Calpain-9 Explained

Calpain-9 is a protein that in humans is encoded by the CAPN9 gene.^{[1] [2] [3]}

Calpains are ubiquitous, well-conserved family of calcium-dependent, cysteine proteases. The calpain proteins are heterodimers consisting of an invariant small subunit and variable large subunits. The large subunit possesses a cysteine protease domain, and both subunits possess calcium-binding domains. Calpains have been implicated in neurodegenerative processes, as their activation can be triggered by calcium influx and oxidative stress. The protein encoded by this gene is expressed predominantly in stomach and small intestine and may have specialized functions in the digestive tract. This gene is thought to be associated with gastric cancer. Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene.

Further reading

• Huang Y, Wang KK . The calpain family and human disease . Trends in Molecular Medicine . 7 . 8 . 355–362 . 2001 . 11516996 . 10.1016/S1471-4914(01)02049-4 .
• Suzuki K . Calpain: novel family members, activation, and physiologic function . Biol. Chem. Hoppe-Seyler . 376 . 9 . 523–9 . 1996 . 8561910 . 10.1515/bchm3.1995.376.9.523. vanc. Sorimachi H . Yoshizawa T . 3 . Kinbara . K . Ishiura . S .
• Davis TL . The crystal structures of human calpains 1 and 9 imply diverse mechanisms of action and auto-inhibition . J. Mol. Biol. . 366 . 1 . 216–229 . 2007 . 17157313 . 10.1016/j.jmb.2006.11.037 . vanc. Walker JR . Finerty PJ . 3 . MacKenzie . Farrell . Newman . Elena M. . Dhe-Paganon . Sirano .
• Strausberg RL . 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 . 16899–16903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . vanc. Feingold EA . Grouse LH . 3 . Derge . JG . Klausner . RD . Collins . FS . Wagner . L . Shenmen . CM . Schuler . GD . 2002PNAS...9916899M . free .
• Lee HJ . Characterization of a human digestive tract-specific calpain, nCL-4, expressed in the baculovirus system . Arch. Biochem. Biophys. . 362 . 1 . 22–31 . 1999 . 9917325 . 10.1006/abbi.1998.1021 . vanc. Tomioka S . Kinbara K . 3 . Masumoto . H . Jeong . SY . Sorimachi . H . Ishiura . S . Suzuki . K .

External links

• • The MEROPS online database for peptidases and their inhibitors: C02.006

Notes and References

1. Lee HJ, Sorimachi H, Jeong SY, Ishiura S, Suzuki K . Molecular cloning and characterization of a novel tissue-specific calpain predominantly expressed in the digestive tract . Biol Chem . 379 . 2 . 175–184 . May 1998 . 9524069 . 10.1515/bchm.1998.379.2.175 . 37483841 .
2. Yoshikawa Y, Mukai H, Hino F, Asada K, Kato I . Isolation of two novel genes, down-regulated in gastric cancer . Jpn J Cancer Res . 91 . 5 . 459–63 . Jul 2000 . 10835488 . 5926377 . 10.1111/j.1349-7006.2000.tb00967.x.
3. Web site: Entrez Gene: CAPN9 calpain 9.