Peptidyl-prolyl cis-trans isomerase E (PPIE)

Peptidyl-prolyl cis-trans isomerase E (PPIE) is an enzyme belonging to the cyclophilin family and is encoded by the PPIE gene in humans[1][2][3]. PPIE catalyzes the cis-trans isomerization of proline residues in peptide bonds, a key process in facilitating correct protein folding and repair[1][3]. PPIE Contains a cyclophilin-type isomerase domain and an N-terminal RNA recognition motif, allowing it to function both as a protein chaperone and RNA-binding protein involved in pre-mRNA splicing and chromatin remodeling complexes[1][2][3]. It has been implicated in mitochondrial metabolism, apoptosis, immune response, and inflammation, as well as in the replication of certain viruses and in various forms of cancer[1][3]. PPIE is known to bind cyclosporin A—a clinically important immunosuppressant—resulting in inhibition of calcineurin and suppression of T-cell activation[1]. PPIE has emerging roles as a regulator in transcription-coupled nucleotide excision repair, and is a nuclear cyclophilin interacting with various spliceosomal complexes and chromatin modifiers[2][3]. Its physiological and pathological roles are under active investigation, particularly in relation to immune modulation, infectious disease, and cancer biology[1][2][3].

Other names

Cyclophilin ECyclophilin-33CyP-33PPIase ECYP33Rotamase ECypEMGC3736MGC111222peptidylprolyl isomerase E (cyclophilin E)isoform 1

Inhibition of isomerase activity: Cyclosporin A binds to PPIE, forming a CsA-cyclophilin complex that inhibits calcineurin, blocking T-cell activation signaling pathways[1][2]. Inhibition of viral replication: By analogy to other cyclophilins, inhibition may block HIV-1 and influenza replication in certain contexts[1].