CPN1 explained

Carboxypeptidase N catalytic chain is an enzyme that in humans is encoded by the CPN1 gene.^{[1] [2] [3]}

Carboxypeptidase N is a plasma metallo-protease that cleaves basic amino acids from the C terminal of peptides and proteins. The enzyme is important in the regulation of peptides like kinins and anaphylatoxins, and has also been known as kininase-1 and anaphylatoxin inactivator. This enzyme is a tetramer composed of two identical regulatory subunits and two identical catalytic subunits; this gene encodes the catalytic subunit. Mutations in this gene can be associated with angioedema or chronic urticaria resulting from carboxypeptidase N deficiency.

In melanocytic cells CPN1 gene expression may be regulated by MITF.^[4]

Further reading

• Matthews KW, Mueller-Ortiz SL, Wetsel RA . Carboxypeptidase N: a pleiotropic regulator of inflammation. . Mol. Immunol. . 40 . 11 . 785–93 . 2004 . 14687935 . 10.1016/j.molimm.2003.10.002 .
• Book: Gebhard W, Schube M, Eulitz M . CDNA Cloning of Kininase 1 . Kinins V . Advances in Experimental Medicine and Biology . 247B . 261–4 . 1990 . 2610070 . 10.1007/978-1-4615-9546-5_43. 2024-03-27 . 978-1-4615-9548-9 .
• Skidgel RA, Bennett CD, Schilling JW . Amino acid sequence of the N-terminus and selected tryptic peptides of the active subunit of human plasma carboxypeptidase N: comparison with other carboxypeptidases. . Biochem. Biophys. Res. Commun. . 154 . 3 . 1323–9 . 1988 . 3408501 . 10.1016/0006-291X(88)90284-7 . etal.
• Hendriks D, Vingron M, Vriend G . On the specificity of carboxypeptidase N, a comparative study. . Biol. Chem. Hoppe-Seyler . 374 . 9 . 843–9 . 1994 . 8267877 . 10.1515/bchm3.1993.374.7-12.843. etal.
• Sato T, Miwa T, Akatsu H . Pro-carboxypeptidase R is an acute phase protein in the mouse, whereas carboxypeptidase N is not. . J. Immunol. . 165 . 2 . 1053–8 . 2000 . 10878383 . 10.4049/jimmunol.165.2.1053. etal. free .
• Campbell WD, Lazoura E, Okada N, Okada H . Inactivation of C3a and C5a octapeptides by carboxypeptidase R and carboxypeptidase N. . Microbiol. Immunol. . 46 . 2 . 131–4 . 2002 . 11939578 . 10.1111/j.1348-0421.2002.tb02669.x. 33755040 . free .
• Strausberg RL, Feingold EA, Grouse LH . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences. . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . 2002PNAS...9916899M . etal. free .
• Cao H, Hegele RA . DNA polymorphism and mutations in CPN1, including the genomic basis of carboxypeptidase N deficiency. . J. Hum. Genet. . 48 . 1 . 20–2 . 2003 . 12560874 . 10.1007/s100380300003 . free .
• Shimomura Y, Kawamura T, Komura H . Modulation of procarboxypeptidase R (ProCPR) activation by complementary peptides to thrombomodulin. . Microbiol. Immunol. . 47 . 3 . 241–5 . 2003 . 12725295 . 10.1111/j.1348-0421.2003.tb03383.x. 24243086 . etal. free .
• Gerhard DS, Wagner L, Feingold EA . The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). . Genome Res. . 14 . 10B . 2121–7 . 2004 . 15489334 . 10.1101/gr.2596504 . 528928 . etal.
• Davis DA, Singer KE, De La Luz Sierra M . Identification of carboxypeptidase N as an enzyme responsible for C-terminal cleavage of stromal cell-derived factor-1alpha in the circulation. . Blood . 105 . 12 . 4561–8 . 2005 . 15718415 . 10.1182/blood-2004-12-4618 . 1895000 . etal.
• Rual JF, Venkatesan K, Hao T . Towards a proteome-scale map of the human protein-protein interaction network. . Nature . 437 . 7062 . 1173–8 . 2005 . 16189514 . 10.1038/nature04209 . 2005Natur.437.1173R . 4427026 . etal.

Notes and References

1. Riley DA, Tan F, Miletich DJ, Skidgel RA . Chromosomal localization of the genes for human carboxypeptidase D (CPD) and the active 50-kilodalton subunit of human carboxypeptidase N (CPN1) . Genomics . 50 . 1 . 105–8 . Apr 1999 . 9628828 . 10.1006/geno.1998.5295 .
2. Gebhard W, Schube M, Eulitz M . cDNA cloning and complete primary structure of the small, active subunit of human carboxypeptidase N (kininase 1) . Eur J Biochem . 178 . 3 . 603–7 . Mar 1989 . 2912725 . 10.1111/j.1432-1033.1989.tb14488.x . free .
3. Web site: Entrez Gene: CPN1 carboxypeptidase N, polypeptide 1.
4. Hoek KS, Schlegel NC, Eichhoff OM . Novel MITF targets identified using a two-step DNA microarray strategy . Pigment Cell Melanoma Res. . 21 . 6 . 665–76 . 2008 . 19067971 . 10.1111/j.1755-148X.2008.00505.x . 24698373 . etal. free .