=== UNIPROT METADATA ===
UniProt ID: Q9FN03
Entry Name: UVR8_ARATH
Gene Name: UVR8
Locus Tag: At5g63860 {ECO:0000312|Araport:AT5G63860}
Protein Name: Ultraviolet-B receptor UVR8
Organism: Arabidopsis thaliana (Mouse-ear cress)
NCBI Taxonomy ID: 3702
Function: UV-B specific signaling component that acts as a UV-B photoreceptor and plays a key role in establishing UV-protective responses in plants. Upon UV-B irradiation, UVR8 undergoes an immediate switch from homodimer to monomer, accumulates in the nucleus, interacts with the photomorphogenic repressor COP1 and regulates the expression of the transcription factor HY5 by associating with chromatin (through histone H2B binding) in the HY5 promoter region. UVR8 is involved in controlling aspects of leaf growth and morphogenesis in response to UV- B, is required for normal progression of endocycle and has a regulatory role in stomatal differentiation. Is required for plant circadian clock response to photomorphogenic UV-B light, partly through the transcriptional activation of responsive clock genes. Promotes photosynthetic efficiency at elevated levels of UV-B. Plays a role in mediating the effects of UV-B radiation on pathogen resistance by controlling the expression of the sinapate biosynthetic pathway. The two tryptophans, Trp-285 and Trp-233, serve collectively as the UV-B chromophore.
Subcellular Location: Nucleus
Subunit: Homodimer in the absence of UV-B, but absorption of UV-B induces monomerization of UVR8 and interaction with COP1. Interacts with RUP1, RUP2 and histone H2B.
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Prepare a comprehensive literature-backed research report for GO annotation review of the target gene.
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Structure the report as:
Use citations for all substantive claims.
UVR8 (UV RESISTANCE LOCUS 8) is a UV-B–specific photoreceptor that initiates UV-B signaling via a light-triggered homodimer → monomer photoconversion mediated by intrinsic tryptophan chromophores (especially Trp285 and Trp233) rather than by any enzymatic catalysis or proteolytic maturation. Upon UV-B activation, UVR8 monomers interact with COP1, resulting in transcriptional reprogramming (largely via HY5/HYH) that drives UV-protective acclimation (e.g., phenylpropanoid/flavonoid production) and characteristic photomorphogenic outputs. Strong, recent mechanistic work (2023–2024) refines regulation of the pathway: RUP2-mediated redimerization is explained structurally by two binding interfaces, and UVR8 phosphorylation (S402) modulates partner binding (especially RUP1/2) and flavonoid outcomes. UVR8 is predominantly cytoplasmic in the absence of UV-B but shows rapid UV-B–induced nuclear accumulation (minutes), where signaling is executed. Evidence that UVR8 directly binds chromatin/histones (H2B) is conflicting, with earlier ChIP/histone-binding reports but later rigorous ChIP/nucleosome-binding experiments failing to confirm specific chromatin association.
Critically for GO curation, available evidence does not support annotation of UVR8 with proteolytic activation/processing, apoptosis/pyroptosis-like pathways, neuronal/synaptic roles, or mammalian inflammatory signaling. UV-induced programmed cell death in plants is typically attributed to damage/ROS/MAPK stress pathways, which are conceptually distinct from the UVR8-mediated photomorphogenic/acclimation pathway.
A curated evidence synopsis (with quantitative details) is provided below.
| Aspect | Key claim | Evidence type/method | Strength/notes for GO (core vs context-specific; disputed) | Key citations with DOI/URL and publication date |
|---|---|---|---|---|
| MF | UVR8 is a UV-B photoreceptor that uses intrinsic tryptophans as chromophores; Trp285 is central, with Trp233 also critical for activation. | Structural/biochemical studies summarized in reviews; mutational analysis of Trp residues; UV-B-induced monomerization assays by non-boiled SDS-PAGE, SEC, fluorescence, CD. | Core MF. Best-supported molecular activity is photoreception, not enzyme catalysis. Suitable for UV-B photoreceptor/light sensing annotations. (tilbrook2013theuvr8uvb pages 5-6, yang2015howdoesphotoreceptor pages 3-4) | Tilbrook et al., 2013, The Arabidopsis Book, doi:10.1199/tab.0164, https://doi.org/10.1199/tab.0164, Jun 2013; Yang et al., 2015, Photochem Photobiol, doi:10.1111/php.12470, https://doi.org/10.1111/php.12470, Sep 2015 |
| MF | UVR8 activation is a homodimer → monomer switch driven by disruption of intersubunit salt bridges after UV-B absorption. | Mutant analysis (e.g., W285A constitutive monomer; W285F constitutive dimer; R286A monomer), biochemical monomer/dimer assays. | Core MF/mechanism. Activation is conformational switching, not proteolytic maturation. Avoid cleavage/processing annotations. (tilbrook2013theuvr8uvb pages 5-6, jenkins2014theuvbphotoreceptor pages 4-5) | Tilbrook et al., 2013, doi:10.1199/tab.0164, https://doi.org/10.1199/tab.0164, Jun 2013; Jenkins, 2014, Plant Cell, doi:10.1105/tpc.113.119446, https://doi.org/10.1105/tpc.113.119446, Jan 2014 |
| Complex | The active monomer binds COP1; UVR8–COP1 interaction is required for downstream UV-B signaling. | Yeast, co-IP from plant tissue, heterologous mammalian-cell interaction assays, genetics. | Core signaling complex/function. Strong support for physical interaction after photoactivation. Good basis for protein binding / signaling complex annotations. (tilbrook2013theuvr8uvb pages 7-9, tilbrook2013theuvr8uvb pages 9-11) | Tilbrook et al., 2013, doi:10.1199/tab.0164, https://doi.org/10.1199/tab.0164, Jun 2013; Yin et al. context in reviews, summarized by Tilbrook/Jenkins |
| Regulation | UVR8 C-terminal C27/VP motif is essential for signaling and mediates interactions with COP1 and RUP proteins. | Deletion/motif mutagenesis; interaction assays; signaling phenotypes. | Core regulatory feature. Appropriate for annotations tied to UV-B signaling complex formation, but not as an independent enzymatic activity. (tilbrook2013theuvr8uvb pages 9-11, wang2023rup2facilitatesuvr8 pages 3-6) | Tilbrook et al., 2013, doi:10.1199/tab.0164, https://doi.org/10.1199/tab.0164, Jun 2013; Wang et al., 2023, Plant Communications, doi:10.1016/j.xplc.2022.100428, https://doi.org/10.1016/j.xplc.2022.100428, Jan 2023 |
| Regulation | RUP1/RUP2 are negative regulators that promote UVR8 return to the inactive dimer; in vivo redimerization occurs in 1–2 h. | Genetics, biochemical dark reversion assays, co-expression assays, non-boiled SDS-PAGE. | Core negative feedback regulation of UVR8 pathway. Useful for regulation-of-signaling annotations; not a separate MF of UVR8 itself. (tilbrook2013theuvr8uvb pages 5-6, heijde2013reversionofthe pages 4-5) | Heijde & Ulm, 2013, PNAS, doi:10.1073/pnas.1214237110, https://doi.org/10.1073/pnas.1214237110, Dec 2013; Tilbrook et al., 2013, doi:10.1199/tab.0164, https://doi.org/10.1199/tab.0164, Jun 2013 |
| Regulation | RUP2 promotes UVR8 redimerization via two interfaces; solved complex at 2.0 Šwith ~1620 Ų buried surface area. Interface 1 involves C27/VP motif; interface 2 contacts the UVR8 core. | X-ray crystal structure; in vitro redimerization; mutagenesis of UVR8 and RUP2; in planta reversion assays. | Strong recent mechanistic support for UVR8 pathway termination. Excellent for curator confidence in negative regulation but still a regulatory mechanism, not localization. (wang2023rup2facilitatesuvr8 pages 3-6, wang2023rup2facilitatesuvr8 pages 1-3, wang2023rup2facilitatesuvr8 media cc99b673) | Wang et al., 2023, Plant Communications, doi:10.1016/j.xplc.2022.100428, https://doi.org/10.1016/j.xplc.2022.100428, Jan 2023 |
| CC | UVR8 is present in both cytoplasm and nucleus, with most protein cytoplasmic before UV-B; UV-B triggers nuclear accumulation detectable in about 5 min, with ~90% of nuclei showing signal. | GFP/CFP fusions, cell fractionation, microscopy. | Strong CC support for nucleus and cytoplasm with condition dependence. Nuclear localization is stimulus-dependent; avoid unconditional “nuclear resident only” interpretation. (tilbrook2013theuvr8uvb pages 6-7, jenkins2014theuvbphotoreceptor pages 8-9) | Jenkins, 2014, doi:10.1105/tpc.113.119446, https://doi.org/10.1105/tpc.113.119446, Jan 2014; Tilbrook et al., 2013, doi:10.1199/tab.0164, https://doi.org/10.1199/tab.0164, Jun 2013 |
| CC | UVR8 lacks a clear canonical NLS; the N-terminal 23 aa are required for UV-B-induced nuclear accumulation. Nuclear localization alone is insufficient for signaling. | Deletion constructs, localization assays, signaling phenotypes. | Useful caveat for CC curation. Supports regulated nuclear import/retention, but not maturation by cleavage or constitutive nuclear localization. (tilbrook2013theuvr8uvb pages 6-7, tilbrook2013theuvr8uvb pages 9-11) | Tilbrook et al., 2013, doi:10.1199/tab.0164, https://doi.org/10.1199/tab.0164, Jun 2013 |
| BP | UVR8 is the core receptor for UV-B signaling / photomorphogenesis, including hypocotyl growth inhibition and cotyledon opening. | Genetics (uvr8, cop1, rup mutants), transcript changes, phenotype assays. | Core BP. Best-supported biological-process annotation. (jenkins2014theuvbphotoreceptor pages 4-5, tilbrook2013theuvr8uvb pages 13-14) | Jenkins, 2014, doi:10.1105/tpc.113.119446, https://doi.org/10.1105/tpc.113.119446, Jan 2014; Tilbrook et al., 2013, doi:10.1199/tab.0164, https://doi.org/10.1199/tab.0164, Jun 2013 |
| BP | UVR8 promotes UV-protective phenylpropanoid/flavonoid biosynthesis, including CHS induction; mature leaves show regulation of >70 genes, seedlings several hundred genes. | Transcriptomics, mutant phenotypes, metabolite analysis under UV-B/solar UV. | Core-to-strong BP. Well supported as acclimation/protective metabolism downstream of UV-B sensing. (jenkins2014theuvbphotoreceptor pages 2-3, morales2013multiplerolesfor pages 1-2) | Jenkins, 2014, doi:10.1105/tpc.113.119446, https://doi.org/10.1105/tpc.113.119446, Jan 2014; Morales et al., 2013, Plant Physiol., doi:10.1104/pp.112.211375, https://doi.org/10.1104/pp.112.211375, Dec 2013 |
| Regulation | UVR8 signaling is modulated by S402 phosphorylation in the C27 region; UV-B causes ~1.5-fold higher ^32P incorporation, and S402A retains only ~28% of WT labeling under UV-B. | In vivo ^32P labeling, IP-mass spectrometry, phosphomimetic/phosphonull transgenics. | Recent strong regulatory evidence. Supports pathway modulation, especially flavonoid outputs; not yet a core defining annotation over photoreception itself. (liu2024phosphorylationofarabidopsis pages 1-2, liu2024phosphorylationofarabidopsis pages 2-3) | Liu et al., 2024, Nature Communications, doi:10.1038/s41467-024-45575-7, https://doi.org/10.1038/s41467-024-45575-7, Feb 2024 |
| Regulation | S402 phosphorylation is mainly nuclear, rises within ~6 h of UV-B, and strongly promotes RUP1/2 binding without consistent COP1-binding change. | Nuclear fractionation, phospho-specific detection, co-IP, transgenic complementation. | Emerging but high-quality mechanistic detail. Good for nuanced regulation notes; likely too fine-grained for high-level core GO unless supported by direct assay-specific terms. (liu2024phosphorylationofarabidopsis pages 5-6, liu2024phosphorylationofarabidopsis pages 2-3) | Liu et al., 2024, Nature Communications, doi:10.1038/s41467-024-45575-7, https://doi.org/10.1038/s41467-024-45575-7, Feb 2024 |
| BP | UVR8-dependent chromatin/histone acetylation changes accompany transcriptional regulation; ChIP-seq found 133 loci with UV-B-induced, UVR8-dependent H3K9/14 diacetylation, with 39% overlapping known UVR8-regulated genes. | ChIP-qPCR, ChIP-seq for histone marks, RT-qPCR, mutants (uvr8, hy5/hyh). | Moderate support for transcriptional/chromatin regulation downstream of UVR8. Safer to annotate regulation of transcription than direct chromatin binding by UVR8. (velanis2016regulationoftranscription pages 12-15) | Velanis et al., 2016, Plant Molecular Biology, doi:10.1007/s11103-016-0522-3, https://doi.org/10.1007/s11103-016-0522-3, Aug 2016 |
| CC/Complex | Direct UVR8 binding to chromatin/histone H2B was reported earlier, but is disputed. Early studies found histone/H2B association and ChIP recovery at HY5/MYB12/CRYD loci. | Histone-agarose binding, chromatin preparations, ChIP. | Disputed; high annotation risk. Do not treat chromatin/H2B binding as settled core function without qualifier/evidence code scrutiny. (jenkins2014theuvbphotoreceptor pages 10-11, tilbrook2013theuvr8uvb pages 6-7) | Jenkins, 2014, doi:10.1105/tpc.113.119446, https://doi.org/10.1105/tpc.113.119446, Jan 2014; Tilbrook et al., 2013, doi:10.1199/tab.0164, https://doi.org/10.1199/tab.0164, Jun 2013 |
| CC/Complex | Re-evaluation found no convincing UVR8 chromatin association at tested loci and no in vitro nucleosome binding; RCC1-like histone/DNA-binding residues are not conserved in UVR8. | Quantitative ChIP-qPCR with endogenous and tagged UVR8, anti-GFP/anti-UVR8 controls, in vitro nucleosome-binding assays, structural comparison. | Best current cautionary evidence. Avoid direct chromatin-binding or histone-H2B-binding GO assertions unless tied to older specific evidence and flagged as controversial. (binkert2016revisitingchromatinbinding pages 1-2, binkert2016revisitingchromatinbinding pages 2-4, binkert2016revisitingchromatinbinding pages 4-5) | Binkert et al., 2016, BMC Plant Biology, doi:10.1186/s12870-016-0732-5, https://doi.org/10.1186/s12870-016-0732-5, Feb 2016 |
| BP | UVR8 also affects stomatal index, endoreduplication, circadian clock entrainment, and leaf/epidermal morphogenesis under UV-B. | Mutant phenotyping, clock gene transcript analyses, developmental assays. | Supported but more context-specific/pleiotropic than core UV-B photoreception and flavonoid induction. Use narrower downstream-process annotations cautiously. (jenkins2014theuvbphotoreceptor pages 4-5, jenkins2014theuvbphotoreceptor pages 2-3) | Jenkins, 2014, doi:10.1105/tpc.113.119446, https://doi.org/10.1105/tpc.113.119446, Jan 2014 |
| BP | Contributions to pathogen resistance and improved photosynthetic performance under sunlight/UV are reported downstream of UVR8-regulated sinapate/phenolic and transcriptional responses. | Solar UV experiments, pathogen assays, transcript/metabolite profiling. | Context-specific downstream outcomes. Real biology, but higher risk of over-annotation as core function; better treated as secondary consequences of UV-B signaling/acclimation. (jenkins2014theuvbphotoreceptor pages 2-3, jenkins2014theuvbphotoreceptor pages 3-4) | Jenkins, 2014, doi:10.1105/tpc.113.119446, https://doi.org/10.1105/tpc.113.119446, Jan 2014 |
| Regulation | No evidence supports proteolytic activation of UVR8; activation is reversible photoconversion. UVR8 is distinct from UV-B damage/ROS/MAPK pathways linked to plant PCD. | Core UVR8 mechanistic literature and UV-induced cell-death reviews. | Important negative curation point. Avoid annotations for proteolytic processing, apoptosis, pyroptosis, inflammatory signaling, neuronal/synaptic roles. (jenkins2014theuvbphotoreceptor pages 3-4, nawkar2013uvinducedcelldeath pages 6-8, tilbrook2013theuvr8uvb pages 6-7, nawkar2013uvinducedcelldeath pages 1-3) | Jenkins, 2014, doi:10.1105/tpc.113.119446, https://doi.org/10.1105/tpc.113.119446, Jan 2014; Nawkar et al., 2013, Int J Mol Sci., doi:10.3390/ijms14011608, https://doi.org/10.3390/ijms14011608, Jan 2013; Tilbrook et al., 2013, doi:10.1199/tab.0164, https://doi.org/10.1199/tab.0164, Jun 2013 |
Table: This table summarizes the strongest molecular function, biological process, localization, complex, and regulatory evidence for Arabidopsis UVR8, with emphasis on GO curation confidence and annotation risk. It highlights core functions versus context-specific or disputed claims and includes key quantitative details from foundational and recent studies.
UVR8’s best-supported “molecular function” is photoreception of UV-B radiation. UVR8 lacks an exogenous chromophore; instead, UV-B is absorbed by intrinsic tryptophan residues clustered at the dimer interface. Mutational evidence highlights Trp285 as the principal chromophore residue with Trp233 also essential for correct photoperception/photoconversion, consistent with UVR8 functioning as a UV-B receptor rather than as an enzyme with a substrate-binding pocket. (tilbrook2013theuvr8uvb pages 5-6, yang2015howdoesphotoreceptor pages 3-4)
Activation is a reversible conformational switch: UV-B perception triggers UVR8 homodimer dissociation into monomers by disrupting an intersubunit salt-bridge network. Constitutive monomer and constitutive dimer mutants (e.g., W285A versus W285F) support that monomerization is the signaling-competent state. (tilbrook2013theuvr8uvb pages 5-6, jenkins2014theuvbphotoreceptor pages 4-5)
A conserved C-terminal 27-aa region (C27) is required for signaling output: C27 deletion mutants can still monomerize and accumulate in the nucleus but show compromised signaling, indicating that photoconversion/nuclear presence is necessary but not sufficient without appropriate protein–protein interaction interfaces. (tilbrook2013theuvr8uvb pages 9-11)
COP1 binding: UVR8 monomers interact with COP1 in a UV-B-dependent manner; genetic and interaction data support that COP1 binds the monomeric UVR8 state (consistent with constitutive monomer/dimer UVR8 mutant behaviors). (tilbrook2013theuvr8uvb pages 7-9, tilbrook2013theuvr8uvb pages 9-11)
RUP1/RUP2 binding (negative feedback): RUP proteins bind UVR8 (including UVR8W285A in a UV-B-independent fashion) and facilitate UVR8 return to the homodimeric ground state. A high-resolution structure (2.0 Å) shows RUP2–UVR8 heterodimerization via two interfaces, one involving the C27/VP region and one involving the UVR8 core, explaining accelerated redimerization relative to autonomous recovery. (wang2023rup2facilitatesuvr8 pages 1-3, wang2023rup2facilitatesuvr8 pages 3-6)
Phosphorylation-dependent binding modulation (2024): UVR8 is phosphorylated at multiple sites; Ser402 in C27 is the principal UV-B-stimulated site. A phosphomimetic S402D variant shows strongly increased binding to RUP1/2 (with no consistent COP1 binding change), linking post-translational modification to selective partner engagement and output tuning. Quantitatively, ^32P incorporation into UVR8 rose ~1.5-fold after 24 h UV-B; S402A retained ~28% of WT labeling under UV-B. (liu2024phosphorylationofarabidopsis pages 2-3, liu2024phosphorylationofarabidopsis pages 5-6)
Across core UVR8 mechanistic sources, UVR8 activation is repeatedly described as photoconversion (dimer→monomer) without proteolytic cleavage, and no experimentally supported UVR8 cleavage/maturation step is presented. Thus, proteolytic processing should not be annotated as a UVR8 activation mechanism. (jenkins2014theuvbphotoreceptor pages 4-5, tilbrook2013theuvr8uvb pages 6-7)
UV-B photomorphogenesis and UV-B signaling: UVR8 mediates canonical low-fluence UV-B photomorphogenic outputs such as hypocotyl growth inhibition and broader developmental photomorphogenesis responses. These are core UVR8 pathway phenotypes and are strengthened by UVR8–COP1 interaction evidence and genetic phenotypes. (jenkins2014theuvbphotoreceptor pages 4-5, tilbrook2013theuvr8uvb pages 13-14)
UV-protective secondary metabolism: UVR8 promotes transcriptional induction of phenylpropanoid/flavonoid pathway genes (e.g., CHS) and accumulation of UV-absorbing/photoprotective metabolites. Transcriptomic analyses report UVR8 regulates >70 genes in mature leaves and several hundred genes in seedlings under UV-B. (jenkins2014theuvbphotoreceptor pages 2-3, morales2013multiplerolesfor pages 1-2)
Transcriptional regulation with chromatin mark changes: UVR8 signaling correlates with UV-B-induced histone acetylation changes at UVR8-responsive loci. A ChIP-seq study identified 133 loci with UV-B-induced, UVR8-dependent H3K9/14 diacetylation, with 39% overlapping previously known UVR8-regulated genes. This supports annotating UVR8 as a regulator of transcriptional responses to UV-B, though it does not alone prove UVR8 is a chromatin-binding protein. (velanis2016regulationoftranscription pages 12-15)
UVR8 has documented roles in additional phenotypes/processes including leaf growth and epidermal cell expansion, stomatal index increase, endoreduplication in epidermal cells, and circadian clock entrainment by low-fluence UV-B. These are experimentally supported phenotypic outputs but may reflect downstream transcriptional and hormonal network effects rather than UVR8 “core biochemical function.” (jenkins2014theuvbphotoreceptor pages 4-5, jenkins2014theuvbphotoreceptor pages 2-3)
UVR8-dependent changes also associate with pathogen resistance and other stress interactions under solar UV (e.g., reduced UV-B–enhanced resistance to Botrytis cinerea in uvr8 mutants). These are biologically meaningful but are best treated as downstream consequences of UV-B acclimation programs, not as defining UVR8 molecular function. (jenkins2014theuvbphotoreceptor pages 3-4)
Plant UV-induced programmed cell death is commonly attributed to stress/damage pathways (e.g., ROS and MAPK cascades) distinct from UVR8 photomorphogenesis. A UV-induced cell-death review explicitly separates the UVR8-regulated photomorphogenic pathway from UV-B stress/MAPK pathways implicated in PCD and describes the role of UVR8 under stress as unclear/“obscure,” providing no direct UVR8→PCD mechanism. (nawkar2013uvinducedcelldeath pages 6-8, nawkar2013uvinducedcelldeath pages 1-3)
UVR8 is present in both cytoplasmic and nuclear pools, with the majority cytoplasmic before UV-B and a smaller nuclear pool. UV-B rapidly increases nuclear accumulation: microscopy/fusion-protein studies report nuclear localization detectable in ~5 minutes, with ~90% of nuclei showing signal after UV-B. Total UVR8 protein abundance does not change substantially during this relocalization. (jenkins2014theuvbphotoreceptor pages 8-9, tilbrook2013theuvr8uvb pages 6-7)
UVR8 lacks an obvious canonical NLS, but the N-terminal 23 amino acids are required for UV-B-induced nuclear accumulation. Notably, nuclear localization alone is insufficient to activate signaling; UV-B/monomerization remains required. (tilbrook2013theuvr8uvb pages 6-7)
UVR8–COP1 complex: UV-B triggers UVR8–COP1 interaction; COP1 accumulates in the nucleus upon UV-B, consistent with nuclear execution of UVR8 signaling. (tilbrook2013theuvr8uvb pages 7-9, jenkins2014theuvbphotoreceptor pages 8-9)
UVR8–RUP module: RUP1/2 accelerate UVR8 redimerization and terminate signaling. Genetic evidence indicates RUP-mediated redimerization occurs independently of COP1, consistent with a negative-feedback module that resets UVR8’s ground state. (heijde2013reversionofthe pages 4-5)
RUP2 two-interface model (visual evidence): Structural data depict the RUP2–UVR8 complex and two interfaces supporting redimerization acceleration; these panels are important for curator interpretation of the molecular mechanism of negative feedback. (wang2023rup2facilitatesuvr8 media cc99b673, wang2023rup2facilitatesuvr8 media 33c4c55d)
Earlier studies (summarized in major reviews) reported UVR8 recovery in chromatin preparations, ChIP recovery at promoters of UVR8-regulated genes, and preferential binding to histone H2B in histone-agarose assays, suggesting chromatin association. (jenkins2014theuvbphotoreceptor pages 10-11, tilbrook2013theuvr8uvb pages 6-7)
However, a careful re-examination using controlled ChIP-qPCR (endogenous UVR8 and tagged UVR8), matched crosslinked chromatin pools, and in vitro nucleosome-binding assays did not detect UVR8 association at HY5/MYB12 loci and found recombinant UVR8 does not bind nucleosomes, arguing against a core “chromatin binding” function. Thus, direct chromatin-binding annotations should be treated as high risk or qualified. (binkert2016revisitingchromatinbinding pages 2-4, binkert2016revisitingchromatinbinding pages 1-2)
Recent primary (2023–2024):
- Liu W. et al. Nature Communications (Feb 2024). “Phosphorylation of Arabidopsis UVR8 photoreceptor modulates protein interactions and responses to UV-B radiation.” https://doi.org/10.1038/s41467-024-45575-7 (liu2024phosphorylationofarabidopsis pages 2-3, liu2024phosphorylationofarabidopsis pages 5-6)
- Wang L. et al. Plant Communications (Jan 2023). “RUP2 facilitates UVR8 redimerization via two interfaces.” https://doi.org/10.1016/j.xplc.2022.100428 (wang2023rup2facilitatesuvr8 pages 1-3, wang2023rup2facilitatesuvr8 pages 3-6)
Foundational reviews / synthesis:
- Jenkins GI. The Plant Cell (Jan 2014). “The UV-B Photoreceptor UVR8: From Structure to Physiology.” https://doi.org/10.1105/tpc.113.119446 (jenkins2014theuvbphotoreceptor pages 4-5, jenkins2014theuvbphotoreceptor pages 2-3)
- Tilbrook K. et al. The Arabidopsis Book (Jun 2013). “The UVR8 UV-B Photoreceptor: Perception, Signaling and Response.” https://doi.org/10.1199/tab.0164 (tilbrook2013theuvr8uvb pages 6-7, tilbrook2013theuvr8uvb pages 9-11)
Chromatin association dispute:
- Binkert M. et al. BMC Plant Biology (Feb 2016). “Revisiting chromatin binding of the Arabidopsis UV-B photoreceptor UVR8.” https://doi.org/10.1186/s12870-016-0732-5 (binkert2016revisitingchromatinbinding pages 2-4, binkert2016revisitingchromatinbinding pages 1-2)
- Velanis CN. et al. Plant Molecular Biology (Aug 2016). “Regulation of transcription by the Arabidopsis UVR8 photoreceptor involves a specific histone modification.” https://doi.org/10.1007/s11103-016-0522-3 (velanis2016regulationoftranscription pages 12-15)
UVR8 vs UV-induced cell death context:
- Nawkar GM. et al. International Journal of Molecular Sciences (Jan 2013). “UV-Induced Cell Death in Plants.” https://doi.org/10.3390/ijms14011608 (nawkar2013uvinducedcelldeath pages 6-8, nawkar2013uvinducedcelldeath pages 1-3)
In applied settings, UVR8 is widely treated as a molecular handle to engineer UV-B responses and UV-protective metabolite production (e.g., enhancing phenylpropanoid/flavonoid accumulation) and as a model photoswitch in heterologous contexts; however, within the provided evidence corpus here, the strongest directly citable recent “implementation-level” evidence pertains to mechanistic control of flavonoid biosynthesis via UVR8 phosphorylation (S402) and negative-feedback resetting via RUP2 structure/function, which could inform crop or synthetic biology strategies. (liu2024phosphorylationofarabidopsis pages 5-6, wang2023rup2facilitatesuvr8 pages 3-6)
References
(tilbrook2013theuvr8uvb pages 5-6): Kimberley Tilbrook, Adriana B. Arongaus, Melanie Binkert, Marc Heijde, Ruohe Yin, and Roman Ulm. The uvr8 uv-b photoreceptor: perception, signaling and response. The Arabidopsis Book, 2013:e0164, Jun 2013. URL: https://doi.org/10.1199/tab.0164, doi:10.1199/tab.0164. This article has 362 citations and is from a peer-reviewed journal.
(yang2015howdoesphotoreceptor pages 3-4): Xiaojing Yang, Sherwin Montano, and Zhong Ren. How does photoreceptor uvr8 perceive a uv‐b signal? Photochemistry and Photobiology, 91:993-1003, Sep 2015. URL: https://doi.org/10.1111/php.12470, doi:10.1111/php.12470. This article has 32 citations and is from a peer-reviewed journal.
(jenkins2014theuvbphotoreceptor pages 4-5): Gareth I. Jenkins. The uv-b photoreceptor uvr8: from structure to physiology. Plant Cell, 26:21-37, Jan 2014. URL: https://doi.org/10.1105/tpc.113.119446, doi:10.1105/tpc.113.119446. This article has 463 citations and is from a highest quality peer-reviewed journal.
(tilbrook2013theuvr8uvb pages 7-9): Kimberley Tilbrook, Adriana B. Arongaus, Melanie Binkert, Marc Heijde, Ruohe Yin, and Roman Ulm. The uvr8 uv-b photoreceptor: perception, signaling and response. The Arabidopsis Book, 2013:e0164, Jun 2013. URL: https://doi.org/10.1199/tab.0164, doi:10.1199/tab.0164. This article has 362 citations and is from a peer-reviewed journal.
(tilbrook2013theuvr8uvb pages 9-11): Kimberley Tilbrook, Adriana B. Arongaus, Melanie Binkert, Marc Heijde, Ruohe Yin, and Roman Ulm. The uvr8 uv-b photoreceptor: perception, signaling and response. The Arabidopsis Book, 2013:e0164, Jun 2013. URL: https://doi.org/10.1199/tab.0164, doi:10.1199/tab.0164. This article has 362 citations and is from a peer-reviewed journal.
(wang2023rup2facilitatesuvr8 pages 3-6): Lixia Wang, Yidong Wang, Hongfei Chang, Hui Ren, Xinquan Wu, Jia Wen, Zeyuan Guan, Ling Ma, Liang Qiu, Junjie Yan, Delin Zhang, Xi Huang, and Ping Yin. Rup2 facilitates uvr8 redimerization via two interfaces. Jan 2023. URL: https://doi.org/10.1016/j.xplc.2022.100428, doi:10.1016/j.xplc.2022.100428. This article has 23 citations and is from a peer-reviewed journal.
(heijde2013reversionofthe pages 4-5): Marc Heijde and Roman Ulm. Reversion of the arabidopsis uv-b photoreceptor uvr8 to the homodimeric ground state. Proceedings of the National Academy of Sciences, 110:1113-1118, Dec 2013. URL: https://doi.org/10.1073/pnas.1214237110, doi:10.1073/pnas.1214237110. This article has 261 citations and is from a highest quality peer-reviewed journal.
(wang2023rup2facilitatesuvr8 pages 1-3): Lixia Wang, Yidong Wang, Hongfei Chang, Hui Ren, Xinquan Wu, Jia Wen, Zeyuan Guan, Ling Ma, Liang Qiu, Junjie Yan, Delin Zhang, Xi Huang, and Ping Yin. Rup2 facilitates uvr8 redimerization via two interfaces. Jan 2023. URL: https://doi.org/10.1016/j.xplc.2022.100428, doi:10.1016/j.xplc.2022.100428. This article has 23 citations and is from a peer-reviewed journal.
(wang2023rup2facilitatesuvr8 media cc99b673): Lixia Wang, Yidong Wang, Hongfei Chang, Hui Ren, Xinquan Wu, Jia Wen, Zeyuan Guan, Ling Ma, Liang Qiu, Junjie Yan, Delin Zhang, Xi Huang, and Ping Yin. Rup2 facilitates uvr8 redimerization via two interfaces. Jan 2023. URL: https://doi.org/10.1016/j.xplc.2022.100428, doi:10.1016/j.xplc.2022.100428. This article has 23 citations and is from a peer-reviewed journal.
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(jenkins2014theuvbphotoreceptor pages 2-3): Gareth I. Jenkins. The uv-b photoreceptor uvr8: from structure to physiology. Plant Cell, 26:21-37, Jan 2014. URL: https://doi.org/10.1105/tpc.113.119446, doi:10.1105/tpc.113.119446. This article has 463 citations and is from a highest quality peer-reviewed journal.
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(binkert2016revisitingchromatinbinding pages 2-4): Melanie Binkert, Carlos D. Crocco, Babatunde Ekundayo, Kelvin Lau, Sarah Raffelberg, Kimberley Tilbrook, Ruohe Yin, Richard Chappuis, Thomas Schalch, and Roman Ulm. Revisiting chromatin binding of the arabidopsis uv-b photoreceptor uvr8. BMC Plant Biology, Feb 2016. URL: https://doi.org/10.1186/s12870-016-0732-5, doi:10.1186/s12870-016-0732-5. This article has 45 citations and is from a peer-reviewed journal.
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(wang2023rup2facilitatesuvr8 media 33c4c55d): Lixia Wang, Yidong Wang, Hongfei Chang, Hui Ren, Xinquan Wu, Jia Wen, Zeyuan Guan, Ling Ma, Liang Qiu, Junjie Yan, Delin Zhang, Xi Huang, and Ping Yin. Rup2 facilitates uvr8 redimerization via two interfaces. Jan 2023. URL: https://doi.org/10.1016/j.xplc.2022.100428, doi:10.1016/j.xplc.2022.100428. This article has 23 citations and is from a peer-reviewed journal.