An immunophilin that binds M(r) 90,000 heat shock protein: main structural features of a mammalian p59 protein.
In the rabbit, a p59 protein included in the untransformed, non-DNA binding, "8-9S," steroid receptor complexes binds heat shock protein M(r) approximately 90,000 (hsp90). Sequence data [Lebeau, M. C., Massol, N., Herrick, J., Faber, L. E., Renoir, J. M., Radanyi, C. & Baulieu, E. E. (1992) J. Biol. Chem. 267, 4281-4284] and hydrophobic cluster analysis delineate, from the N terminus, two successive domains closely related to the immunosuppressant FK506 binding immunophilin FKBP (FK506 binding protein), consistent with recent purification of the human p56 immunophilin cognate protein by FK506 affinity chromatography [Yem, A. W., Tomasselli, A. G., Heinrikson, R. L., Zurcher-Neely, H., Ruff, V. A., Johnson, R. A. & Deibel, M. R., Jr. (1992) J. Biol. Chem. 267, 2868-2871]. The first FKBP-like domain demonstrates all structural characteristics known to be necessary for immunosuppressant binding and for peptidylprolyl cis-trans isomerase (rotamase) activity. Hence, p59 is a "hsp binding immunophilin" (HBI). It is thus speculated that hsp binding immunophilin may help the assembly/disassembly mechanisms involved in steroid receptor trafficking and activity and participate in the poorly understood hsp90 function. ATP/GTP binding likely occurs within the second FKBP-like domain, near the FK506 binding site on the FKBP template. A third domain detected by the hydrophobic cluster analysis method is distantly structurally related to the two first FKBP-like domains and is followed by the C-terminal part of the protein, which contains a calmodulin binding consensus sequence. Hsp binding immunophilin may be involved in a number of immunological, endocrinological, and chaperone-mediated pathways.
Callebaut
I
I
Département des Macromolécules Biologiques, Centre National de la Recherche Scientifique URA09, Paris, France.
Renoir
J M
JM
Lebeau
M C
MC
Massol
N
N
Burny
A
A
Baulieu
E E
EE
Mornon
J P
JP
D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011817:Rabbits; D011987:Receptors, Steroid / Q000737:chemistry; D016415:Sequence Alignment; D022021:Tacrolimus Binding Proteins
D002352:Carrier Proteins; D006360:Heat-Shock Proteins; D011987:Receptors, Steroid; D022021:Tacrolimus Binding Proteins