An efficient reduced-lattice model of IPR for probing Ca dynamics.

Numerous cellular processes are regulated by Ca signals, and the endoplasmic reticulum (ER) membrane's inositol triphosphate receptor (IPR) is critical for modulating intracellular Ca dynamics. The IPRs are seen to be clustered in a variety of cell types. The combination of IPRs clustering and IPRs-mediated Ca-induced Ca release results in the hierarchical organization of the Ca signals, which challenges the numerical simulation given the multiple spatial and temporal scales that must be covered. The previous methods rather ignore the spatial feature of IPRs or fail to coordinate the conflicts between the real biological relevance and the computational cost. In this work, a general and efficient reduced-lattice model is presented for the simulation of IPRs-mediated multiscale Ca dynamics. The model highlights biological details that make up the majority of the calcium events, including IPRs clustering and calcium domains, and it reduces the complexity by approximating the minor details. The model's extensibility provides fresh insights into the function of IPRs in producing global Ca events and supports the research under more physiological circumstances. Our work contributes to a novel toolkit for modeling multiscale Ca dynamics and advances knowledge of Ca signals.