Figure 7.

Speculative model for the role of mapmodulin in modulating MAP-microtubule interaction. Dynein-based vesicle translocation is inhibited by the presence of MAPs. By binding to the microtubule-binding domain of a MAP, mapmodulin may influence the association rate of MAPs onto microtubules, and thereby facilitate the translocation of motors and cargo. Such activity might also facilitate kinesin-driven motility. Mapmodulin is found both in soluble and membrane-bound forms. An attractive scenario would be that it is the membrane bound form that provides local MAP release in conjunction with organelle translocation.