http://www.creativebiomart.net/description_382707_12.htm

PPIases contains 1 PPIase cyclophilin-type domain and belongs to the cyclophilin-type PPIase family, PPIL3 subfamily. It also is a member of the immunophilin protein family. Members of this family play a role in immunoregulation and basic cellular processes involving protein folding and trafficking. PPIases catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and accelerate the folding of proteins. It also may be involved in pre-mRNA splicing.PPIases has a very high substrate specificity for the four-residue peptide Ala-Ala-Pro-Phe only when the proline peptide bond is in the trans state. It is a cis-trans prolyl isomerase that binds the immunosuppressants FK506 and rapamycin. It interacts with several intracellular signal transduction proteins including type I TGF-beta receptor. It also interacts with multiple intracellular calcium release channels, and coordinates multi-protein complex formation of the tetrameric skeletal muscle ryanodine receptor.