Calpains are a ubiquitous, well-conserved family of calcium-dependent, cysteine proteases. Calpain families have been implicated in neurodegenerative processes, as their activation can be triggered by calcium influx and oxidative stress. Calpain I and II are heterodimeric with distinct large subunits associated with common small subunits, all of which are encoded by different genes. The small regulatory subunit consists of an N-terminal domain, containing about 30% glycine residues and a C-terminal Ca-binding domain.[4] Two transcript variants encoding the same protein have been identified for this gene.[3]
Functions
Myotonic dystrophy
This gene encodes a small subunit common to both calpain I and II and is associated with myotonic dystrophy.[3]
Biomarker
Elevated expression of Capn4 has been found to be associated with progression of various cancers such as hepatocellular and renal carcinoma.
[5]
↑Lin GD, Chattopadhyay D, Maki M, Wang KK, Carson M, Jin L, Yuen PW, Takano E, Hatanaka M, DeLucas LJ, Narayana SV (July 1997). "Crystal structure of calcium bound domain VI of calpain at 1.9 A resolution and its role in enzyme assembly, regulation, and inhibitor binding". Nature Structural Biology. 4 (7): 539–47. PMID9228946.
↑Zhuang Q, Qian X, Cao Y, Fan M, Xu X, He X (April 2014). "Capn4 mRNA level is correlated with tumour progression and clinical outcome in clear cell renal cell carcinoma". The Journal of International Medical Research. 42 (2): 282–91. doi:10.1177/0300060513505524. PMID24514433.
Reverter D, Sorimachi H, Bode W (August 2001). "The structure of calcium-free human m-calpain: implications for calcium activation and function". Trends in Cardiovascular Medicine. 11 (6): 222–9. doi:10.1016/S1050-1738(01)00112-8. PMID11673052.
Banik NL, DeVries GH, Neuberger T, Russell T, Chakrabarti AK, Hogan EL (July 1991). "Calcium-activated neutral proteinase (CANP; calpain) activity in Schwann cells: immunofluorescence localization and compartmentation of mu- and mCANP". Journal of Neuroscience Research. 29 (3): 346–54. doi:10.1002/jnr.490290310. PMID1656060.
Ohno S, Minoshima S, Kudoh J, Fukuyama R, Shimizu Y, Ohmi-Imajoh S, Shimizu N, Suzuki K (1990). "Four genes for the calpain family locate on four distinct human chromosomes". Cytogenetics and Cell Genetics. 53 (4): 225–9. doi:10.1159/000132937. PMID2209092.
Andersson B, Wentland MA, Ricafrente JY, Liu W, Gibbs RA (April 1996). "A "double adaptor" method for improved shotgun library construction". Analytical Biochemistry. 236 (1): 107–13. doi:10.1006/abio.1996.0138. PMID8619474.
Zhang W, Lane RD, Mellgren RL (August 1996). "The major calpain isozymes are long-lived proteins. Design of an antisense strategy for calpain depletion in cultured cells". The Journal of Biological Chemistry. 271 (31): 18825–30. doi:10.1074/jbc.271.31.18825. PMID8702541.
Masumoto H, Nakagawa K, Irie S, Sorimachi H, Suzuki K, Bourenkov GP, Bartunik H, Fernandez-Catalan C, Bode W, Strobl S (January 2000). "Crystallization and preliminary X-ray analysis of recombinant full-length human m-calpain". Acta Crystallographica Section D. 56 (Pt 1): 73–5. doi:10.1107/S0907444999013748. PMID10666632.
Dias Neto E, Correa RG, Verjovski-Almeida S, Briones MR, Nagai MA, da Silva W, Zago MA, Bordin S, Costa FF, Goldman GH, Carvalho AF, Matsukuma A, Baia GS, Simpson DH, Brunstein A, de Oliveira PS, Bucher P, Jongeneel CV, O'Hare MJ, Soares F, Brentani RR, Reis LF, de Souza SJ, Simpson AJ (March 2000). "Shotgun sequencing of the human transcriptome with ORF expressed sequence tags". Proceedings of the National Academy of Sciences of the United States of America. 97 (7): 3491–6. doi:10.1073/pnas.97.7.3491. PMC16267. PMID10737800.
Reverter D, Strobl S, Fernandez-Catalan C, Sorimachi H, Suzuki K, Bode W (May 2001). "Structural basis for possible calcium-induced activation mechanisms of calpains". Biological Chemistry. 382 (5): 753–66. doi:10.1515/BC.2001.091. PMID11517928.