IP3Rs puff along: A SNAPpy dance with IP3 and Ca2

Abstract

Concerted openings of clustered inositol 1,4,5-trisphosphate receptors (IP₃Rs) result in short, localized Ca²⁺ bursts, also called puffs, which are crucial regulators of Ca²⁺-dependent signaling processes. However, the processes regulating Ca²⁺ puff amplitude (average ∼0.5 ΔF/F₀) 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 Ca²⁺ puff amplitude is independent of IP₃R cluster density and that the termination of IP₃R Ca²⁺ puff is regulated by IP₃ dissociation, illuminating the steps of this regulatory dance.