Carboxypeptidase A6 Explained

Carboxypeptidase A6 (CPA6) is a metallocarboxypeptidase enzyme that in humans is encoded by the CPA6 gene.^[1] It is highly expressed in the adult mouse olfactory bulb and is broadly expressed in the embryonic brain and other tissues.^[2]

The protein encoded by this gene belongs to the family of carboxypeptidases, which catalyze the release of C-terminal amino acid, and have functions ranging from digestion of food to selective biosynthesis of neuroendocrine peptides. Polymorphic variants and a reciprocal translocation t(6;8)(q26;q13) involving this gene, have been associated with Duane retraction syndrome.^[1]

CPA6 processes several neuropeptides, including [Met]- and [Leu]-enkephalin, angiotensin I, and neurotensin in vitro. Whereas CPA6 is capable of converting the enkephalins and neurotensin into inactive forms, it can convert the inactive angiotensin I into the active angiotensin II. CPA6 may have additional roles in processing peptides and proteins in vivo, but the nature of these substrates and the effects of these cleavages are currently unknown.

See also

• Carboxypeptidase A inhibitor
• Carboxypeptidase

Further reading

• Wei . S. . Segura . S. . Vendrell . J. . Aviles . F. X. . Lanoue . E. . Day . R. . Feng . Y. . Fricker . L. D. . Identification and characterization of three members of the human metallocarboxypeptidase gene family . The Journal of Biological Chemistry . 277 . 17 . 14954–14964 . 10.1074/jbc.M112254200 . 2002 . 11836249. free .
• Pizzuti . A. . Calabrese . G. . Bozzali . M. . Telvi . L. . Morizio . E. . Guida . V. . Gatta . V. . Stuppia . L. . Ion . A. . Palka . G. . Dallapiccola . B. . A peptidase gene in chromosome 8q is disrupted by a balanced translocation in a duane syndrome patient . Investigative Ophthalmology & Visual Science . 43 . 12 . 3609–3612 . 2002 . 12454025.
• Lyons . P. J. . Callaway . M. B. . Fricker . L. D. . Characterization of Carboxypeptidase A6, an Extracellular Matrix Peptidase . 10.1074/jbc.M707680200 . Journal of Biological Chemistry . 283 . 11 . 7054–7063 . 2008 . 18178555. free .
• Sharif . S. A. . Du . X. . Myles . T. . Song . J. J. . Price . E. . Lee . D. M. . Goodman . S. B. . Nagashima . M. . Morser . J. . Robinson . 10.1002/art.24814 . W. H. . Leung . L. L. K. . Thrombin-activatable carboxypeptidase B cleavage of osteopontin regulates neutrophil survival and synoviocyte binding in rheumatoid arthritis . Arthritis & Rheumatism . 60 . 10 . 2902–2912 . 2009 . 19790060. 3757557.
• Lyons . P. J. . Fricker . L. D. . Substrate Specificity of Human Carboxypeptidase A6 . 10.1074/jbc.M110.158626 . Journal of Biological Chemistry . 285 . 49 . 38234–38242 . 2010 . 2992257 . 20855895. free .

Notes and References

1. Web site: Entrez Gene: Carboxypeptidase A6. 2011-11-25 .
2. Lyons PJ, Callaway MB, Fricker LD . Characterization of carboxypeptidase A6, an extracellular matrix peptidase . The Journal of Biological Chemistry . 283 . 11 . 7054–63 . March 2008 . 18178555 . 10.1074/jbc.M707680200 . free .