Dynamic balance between vesicle transport and microtubule growth enables neurite outgrowth
Fig 7
Redundancies among microtubule growth Level-3 sibling SCPs.
(A) Summary of the basic reaction for the simulation of MT growth. (See S1 Fig) for details. (B), (C), (D) & (E) Level-3 SCPs that define sub-functions of the Level-2 SCP Dynamic MT growth show complementary activities to allow NOG without violation of the model constraints. Multiple combinations of the SCP activities Tubulin Sequestration, GTP Hydrolysis and Nucleation of Dynamic MTs enable NOG with a given velocity. (B-C) The influence of the SCPs Tubulin Sequestration (which determines the effective tubulin concentration) and GTP Hydrolysis on the length distribution (B) and degradation rate (C) of the dynamic MTs were determined in a pre-simulation using a stochastic model for the simulation of single dynamic MT growth (Margolin et al). Colored lines refer to the selected GTP hydrolysis rates shown in (B) and (C) (pink: 0.72/sec, d) and (yellow: 0.675/sec, e). (D-E) Multiple combinations of dynamic MT nucleation rates and effective tubulin concentrations allow NOG under a given velocity for each GTP hydrolysis rate, as shown for the hydrolysis rate of 0.72/sec (d) and 0.675/sec (e). (F) Velocities in (D) and (E) were color coded as indicated.