Details

Autor(en) / Beteiligte

• Lebihan, S.
• Renoir, J.M.
• Radanyi, C.
• Chambraud, B.
• Joulin, V.
• Catelli, M.G.
• Baulieu, E.E.

Titel

The Mammalian Heat Shock Protein Binding Immunophilin (p59/HBI) Is an ATP and GTP Binding Protein

Ist Teil von

• Biochemical and biophysical research communications, 1993-09, Vol.195 (2), p.600-607

Ort / Verlag

San Diego, CA: Elsevier Inc

Erscheinungsjahr

1993

Link zum Volltext

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• A protein of Mr 59,000 (p59) was recently cloned and identified as a H eat shock protein B inding I mmunophilin (p59/HBI). It participates to the heterooligomeric, non-DNA binding form of steroid receptors, in association with the heat shock protein of Mr 90,000 (hsp90). It binds the immunosuppressants FK506 and rapamycin and possesses three FKBP-12 (FK506 binding protein of Mr 12,000) - like domains (I to III), plus a tail containing a putative calmodulin binding site (domain IV). Following expression in E. Coli and purification on Glutathione-Sepharose of either the full-length recombinant p59/HBI, or the recombinant FKBP-like domains, we demonstrate by autoradiography of [α 32P]-8-azido ATP and of [α 32P]-8-azido GTP photoaffinity labeled complexes, that an ATP (GTP) binding site is located in the domain II. This nucleotide binding property is also found with the highly purified rabbit uterus p59/HBI. The latter, but not the recombinant protein, can be phosphorylated in vitro in the presence of Mn ++ and/or of Ca ++/Calmodulin in an ATP but not GTP dependent manner, suggesting copurification of a CaM kinase II-like enzyme. Thus it appears that p59/HBI is a multifunctional immunophilin which may be at the crossroad of the endocrine and immunological systems.