|
|
| Line 3: |
Line 3: |
| | <StructureSection load='6qtq' size='340' side='right'caption='[[6qtq]], [[Resolution|resolution]] 1.30Å' scene=''> | | <StructureSection load='6qtq' size='340' side='right'caption='[[6qtq]], [[Resolution|resolution]] 1.30Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[6qtq]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6QTQ OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6QTQ FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[6qtq]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6QTQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6QTQ FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.3Å</td></tr> |
| - | <tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=CSO:S-HYDROXYCYSTEINE'>CSO</scene></td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=CSO:S-HYDROXYCYSTEINE'>CSO</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/RING-type_E3_ubiquitin_transferase RING-type E3 ubiquitin transferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.2.27 2.3.2.27] </span></td></tr>
| + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6qtq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6qtq OCA], [https://pdbe.org/6qtq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6qtq RCSB], [https://www.ebi.ac.uk/pdbsum/6qtq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6qtq ProSAT]</span></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6qtq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6qtq OCA], [http://pdbe.org/6qtq PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6qtq RCSB], [http://www.ebi.ac.uk/pdbsum/6qtq PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6qtq ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/COP1_ARATH COP1_ARATH]] E3 ubiquitin-protein ligase that acts as a repressor of photomorphogenesis and as an activator of etiolation in darkness. E3 ubiquitin ligases accept ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and then directly transfers the ubiquitin to targeted substrates. Represses photomorphogenesis in darkness by mediating ubiquitination and subsequent proteasomal degradation of light-induced transcription factors such as HY5, HYH and LAF1. Down-regulates MYB21, probably via ubiquitination process. Light stimuli abrogate the repression of photomorphogenesis, possibly due to its localization to the cytoplasm. Could play a role in switching between skotomorphogenetic and photomorphogenetic pathways.<ref>PMID:11967090</ref> <ref>PMID:12023303</ref> [[http://www.uniprot.org/uniprot/UVR8_ARATH UVR8_ARATH]] UV-B specific signaling component that acts as 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.<ref>PMID:16330762</ref> <ref>PMID:17720867</ref> <ref>PMID:18055587</ref> <ref>PMID:19165148</ref> <ref>PMID:19402876</ref> <ref>PMID:21041653</ref> <ref>PMID:21395889</ref> <ref>PMID:21454788</ref> <ref>PMID:22447155</ref> <ref>PMID:23161229</ref> <ref>PMID:23012433</ref> <ref>PMID:22988111</ref> | + | [https://www.uniprot.org/uniprot/COP1_ARATH COP1_ARATH] E3 ubiquitin-protein ligase that acts as a repressor of photomorphogenesis and as an activator of etiolation in darkness. E3 ubiquitin ligases accept ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and then directly transfers the ubiquitin to targeted substrates. Represses photomorphogenesis in darkness by mediating ubiquitination and subsequent proteasomal degradation of light-induced transcription factors such as HY5, HYH and LAF1. Down-regulates MYB21, probably via ubiquitination process. Light stimuli abrogate the repression of photomorphogenesis, possibly due to its localization to the cytoplasm. Could play a role in switching between skotomorphogenetic and photomorphogenetic pathways.<ref>PMID:11967090</ref> <ref>PMID:12023303</ref> |
| | + | <div style="background-color:#fffaf0;"> |
| | + | == Publication Abstract from PubMed == |
| | + | Plants sense different parts of the sun's light spectrum using distinct photoreceptors, which signal through the E3 ubiquitin ligase COP1. Here, we analyze why many COP1-interacting transcription factors and photoreceptors harbor sequence-divergent Val-Pro (VP) motifs that bind COP1 with different binding affinities. Crystal structures of the VP motifs of the UV-B photoreceptor UVR8 and the transcription factor HY5 in complex with COP1, quantitative binding assays, and reverse genetic experiments together suggest that UVR8 and HY5 compete for COP1. Photoactivation of UVR8 leads to high-affinity cooperative binding of its VP motif and its photosensing core to COP1, preventing COP1 binding to its substrate HY5. UVR8-VP motif chimeras suggest that UV-B signaling specificity resides in the UVR8 photoreceptor core. Different COP1-VP peptide motif complexes highlight sequence fingerprints required for COP1 targeting. The blue-light photoreceptors CRY1 and CRY2 also compete with transcription factors for COP1 binding using similar VP motifs. Thus, our work reveals that different photoreceptors and their signaling components compete for COP1 via a conserved mechanism to control different light signaling cascades. |
| | + | |
| | + | Plant photoreceptors and their signaling components compete for COP1 binding via VP peptide motifs.,Lau K, Podolec R, Chappuis R, Ulm R, Hothorn M EMBO J. 2019 Sep 16;38(18):e102140. doi: 10.15252/embj.2019102140. Epub 2019 Jul , 15. PMID:31304983<ref>PMID:31304983</ref> |
| | + | |
| | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> |
| | + | </div> |
| | + | <div class="pdbe-citations 6qtq" style="background-color:#fffaf0;"></div> |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| | + | [[Category: Arabidopsis thaliana]] |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: RING-type E3 ubiquitin transferase]]
| + | [[Category: Hothorn M]] |
| - | [[Category: Hothorn, M]] | + | [[Category: Lau K]] |
| - | [[Category: Lau, K]] | + | |
| - | [[Category: Complex]]
| + | |
| - | [[Category: Plant protein]]
| + | |
| Structural highlights
Function
COP1_ARATH E3 ubiquitin-protein ligase that acts as a repressor of photomorphogenesis and as an activator of etiolation in darkness. E3 ubiquitin ligases accept ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and then directly transfers the ubiquitin to targeted substrates. Represses photomorphogenesis in darkness by mediating ubiquitination and subsequent proteasomal degradation of light-induced transcription factors such as HY5, HYH and LAF1. Down-regulates MYB21, probably via ubiquitination process. Light stimuli abrogate the repression of photomorphogenesis, possibly due to its localization to the cytoplasm. Could play a role in switching between skotomorphogenetic and photomorphogenetic pathways.[1] [2]
Publication Abstract from PubMed
Plants sense different parts of the sun's light spectrum using distinct photoreceptors, which signal through the E3 ubiquitin ligase COP1. Here, we analyze why many COP1-interacting transcription factors and photoreceptors harbor sequence-divergent Val-Pro (VP) motifs that bind COP1 with different binding affinities. Crystal structures of the VP motifs of the UV-B photoreceptor UVR8 and the transcription factor HY5 in complex with COP1, quantitative binding assays, and reverse genetic experiments together suggest that UVR8 and HY5 compete for COP1. Photoactivation of UVR8 leads to high-affinity cooperative binding of its VP motif and its photosensing core to COP1, preventing COP1 binding to its substrate HY5. UVR8-VP motif chimeras suggest that UV-B signaling specificity resides in the UVR8 photoreceptor core. Different COP1-VP peptide motif complexes highlight sequence fingerprints required for COP1 targeting. The blue-light photoreceptors CRY1 and CRY2 also compete with transcription factors for COP1 binding using similar VP motifs. Thus, our work reveals that different photoreceptors and their signaling components compete for COP1 via a conserved mechanism to control different light signaling cascades.
Plant photoreceptors and their signaling components compete for COP1 binding via VP peptide motifs.,Lau K, Podolec R, Chappuis R, Ulm R, Hothorn M EMBO J. 2019 Sep 16;38(18):e102140. doi: 10.15252/embj.2019102140. Epub 2019 Jul , 15. PMID:31304983[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Shin B, Choi G, Yi H, Yang S, Cho I, Kim J, Lee S, Paek NC, Kim JH, Song PS, Choi G. AtMYB21, a gene encoding a flower-specific transcription factor, is regulated by COP1. Plant J. 2002 Apr;30(1):23-32. PMID:11967090
- ↑ Holm M, Ma LG, Qu LJ, Deng XW. Two interacting bZIP proteins are direct targets of COP1-mediated control of light-dependent gene expression in Arabidopsis. Genes Dev. 2002 May 15;16(10):1247-59. PMID:12023303 doi:http://dx.doi.org/10.1101/gad.969702
- ↑ Lau K, Podolec R, Chappuis R, Ulm R, Hothorn M. Plant photoreceptors and their signaling components compete for COP1 binding via VP peptide motifs. EMBO J. 2019 Sep 16;38(18):e102140. PMID:31304983 doi:10.15252/embj.2019102140
|
