Yeast molecular chaperones and the mechanism of steroid hormone action

The yeast Saccharomyces cerevisiae has become a valuable tool for the analysis of steroid action in vivo. Results from studies using yeast have been productive Ibv understanding the role of molecular chaperones, especially Hsp90 and its cochaperones, in regulating the activation of heterologously expressed steroid hormone receptors. The methodology for these investigations involves assaying receptor function in yeast strains with deletions or mutations in the genes encoding molecular chapel one proteins. The information obtained thus far indicates that rite Hsp90 chaperone machine functions in vivo to maintain steroid receptors in a high-affinity hormone-binding conformation and also in downstream events of the activation pathway. (C) 1997, Elsevier, Science Inc.