title: Rabbit FKBP59-heat shock protein binding immunophillin (HBI) is a calmodulin binding protein.
abstract: FKBP59-HBI, a heat shock protein hsp90-binding immunophilin that was originally detected in heterooligomer forms of steroid receptors, is retained on Calmodulin (CAM)-Sepharose 4B in the presence of 2 mM Ca2+ and is eluted by EGTA, demonstrating a specific p59-CAM interaction. The p59 amino acid sequence reveals the presence of two putative CAM binding sites in a helix regions of the protein, as well as PEST sequences which are generally present in CAM-binding proteins. In vitro proteolysis by calpain II (a Ca(2+)-activated neutral protease), another feature of CAM-binding proteins, generates shorter peptides revealed by the mAb EC1, but not by the pAb 173 which recognizes the C-terminal of the protein. The potential function of CAM binding by the hsp90-binding immunophilin is discussed.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale U 33, Lab. Hormones, Hôpital de Bicêtre, Le Kremlin Bicêtre, France.
authors.forename: N
authors.initials: N
authors.lastname: Massol
authors.forename: M C
authors.initials: MC
authors.lastname: Lebeau
authors.forename: J M
authors.initials: JM
authors.lastname: Renoir
authors.forename: L E
authors.initials: LE
authors.lastname: Faber
authors.forename: E E
authors.initials: EE
authors.lastname: Baulieu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D002148:Calmodulin-Binding Proteins / Q000737:chemistry*; D002352:Carrier Proteins / Q000737:chemistry*; D006360:Heat-Shock Proteins / Q000737:chemistry*; D006860:Hydrogen Bonding; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011817:Rabbits; D016559:Tacrolimus / Q000378:metabolism*; D022021:Tacrolimus Binding Proteins
chemical_list: D002148:Calmodulin-Binding Proteins; D002352:Carrier Proteins; D006360:Heat-Shock Proteins; D022021:Tacrolimus Binding Proteins; D002118:Calcium; D016559:Tacrolimus