Appendix 1—table 13. Initial conditions and diffusion coefficients used in the model.

#	Species	Initial value	Diffusion	Ref.
SIC1	Ca2+	0.001 µM	100 $\frac{\mu m^2}{s}$	(Donahue and Abercrombie, 1987), Est. from steady state
SIC2	CaM	2.9 µM	10 $\frac{\mu m^2}{s}$	Est. from steady state*
SIC3	Ca2CaM	0.1 µM	10 $\frac{\mu m^2}{s}$	Est. from steady state*
SIC4	Ca3CaM	4 x 10−3 µM	10 $\frac{\mu m^2}{s}$	Est. from steady state*
SIC5	Ca4CaM	1 x 10−2 µM	10 $\frac{\mu m^2}{s}$	Est. from steady state*
SIC6	R2	0.04 µM	10 $\frac{\mu m^2}{s}$	Est. from steady state*
SIC7	R2C2	0.2 µM	10 $\frac{\mu m^2}{s}$	Est. from steady state*
SIC8	PKA	0.05 µM	0.01 $\frac{\mu m^2}{s}$	Est. from steady state, diffusion fitted
SIC9	PDE1	0.9 µM	10 $\frac{\mu m^2}{s}$	Est. from steady state*
SIC10	PDE1act	1 x 10−3 µM	10 $\frac{\mu m^2}{s}$	Est. from steady state*
SIC11	CaMPDE1	1 x 10−3 µM	10 $\frac{\mu m^2}{s}$	Est. from steady state*
SIC12	AC	4 x 10−10 $\frac{mol}{m^2}$	0	Est.
SIC13	CaMAC	0 $\frac{mol}{m^2}$	0	Est.
SIC14	ACact	0 $\frac{mol}{m^2}$	0	Est.
SIC15	ACind	4 x 10−10 $\frac{mol}{m^2}$	1 $\frac{\mu m^2}{s}$	Est.†
SIC16	V	−60 mV	1 $\frac{\mu m^2}{s}$	Fridlyand et al., 2003; Ni et al., 2011†
SIC17	cAMP	4 x 10−6 µM	60 $\frac{\mu m^2}{s}$	Agarwal et al., 2016, Est. from steady state

*For all cytosolic species without well-constrained diffusions, we used 10 $\frac{\mu m^2}{s}$.

^†For all membrane species without well-constrained diffusions we used 1 $\frac{\mu m^2}{s}$.