Stochastic properties of Ca(2+) release of inositol 1,4,5-trisphosphate receptor clusters.
Intracellular Ca(2+) release is controlled by inositol 1,4,5-trisphosphate (IP(3)) receptors or ryanodine receptors. These receptors are typically distributed in clusters with several or tens of channels. The random opening and closing of these channels introduces stochasticity into the elementary calcium release mechanism. Stochastic release events have been experimentally observed in a variety of cell types and have been termed sparks and puffs. We put forward a stochastic version of the Li-Rinzel model (the deactivation binding process is described by a Markovian scheme) and a computationally more efficient Langevin approach to model the stochastic Ca(2+) oscillation of single clusters. Statistical properties such as Ca(2+) puff amplitudes, lifetimes, and interpuff intervals are studied with both models and compared with experimental observations. For clusters with tens of channels, a simply decaying amplitude distribution is typically observed at low IP(3) concentration, while a single peak distribution appears at high IP(3) concentration.
Shuai
Jian-Wei
JW
Department of Physics and Astronomy and Institute for Quantitative Biology, Ohio University, Athens, Ohio 45701, USA. shuai@helios.phy.ohiou.edu
Jung
Peter
P
D001703:Biophysics / Q000379:methods*; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D015544:Inositol 1,4,5-Trisphosphate / Q000737:chemistry* / Q000378:metabolism; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008390:Markov Chains; D016011:Normal Distribution; D009991:Oscillometry; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry* / Q000378:metabolism*; D013269:Stochastic Processes; D013997:Time Factors
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D018160:Receptors, Cytoplasmic and Nuclear; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium