Source 1primary paper2007The Plant Journal
Toolkit/active phytochrome binding domain
active phytochrome binding domain
Also known as: APB domain
Taxonomy: Mechanism Branch / Component. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
The active phytochrome binding (APB) domain is a protein interaction module present in most phytochrome-interacting factors (PIFs) that mediates binding to light-activated phytochrome B (phyB). In Arabidopsis PIF4 and PIF5, this domain is required for phyB-associated, phosphorylation-preceded, proteasome-sensitive degradation in a light-regulated shade-avoidance pathway.
Usefulness & Problems
Why this is useful
The APB domain is useful as a light-responsive interaction element because it confers association with activated phyB and links that interaction to regulated protein turnover in specific PIF contexts. This makes it relevant for studying or engineering light-controlled transcriptional regulation and degradation processes tied to phytochrome signaling.
Problem solved
This domain helps solve the problem of coupling light perception by phyB to selective regulation of downstream transcription factors. The cited work specifically supports a role in mediating light-dependent control of PIF4 and PIF5 stability during shade-avoidance signaling.
Problem links
Need conditional protein clearance
DerivedThe active phytochrome binding (APB) domain is a protein domain present in most phytochrome-interacting factors (PIFs) that mediates interaction with light-activated phytochrome B (phyB). In the cited Arabidopsis shade-avoidance context, this domain is required for phyB-associated degradation of the bHLH transcription factors PIF4 and PIF5.
Need precise spatiotemporal control with light input
DerivedThe active phytochrome binding (APB) domain is a protein domain present in most phytochrome-interacting factors (PIFs) that mediates interaction with light-activated phytochrome B (phyB). In the cited Arabidopsis shade-avoidance context, this domain is required for phyB-associated degradation of the bHLH transcription factors PIF4 and PIF5.
Need tighter control over gene expression timing or amplitude
DerivedThe active phytochrome binding (APB) domain is a protein domain present in most phytochrome-interacting factors (PIFs) that mediates interaction with light-activated phytochrome B (phyB). In the cited Arabidopsis shade-avoidance context, this domain is required for phyB-associated degradation of the bHLH transcription factors PIF4 and PIF5.
Taxonomy & Function
Primary hierarchy
Mechanism Branch
Component: A low-level protein part used inside a larger architecture that realizes a mechanism.
Mechanisms
Degradationlight-dependent protein-protein interactionlight-dependent protein-protein interactionlight-dependent protein-protein interaction with activated phytochrome bphosphorylation-associated degradationphosphorylation-associated degradationphosphorylation-associated proteasome-sensitive degradationproteasome-sensitive degradationproteasome-sensitive degradationTechniques
No technique tags yet.
Target processes
degradationtranscriptionInput: Light
Implementation Constraints
cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationimplementation constraint: spectral hardware requirementoperating role: regulatorswitch architecture: single chain
The evidence indicates that the APB domain functions in the context of PIF proteins, where it mediates interaction with light-activated phyB. For PIF4 and PIF5, degradation is phosphorylation-associated and proteasome-sensitive, so implementations relying on turnover would depend on activated phyB and intact cellular degradation machinery; no construct architecture or expression-system optimization is described.
The supplied evidence is centered on Arabidopsis PIF4 and PIF5 in the shade-avoidance pathway and does not establish performance across diverse hosts, constructs, or synthetic applications. Quantitative properties such as binding affinity, kinetics, spectral parameters, and transferability as a standalone engineered module are not provided.
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Supporting Sources
Ranked Claims
The constitutive shade-avoidance phenotype of phyB mutants partially reverts in the absence of PIF4 and PIF5.
Consistent with this idea, the constitutive shade-avoidance phenotype of phyB mutants partially reverts in the absence of PIF4 and PIF5.
The constitutive shade-avoidance phenotype of phyB mutants partially reverts in the absence of PIF4 and PIF5.
Consistent with this idea, the constitutive shade-avoidance phenotype of phyB mutants partially reverts in the absence of PIF4 and PIF5.
The constitutive shade-avoidance phenotype of phyB mutants partially reverts in the absence of PIF4 and PIF5.
Consistent with this idea, the constitutive shade-avoidance phenotype of phyB mutants partially reverts in the absence of PIF4 and PIF5.
The constitutive shade-avoidance phenotype of phyB mutants partially reverts in the absence of PIF4 and PIF5.
Consistent with this idea, the constitutive shade-avoidance phenotype of phyB mutants partially reverts in the absence of PIF4 and PIF5.
The constitutive shade-avoidance phenotype of phyB mutants partially reverts in the absence of PIF4 and PIF5.
Consistent with this idea, the constitutive shade-avoidance phenotype of phyB mutants partially reverts in the absence of PIF4 and PIF5.
Shade avoidance in dense vegetation is triggered at least partially by reduced phytochrome-mediated degradation of transcription factors such as PIF4 and PIF5.
Our data suggest that, in dense vegetation, which is rich in far-red light, shade avoidance is triggered, at least partially, as a consequence of reduced phytochrome-mediated degradation of transcription factors such as PIF4 and PIF5.
Shade avoidance in dense vegetation is triggered at least partially by reduced phytochrome-mediated degradation of transcription factors such as PIF4 and PIF5.
Our data suggest that, in dense vegetation, which is rich in far-red light, shade avoidance is triggered, at least partially, as a consequence of reduced phytochrome-mediated degradation of transcription factors such as PIF4 and PIF5.
Shade avoidance in dense vegetation is triggered at least partially by reduced phytochrome-mediated degradation of transcription factors such as PIF4 and PIF5.
Our data suggest that, in dense vegetation, which is rich in far-red light, shade avoidance is triggered, at least partially, as a consequence of reduced phytochrome-mediated degradation of transcription factors such as PIF4 and PIF5.
Shade avoidance in dense vegetation is triggered at least partially by reduced phytochrome-mediated degradation of transcription factors such as PIF4 and PIF5.
Our data suggest that, in dense vegetation, which is rich in far-red light, shade avoidance is triggered, at least partially, as a consequence of reduced phytochrome-mediated degradation of transcription factors such as PIF4 and PIF5.
Shade avoidance in dense vegetation is triggered at least partially by reduced phytochrome-mediated degradation of transcription factors such as PIF4 and PIF5.
Our data suggest that, in dense vegetation, which is rich in far-red light, shade avoidance is triggered, at least partially, as a consequence of reduced phytochrome-mediated degradation of transcription factors such as PIF4 and PIF5.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Approval Evidence
1 source1 linked approval claimfirst-pass slug active-phytochrome-binding-domain
most of the PIFs contain an active phytochrome binding (APB) domain that mediates their interaction with light-activated phytochrome B (phyB).
Source:
mechanistic requirementsupports
Degradation of PIF4 and PIF5 is preceded by phosphorylation, requires the APB domain, and is sensitive to proteasome inhibitors, suggesting degradation upon interaction with light-activated phyB.
Degradation of these transcription factors is preceded by phosphorylation, requires the APB domain and is sensitive to inhibitors of the proteasome, suggesting that PIF4 and PIF5 are degraded upon interaction with light-activated phyB.
Source:
Comparisons
Source-backed strengths
Evidence supports a direct mechanistic connection between the APB domain and interaction with light-activated phyB. In PIF4 and PIF5, APB-dependent degradation is preceded by phosphorylation and is sensitive to proteasome inhibitors, providing a defined route from light input to protein destabilization.
Compared with blue light-responsive Cas13b mRNA knockdown system
active phytochrome binding domain and blue light-responsive Cas13b mRNA knockdown system address a similar problem space because they share degradation, transcription.
Shared frame: shared target processes: degradation, transcription; shared mechanisms: degradation; same primary input modality: light
Compared with CRY1
active phytochrome binding domain and CRY1 address a similar problem space because they share degradation, transcription.
Shared frame: same top-level item type; shared target processes: degradation, transcription; shared mechanisms: degradation; same primary input modality: light
Relative tradeoffs: appears more independently replicated; looks easier to implement in practice.
Compared with photosensitive degron
active phytochrome binding domain and photosensitive degron address a similar problem space because they share degradation.
Shared frame: same top-level item type; shared target processes: degradation; shared mechanisms: degradation; same primary input modality: light
Relative tradeoffs: appears more independently replicated; looks easier to implement in practice.
Ranked Citations
- 1.