Carbonic anhydrase VI explained

Carbonic anhydrase 6 is an enzyme that in humans is encoded by the CA6 gene.^{[1] [2]} It is also called 'gustin' because of its presence in saliva, and lower-than-normal levels of salivary zinc in individuals with hypogeusia.^{[3] [4]}

Function

The protein encoded by this gene is one of several isozymes of carbonic anhydrase. This protein is abundantly found in salivary glands and saliva and protein may play a role in the reversible hydratation of carbon dioxide, though its function in saliva is unknown.^[2]

It has been suggested that CA VI participates in the maintenance of appropriate pH homeostasis on tooth surfaces as well as in the mucosa of the gastrointestinal canal.

Further reading

• Nishimori I, FujikawaAdachi K, Onishi S, Hollingsworth MA . Carbonic anhydrase in human pancreas: hypotheses for the pathophysiological roles of CA isozymes . Annals of the New York Academy of Sciences . 880 . 5–16 . June 1999 . 1 . 10415846 . 10.1111/j.1749-6632.1999.tb09505.x . 1999NYASA.880....5N . 42868610 .
• Kivela J, Parkkila S, Parkkila AK, Leinonen J, Rajaniemi H . Salivary carbonic anhydrase isoenzyme VI . The Journal of Physiology . 520 Pt 2 . 315–20 . October 1999 . 2 . 10523402 . 2269599 . 10.1111/j.1469-7793.1999.t01-1-00315.x .
• Nishimori I, Onishi S . Carbonic anhydrase isozymes in the human pancreas . Digestive and Liver Disease . 33 . 1 . 68–74 . 2001 . 11303978 . 10.1016/s1590-8658(01)80138-9 .
• Aldred P, Fu P, Barrett G, Penschow JD, Wright RD, Coghlan JP, Fernley RT . Human secreted carbonic anhydrase: cDNA cloning, nucleotide sequence, and hybridization histochemistry . Biochemistry . 30 . 2 . 569–75 . January 1991 . 1899030 . 10.1021/bi00216a035 .
• Parkkila S, Kaunisto K, Rajaniemi L, Kumpulainen T, Jokinen K, Rajaniemi H . Immunohistochemical localization of carbonic anhydrase isoenzymes VI, II, and I in human parotid and submandibular glands . The Journal of Histochemistry and Cytochemistry . 38 . 7 . 941–7 . July 1990 . 2113069 . 10.1177/38.7.2113069 . free .
• Murakami H, Sly WS . Purification and characterization of human salivary carbonic anhydrase . The Journal of Biological Chemistry . 262 . 3 . 1382–8 . January 1987 . 10.1016/S0021-9258(19)75797-4 . 2433278 . free .
• Sutherland GR, Baker E, Fernandez KE, Callen DF, Aldred P, Coghlan JP, Wright RD, Fernley RT . Grant Robert Sutherland . The gene for human carbonic anhydrase VI(CA6) is on the tip of the short arm of chromosome 1 . Cytogenetics and Cell Genetics . 50 . 2–3 . 149–50 . 1989 . 2505973 . 10.1159/000132746 .
• Ogawa Y, Hong SS, Toyosawa S, Kuwahara H, Shimazaki M, Yagi T . Immunoelectron microscopy of carbonic anhydrase isozyme VI in human submandibular gland: comparison with isozymes I and II . The Journal of Histochemistry and Cytochemistry . 41 . 3 . 343–51 . March 1993 . 8429198 . 10.1177/41.3.8429198 . free .
• Kivelä J, Parkkila S, Waheed A, Parkkila AK, Sly WS, Rajaniemi H . Secretory carbonic anhydrase isoenzyme (CA VI) in human serum . Clinical Chemistry . 43 . 12 . 2318–22 . December 1997 . 10.1093/clinchem/43.12.2318 . 9439449 . free .
• Thatcher BJ, Doherty AE, Orvisky E, Martin BM, Henkin RI . Gustin from human parotid saliva is carbonic anhydrase VI . Biochemical and Biophysical Research Communications . 250 . 3 . 635–41 . September 1998 . 9784398 . 10.1006/bbrc.1998.9356 .
• Leinonen J, Kivelä J, Parkkila S, Parkkila AK, Rajaniemi H . Salivary carbonic anhydrase isoenzyme VI is located in the human enamel pellicle . Caries Research . 33 . 3 . 185–90 . 1999 . 10207193 . 10.1159/000016515 . 44344754 .
• Redman RS, Peagler FD, Johansson I . Immunohistochemical localization of carbonic anhydrases I, II, and VI in the developing rat sublingual and submandibular glands . The Anatomical Record . 258 . 3 . 269–76 . March 2000 . 10705347 . 10.1002/(SICI)1097-0185(20000301)258:3<269::AID-AR6>3.0.CO;2-Y . free .
• Leinonen J, Parkkila S, Kaunisto K, Koivunen P, Rajaniemi H . Secretion of carbonic anhydrase isoenzyme VI (CA VI) from human and rat lingual serous von Ebner's glands . The Journal of Histochemistry and Cytochemistry . 49 . 5 . 657–62 . May 2001 . 11304804 . 10.1177/002215540104900513 . free .
• Karhumaa P, Leinonen J, Parkkila S, Kaunisto K, Tapanainen J, Rajaniemi H . The identification of secreted carbonic anhydrase VI as a constitutive glycoprotein of human and rat milk . Proceedings of the National Academy of Sciences of the United States of America . 98 . 20 . 11604–8 . September 2001 . 11553764 . 58776 . 10.1073/pnas.121172598 . 2001PNAS...9811604K . free .

Notes and References

1. White PS, Jensen SJ, Rajalingam V, Stairs D, Sulman EP, Maris JM, Biegel JA, Wooster R, Brodeur GM . Physical mapping of the CA6, ENO1, and SLC2A5 (GLUT5) genes and reassignment of SLC2A5 to 1p36.2 . Cytogenetics and Cell Genetics . 81 . 1 . 60–4 . Oct 1998 . 9691177 . 10.1159/000014989 . 46770845 .
2. Web site: Entrez Gene: CA6 carbonic anhydrase VI.
3. Henkin RI, Mueller CW, Wolf RO . Estimation of zinc concentration of parotid saliva by flameless atomic absorption spectrophotometry in normal subjects and in patients with idiopathic hypogeusia . The Journal of Laboratory and Clinical Medicine . 86 . 1 . 175–80 . July 1975 . 1151138 .
4. Henkin RI, Lippoldt RE, Bilstad J, Edelhoch H . A zinc protein isolated from human parotid saliva . Proceedings of the National Academy of Sciences of the United States of America . 72 . 2 . 488–92 . February 1975 . 1054831 . 432337 . 10.1073/pnas.72.2.488. 1975PNAS...72..488H . free .