HspBP1 Is the Negative Regulator of the Bovine Progesterone Receptor

Park, K.M.;Song, J.W.

  • Received : 2002.12.17
  • Accepted : 2003.05.20
  • Published : 2003.09.01


We have investigated whether HspBP1, a Hsp70 binding protein, could have effect on the assembly of the bovine progesterone receptor (bPR) with a chaperone complex consisting of bovine Hsp90 (bHsp90), bovine Hsp70 (bHsp70), Hop, Ydj-1, and p23. The bPR, isolated in its native conformation, loses its function to interact with progesterone hormone in the absence of this protein complex. However, in the presence of bHsp90, bHsp70, Hop, p23 and Ydj-1, its function could be restored in vitro. Our findings here indicate that the inclusion of HspBP1 to five-protein system prevented the proper assembly of progesterone receptor-chaperone complex and induce the loss of bPR ability to interact with hormone. Immunoprecipitation assays of bPR with HspBP1 show that the presence of HspBP1 did not have any effect on the assembly of Ydj-1 and bHsp70 with the progesterone receptor. However, further assembly of Hsp90, Hop and p23 was completely prevented and the function of the bPR was lost. In vitro competition and protein folding assays indicated that the binding of HspBP1 to bHsp70 prevented the ternary complex formation of bHsp70, bHsp90, and Hop. These results indicate that HspBP1 is a negative regulator of the assembly of Hsp90, Hop and Hsp70, and thus, prevent the proper maturation of unliganded bPR with chaperones assembly system.


HspBP1;Bovine Progesterone Receptor;Chaperones;Folding


  1. Caplan, A. J., J. Tsai, P. J. Casey and M. G. Douglas. 1992. Farnesylation of YDJ1p is required for function at elevated growth temperatures in Saccharomyces cerevisiae. J. Biol. Chem. 267:18890-18895.
  2. Dittmar, K. D., M. Banach, M. D. Galigniana and W. B. Pratt. 1998. The role of DnaJ-like proteins in glucocorticoid receptor.hsp90 heterocomplex assembly by the reconstituted hsp90.p60.hsp70 foldosome complex. J. Biol. Chem. 273:7358-7366.
  3. Kabani, M., C. McLellan, D. A. Raynes, V. Guerriero and J. L. Boradsky. 2002. HspBP1, a homologue of the yeast Fes1 and Sls1 proteins, is an Hsc70 nucleotide exchange factor. FEBS Lett. 531:339-342.
  4. Minami, Y., J. Hohfeld, K. Ohtsuka and F. U. Hartl. 1996. Regulation of the heat-shock protein 70 reaction cycle by the mammalian Dna J homolog, Hsp40, J. Biol. Chem. 271:19617-19624.
  5. Cheung, J. and D. F. Smith. 2000. Molecular chaperone interactions with steroid receptors: an update. Mol. Endocrinol. 14:939-946.
  6. Scheufler, C., A. Brinker, G. Bourenkov, S. Pegoraro, L. Moroder, H. Bartunik, F. U. Hartl and I. Moarefi. 2000. Structure of TPR domain-peptide complexes: critical elements in the assembly of the Hsp70-Hsp90 multichaperone machine. Cell. 101:199-210.
  7. Barent, R. L., S. C. Nair, D. C. Carr, Y. Ruan, R. A. Rimerman, J. Fulton, Y. Zhang and D. F. Smith. 1998. Analysis of FKBP51/FKBP52 chimeras and mutants for Hsp90 binding and association with progesterone receptor complexes. Mol. Endocrinol. 12:342-354.
  8. Johnson, J. L. and D. O. Toft. 1995. Binding of p23 and hsp90 during assembly with the progesterone receptor. Mol. Endocrinol. 10:670-678.
  9. Smith, D. F., W. P. Sullivan, T. N. Marion, K. Zaitsu, B. Madden, D. J. McCormick and D. O. Toft. 1993. Identification of a 60-kilodalton stress-related protein, p60, which interacts with hsp90 and hsp70. Mol. Cell Biol. 13:869-876.
  10. Pratt, W. B. and D. O. Toft. 1997. Steroid Receptor Interactions with Heat Shock Protein and Immunophilin Chaperones. Endocrine Reviews. 18:306-360.
  11. Raynes, D. A. and V. Jr. Guerriero. 1998. Inhibition of Hsp70 ATPase activity and protein renaturation by a novel Hsp70-binding protein. J. Biol. Chem. 273:32883-32888.
  12. Smith, D. F. and D. O. Toft. 1993. Steroid receptors and their associated proteins. Mol. Endocrinol. 7:4-11.
  13. K. H. Liu. 2003. Production of retinol-binding protein by caprine conceptus during th time period of maternal recognition of pregnancy. Asian-Aust. J. Anim. Sci. 16:962-967.
  14. Smith, D. F., L. Whitesell, S. C. Nair, S. Chen, V. Prapapanich, and R. A. Rimerman. 1995. Progesterone receptor structure and function altered by geldanamycin, an hsp90-binding agent. Mol. Cell Biol. 15:6804-6812.
  15. Johnson, J. L., T. G. Beito, C. J. Krco and D. O. Toft. 1994. Characterization of a novel 23-kilodalton protein of unactive progesterone receptor complexes. Mol. Cell. Biol. 14:1956-1963.
  16. Schumacher, R. J., R. Hurst, W. P. Sullivan, N. J. McMahon, D. O. Toft and R. L. Matts. 1994. ATP-dependent chaparoning activity of reticulocyte lysate. J. Biol. Chem. 269:9493–9499.
  17. Smith, D. F., D. B. Schowalter, S. L. Kost and D. O. Toft. 1990. Reconstitution of progesterone receptor with heat shock proteins. Mol. Endocrinol. 4:1704-1711.
  18. Young, J. C. and F. U. Hartl. 2000. Polypeptide release by Hsp90 involves ATP hydrolysis and is enhanced by the co-chaperone p23. EMBO J. 19:5930-5940.
  19. Chen, S. and D. F. Smith. 1998. Hop as an adaptor in the heat shock protein 70 (Hsp70) and hsp90 chaperone machinery. J. Biol. Chem. 273:35194-35200.
  20. Jensen, E. V. 1991. Steroid hormone receptors. In: (Ed. G. Seifert) Cell Receptors. Current Topics in Pathology. Springer-Verlag, Heidelberg, 83:365-431.
  21. Kosano, H., B. Stensgard, M. C. Charlesworth, N. McMahon and D. O. Toft. 1998. The assembly of progesterone receptor-hsp90 complexes using purified proteins. J. Biol. Chem. 273:32973-32979.
  22. Hernandez, M. P., A. Chadli and D. O. Toft. 2002. HSP40 binding is the first step in the HSP90 chaperoning pathway for the progesterone receptor. J. Biol. Chem. 277:11873-11881.


Supported by : Korea Research Foundation