Repression of Transcriptional Activity of Estrogen Receptor α by a Cullin3/SPOP Ubiquitin E3 Ligase Complex

  • Byun, Boohyeong (Department of Oriental Medicine, Daegu Haany University) ;
  • Jung, Yunhwa (Department of Biological Sciences, Korea Advanced Institute of Science and Technology)
  • Received : 2007.08.04
  • Accepted : 2007.10.21
  • Published : 2008.04.30


The role of SPOP in the ubiquitination of $ER{\alpha}$ by the Cullin3-based E3 ubiquitin ligase complex was investigated. We showed that the N-terminal region of SPOP containing the MATH domain interacts with the AF-2 domain of $ER{\alpha}$ in cultured human embryonic 293 cells. SPOP was required for coimmunoprecipitation of $ER{\alpha}$ with Cullin3. This is the first report of the essential role of SPOP in $ER{\alpha}$ ubiquitination by the Cullin3-based E3 ubiquitin ligase complex. We also demonstrated repression of the transactivation capability of $ER{\alpha}$ in cultured mammalian cells.


  1. Kwon, J.E., La, M., Oh, K.H., Oh, Y.M., Kim, G.R., Seol, J.H., Baek, S.H., Chiba, T., Tanaka, K., Bang, O. S., et al. (2006). BTB domain-containing speckle-type POZ protein (SPOP) serves as an adaptor of Daxx for ubiquitination by Cul3- based ubiquitin ligase. J. Biol. Chem. 281, 12664-12672
  2. La, M., Kim, K., Park, J., Won, J., Lee, J.H., Fu, Y.M., Meadows, G.G., and Joe, C.O. (2004). Daxx-mediated transcriptional repression of MMP1 gene is reversed by SPOP. Biochem. Biophys. Res. Commun. 320, 760-765
  3. Nawaz, Z., Lonard, D.M., Dennis, A.P., Smith, C.L., and O'Malley, B.W. (1999). Proteasome-dependent degradation of the human estrogen receptor. Proc. Natl. Acad. Sci. USA 96, 1858-1862
  4. Schaefer, H., and Rongo, C. (2006). KEL-8 is a substrate receptor for CUL3-dependent ubiquitin ligase that regulates synaptic glutamate receptor turnover. Mol. Biol. Cell 17, 1250-1260
  5. Shoker, B.S., Jarvis, C., Clarke, R.B., Anderson, E., Hewlett, J., Davies, M.P., Sibson, D.R., and Sloane, J.P. (1999). Estrogen receptor-positive proliferating cells in the normal and precancerous breast. Am J. Pathol. 155, 1811-1815
  6. Wilkins, A., Ping, Q., and Carpenter, C.L. (2004). RhoBTB2 is a substrate of the mammalian Cul3 ubiquitin ligase complex. Genes Dev. 18, 856-861
  7. Ikeda, K., and Inoue, S. (2004). Estrogen receptors and their downstream targets in cancer. Arch. Histol. Cytol. 67, 435-442
  8. Lonard, D.M., Nawaz, Z., Smith, C.L., and O'Malley, B.W. (2000). The 26S proteasome is required for estrogen receptor-alpha and coactivator turnover and for efficient estrogen receptor-alpha transactivation. Mol. Cell 5, 939-948
  9. Marsaud, V., Gougelet, A., Maillard, S., and Renoir, J.M. (2003). Various phosphorylation pathways, depending on agonist and antagonist binding to endogenous estrogen receptor alpha (ERalpha), differentially affect ERalpha extractability, proteasome-mediated stability, and transcriptional activity in human breast cancer cells. Mol. Endocrinol. 17, 2013-2027
  10. Nagai, Y., Kojima, T., Muro, Y., Hachiya, T., Nishizawa, Y., Wakabayashi, T., and Hagiwara, M. (1997). Identification of a novel nuclear speckle-type protein, SPOP. FEBS Lett. 418, 23-26
  11. Leclercq, G., Lacroix, M., Laios, I., and Laurent, G. (2006). Estrogen receptor alpha: impact of ligands on intracellular shuttling and turnover rate in breast cancer cells. Curr. Cancer Drug Targets 6, 39-64
  12. Reid, G., Hubner, M.R., Metivier, R., Brand, H., Denger, S., Manu, D., Beaudouin, J., Ellenberg, J., and Gannon, F. (2003). Cyclic, proteasome-mediated turnover of unliganded and liganded ERalpha on responsive promoters is an integral feature of estrogen signaling. Mol. Cell 11, 695-707
  13. Pintard, L., Willems, A., and Peter, M. (2004). Cullin-based ubiquitin ligases: Cul3-BTB complexes join the family. EMBO J. 23, 1681-1687
  14. Kim, S.H., Lee, S.U., Kim, M.H., Kim, B.T., and Min, Y.K. (2005). Mitogenic estrogen metabolites alter the expression of 17beta-estradiol-regulated proteins including heat shock proteins in human MCF-7 breast cancer cells. Mol. Cells 20, 378-384
  15. Metzger, D., Berry, M., Ali, S., and Chambon, P. (1995). Effect of antagonists on DNA binding properties of the human estrogen receptor in vitro and in vivo. Mol. Endocrinol. 9, 579-591
  16. Alarid, E.T., Preisler-Mashek, M.T., and Solodin, N.M. (2003). Thyroid hormone is an inhibitor of estrogen-induced degradation of estrogen receptor-alpha protein: estrogen-dependent proteolysis is not essential for receptor transactivation function in the pituitary. Endocrinology 144, 3469-3476
  17. Kobayashi, A., Kang, M.I., Okawa, H., Ohtsuji, M., Zenke, Y., Chiba, T., Igarashi, K., and Yamamoto, M. (2004). Oxidative stress sensor Keap1 functions as an adaptor for Cul3-based E3 ligase to regulate proteasomal degradation of Nrf2. Mol. Cell. Biol. 24, 7130-7139
  18. Hernandez-Munoz, I., Lund, A.H., van der Stoop, P., Boutsma, E., Muijrers, I., Verhoeven, E., Nusinow, D.A., Panning, B., Marahrens, Y., and van Lohuizen, M. (2005). Stable X chromosome inactivation involves the PRC1 Polycomb complex and requires histone MACROH2A1 and the CULLIN3/SPOP ubiquitin E3 ligase. Proc. Natl. Acad. Sci. USA 102, 7635-7640
  19. Fan, M., Nakshatri, H., and Nephew, K.P. (2004). Inhibiting proteasomal proteolysis sustains estrogen receptor-alpha activation. Mol. Endocrinol 18, 2603-2615
  20. Scholl, S., and Lippman, M.E. (1984). The estrogen receptor in MCF-7 cells: evidence from dense amino acid labeling for rapid turnover and a dimeric model of activated nuclear receptor. Endocrinology 115, 1295-1301