Spatial Parameterization of Attachment Processes in Molecular Motor-Cargo Systems

Intracellular transport is conducted largely by molecular motor proteins which process along cytoskeletal filaments, from which they can attach or detach. We describe an analytical framework to characterize motor attachment or reattachment rates to microtubules as a function of the physical and geometric properties of the motor, the cargo to which it is attached, and possibly a second motor attached to the same cargo and a microtubule. The biophysical model is coarse-grained at the level of the macromolecular motors and formulated in terms of stochastic differential equations, allowing for rotation of the cargo and nonlinear force laws for the motor-cargo tether.