TY - JOUR
T1 - Analysis of molecular diffusion by first-passage time variance identifies the size of confinement zones
AU - Rajani, Vishaal
AU - Carrero, Gustavo
AU - Golan, David E.
AU - De Vries, Gerda
AU - Cairo, Christopher W.
N1 - Funding Information:
V.R. acknowledges support through a fellowship from the Pacific Institute for the Mathematical Sciences International Graduate Training Centre and a Natural Sciences and Engineering Research Council of Canada Alexander Graham Bell Canada Graduate Scholarship. G.C. acknowledges support from the Athabasca University Research Incentive Grant (AU- RIG). D.E.G. acknowledges support by the National Institutes of Health (grant R01-HL32854). The authors acknowledge funding from the Natural Sciences and Engineering Research Council of Canada Discovery grants (GdeV, C.W.C.). C.W.C. acknowledges support from the Alberta Ingenuity Centre for Carbohydrate Science.
PY - 2011/3/16
Y1 - 2011/3/16
N2 - The diffusion of receptors within the two-dimensional environment of the plasma membrane is a complex process. Although certain components diffuse according to a random walk model (Brownian diffusion), an overwhelming body of work has found that membrane diffusion is nonideal (anomalous diffusion). One of the most powerful methods for studying membrane diffusion is single particle tracking (SPT), which records the trajectory of a label attached to a membrane component of interest. One of the outstanding problems in SPT is the analysis of data to identify the presence of heterogeneity. We have adapted a firstpassage time (FPT) algorithm, originally developed for the interpretation of animal movement, for the analysis of SPT data. We discuss the general application of the FPT analysis to molecular diffusion, and use simulations to test the method against data containing known regions of confinement. We conclude that FPT can be used to identify the presence and size of confinement within trajectories of the receptor LFA-1, and these results are consistent with previous reports on the size of LFA-1 clusters. The analysis of trajectory data for cell surface receptors by FPT provides a robust method to determine the presence and size of confined regions of diffusion.
AB - The diffusion of receptors within the two-dimensional environment of the plasma membrane is a complex process. Although certain components diffuse according to a random walk model (Brownian diffusion), an overwhelming body of work has found that membrane diffusion is nonideal (anomalous diffusion). One of the most powerful methods for studying membrane diffusion is single particle tracking (SPT), which records the trajectory of a label attached to a membrane component of interest. One of the outstanding problems in SPT is the analysis of data to identify the presence of heterogeneity. We have adapted a firstpassage time (FPT) algorithm, originally developed for the interpretation of animal movement, for the analysis of SPT data. We discuss the general application of the FPT analysis to molecular diffusion, and use simulations to test the method against data containing known regions of confinement. We conclude that FPT can be used to identify the presence and size of confinement within trajectories of the receptor LFA-1, and these results are consistent with previous reports on the size of LFA-1 clusters. The analysis of trajectory data for cell surface receptors by FPT provides a robust method to determine the presence and size of confined regions of diffusion.
UR - http://www.scopus.com/inward/record.url?scp=79953862262&partnerID=8YFLogxK
U2 - 10.1016/j.bpj.2011.01.064
DO - 10.1016/j.bpj.2011.01.064
M3 - Journal Article
AN - SCOPUS:79953862262
SN - 0006-3495
VL - 100
SP - 1463
EP - 1472
JO - Biophysical Journal
JF - Biophysical Journal
IS - 6
ER -