Peptidyl-prolyl cis-trans isomerase NIMA-interacting 4 (PIN4)

Peptidyl-prolyl cis-trans isomerase NIMA-interacting 4 (PIN4) is a member of the parvulin subfamily of peptidyl-prolyl cis-trans isomerases (PPIases), enzymes that catalyze the isomerization of peptide bonds at prolyl residues, thereby regulating protein folding and function[1][2][5]. The human PIN4 gene encodes two main isoforms through alternative transcription: Par14 and Par17. Par14 is primarily involved in ribosomal RNA processing, chromatin remodeling, and ribosome biogenesis, while Par17 contains an amphipathic N-terminal helix and shares some DNA-binding and regulatory activities[2][1]. PIN4 may also participate in mitochondrial function and microtubule polymerization[1][2]. It is implicated in several diseases including prostate cancer and hepatocellular carcinoma, partly through its roles in the cell cycle and interaction with viral proteins. It significantly supports hepatitis B virus replication by stabilizing viral core particles and regulating transcription. PIN4 is a validated enzyme target, and small-molecule inhibitors such as juglone and other parvulin impeders are being explored for potential therapeutic applications, particularly in cancer and viral diseases[2].

Other names

PAR14PAR17EPVHParvulin-14Parvulin-17ParvulinhPar14hPar17hEPVHRotamase PIN4Peptidylprolyl cis/trans isomerase, NIMA-interacting 4Peptidyl-prolyl cis-trans isomerase Pin4Peptidyl-prolyl cis/trans isomerase EPVHEukaryotic parvulin homologPPIase PIN4

Inhibition of cis/trans isomerase activity, leading to impaired protein folding and decreased cell proliferation[2]. Disruption of HBV replication by interfering with PIN4’s stabilization and function in viral lifecycles[2].