Characterization and cooperative dynamics of kinesin motor proteins in intracellular transport
type: CreativeWork
description: Intracellular transport is typically carried out by teams of motor proteins rather than by isolated molecules, yet the rules governing multi-motor coordination remain poorly understood because motor number, spacing, and composition are difficult to control experimentally. In this dissertation, I developed both the molecular engineering and nanostructural framework needed to address this problem. I designed a modular plasmid toolkit for controlled kinesin expression and purification, and I created a novel DNA origami scaffold that allows motors to be positioned with defined stoichiometry and geometry on a rigid cargo-like platform. Together, these advances provided a programmable experimental system for dissecting how kinesin-1 ensembles and mixed kinesin-1/kinesin-14 assemblies behave under well-defined structural conditions.Using this platform, I found that motor valency strongly enhances attachment persistence and transport robustness, but that the magnitude and interpretation of this effect depend on nucleotide state and ensemble architecture. In weak-binding ADP conditions, increasing kinesin-1 copy number strongly stabilized microtubule association, revealing that additional motors provide a disproportionate rescue benefit in vulnerable binding regimes. In ATP, processivity increased with motor number while velocity changed comparatively little, but the motor-number dependence was more geometry- and preprocessing-sensitive, motivating statistical and modeling analysis. Direct mean-field modeling captured the ADP results reasonably well but proved fragile for ATP, whereas a microstate continuous-time Markov chain model with a global attachment scale regularized this instability and supported an ensemble-rescue interpretation. Finally, introducing antagonistic kinesin-14 reduced kinesin-1-driven transport and produced tunable mixed-motor behavior, showing that this engineered platform can reveal how motor copy number, geometry, and opposition collectively regulat…
abstract: Intracellular transport is typically carried out by teams of motor proteins rather than by isolated molecules, yet the rules governing multi-motor coordination remain poorly understood because motor number, spacing, and composition are difficult to control experimentally. In this dissertation, I developed both the molecular engineering and nanostructural framework needed to address this problem. I designed a modular plasmid toolkit for controlled kinesin expression and purification, and I created a novel DNA origami scaffold that allows motors to be positioned with defined stoichiometry and geometry on a rigid cargo-like platform. Together, these advances provided a programmable experimental system for dissecting how kinesin-1 ensembles and mixed kinesin-1/kinesin-14 assemblies behave under well-defined structural conditions.Using this platform, I found that motor valency strongly enhances attachment persistence and transport robustness, but that the magnitude and interpretation of this effect depend on nucleotide state and ensemble architecture. In weak-binding ADP conditions, increasing kinesin-1 copy number strongly stabilized microtubule association, revealing that additional motors provide a disproportionate rescue benefit in vulnerable binding regimes. In ATP, processivity increased with motor number while velocity changed comparatively little, but the motor-number dependence was more geometry- and preprocessing-sensitive, motivating statistical and modeling analysis. Direct mean-field modeling captured the ADP results reasonably well but proved fragile for ATP, whereas a microstate continuous-time Markov chain model with a global attachment scale regularized this instability and supported an ensemble-rescue interpretation. Finally, introducing antagonistic kinesin-14 reduced kinesin-1-driven transport and produced tunable mixed-motor behavior, showing that this engineered platform can reveal how motor copy number, geometry, and opposition collectively regulat…
author: Alizadeh, Vahid
language: eng
keywords: Bioengineering, Biophysics, Molecular biology, Cooperative motility, DNA origami, Kinesin, Plasmid cloning, Single molecule assay
license: http://rightsstatements.org/vocab/InC/1.0/
date published: 2026-05
date modified: 2026-07-27T21:22:02Z
provider: Temple University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Temple University. Libraries