Stochastic simulation of actin dynamics reveals the role of annealing and fragmentation

Joseph Fass, Chi Pak, James Bamburg, Alex Mogilner

Research output: Contribution to journalArticle

Abstract

Recent observations of F-actin dynamics call for theoretical models to interpret and understand the quantitative data. A number of existing models rely on simplifications and do not take into account F-actin fragmentation and annealing. We use Gillespie's algorithm for stochastic simulations of the F-actin dynamics including fragmentation and annealing. The simulations vividly illustrate that fragmentation and annealing have little influence on the shape of the polymerization curve and on nucleotide profiles within filaments but drastically affect the F-actin length distribution, making it exponential. We find that recent surprising measurements of high length diffusivity at the critical concentration cannot be explained by fragmentation and annealing events unless both fragmentation rates and frequency of undetected fragmentation and annealing events are greater than previously thought. The simulations compare well with experimentally measured actin polymerization data and lend additional support to a number of existing theoretical models.

Original languageEnglish (US)
Pages (from-to)173-183
Number of pages11
JournalJournal of Theoretical Biology
Volume252
Issue number1
DOIs
StatePublished - May 7 2008

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Keywords

  • Cytoskeleton
  • Monte Carlo simulations
  • Polymer length

ASJC Scopus subject areas

  • Statistics and Probability
  • Modeling and Simulation
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)
  • Agricultural and Biological Sciences(all)
  • Applied Mathematics

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