title: [Effect of immunosuppressants FK506 and rapamycin on the function of progesterone receptor: protein "p59-HBI", intersection between immunology and endocrinology?].
abstract: In the absence of hormonal ligand, inactive, heterooligomeric, 8-10S steroid receptor complexes include a p59 protein (apparent M(r) approximately 59 kDa) bound to th heat shock protein hsp90 (apparent M(r) approximately 90 kDa), which itself binds to the ligand binding domain LBD of the receptor molecule, p59 is thus an hsp binding immunophilin HBI, which, through its interaction with a chaperone, may intervene in several cellular functions. We report that, in cell-free experiments at 0 degrees C, FK506 and rapamycin do not release p59 nor hsp90 from the 9.5S rabbit uterus progesterone receptor, suggesting that the binding of p59 to hsp90 does not interfere with the rotamase site of HBI. There is no "transformation/activation" of the receptor, but an up to 2 fold increase in progesterone agonist and antagonist binding to the receptor is observed. It is suggested that a functional interaction between HBI and receptor activity may be mediated by hsp90.
authors.affiliation: Laboratoire Hormones, Faculté de Médecine de Bicêtre, Université Paris-Sud.
authors.forename: J M
authors.initials: JM
authors.lastname: Renoir
authors.forename: C
authors.initials: C
authors.lastname: Radanyi
authors.forename: E E
authors.initials: EE
authors.lastname: Baulieu
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000378:metabolism*; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D066298:In Vitro Techniques; D011090:Polyenes / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D011817:Rabbits; D011980:Receptors, Progesterone / Q000276:immunology / Q000378:metabolism*; D020123:Sirolimus; D016559:Tacrolimus / Q000494:pharmacology*; D022021:Tacrolimus Binding Proteins; D014461:Ultracentrifugation
chemical_list: D002352:Carrier Proteins; D006360:Heat-Shock Proteins; D007166:Immunosuppressive Agents; D011090:Polyenes; D011980:Receptors, Progesterone; D022021:Tacrolimus Binding Proteins; D020123:Sirolimus; D016559:Tacrolimus
vernacular_title: Un effet des immunosuppresseurs FK506 et rapamycine sur le fonctionnement du récepteur de la progestérone: la protéine "p59-HBI", un carrefour de l'immunologie et de l'endocrinologie?