Figure 7.

Two γ-subunit model (γ_fast and γ_slow) shows that the ratio of γ_fast:γ_slow regulates the distribution of Ca²⁺ oscillation characteristics in a cell population. We invoked different ratios of fast and slow γ subunits by varying m1 and m2 values in the model from 0 to 1 (model description in the Supporting Material). Changes in number (a) and duration (b) of Ca²⁺ spikes in response to increasing the fraction of γ_fast at different input doses (black: low; red: high dose). Increasing the fraction of γ_fast induces a shift in distribution of Ca²⁺ oscillation pattern in a HeLa cell population. (c and d) Simulated distribution of Ca²⁺ spikes in a cell population containing different percentages of γ_fast. (e and f) Experimentally observed distribution of Ca²⁺ spikes in γ11 knockdown, control shRNA, and γ11 cell populations. n_control = 150, n_{γ11-knockdown} = 90, n = number of cells studied. For both experiment and simulation, nonparametric kernel density function was fitted to the distribution of the number and duration of Ca²⁺ spiking in a cell population. (N_exp = 3). Details about the simulation of population response is in the Supporting Material, section 2.3. To see this figure in color, go online.