Abstract
Concerted openings of clustered inositol 1,4,5-trisphosphate receptors (IP(3)Rs) result in short, localized Ca(2+) bursts, also called puffs, which are crucial regulators of Ca(2+)-dependent signaling processes. However, the processes regulating Ca(2+) puff amplitude (average ∼0.5 ΔF/F(0)) and duration (at half-maximal; average ∼25-30 ms) have yet to be elucidated. A recent study in JBC by Smith and Taylor determined that Ca(2+) puff amplitude is independent of IP(3)R cluster density and that the termination of IP(3)R Ca(2+) puff is regulated by IP(3) dissociation, illuminating the steps of this regulatory dance.