Tunability of calcium dynamics by signaling inputs and cell-cell communication in pancreatic beta cells

In addition to frequently occurring stable all-or-none responses, live cells can display more complex response dynamics, e.g., oscillations in the activity/concentration of biomolecules. While the emergence and function of oscillatory dynamics have been heavily investigated, fewer efforts have been spent on whether cells can fine-tune different aspects of an oscillatory signal (e.g., peakwidth, duty cycle, and frequency) and whether this fine-tuning can allow oscillatory signals to convey different information. In this study, we investigate glucose-induced calcium (Ca ²⁺ ) oscillation in MIN6 cells, finding that the spontaneous or induced changes in the phosphatidylinositol 4,5-bisphosphate (PIP2) level during Ca ²⁺ oscillation can modulate the peakwidth of individual Ca ²⁺ spikes. Additionally, using a combination of optogenetics and Ca ²⁺ imaging, we demonstrate that variation of the widths and frequencies of Ca ²⁺ spikes can exert strong influence on coupling between neighboring MIN6 cells.