The Mechanochemistry of Endocytosis (original) (raw)
Figure 3
Fitting of the results calculated from the model to experimental results.
(A) Timelines of functional modules during endocytosis in budding yeast (continuous lines represent calculated values, and the discontinuous lines are experimental measurements—same as Figure 1A—with standard deviation). In the model, the instantaneous total levels for the individual modules (except for actin) at the endocytic site were obtained by summing their local levels over their respective locations on the membrane surface. The instantaneous total level of actin was obtained by summing over the entire bud region the product of the local actin level and its distance from cell cortex (proportional to the length of the actin filaments). To obtain the intensity plot for each of the modules, we normalized the curve for its total levels over time in accordance to its respective peak value. We then scaled the resulting curve by setting its peak value to be the same as that of the peak intensity measured experimentally. We thus can compare the computed time-lapse curve for each module to those from experimental observations. (B) Calculated endocytic membrane shape changes. The calculation of membrane shape was carried out in 3-D. Membrane shape is shown in 2-D for clarity. The parameters in the model used for curve fitting are listed in Table 1 in Protocol S1. If not stated otherwise, the parameters are fixed throughout this paper.