The molecular chaperones Hsp90 and Hsc70 are both necessary and sufficient to activate hormone binding by glucocorticoid receptor

被引:86
作者
Rajapandi, T [1 ]
Greene, LE [1 ]
Eisenberg, E [1 ]
机构
[1] NHLBI, Cell Biol Lab, NIH, Bethesda, MD 20892 USA
关键词
D O I
10.1074/jbc.M002035200
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Glucocorticoid receptors must be complexed with Hsp90 in order to bind steroids, and it has been reported that at least three other proteins, Hop, Hsc70, and a J-domain protein (either Hsp40 or Ydj1), are required for formation of active Hsp90-steroid receptor complex. In the present study, we reinvestigated activation of stripped steroid receptors isolated from either L cells or WCL2 cells. Surprisingly, we found, using highly purified proteins, that only Hsp90 and Hsc70 are required for the activation of glucocorticoid receptors in the presence of steroids; In the absence of steroids, either p23 or molybdate are also required as reported previously. Addition of Hop or Ydj1 had no affect on the rate or magnitude of the activation of the stripped receptors, and quantitative Western blots confirmed that neither Hop or Hsp40 were present in our protein preparations or in the stripped receptors. Furthermore, a truncated recombinant Hsp70 that does not bind Hop or Hsp40 was as effective as wild-type Hsp70 in activating stripped receptor. Since Hsc70 does not bind directly to Hsp90 but both proteins bind to Hop, it has been suggested that Hop acts as a bridge between Hsp90 and Hsp70. However, we found that after Hsc70 or Hsp90 bind directly to the stripped receptors, they are fully reactivated by Hsp90 or Hsc70, respectively. We, therefore, conclude that Hsp90 and Hsc70 bind independently to stripped glucocorticoid receptors and alone are sufficient to activate them to bind steroids.
引用
收藏
页码:22597 / 22604
页数:8
相关论文
共 26 条
[1]  
CAPLAN AJ, 1992, J BIOL CHEM, V267, P18890
[2]   In vivo analysis of the Hsp90 cochaperone Sti1 (p60) [J].
Chang, HCJ ;
Nathan, DF ;
Lindquist, S .
MOLECULAR AND CELLULAR BIOLOGY, 1997, 17 (01) :318-325
[3]   Interactions of p60, a mediator of progesterone receptor assembly, with heat shock proteins hsp90 and hsp70 [J].
Chen, SY ;
Prapapanich, V ;
Rimerman, RA ;
Honore, B ;
Smith, DF .
MOLECULAR ENDOCRINOLOGY, 1996, 10 (06) :682-693
[4]   Hop as an adaptor in the heat shock protein 70 (Hsp70) and Hsp90 chaperone machinery [J].
Chen, SY ;
Smith, DF .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1998, 273 (52) :35194-35200
[5]   The carboxy-terminal domain of Hsc70 provides binding sites for a distinct set of chaperone cofactors [J].
Demand, J ;
Lüders, J ;
Höhfeld, J .
MOLECULAR AND CELLULAR BIOLOGY, 1998, 18 (04) :2023-2028
[6]   Folding of the glucocorticoid receptor by the reconstituted hsp90-based chaperone machinery - The initial hsp90-p60-hsp70-dependent step is sufficient for creating the steroid binding conformation [J].
Dittmar, KD ;
Pratt, WB .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1997, 272 (20) :13047-13054
[7]   The role of DnaJ-like proteins in glucocorticoid receptor•hsp90 heterocomplex assembly by the reconstituted hsp90•p60•hsp70 foldosome complex [J].
Dittmar, KD ;
Banach, M ;
Galigniana, MD ;
Pratt, WB .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1998, 273 (13) :7358-7366
[8]   Reconstitution of the steroid receptor center dot hsp90 heterocomplex assembly system of rabbit reticulocyte lysate [J].
Dittmar, KD ;
Hutchison, KA ;
OwensGrillo, JK ;
Pratt, WB .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1996, 271 (22) :12833-12839
[9]   Folding of the glucocorticoid receptor by the heat shock protein (hsp) 90-based chaperone machinery - The role of p23 is to stabilize receptor-hsp90 heterocomplexes formed by hsp90-p60-hsp70 [J].
Dittmar, KD ;
Demady, DR ;
Stancato, LF ;
Krishna, P ;
Pratt, WB .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1997, 272 (34) :21213-21220
[10]  
GREENE LE, 1990, J BIOL CHEM, V265, P6682