Figure 2.

Steady-state protein concentration profiles along the protrusion (a and b) or as a function of the protrusion height h (c). (a) Simple diffusion with a sink at the tip (dotted line) or without it (solid line). (b) Profile of minus-end-directed myosin-VI (solid line) and cargo proteins that are localized to the base by binding to myosin-VI (dotted line). (c) Examples of possible concentrations of tip-directed myosins and their cargoes at the protrusion tip.