Peptidyl-prolyl cis-trans isomerase G (PPIG)

Peptidyl-prolyl cis-trans isomerase G (PPIG), also known as cyclophilin G, is an enzyme of the cyclophilin family that catalyzes cis-trans isomerization of proline residues in proteins, facilitating proper protein folding[1][2]. PPIG is located in the cytosol and nuclear speckles, with key roles in regulating pre-mRNA splicing by modulating the localization and interactions of SR (serine/arginine-rich) splicing factors[2]. It is particularly involved in the maturation and alternative splicing of fibronectin mRNA and is implicated in disease-associated alternative splicing events, such as in psoriasis. PPIG is part of a broader network of cyclophilins important for vital cellular processes, including cell cycle progression, gene expression regulation, protein folding, and potentially certain disease states[2][3]. There are currently no approved drugs that selectively target PPIG, and it is not used as a clinical biomarker or target for specific therapies as of 2025.

Other names

Cyclophilin GSR-cyclophilinSRCypSCAF10CARS-CypPPIase GPeptidylprolyl isomerase GSR-related CTD-associated factor 10CYP

For cyclophilins in general: Inhibition of isomerase activity (e.g., cyclosporine binding blocks PPIase enzymatic activity)[1] For PPIG specifically: No approved mechanism of action for targeted pharmacological intervention as of 2025.