It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides.
Proposed to act as a co-chaperone in HSP90 complexes such as in unligated steroid receptors heterocomplexes.
Different co-chaperones seem to compete for association with HSP90 thus establishing distinct HSP90-co-chaperone-receptor complexes with the potential to exert tissue-specific receptor activity control.
May have a preference for estrogen receptor complexes and is not found in glucocorticoid receptor complexes.
May be involved in cytoplasmic dynein-dependent movement of the receptor from the cytoplasm to the nucleus.
May regulate MYB by inhibiting its DNA-binding activity.
Involved in regulation of AHR signaling by promoting the formation of the AHR:ARNT dimer, the function is independent of HSP90 but requires the chaperone activity.
Involved in regulation of UV radiation-induced apoptosis.