Cell Size at S Phase Initiation: An Emergent Property of the G1/S Network
Figure 9
Regulation of the Critical Cell Size PS Necessary To Undergo G1/S Transition
(A) Sensitivity analysis of PS. For each curve, an individual parameter has been varied from 0.1-fold to 10-fold. Black line: growth rate (kgrowth, k1, k2 concomitantly); black dashed line: initial concentration of Far1 (far1cyt[0]); gray dashed line: initial concentration of Cln3 (cln3cyt[0]); gray line: binding value of Sic1 to the Cdk1-Clb5,6 complex (k32).
(B) Simulation of the G1/S transition in elutriated cells indicates how the setting of PS is achieved. Cells start at a volume of 1 and grow with different kinetics in glucose (solid line) and ethanol (dotted line). Overcoming of the first and second threshold, as identified by simulation, is shown by circled symbols (gray, first threshold; black, second threshold).