TY - JOUR
T1 - Kinetic overshoot in actin network assembly induced jointly by branching and capping proteins
AU - Kang, Hyeran
AU - Carlsson, Anders E.
AU - Tang, Jay X.
PY - 2009/10/9
Y1 - 2009/10/9
N2 - We report an experimental study of the kinetics of actin assembly mediated by branching and capping proteins. Our findings confirm the recent prediction of a "branching explosion" occurring during polymerization. Fluorescence imaging shows a number of actin filaments with branches within a few minutes of polymerization, induced by the activated branching protein complex Arp2/3, but the number of visible branches decreases over time. The light-scattering intensity displays an overshoot as a function of time, which we attribute to the formation of highly branched clusters early in polymerization. Furthermore, the overshoot occurs over a limited range of the ratio of concentrations of branching and capping proteins, also consistent with the theoretical model. These results establish a natural link between the kinetic theory of actin assembly in vitro and the cytoskeletal structure and actin dynamics in motile cells.
AB - We report an experimental study of the kinetics of actin assembly mediated by branching and capping proteins. Our findings confirm the recent prediction of a "branching explosion" occurring during polymerization. Fluorescence imaging shows a number of actin filaments with branches within a few minutes of polymerization, induced by the activated branching protein complex Arp2/3, but the number of visible branches decreases over time. The light-scattering intensity displays an overshoot as a function of time, which we attribute to the formation of highly branched clusters early in polymerization. Furthermore, the overshoot occurs over a limited range of the ratio of concentrations of branching and capping proteins, also consistent with the theoretical model. These results establish a natural link between the kinetic theory of actin assembly in vitro and the cytoskeletal structure and actin dynamics in motile cells.
UR - http://www.scopus.com/inward/record.url?scp=70350150510&partnerID=8YFLogxK
U2 - 10.1103/PhysRevE.80.041913
DO - 10.1103/PhysRevE.80.041913
M3 - Article
AN - SCOPUS:70350150510
SN - 1539-3755
VL - 80
JO - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics
JF - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics
IS - 4
M1 - 041913
ER -