Toolkit/BcLOV4

BcLOV4

Multi-Component Switch·Research·Since 2018

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.

Problem links

Need conditional control of signaling activity

Derived

BcLOV4 is a blue-light-responsive photoreceptor from Botrytis cinerea that functions as a single-component optogenetic membrane recruitment module. Upon illumination, it rapidly translocates from the cytosol to the plasma membrane through direct protein-lipid electrostatic interaction, and cargo proteins such as RhoA or RhoA-activating GEFs can be fused to it for light-regulated membrane localization.

Need inducible protein relocalization or recruitment

Derived

BcLOV4 is a blue-light-responsive photoreceptor from Botrytis cinerea that functions as a single-component optogenetic membrane recruitment module. Upon illumination, it rapidly translocates from the cytosol to the plasma membrane through direct protein-lipid electrostatic interaction, and cargo proteins such as RhoA or RhoA-activating GEFs can be fused to it for light-regulated membrane localization.

Need precise spatiotemporal control with light input

Derived

BcLOV4 is a blue-light-responsive photoreceptor from Botrytis cinerea that functions as a single-component optogenetic membrane recruitment module. Upon illumination, it rapidly translocates from the cytosol to the plasma membrane through direct protein-lipid electrostatic interaction, and cargo proteins such as RhoA or RhoA-activating GEFs can be fused to it for light-regulated membrane localization.

Taxonomy & Function

Implementation Constraints

cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationimplementation constraint: multi component delivery burdenimplementation constraint: spectral hardware requirementoperating role: sensorswitch architecture: multi componentswitch architecture: recruitment

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

Ranked Claims

Claim 1engineering resultsupports2023Source 2needs review

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
Claim 2mechanismsupports2021Source 4needs review

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
Claim 3tool mechanismsupports2021Source 3needs review

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.
Claim 4binding specificitysupports2018Source 1needs review

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.
Claim 5class generalizationsupports2018Source 1needs review

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.
Claim 6localization kineticssupports2018Source 1needs review

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
Claim 7mechanismsupports2018Source 1needs review

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)
Claim 8tool capabilitysupports2018Source 1needs review

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

Compared with Cry2

BcLOV4 and Cry2 address a similar problem space because they share localization, signaling.

Shared frame: same top-level item type; shared target processes: localization, signaling; shared mechanisms: membrane_recruitment; same primary input modality: light

Strengths here: looks easier to implement in practice; may avoid an exogenous cofactor requirement.

Relative tradeoffs: appears more independently replicated.

Compared with iLID/SspB

BcLOV4 and iLID/SspB address a similar problem space because they share localization, signaling.

Shared frame: same top-level item type; shared target processes: localization, signaling; shared mechanisms: membrane_recruitment; same primary input modality: light

Relative tradeoffs: appears more independently replicated.

Compared with optoTGFBRs

BcLOV4 and optoTGFBRs address a similar problem space because they share localization, signaling.

Shared frame: same top-level item type; shared target processes: localization, signaling; shared mechanisms: membrane_recruitment; same primary input modality: light

Strengths here: appears more independently replicated; looks easier to implement in practice.

Ranked Citations

  1. 1.
    FoundationalSource 1Proceedings of the National Academy of Sciences2018Claim 4Claim 5Claim 6

    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. 2.
    FoundationalSource 22023Claim 1

    Derived from 1 linked claims. Example evidence: 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

  3. 3.
    FoundationalSource 32021Claim 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. 4.
    FoundationalSource 4Advanced Biology2021Claim 2

    Derived from 1 linked claims. Example evidence: BcLOV4, a photoreceptor that can be dynamically recruited to the plasma membrane by a light-regulated protein-lipid electrostatic interaction with the inner leaflet