The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

COP1  -  E3 ubiquitin-protein ligase COP1

Arabidopsis thaliana

Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of COP1


High impact information on COP1

  • This constitutive photomorphogenic (COP) phenotype was not observed for mutants of cct1 corresponding to previously described cry1 alleles [4].
  • COP1 interacts directly with HY5 in the nucleus to regulate its activity negatively [5].
  • Little is known regarding how light signals perceived by photoreceptors are transduced to regulate COP1 [6].
  • Taken together, our results show that HFR1 is ubiquitinated by COP1 E3 ligase and marked for post-translational degradation during photomorphogenesis [2].
  • COP10 is a ubiquitin-conjugating enzyme variant (UEV), which is thought to act together with COP1, DET1, and the COP9 signalosome (CSN) in Arabidopsis to repress photomorphogenesis [7].

Biological context of COP1

  • Here we show that both photoactivated cryptochromes repress COP1 activity through a direct protein-protein contact and that this direct regulation is primarily responsible for the cryptochrome-mediated blue light regulation of seedling photomorphogenic development and genome expression profile [6].
  • We propose that COP1 mediates light control of gene expression through targeted degradation of multiple photomorphogenesis-promoting transcription factors in the nucleus [8].
  • Although epistasis of a putative null cop1-5 mutation over a hy5 mutation implied that COP1 acts downstream of HY5, the same hy5 mutation can suppress the dark photomorphogenic phenotypes (including hypocotyl elongation and cotyledon cellular differentiation) of the weak cop1-6 mutation [9].
  • This relationship suggests a role for the ATH1 protein in the signal transduction pathway downstream of COP1 [10].
  • The subnuclear localization signal overlaps two previously characterized motifs, a cytoplasmic localization signal and a putative alpha-helical coiled-coil domain that has been implicated in COP1 dimerization [11].

Anatomical context of COP1


Associations of COP1 with chemical compounds

  • The phyA PAS domain interacts with the COP1 WD40 domain [14].
  • Our data suggest that FIN219 may define a critical link for phytochrome A-mediated far-red inactivation of COP1 and a possible cross-talk juncture between auxin regulation and phytochrome signaling [15].
  • COP1 possesses a leucine-rich nuclear-exclusion signal that resides in a domain implicated in COP1 dimerization [16].
  • COP1, another COP/DET/FUS protein, is itself not a subunit of the COP9 signalosome [17].
  • One of the isolated mutants, eid6, is a novel recessive allele of the COP1 gene (constitutive photomorphogenic 1) that carries an amino acid transition in a conserved histidine residue of the RING finger domain [18].

Physical interactions of COP1

  • Coimmunoprecipitation studies showed that CRY1 was bound to COP1 in extracts from both dark- and light-grown Arabidopsis [19].
  • It was shown that in the dark, COP1 directly interacts with the bZIP transcription factor HY5, a positive regulator of photomorphogenesis, and promotes its proteasome-mediated degradation [8].
  • The SPA2 protein is constitutively nuclear localized in planta and can physically interact with the repressor COP1 [20].
  • The Arabidopsis CIP7 protein was identified by its capability to interact with COP1 [21].
  • COP10 is part of a nuclear protein complex and capable of directly interacting with both COP1 and the COP9 signalosome [22].

Enzymatic interactions of COP1

  • Both HFR1 and HFR1(DeltaN) can be ubiquitinated by COP1, although with different efficiencies [2].

Co-localisations of COP1

  • A green fluorescent protein-COL3 fusion protein colocalizes with COP1 to nuclear speckles when transiently expressed in plant cells [23].

Regulatory relationships of COP1

  • In transgenic plants, HFR1 levels are significantly elevated upon induced expression of a dominant-negative COP1 mutant that interferes with endogenous COP1 E3 activity [2].
  • Taken together, our data indicate that CIP7 acts as a positive regulator of light-regulated genes and is a potential direct downstream target of COP1 for mediating light control of gene expression [21].
  • Here, we show that COP1 negatively regulates HY5, a bZIP protein and a positive regulator of photomorphogenic development [24].
  • The results indicate that COP1 is required to repress the AtMYB21 gene in seedlings, and the pleiotropic phenotypes shown in the cop1 mutant are due to the combination of misregulation of genuine light-signalling components and other tissue-specific factors [25].
  • CIP4 expression is light inducible and regulated by COP1 [26].

Other interactions of COP1

  • The signaling mechanism of Arabidopsis CRY1 involves direct interaction with COP1 [19].
  • SUPPRESSOR OF PHYTOCHROME A-105 family proteins (SPA1 to SPA4) that are required for COP1 function in dark and visible light are not essential in the response to UV-B [27].
  • We demonstrate that accumulation of PIF3 in the nucleus in dark requires constitutive photomorphogenesis 1 (COP1), a negative regulator of photomorphogenesis, and show that red (R) and far-red light (FR) induce rapid degradation of the PIF3 protein [28].
  • The allele specific effect of cop1 mutations on the CIP8 protein accumulation in seedlings indicates that its stability in vivo is dependent on the COP1 protein [29].
  • COP1 specifically targets HY5 for degradation via the 26S proteasome in the dark through their direct physical interaction [6].

Analytical, diagnostic and therapeutic context of COP1


  1. Ring finger motif of Arabidopsis thaliana COP1 defines a new class of zinc-binding domain. von Arnim, A.G., Deng, X.W. J. Biol. Chem. (1993) [Pubmed]
  2. HFR1 is targeted by COP1 E3 ligase for post-translational proteolysis during phytochrome A signaling. Jang, I.C., Yang, J.Y., Seo, H.S., Chua, N.H. Genes Dev. (2005) [Pubmed]
  3. Overexpression of constitutive differential growth 1 gene, which encodes a RLCKVII-subfamily protein kinase, causes abnormal differential and elongation growth after organ differentiation in Arabidopsis. Muto, H., Yabe, N., Asami, T., Hasunuma, K., Yamamoto, K.T. Plant Physiol. (2004) [Pubmed]
  4. The C termini of Arabidopsis cryptochromes mediate a constitutive light response. Yang, H.Q., Wu, Y.J., Tang, R.H., Liu, D., Liu, Y., Cashmore, A.R. Cell (2000) [Pubmed]
  5. Targeted destabilization of HY5 during light-regulated development of Arabidopsis. Osterlund, M.T., Hardtke, C.S., Wei, N., Deng, X.W. Nature (2000) [Pubmed]
  6. Direct interaction of Arabidopsis cryptochromes with COP1 in light control development. Wang, H., Ma, L.G., Li, J.M., Zhao, H.Y., Deng, X.W. Science (2001) [Pubmed]
  7. Arabidopsis COP10 forms a complex with DDB1 and DET1 in vivo and enhances the activity of ubiquitin conjugating enzymes. Yanagawa, Y., Sullivan, J.A., Komatsu, S., Gusmaroli, G., Suzuki, G., Yin, J., Ishibashi, T., Saijo, Y., Rubio, V., Kimura, S., Wang, J., Deng, X.W. Genes Dev. (2004) [Pubmed]
  8. Two interacting bZIP proteins are direct targets of COP1-mediated control of light-dependent gene expression in Arabidopsis. Holm, M., Ma, L.G., Qu, L.J., Deng, X.W. Genes Dev. (2002) [Pubmed]
  9. Regulatory hierarchy of photomorphogenic loci: allele-specific and light-dependent interaction between the HY5 and COP1 loci. Ang, L.H., Deng, X.W. Plant Cell (1994) [Pubmed]
  10. The homeobox gene ATH1 of Arabidopsis is derepressed in the photomorphogenic mutants cop1 and det1. Quaedvlieg, N., Dockx, J., Rook, F., Weisbeek, P., Smeekens, S. Plant Cell (1995) [Pubmed]
  11. A novel motif mediates the targeting of the Arabidopsis COP1 protein to subnuclear foci. Stacey, M.G., von Arnim, A.G. J. Biol. Chem. (1999) [Pubmed]
  12. Promotion of photomorphogenesis by COP1. Boccalandro, H.E., Rossi, M.C., Saijo, Y., Deng, X.W., Casal, J.J. Plant Mol. Biol. (2004) [Pubmed]
  13. Brassinolide may control aquaporin activities in Arabidopsis thaliana. Morillon, R., Catterou, M., Sangwan, R.S., Sangwan, B.S., Lassalles, J.P. Planta (2001) [Pubmed]
  14. Photoreceptor ubiquitination by COP1 E3 ligase desensitizes phytochrome A signaling. Seo, H.S., Watanabe, E., Tokutomi, S., Nagatani, A., Chua, N.H. Genes Dev. (2004) [Pubmed]
  15. FIN219, an auxin-regulated gene, defines a link between phytochrome A and the downstream regulator COP1 in light control of Arabidopsis development. Hsieh, H.L., Okamoto, H., Wang, M., Ang, L.H., Matsui, M., Goodman, H., Deng, X.W. Genes Dev. (2000) [Pubmed]
  16. The Arabidopsis repressor of light signaling, COP1, is regulated by nuclear exclusion: mutational analysis by bioluminescence resonance energy transfer. Subramanian, C., Kim, B.H., Lyssenko, N.N., Xu, X., Johnson, C.H., von Arnim, A.G. Proc. Natl. Acad. Sci. U.S.A. (2004) [Pubmed]
  17. The COP/DET/FUS proteins-regulators of eukaryotic growth and development. Schwechheimer, C., Deng, X.W. Semin. Cell Dev. Biol. (2000) [Pubmed]
  18. Characterization of a novel non-constitutive photomorphogenic cop1 allele. Dieterle, M., Buche, C., Schafer, E., Kretsch, T. Plant Physiol. (2003) [Pubmed]
  19. The signaling mechanism of Arabidopsis CRY1 involves direct interaction with COP1. Yang, H.Q., Tang, R.H., Cashmore, A.R. Plant Cell (2001) [Pubmed]
  20. The SPA quartet: a family of WD-repeat proteins with a central role in suppression of photomorphogenesis in arabidopsis. Laubinger, S., Fittinghoff, K., Hoecker, U. Plant Cell (2004) [Pubmed]
  21. Role of a COP1 interactive protein in mediating light-regulated gene expression in arabidopsis. Yamamoto, Y.Y., Matsui, M., Ang, L.H., Deng, X.W. Plant Cell (1998) [Pubmed]
  22. Arabidopsis COP10 is a ubiquitin-conjugating enzyme variant that acts together with COP1 and the COP9 signalosome in repressing photomorphogenesis. Suzuki, G., Yanagawa, Y., Kwok, S.F., Matsui, M., Deng, X.W. Genes Dev. (2002) [Pubmed]
  23. Arabidopsis CONSTANS-LIKE3 is a positive regulator of red light signaling and root growth. Datta, S., Hettiarachchi, G.H., Deng, X.W., Holm, M. Plant Cell (2006) [Pubmed]
  24. Molecular interaction between COP1 and HY5 defines a regulatory switch for light control of Arabidopsis development. Ang, L.H., Chattopadhyay, S., Wei, N., Oyama, T., Okada, K., Batschauer, A., Deng, X.W. Mol. Cell (1998) [Pubmed]
  25. AtMYB21, a gene encoding a flower-specific transcription factor, is regulated by COP1. Shin, B., Choi, G., Yi, H., Yang, S., Cho, I., Kim, J., Lee, S., Paek, N.C., Kim, J.H., Song, P.S., Choi, G. Plant J. (2002) [Pubmed]
  26. Cip4, a new COP1 target, is a nucleus-localized positive regulator of Arabidopsis photomorphogenesis. Yamamoto, Y.Y., Deng, X., Matsui, M. Plant Cell (2001) [Pubmed]
  27. CONSTITUTIVELY PHOTOMORPHOGENIC1 is required for the UV-B response in Arabidopsis. Oravecz, A., Baumann, A., Máté, Z., Brzezinska, A., Molinier, J., Oakeley, E.J., Adám, E., Schäfer, E., Nagy, F., Ulm, R. Plant Cell (2006) [Pubmed]
  28. Constitutive photomorphogenesis 1 and multiple photoreceptors control degradation of phytochrome interacting factor 3, a transcription factor required for light signaling in Arabidopsis. Bauer, D., Viczián, A., Kircher, S., Nobis, T., Nitschke, R., Kunkel, T., Panigrahi, K.C., Adám, E., Fejes, E., Schäfer, E., Nagy, F. Plant Cell (2004) [Pubmed]
  29. The RING finger motif of photomorphogenic repressor COP1 specifically interacts with the RING-H2 motif of a novel Arabidopsis protein. Torii, K.U., Stoop-Myer, C.D., Okamoto, H., Coleman, J.E., Matsui, M., Deng, X.W. J. Biol. Chem. (1999) [Pubmed]
  30. Functional dissection of Arabidopsis COP1 reveals specific roles of its three structural modules in light control of seedling development. Torii, K.U., McNellis, T.W., Deng, X.W. EMBO J. (1998) [Pubmed]
  31. Modular domain structure of Arabidopsis COP1. Reconstitution of activity by fragment complementation and mutational analysis of a nuclear localization signal in planta. Stacey, M.G., Kopp, O.R., Kim, T.H., von Arnim, A.G. Plant Physiol. (2000) [Pubmed]
  32. A FUSCA gene of Arabidopsis encodes a novel protein essential for plant development. Castle, L.A., Meinke, D.W. Plant Cell (1994) [Pubmed]
  33. Molecular cloning and sequencing of the cDNA of cop1 gene from Pisum sativum. Zhao, L., Wang, C., Zhu, Y., Zhao, J., Wu, X. Biochim. Biophys. Acta (1998) [Pubmed]
WikiGenes - Universities