In skeletal muscle excitation-contraction coupling, a voltage-gated calcium channel directly activates opening of the calcium release channel (RyR1) in the sarcoplasmic reticulum that supplies the calcium signal triggering contraction. In addition, a retrograde signal from the RyR1 facilitates gating of the voltage-gated calcium channel. Recent studies of RyR1 mutants, including the article by Bannister et al. in this issue of the Biophysical Journal, advance our understanding of the signaling mechanism, although the physiological significance of retrograde coupling remains elusive.
Flucher, B. E. (2016, February 23). Retrograde Coupling: Muscle’s Orphan Signaling Pathway? Biophysical Journal. Biophysical Society. https://doi.org/10.1016/j.bpj.2015.12.032