XPNPEP3 Proteins

Protein Information

XPNPEP3, also known as X-Prolyl Aminopeptidase 3, is a gene located on chromosome 22q that encodes an enzyme involved in the processing of mitochondrial matrix proteins. The enzyme is classified under the M24B subfamily of metallopeptidases, which specifically remove the N-terminal amino acid from oligopeptides where the penultimate residue is proline. XPNPEP3 is implicated in conditions such as cystic kidney disease and participates in TNF-TNFR2 cellular signaling pathways. Its yeast and plant homologs, like Icp55, perform similar functions by stabilizing proteins after import into the mitochondrial matrix. Mutations in XPNPEP3 are associated with defects in ciliary structure and function, contributing to the phenotypic spectrum seen in nephronophthisis-related ciliopathies (NPHP-RCs). The crystal structure of XPNPEP3 has been resolved at 1.65 A resolution, revealing its interaction with inhibitors such as apstatin. Furthermore, XPNPEP3 is identified as a transcriptional target of the canonical Wnt/beta-catenin signaling pathway, with elevated transcript levels observed in tumors exhibiting activated Wnt signaling.

Synonyms

Aminopeptidase P3; APP3; E430012M05Rik; ICP55; Intermediate Cleaving Peptidase 55; NPHPL1; probable Xaa-Pro aminopeptidase 3; Xaa-Pro aminopeptidase 3; Xpnpep3; X-Pro aminopeptidase 3; X-prolyl aminopeptidase (aminopeptidase P) 3, putative; X-prolyl aminopeptidase 3; X-prolyl aminopeptidase 3, mitochondrial