Comparing skeletal and cardiac calsequestrin structures and their calcium binding: a proposed mechanism for coupled calcium binding and protein polymerization
1sji is a 2 chain structure with sequence from Canis lupus familiaris. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
CASQ2_CANLF Calsequestrin is a high-capacity, moderate affinity, calcium-binding protein and thus acts as an internal calcium store in muscle (PubMed:3427023). Calcium ions are bound by clusters of acidic residues at the protein surface, especially at the interface between subunits. Can bind around 60 Ca(2+) ions. Regulates the release of lumenal Ca(2+) via the calcium release channel RYR2; this plays an important role in triggering muscle contraction. Plays a role in excitation-contraction coupling in the heart and in regulating the rate of heart beats.[1][2][3]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
References
↑Park H, Park IY, Kim E, Youn B, Fields K, Dunker AK, Kang C. Comparing skeletal and cardiac calsequestrin structures and their calcium binding: a proposed mechanism for coupled calcium binding and protein polymerization. J Biol Chem. 2004 Apr 23;279(17):18026-33. Epub 2004 Feb 10. PMID:14871888 doi:10.1074/jbc.M311553200
↑Kirchhefer U, Wehrmeister D, Postma AV, Pohlentz G, Mormann M, Kucerova D, Müller FU, Schmitz W, Schulze-Bahr E, Wilde AA, Neumann J. The human CASQ2 mutation K206N is associated with hyperglycosylation and altered cellular calcium handling. J Mol Cell Cardiol. 2010 Jul;49(1):95-105. PMID:20302875 doi:10.1016/j.yjmcc.2010.03.006
↑Slupsky JR, Ohnishi M, Carpenter MR, Reithmeier RA. Characterization of cardiac calsequestrin. Biochemistry. 1987 Oct 6;26(20):6539-44. PMID:3427023 doi:10.1021/bi00394a038
