S100A1B Protein (Active)

S100 proteins, such as S100A1 (S100 calcium-binding protein A1), are small, acidic Ca (2+) -binding proteins that transduce Ca (2+) signals via interaction with intracellular target proteins. The protein encoded by this gene is a member of the S100 family of proteins containing 4 EF-hand calcium-binding motifs in its dimerized form. S100A1 is preferentially expressed in myocardial tissue and has been found to colocalize with the sarcoplasmic reticulum (SR) and the contractile filaments in cardiac tissue. Its overexpression enhances cardiac contractile performance and establish the concept of S100A1 as a regulator of myocardial contractility. S100A1 thus improves cardiac contractile performance both by regulating SR Ca (2+) handling and myofibrillar Ca (2+) responsiveness.

Mandinova, A., Atar, D., Schafer, B. W., Spiess, M., Aebi, U., Heizmann, C. W. Distinct subcellular localization of calcium binding S100 proteins in human smooth muscle cells and their relocation in response to rises in intracellular calcium. J. Cell Sci. 111: 2043-2054, 1998. Marenholz I, Heizmann CW, Fritz G (October 2004) . "S100 proteins in mouse and man: from evolution to function and pathology (including an update of the nomenclature) ". Biochem. Biophys. Res. Commun. 322 (4) : 1111–22. Most P, Bernotat J, Ehlermann P, Pleger ST, Reppel M, Börries M, Niroomand F, Pieske B, Janssen PM, Eschenhagen T, Karczewski P, Smith GL, Koch WJ, Katus HA, Remppis A (November 2001) . "S100A1: a regulator of myocardial contractility". Proc. Natl. Acad. Sci. U.S.A. 98 (24) : 13889–94.