Receptor accessory folding helper enzymes: the functional role of peptidyl prolyl cis/trans isomerases
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Updated: Oct 8, 2026

Förster Resonance Energy Transfer Mapping: A New Methodology to Elucidate Global Structural Features
Published on: March 16, 2022
1Max Planck Research Unit for Enzymology of Protein Folding, Weinbergweg 22, 06120, Halle/Saale, Germany. schiene@enzyme-halle.mpg.de
Abstract:
Receptor accessory peptidyl prolyl cis/trans isomerases (PPIases) of the FKBP and cyclophilin types form receptor heterocomplexes with different stabilities. PPIases have been found to associate with other receptor heterocomplex constituents via either proline-directed active sites or additional domains of the enzymes. The single-domain PPIases FKBP12 and FKBP12.6 are shown to interact with receptor protein kinases and calcium channels at their active sites. In contrast, heterooligomeric nuclear receptors contain multi-domain PPIases like FKBP51, FKBP52 or cyclophilin 40 that directly interact with the chaperone hsp90 via the tetratricopeptide repeat modules of the folding helper enzymes. PPIases play a critical role in the functional arrangement of components within receptor heterocomplexes.
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