A PATHWAY OF MULTI-CHAPERONE INTERACTIONS COMMON TO DIVERSE REGULATORY PROTEINS - ESTROGEN-RECEPTOR, FES TYROSINE KINASE, HEAT-SHOCK TRANSCRIPTION FACTOR HSF1, AND THE ARYL-HYDROCARBON RECEPTOR
Sc. Nair et al., A PATHWAY OF MULTI-CHAPERONE INTERACTIONS COMMON TO DIVERSE REGULATORY PROTEINS - ESTROGEN-RECEPTOR, FES TYROSINE KINASE, HEAT-SHOCK TRANSCRIPTION FACTOR HSF1, AND THE ARYL-HYDROCARBON RECEPTOR, Cell stress & chaperones, 1(4), 1996, pp. 237-250
A variety of regulatory proteins, including different classes of trans
cription factors and protein kinases, have been identified in complexe
s with Hsp90. On careful examination of unactivated progesterone recep
tor complexes, eight different protein participants have been identifi
ed, and each can be considered a component of the cytoplasmic molecula
r chaperone machinery. These proteins are Hsp90, Hsp70, Hip, p60, p23,
FKBP51, FKBP52 and Cyp40. Studies in a cell-free assembly system have
helped to define a highly ordered, dynamic pathway for assembly of pr
ogesterone receptor complexes. In the present study, target proteins o
ther than progesterone receptor were used in this cell-free system to
assemble complexes in vitro and to compare the composition of resultin
g complexes. Targets used were human estrogen receptor, human Fes prot
ein-tyrosine kinase, human heat shock transcription factor Hsf1, and h
uman aryl hydrocarbon receptor. The striking similarity of resulting t
arget complexes with previously characterized progesterone receptor co
mplexes suggest that each of these targets undergoes a common assembly
pathway involving multiple chaperone components in addition to Hsp90.