Actin Cross-Linkers and the Shape of Stereocilia

作者:Lenz Martin*; Prost Jacques; Joanny Jean Francois
来源:Biophysical Journal, 2010, 99(8): 2423-2433.
DOI:10.1016/j.bpj.2010.07.065

摘要

Stereocilia are actin-based cellular protrusions essential for hearing. We propose that they are shaped by the detachment dynamics of actin cross-linkers, in particular espin. We account for experimentally observed stereocilium shapes, treadmilling velocity to length relationship, espin 1 localization profile, and microvillus length to espin level relationship. If the cross-linkers are allowed to reattach, our model yields a dynamical phase transition toward unbounded growth. Considering the simplified case of a noninteracting, one-filament system, we calculate the length probability distribution in the growing phase and its stationary form in a continuum approximation of the finite-length phase. Numerical simulations of interacting filaments suggest an anomalous power-law divergence of the protrusion length at the growth transition, which could be a universal feature of cross-linked depolymerizing systems.

  • 出版日期2010-10-20