Calponin
Calponin is a calcium binding protein. Calponin tonically inhibits the ATPase activity of myosin in smooth muscle. Phosphorylation of calponin by a protein kinase, which is dependent upon calcium binding to calmodulin, releases the calponin’s inhibition of the smooth muscle ATPase.
Structure and function
Structure and function
Calponin is mainly made up of α-helices with hydrogen bond turns. It is a binding protein and is made up of three domains. These domains in order of appearance are Calponin Homology (CH), regulatory domain (RD), and Click-23, domain that contains the calponin repeats. At the CH domain calponin binds to α-actin and filamin and binds to actin within the RD domain. Calmodulin, when activated by calcium may bind weakly to the CH domain and inhibit calponin binding with α-actin.[2] Calponin is responsible for binding many actin binding proteins, phospholipids, and regulates the actin/myosin interaction. Calponin is also thought to negatively affect the bone making process due to being expressed in high amounts in osteoblasts.[3]
References
References
- ↑ PDB: 1WYP; Tomizawa T, Kigawa T, Koshiba S, Inoue M, Yokoyama S. “RCSB PDB – 1WYP Structure Summary”. RCSB Protein Data Bank. doi:10.2210/pdb1wyp/pdb.
- ↑ Ferjani, I; Fattoum, A; Manai, M; Benyamin, Y; Roustan, C; Maciver, SK (September 2010). “Two distinct regions of calponin share common binding sites on actin resulting in different modes of calponin-actin interaction”. Biochimica et Biophysica Acta. 1804 (9): 1760–7. doi:10.1016/j.bbapap.2010.05.012. PMID 20595006.
- ↑ Maciver S. “The Calponin Family”. Department of Biomedical Sciences, University of Edinburgh. Retrieved 2011-04-25.
External links
External links
- Calponin at the US National Library of Medicine Medical Subject Headings (MeSH)
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