Immunophilins are endogenous cytosolic peptidyl-prolyl isomerases that interconvert between the cis and trans positions.
Immunophilins are targeted by immunosuppressive drugs such as sirolimus, cyclosporin, and tacrolimus. For these drugs in particular, known immunophilins such as cyclophilin catalyze the cis-trans isomerization of peptide bonds, particularly X-Pro peptide bonds. This prolyl isomerase activity can be inhibited by immunosuppressive drugs.
Immunophilins: for the love of proteins. 2006
Immunophilins are chaperones that may also exhibit peptidylprolyl isomerase (PPIase) activity. This review summarizes our knowledge of the two largest families of immunophilins, namely cyclophilin and FK506-binding protein, and a novel chimeric dual-family immunophilin, named FK506- and cyclosporin-binding protein (FCBP). The larger members of each family are modular in nature, consisting of multiple PPIase and/or protein-protein interaction domains. Despite the apparent difference in their sequence and three-dimensional structure, the three families encode similar enzymatic and biological functions. Recent studies have revealed that many immunophilins possess a chaperone function independent of PPIase activity. Knockout animal studies have confirmed multiple essential roles of immunophilins in physiology and development. An immunophilin is indeed a natural 'protein-philin' (Greek 'philin' = friend) that interacts with proteins to guide their proper folding and assembly.
Hugo Gene Family: Immunophilins
- Cyclophilin peptidylprolyl isomerases (PPI)
- FKBP prolyl isomerases (FKBP)