Rabbit FKBP59-heat shock protein binding immunophillin (HBI) is a calmodulin binding protein
1992; Elsevier BV; Volume: 187; Issue: 3 Linguagem: Inglês
10.1016/0006-291x(92)90448-t
ISSN1090-2104
AutoresNelly Massol, Marie‐Claire Lebeau, Jack‐Michel Renoir, Lee E. Faber, Étienne-Émile Baulieu,
Tópico(s)Toxin Mechanisms and Immunotoxins
ResumoFKBP59-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 α 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 Ca2+-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.
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