title: A mathematical model of actin filament turnover for fitting FRAP data.
abstract: A novel mathematical model of the actin dynamics in living cells under steady-state conditions has been developed for fluorescence recovery after photobleaching (FRAP) experiments. As opposed to other FRAP fitting models, which use the average lifetime of actins in filaments and the actin turnover rate as fitting parameters, our model operates with unbiased actin association/dissociation rate constants and accounts for the filament length. The mathematical formalism is based on a system of stochastic differential equations. The derived equations were validated on synthetic theoretical data generated by a stochastic simulation algorithm adapted for the simulation of FRAP experiments. Consistent with experimental findings, the results of this work showed that (1) fluorescence recovery is a function of the average filament length, (2) the F-actin turnover and the FRAP are accelerated in the presence of actin nucleating proteins, (3) the FRAP curves may exhibit both a linear and non-linear behaviour depending on the parameters of actin polymerisation, and (4) our model resulted in more accurate parameter estimations of actin dynamics as compared with other FRAP fitting models. Additionally, we provide a computational tool that integrates the model and that can be used for interpretation of FRAP data on actin cytoskeleton.
authors.affiliation: Cytoskeleton and Cell Plasticity Laboratory, Life Sciences Research Unit, Faculty of Science, Technology and Communication, University of Luxembourg, Campus Limpertsberg, Luxembourg 1511, Luxembourg.
authors.forename: Aliaksandr A
authors.initials: AA
authors.lastname: Halavatyi
authors.forename: Petr V
authors.initials: PV
authors.lastname: Nazarov
authors.forename: Ziad
authors.initials: Z
authors.lastname: Al Tanoury
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Apanasovich
authors.forename: Mikalai
authors.initials: M
authors.lastname: Yatskou
authors.forename: Evelyne
authors.initials: E
authors.lastname: Friederich
mesh_terms: D008841:Actin Cytoskeleton / Q000737:chemistry* / Q000378:metabolism; D004058:Diffusion; D036681:Fluorescence Recovery After Photobleaching; D007700:Kinetics; D016014:Linear Models; D008954:Models, Biological; D017711:Nonlinear Dynamics; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary