Calsequestrin is primarily associated with cardiac and skeletal muscle fibers, where it plays a critical role in calcium storage within the sarcoplasmic reticulum. It is particularly relevant in fast-twitch fibers, which require rapid calcium release for quick and powerful contractions. Calsequestrin helps regulate calcium levels during muscle contraction and relaxation, contributing to muscle efficiency and performance.
Striated muscles, like all other muscles, including cardiac and smooth, use a method called the sliding filament theory. This is the current model of how muscles contract and was developed by Hugh Huxley in the 1960's.