Table 1. Parameter estimates relevant to (i) actin dynamics; (ii) Rho-proteins; (iii) phosphoinositide dynamics; and (iv) cell surface mechanics, with sources from which they were obtained.

Parameter	Definition	Value	Source
	-dependent Arp2/3 activation rate		[25]
	Hill coeff. of -mediated Arp2/3 activation		[25]
	Threshold conc. of for Arp2/3 activation		[25]
	Arp2/3 decay rate		[36]
	Arp2/3 diffusion coefficient		[93]
	Arp2/3 nucleation rate		[36]
	saturation constant for Arp2/3 nucleation		[36]
	scale factor (converts units of to conc.)		[36]
	scale factor (converts conc. to units of )		[36]
	actin filament growth rate (free polymerization)		[94], [95]
	actin filament turnover rate		[88], [96]
	barbed end capping rate		[95], [97]
	max reduction of capping by		[25]
	reduction in capping rate near leading edge		[36]
	total levels of Cdc42, Rac, Rho		[36], [91], [98]
	Cdc42, Rac, Rho activation input rates		[36], [91]
	Rho level for half-max inhibition of Cdc42		[36]
	Cdc42 level for half-max inhibition of Rho		[36]
	Hill coeff. of Cdc42-Rho mutual inhibition		[36]
	Cdc42-dependent Rac activation rate		[36]
	Rac-dependent Rho activation rate		[36]
	decay rates of activated Rho-proteins		[99], [100]
	diffusion coeff. of active, inactive Rho-proteins		[62], [101]
	typical basal levels of active Cdc42, Rac, Rho		[36]
	input rate		[92]
	PIP decay rate		[92]
	to baseline conversion rate (by PI5K)		[92]
	to conversion rate		[92]
	to baseline conversion rate (by PI3K)		[92]
	to baseline conversion rate (by PTEN)		[92]
	PI diffusion rate		[101], [102]
	typical basal levels of , ,		[70], [103]
	coupling energy per boundary site		[36]
	cell inelasticity		[36]
	target area of the cell		[36]
	membrane inelasticity		––
	target perimeter of the cell		––
	membrane yield		[36]
	simulation “temperature”		[36]
	effect of Rho on contraction		[36]
	Rho contraction threshold		[36]

Note citations of our earlier works (i.e. [25], [36], [91]–[93]), where many detailed derivations, explanations, and references can be found.