Module 6: Figure elementary events
The elementary events of Ca2+ signalling.
Elementary events are the localized Ca2+ signals that arise from either individual or small groups of ion channels. The localized plumes of Ca2+ have been given different names, depending on the channels that produce them. Voltage-operated channels (VOCs) in the plasma membrane produce sparklets; ryanodine receptors (RYRs) on the sarcoplasmic reticulum (SR) create sparks (and syntillas), whereas the inositol 1,4,5-trisphosphate receptors produce puffs. These intracellular channels have a large conductance and gate so much Ca2+ that results in a local depletion of Ca2+ within the lumen immediately below the channel. This local emptying of the endoplasmic reticulum (ER) store has been visualized and has been called a blink.