Table 2.
Model differential equations
| Reaction | Rate equation |
| 4-K | k_4K * PI |
| 4-P | 0.03 s−1 * PI(4)P |
| 5-Ka | k_5K * PI(4)P |
| 5-Pa | 0.042 s−1 * PIP2 |
| PIP2 to bound PIP2 | (fold_PIP2−1) * 1 s−1 * PIP2−1 s−1 * bound_PIP2 |
| PLCb | k_PLC * GαGTP-PLC * PIP2 |
| PLC on PIP | k_PLC * GαGTP-PLC * PI(4)P |
| IP3ase | k_IP3ase * IP3 |
| DAGase | k_DAGase * DAG |
| h reaction | ((kCa − ((Ca2+cyt + kCa) * h)) * 2.7 µm2 µM−1 s−1) |
| IP3R | 200 * (1 − Ca2+cyt/Ca2+ER) * [(h*IP3*Ca2+cyt)/(IP3 + KIP3)(Ca2+cyt + KCa)]3 |
| SERCA | vP * (Ca2+cyt)2/[kP2 + (Ca2+cyt)2] |
| VSPac | VSP_max * f(VM) * fold_PIP2 * PIP2 |
| IP3_dialysis | k_pipette * (IP3_pipette – IP3_cytosol) |
| PIP2 to KCNQ | 0.05 µm2s−1 * PIP2 * KCNQ − 100 s−1 * PIP2-KCNQ; [Kd = 2,000 µm−2] |
| KCNQ2/3 current | (KCNQ_PIP2)2 |
| PH to PIP2 | 1 µM−1 s−1 * PIP2 * PH − 2 s−1 * PIP2-PH; [Kd = 2 µM] |
| PH to IP3 | 10 µM−1s −1 * IP3 * PH − 1 s−1 * IP3-PH; [Kd = 0.1 µM] |
| LIBRAvIII to IP3 | 1 µM−1s −1 * IP3 * LIBRAvIII − KD_LIBRAvIII* IP3-LIBRAvIII |
| C1 to DAG | 10 µM−1s −1 * PIP2 * PH − KD_C1 * 10 µM−1s−1 * PIP2-PH |
| Ca2+ to Fura-4F | 10 µM−1s −1 * Ca2+ * Fura-4F − KD_Fura-4F * 10 µM−1 s−1 * Ca2+-Fura-4F |
a
Rate constants from Falkenburger et al., 2010b.
b
GαGTP-PLC from model described in Falkenburger et al., 2010a.
c
As in Falkenburger et al., 2010b; f(VM) = 1/(1 + exp(−1.5*qe*(VM − Vhalf)/kBT)) with kBT/qe = 25 mV, Vhalf = 100 mV; VM was 120 mV during the bars “VSP” and −60 mV otherwise [f(120 mV) = 1; f(−60 mV) = 0.00006].