(584v) Modeling Motor-Assisted Intracellular Cargo Transport

Modeling Motor-Assisted Intracellular
Cargo Transport

Michael
Loewenberg, Jennifer Pascal, Arnaud Chauviere, Vittorio
Cristini

Yale University,
New Haven, CT, USA

University of
New Mexico, Albuquerque, NM, USA

Intracellular
transport of cargo, including macromolecules, vesicles and organelles, through
the attachment to microtubules via molecular motors, such as kinesin and dynein, is a complex process that plays a
significant role in cellular function. 
Here, we present an analysis and experimental validation of the unidirectional
traffic-type partial differential equations that describe motor-assisted
intracellular cargo transport (Smith and Simmons 2001). A new analytical
solution is obtained for the case of a single type of molecular motor.  The solution exhibits wave-like
hyperbolic behavior at short times and a convective/diffusive behavior at
longer times.  The long-time
behavior is characterized by two parameters: the mean velocity of the cargo and
a dispersion coefficient that results from the saltatory
mechanism by which cargo binds and unbinds from the motors. The solution and
thus the traffic-type model is tested using stochastic sampling of nanoparticle
trajectories in the squid giant axon (doi 10.1088/1478-3975/9/5/055005). 
We present a generalized analysis of motor-assisted cargo transport for an
arbitrary number of motors, providing numerical results and analytical formulas
that describe the long-time evolution of the system.