The main function of RYR1 is to mediate the release of calcium ions from the sarcoplasmic reticulum into the cytoplasm of muscle cells. When an action potential arrives at the muscle cell, it triggers the opening of the RYR1 channel, allowing calcium ions to move out of the sarcoplasmic reticulum. This increase in cytoplasmic calcium concentration initiates the interaction between actin and myosin, leading to muscle contraction.
