Peptidyl-prolyl cis-trans isomerase A-like 4A (PPIAL4A)

Peptidyl-prolyl cis-trans isomerase A-like 4A (PPIAL4A) is an enzyme of the cyclophilin family that catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides, accelerating protein folding[1]. PPIAL4A is *predicted* to bind cyclosporin A based on sequence homology and gene family, and localizes to the extracellular exosome[1]. Its precise physiological roles are largely unclear, and its functional characterization in human disease remains limited[1]. While it is a paralog of other cyclophilins and may share general functions such as protein folding (like PPIA), most published functions, disease roles, and mechanisms are attributed to more well-characterized cyclophilins (principally PPIA/cyclophilin A), not directly to PPIAL4A[1][2][6][7]. Disease associations include chromosomal deletion syndromes and some cancers, but it is not currently recognized as a well-validated therapeutic target[1]. The attribution of drug interactions or functional roles to PPIAL4A is largely extrapolated with low confidence, and there is evidence of confusion with aliases for other cyclophilins (e.g., PPIAL4B, PPIA). Therefore, PPIAL4A is considered a predicted member of the cyclophilin PPIase enzyme family, with unvalidated or speculative roles as a distinct therapeutic target in current biomedical literature[1][5][7].

Other names

Peptidyl-prolyl cis-trans isomerase A-like 4APPIAL4ACOAS2PPIAL4BPPIase A-like 4ACOAS-2Chromosome one-amplified sequence 2Cyclophilin homolog overexpressed in liver cancerPPIAL4PPIase A-like 4BPPIase A-like 4G

Immunosuppression (for cyclosporin A binding cyclophilins, inferred by homology); isomerase inhibition