Intra-cellular transport by single-headed kinesin KIF1A: effects of single-motor mechano-chemistry and steric interactions

Abstract

In eukaryotic cells, many motor proteins can move simultaneously on a single microtubule track. This leads to interesting collective phenomena like jamming. Recently we reported ({\it Phys. Rev. Lett. {\bf 95}, 118101 (2005)}) a lattice-gas model which describes traffic of unconventional (single-headed) kinesins KIF1A. Here we generalize this model, introducing a novel interaction parameter $c$, to account for an interesting mechano-chemical process which has not been considered in any earlier model. We have been able to extract all the parameters of the model, except $c$, from experimentally measured quantities. In contrast to earlier models of intra-cellular molecular motor traffic, our model assigns distinct ``chemical'' (or, conformational) states to each kinesin to account for the hydrolysis of ATP, the chemical fuel of the motor. Our model makes experimentally testable theoretical predictions. We determine the phase diagram of the model in planes spanned by experimentally controllable parameters, namely, the concentrations of kinesins and ATP. Furthermore, the phase-separated regime is studied in some detail using analytical methods and simulations to determine e.g. the position of shocks. Comparison of our theoretical predictions with experimental results is expected to elucidate the nature of the mechano-chemical process captured by the parameter $c$.

17 pages including 14 embedded EPS figures; accepted for publication in Physical Review E

References in corpus (2)

• Phase Coexistence in Driven One Dimensional Transport
• The Totally Asymmetric Simple Exclusion Process with Langmuir Kinetics

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• Single-Bottleneck Approximation for Driven Lattice Gases with Disorder and Open Boundary Conditions
• Phase diagram of two-lane driven diffusive systems
• Molecular Spiders with Memory
• Traffic of single-headed motor proteins KIF1A: effects of lane changing
• Disordered driven lattice gases with boundary reservoirs and Langmuir kinetics
• Molecular Spiders in One Dimension
• Interaction of molecular motors can enhance their efficiency
• Intra-cellular traffic: bio-molecular motors on filamentary tracks
• Stochastic kinetics of a single headed motor protein: dwell time distribution of KIF1A
• Molecular motors: design, mechanism and control