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. 1998 Nov;10(11):1779–1790. doi: 10.1105/tpc.10.11.1779

Arabidopsis homologs of a c-Jun coactivator are present both in monomeric form and in the COP9 complex, and their abundance is differentially affected by the pleiotropic cop/det/fus mutations.

S F Kwok 1, R Solano 1, T Tsuge 1, D A Chamovitz 1, J R Ecker 1, M Matsui 1, X W Deng 1
PMCID: PMC143959  PMID: 9811788

Abstract

The CONSTITUTIVE PHOTOMORPHOGENIC9 (COP9) complex is a nuclear localized, multisubunit protein complex essential for repression of light-mediated development in Arabidopsis. Mutations that abolish the complex result in constitutive photomorphogenic development in darkness and pleiotropic developmental defects in both light and darkness. Here, we report the identification of two apparently redundant genes, AJH1 and AJH2, that encode a subunit of the COP9 complex. Both AJH1 and AJH2 share high amino acid sequence identity (62 and 63%, respectively) with JAB1, a specific mammalian coactivator of AP-1 transcription. The proteins encoded by these two genes are present in both complex and monomeric forms, whereas complex formation is in part mediated by the direct interaction with FUSCA6. In addition, the stability of the monomeric AJH proteins requires functional COP1 and DEETIOLATED1 loci. Together with the fact that the previously known subunit FUSCA6 is an Arabidopsis homolog of human GPS1, a negative regulator of AP-1 transcription, our data suggest that the COP9 complex may contain both negative and positive regulators of transcription. Therefore, the COP9 complex may achieve its pleiotropic effects on Arabidopsis development by modulating activities of transcription factors in response to environmental stimuli.

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Selected References

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  1. Ang L. H., Chattopadhyay S., Wei N., Oyama T., Okada K., Batschauer A., Deng X. W. Molecular interaction between COP1 and HY5 defines a regulatory switch for light control of Arabidopsis development. Mol Cell. 1998 Jan;1(2):213–222. doi: 10.1016/s1097-2765(00)80022-2. [DOI] [PubMed] [Google Scholar]
  2. Asano K., Vornlocher H. P., Richter-Cook N. J., Merrick W. C., Hinnebusch A. G., Hershey J. W. Structure of cDNAs encoding human eukaryotic initiation factor 3 subunits. Possible roles in RNA binding and macromolecular assembly. J Biol Chem. 1997 Oct 24;272(43):27042–27052. doi: 10.1074/jbc.272.43.27042. [DOI] [PubMed] [Google Scholar]
  3. Bowler C., Neuhaus G., Yamagata H., Chua N. H. Cyclic GMP and calcium mediate phytochrome phototransduction. Cell. 1994 Apr 8;77(1):73–81. doi: 10.1016/0092-8674(94)90236-4. [DOI] [PubMed] [Google Scholar]
  4. Castle L. A., Meinke D. W. A FUSCA gene of Arabidopsis encodes a novel protein essential for plant development. Plant Cell. 1994 Jan;6(1):25–41. doi: 10.1105/tpc.6.1.25. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Chamovitz D. A., Wei N., Osterlund M. T., von Arnim A. G., Staub J. M., Matsui M., Deng X. W. The COP9 complex, a novel multisubunit nuclear regulator involved in light control of a plant developmental switch. Cell. 1996 Jul 12;86(1):115–121. doi: 10.1016/s0092-8674(00)80082-3. [DOI] [PubMed] [Google Scholar]
  6. Chen D. C., Yang B. C., Kuo T. T. One-step transformation of yeast in stationary phase. Curr Genet. 1992 Jan;21(1):83–84. doi: 10.1007/BF00318659. [DOI] [PubMed] [Google Scholar]
  7. Claret F. X., Hibi M., Dhut S., Toda T., Karin M. A new group of conserved coactivators that increase the specificity of AP-1 transcription factors. Nature. 1996 Oct 3;383(6599):453–457. doi: 10.1038/383453a0. [DOI] [PubMed] [Google Scholar]
  8. Deng X. W., Caspar T., Quail P. H. cop1: a regulatory locus involved in light-controlled development and gene expression in Arabidopsis. Genes Dev. 1991 Jul;5(7):1172–1182. doi: 10.1101/gad.5.7.1172. [DOI] [PubMed] [Google Scholar]
  9. Deng X. W. Fresh view of light signal transduction in plants. Cell. 1994 Feb 11;76(3):423–426. doi: 10.1016/0092-8674(94)90107-4. [DOI] [PubMed] [Google Scholar]
  10. Guarente L. Yeast promoters and lacZ fusions designed to study expression of cloned genes in yeast. Methods Enzymol. 1983;101:181–191. doi: 10.1016/0076-6879(83)01013-7. [DOI] [PubMed] [Google Scholar]
  11. Kallunki T., Deng T., Hibi M., Karin M. c-Jun can recruit JNK to phosphorylate dimerization partners via specific docking interactions. Cell. 1996 Nov 29;87(5):929–939. doi: 10.1016/s0092-8674(00)81999-6. [DOI] [PubMed] [Google Scholar]
  12. Kwok S. F., Piekos B., Misera S., Deng X. W. A complement of ten essential and pleiotropic arabidopsis COP/DET/FUS genes is necessary for repression of photomorphogenesis in darkness. Plant Physiol. 1996 Mar;110(3):731–742. doi: 10.1104/pp.110.3.731. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. McNellis T. W., Torii K. U., Deng X. W. Expression of an N-terminal fragment of COP1 confers a dominant-negative effect on light-regulated seedling development in Arabidopsis. Plant Cell. 1996 Sep;8(9):1491–1503. doi: 10.1105/tpc.8.9.1491. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. McNellis T. W., von Arnim A. G., Araki T., Komeda Y., Miséra S., Deng X. W. Genetic and molecular analysis of an allelic series of cop1 mutants suggests functional roles for the multiple protein domains. Plant Cell. 1994 Apr;6(4):487–500. doi: 10.1105/tpc.6.4.487. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. McNellis T. W., von Arnim A. G., Deng X. W. Overexpression of Arabidopsis COP1 results in partial suppression of light-mediated development: evidence for a light-inactivable repressor of photomorphogenesis. Plant Cell. 1994 Oct;6(10):1391–1400. doi: 10.1105/tpc.6.10.1391. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Miséra S., Müller A. J., Weiland-Heidecker U., Jürgens G. The FUSCA genes of Arabidopsis: negative regulators of light responses. Mol Gen Genet. 1994 Aug 2;244(3):242–252. doi: 10.1007/BF00285451. [DOI] [PubMed] [Google Scholar]
  17. Oyama T., Shimura Y., Okada K. The Arabidopsis HY5 gene encodes a bZIP protein that regulates stimulus-induced development of root and hypocotyl. Genes Dev. 1997 Nov 15;11(22):2983–2995. doi: 10.1101/gad.11.22.2983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Pepper A., Delaney T., Washburn T., Poole D., Chory J. DET1, a negative regulator of light-mediated development and gene expression in arabidopsis, encodes a novel nuclear-localized protein. Cell. 1994 Jul 15;78(1):109–116. doi: 10.1016/0092-8674(94)90577-0. [DOI] [PubMed] [Google Scholar]
  19. Romero L. C., Lam E. Guanine nucleotide binding protein involvement in early steps of phytochrome-regulated gene expression. Proc Natl Acad Sci U S A. 1993 Feb 15;90(4):1465–1469. doi: 10.1073/pnas.90.4.1465. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Seeger M., Kraft R., Ferrell K., Bech-Otschir D., Dumdey R., Schade R., Gordon C., Naumann M., Dubiel W. A novel protein complex involved in signal transduction possessing similarities to 26S proteasome subunits. FASEB J. 1998 Apr;12(6):469–478. [PubMed] [Google Scholar]
  21. Shimanuki M., Saka Y., Yanagida M., Toda T. A novel essential fission yeast gene pad1+ positively regulates pap1(+)-dependent transcription and is implicated in the maintenance of chromosome structure. J Cell Sci. 1995 Feb;108(Pt 2):569–579. doi: 10.1242/jcs.108.2.569. [DOI] [PubMed] [Google Scholar]
  22. Spain B. H., Bowdish K. S., Pacal A. R., Staub S. F., Koo D., Chang C. Y., Xie W., Colicelli J. Two human cDNAs, including a homolog of Arabidopsis FUS6 (COP11), suppress G-protein- and mitogen-activated protein kinase-mediated signal transduction in yeast and mammalian cells. Mol Cell Biol. 1996 Dec;16(12):6698–6706. doi: 10.1128/mcb.16.12.6698. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Spataro V., Toda T., Craig R., Seeger M., Dubiel W., Harris A. L., Norbury C. Resistance to diverse drugs and ultraviolet light conferred by overexpression of a novel human 26 S proteasome subunit. J Biol Chem. 1997 Nov 28;272(48):30470–30475. doi: 10.1074/jbc.272.48.30470. [DOI] [PubMed] [Google Scholar]
  24. Staub J. M., Wei N., Deng X. W. Evidence for FUS6 as a component of the nuclear-localized COP9 complex in Arabidopsis. Plant Cell. 1996 Nov;8(11):2047–2056. doi: 10.1105/tpc.8.11.2047. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Toda T., Shimanuki M., Yanagida M. Fission yeast genes that confer resistance to staurosporine encode an AP-1-like transcription factor and a protein kinase related to the mammalian ERK1/MAP2 and budding yeast FUS3 and KSS1 kinases. Genes Dev. 1991 Jan;5(1):60–73. doi: 10.1101/gad.5.1.60. [DOI] [PubMed] [Google Scholar]
  26. Von Arnim Albrecht, Deng Xing-Wang. LIGHT CONTROL OF SEEDLING DEVELOPMENT. Annu Rev Plant Physiol Plant Mol Biol. 1996 Jun;47(NaN):215–243. doi: 10.1146/annurev.arplant.47.1.215. [DOI] [PubMed] [Google Scholar]
  27. Wei N., Chamovitz D. A., Deng X. W. Arabidopsis COP9 is a component of a novel signaling complex mediating light control of development. Cell. 1994 Jul 15;78(1):117–124. doi: 10.1016/0092-8674(94)90578-9. [DOI] [PubMed] [Google Scholar]
  28. Wei N., Deng X. W. COP9: a new genetic locus involved in light-regulated development and gene expression in arabidopsis. Plant Cell. 1992 Dec;4(12):1507–1518. doi: 10.1105/tpc.4.12.1507. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Wei N., Deng X. W. Characterization and purification of the mammalian COP9 complex, a conserved nuclear regulator initially identified as a repressor of photomorphogenesis in higher plants. Photochem Photobiol. 1998 Aug;68(2):237–241. doi: 10.1562/0031-8655(1998)068<0237:capotm>2.3.co;2. [DOI] [PubMed] [Google Scholar]
  30. Wei N., Kwok S. F., von Arnim A. G., Lee A., McNellis T. W., Piekos B., Deng X. W. Arabidopsis COP8, COP10, and COP11 genes are involved in repression of photomorphogenic development in darkness. Plant Cell. 1994 May;6(5):629–643. doi: 10.1105/tpc.6.5.629. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Wei N., Tsuge T., Serino G., Dohmae N., Takio K., Matsui M., Deng X. W. The COP9 complex is conserved between plants and mammals and is related to the 26S proteasome regulatory complex. 1998 Jul 30-Aug 13Curr Biol. 8(16):919–922. doi: 10.1016/s0960-9822(07)00372-7. [DOI] [PubMed] [Google Scholar]
  32. Yamamoto Y. Y., Matsui M., Ang L. H., Deng X. W. Role of a COP1 interactive protein in mediating light-regulated gene expression in arabidopsis. Plant Cell. 1998 Jul;10(7):1083–1094. doi: 10.1105/tpc.10.7.1083. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. von Arnim A. G., Deng X. W. Light inactivation of Arabidopsis photomorphogenic repressor COP1 involves a cell-specific regulation of its nucleocytoplasmic partitioning. Cell. 1994 Dec 16;79(6):1035–1045. doi: 10.1016/0092-8674(94)90034-5. [DOI] [PubMed] [Google Scholar]
  34. von Arnim A. G., Osterlund M. T., Kwok S. F., Deng X. W. Genetic and developmental control of nuclear accumulation of COP1, a repressor of photomorphogenesis in Arabidopsis. Plant Physiol. 1997 Jul;114(3):779–788. doi: 10.1104/pp.114.3.779. [DOI] [PMC free article] [PubMed] [Google Scholar]

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