Modeling of a chromosomal "One-Shot" polymer motor

Blerta Shtylla
Mathematical Biosciences Institute, The Ohio State University

(October 20, 2011 10:30 AM - 11:30 AM)

Modeling of a chromosomal "One-Shot" polymer motor

Abstract

The cytoskeleton of dividing cells is highly dynamic with microtubules stochastically transitioning between states of growth and shortening. In this dynamic environment "primitive" polymeric machines can generate force. In eukaryotic cells, chromosomes move to the cell equator by attaching to multiple dynamic microtubules. Attachment is mediated by complex multi-protein scaffolds called kinetochores. In this talk, we present a mathematical model for force generation at the microtubule/kinetochore interface in eukaryotic cells. Movement is modeled using a jump-diffusion process that incorporates both biased diffusion due to microtubule lattice binding by kinetochore elements as well as thermal ratchet forces due to microtubule polymerization against the kinetochore plate. A key result is that kinetochore motors obey nonlinear force-velocity relations. Finally, time permitting, we extend our modeling to explore how polymeric assemblies might facilitate the motility of the circular chromosome of Caulobacter Crescentus.