This gene encodes a calcium-binding protein with multiple E-F hand domains that relocates from the cytoplasm to the sarcoplasmic reticulum in response to elevated calcium levels. In addition to regulating intracellular calcium homeostasis it also modulates excitation-contraction coupling in the heart. Alternative splicing results in multiple transcript variants encoding distinct proteins. Multiple pseudogenes exist for this gene. [provided by RefSeq, Mar 2012].