Calcium Dynamics Mediated by the Endoplasmic/Sarcoplasmic Reticulum and Related Diseases

The flow of intracellular calcium (Ca(2+)) is critical for the activation and regulation of important biological events that are required in living organisms. As the major Ca(2+) repositories inside the cell, the endoplasmic reticulum (ER) and the sarcoplasmic reticulum (SR) of muscle cells are central in maintaining and amplifying the intracellular Ca(2+) signal. The morphology of these organelles, along with the distribution of key calcium-binding proteins (CaBPs), regulatory proteins, pumps, and receptors fundamentally impact the local and global differences in Ca(2+) release kinetics. In this review, we will discuss the structural and morphological differences between the ER and SR and how they influence localized Ca(2+) release, related diseases, and the need for targeted genetically encoded calcium indicators (GECIs) to study these events.