mediated by a polybasic amphipathic helix in the linker region between the LOV sensor and the C-terminal DUF.
Membrane localization of one such photoreceptor, BcLOV4 from Botrytis cinerea, is directly coupled to its flavin photocycle, and is mediated by a polybasic amphipathic helix in the linker region between the LOV sensor and its C-terminal domain of unknown function (DUF)
Source:
tool capabilitysupports
This work establishes a single-component optogenetic tool with rapid membrane localization kinetics.
this work establishes both a photosensory signal transmission mode and a single-component optogenetic tool with rapid membrane localization kinetics that approaches the diffusion limit
Source:
Comparisons
Source-backed strengths
BcLOV4 shows rapid membrane localization kinetics, with cytosol-to-plasma-membrane translocation reported in about 1 second in model systems. Its membrane binding is directly coupled to the flavin photocycle and mediated by a polybasic amphipathic helix, providing a defined mechanistic basis. The platform supports domain fusion to signaling cargoes such as RhoA or RhoA-activating GEFs, and light-induced clustering has also been observed.
Source:
allowing us to engineer a variant of BcLOV4 that clusters in the cytoplasm and does not associate with the membrane in response to blue light
Ranked Citations
- 1.
Derived from 5 linked claims. Example evidence: The reversible electrostatic interaction is nonselective among anionic phospholipids, exhibiting binding strengths dependent on the total anionic content of the membrane without preference for a specific headgroup.
- 2.
- 3.
Derived from 1 linked claims. Example evidence: RhoA GTPase, or its upstream activating GEF effectors, were fused to BcLOV4, a photoreceptor that can be dynamically recruited to the plasma membrane by a light-regulated protein-lipid electrostatic interaction with the inner leaflet.
- 4.