XPNPEP3

XPNPEP3
Identifiers
AliasesXPNPEP3, APP3, NPHPL1, ICP55, X-prolyl aminopeptidase 3, mitochondrial, X-prolyl aminopeptidase 3
External IDsOMIM: 613553; MGI: 2445217; GeneCards: XPNPEP3
Enzyme activity
EC #BRENDAExPASyKEGGMetaCyc
3.4.11.9↗↗↗↗
Orthologs
DatabasesNCBI: entry; OMA: entry
SpeciesHumanMouse
Entrez

63929

321003

Ensembl

ENSG00000196236

ENSMUSG00000022401

UniProt

Q9NQH7

B7ZMP1

RefSeq (mRNA)

NM_022098
NM_001204827

NM_177310
NM_001347075

RefSeq (protein)

NP_001191756
NP_071381

NP_001334004
NP_796284

Location (UCSC)Chr 22: 40.86 – 40.93 MbChr 15: 81.28 – 81.34 Mb
PubMed search
Wikidata
View/Edit HumanView/Edit Mouse

Xaa-Pro aminopeptidase 3, also known as aminopeptidase P3, is an enzyme that in humans is encoded by the XPNPEP3 gene. XPNPEP3 localizes to mitochondria in renal cells and to kidney tubules in a cell type-specific pattern. Mutations in XPNPEP3 gene have been identified as a cause of a nephronophthisis-like disease.

Structure

Gene

The XPNPEP3 gene is located at chromosome 22q13.2, consisting of 12 exons. Two splice variants of XPNPEP3, APP3m and APP3c, exist in mitochondria and cytosol, respectively.

Protein

APP3m has an N-terminal mitochondrial-targeting sequence (MTS) domain importing APP3m into mitochondria, where the domain is removed proteolytically and APP3m functions as a 51-kDa mature protein. By contrast, APP3c, lacks the MTS and is expressed in the cytosol. Arginine in MTS is required for mitochondrial transport.

Function

XPNPEP3 belongs to a family of X-pro-aminopeptidases (EC 3.4.11.9) that utilize a metal cofactor and remove the N-terminal amino acid from peptides with a proline residue in the penultimate position. It has been found that upon tumor necrosis factor stimulation, XPNPEP3 is released from mitochondria. XPNPEP3 is a new member of the TNF-TNFR2 signaling complex and plays a role in the transduction mechanism of TNFR2 signal which activates both JNK1 and JNK2 pathways. It is also observed that cell death increases upon downregulation of XPNPEP3, suggesting XPNPEP3 exerts an anti-apoptotic function. Deletion of icp55, the S. cerevisiae ortholog of XPNPEP3, increases the proteolytic rate of its substrates through a protein degradation pathway characterized by the N-end rule.

Clinical significance

Mutations in the XPNPEP3 gene are associated with ciliopathy. Recessive mutations in XPNPEP3 gene has been identified as a cause of a nephronophthisis-like disease, characterized by renal interstitial infiltration with fibrosis, tubular atrophy with basement membrane disruption, and cyst development at the corticomedullary renal border. Phenotypic variability might be ascribed to different degrees of loss of function for the 2 different homozygous XPNPEP3 alleles. The ciliary phenotypes unmasked by loss of XPNPEP3 might arise from the loss of XPNPEP3-dependent processing of ciliary proteins.

Interactions

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000196236 – Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000022401 – Ensembl, May 2017
  3. ↑ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ↑ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ↑ "Entrez Gene: X-prolyl aminopeptidase (aminopeptidase P) 3".
  6. 1 2 3 O'Toole JF, Liu Y, Davis EE, Westlake CJ, Attanasio M, Otto EA, et al. (March 2010). "Individuals with mutations in XPNPEP3, which encodes a mitochondrial protein, develop a nephronophthisis-like nephropathy". The Journal of Clinical Investigation. 120 (3): 791–802. doi:10.1172/JCI40076. PMC 2827951. PMID 20179356.
  7. 1 2 3 4 Inoue M, Kamada H, Abe Y, Higashisaka K, Nagano K, Mukai Y, et al. (February 2015). "Aminopeptidase P3, a new member of the TNF-TNFR2 signaling complex, induces phosphorylation of JNK1 and JNK2". Journal of Cell Science. 128 (4): 656–669. doi:10.1242/jcs.149385. PMID 25609706.
  8. 1 2 Erşahin C, Szpaderska AM, Orawski AT, Simmons WH (March 2005). "Aminopeptidase P isozyme expression in human tissues and peripheral blood mononuclear cell fractions". Archives of Biochemistry and Biophysics. 435 (2): 303–310. doi:10.1016/j.abb.2004.12.023. PMID 15708373.
  9. ↑ Whatcott CJ, Meyer-Ficca ML, Meyer RG, Jacobson MK (December 2009). "A specific isoform of poly(ADP-ribose) glycohydrolase is targeted to the mitochondrial matrix by a N-terminal mitochondrial targeting sequence". Experimental Cell Research. 315 (20): 3477–3485. doi:10.1016/j.yexcr.2009.04.005. PMC 2787692. PMID 19389396.
  10. ↑ Weller M (October 2010). "Chemotherapy for low-grade gliomas: when? how? how long?". Neuro-Oncology. 12 (10): 1013. doi:10.1093/neuonc/noq137. PMC 3018930. PMID 20861092.
  11. ↑ Varshavsky A (August 2011). "The N-end rule pathway and regulation by proteolysis". Protein Science. 20 (8): 1298–1345. doi:10.1002/pro.666. PMC 3189519. PMID 21633985.
  12. ↑ Hurd TW, Hildebrandt F (2011). "Mechanisms of nephronophthisis and related ciliopathies". Nephron. Experimental Nephrology. 118 (1): e9–e14. doi:10.1159/000320888. PMC 2992643. PMID 21071979.
  13. ↑ Hildebrandt F, Zhou W (June 2007). "Nephronophthisis-associated ciliopathies". Journal of the American Society of Nephrology. 18 (6): 1855–1871. doi:10.1681/asn.2006121344. PMID 17513324.
  14. ↑ Khanna H, Davis EE, Murga-Zamalloa CA, Estrada-Cuzcano A, Lopez I, den Hollander AI, et al. (June 2009). "A common allele in RPGRIP1L is a modifier of retinal degeneration in ciliopathies". Nature Genetics. 41 (6): 739–745. doi:10.1038/ng.366. PMC 2783476. PMID 19430481.
  15. ↑ Baala L, Audollent S, Martinovic J, Ozilou C, Babron MC, Sivanandamoorthy S, et al. (July 2007). "Pleiotropic effects of CEP290 (NPHP6) mutations extend to Meckel syndrome". American Journal of Human Genetics. 81 (1): 170–179. doi:10.1086/519494. PMC 1950929. PMID 17564974.

Further reading