Uncorrelated changes of subunit stability can generate length-dependent disassembly of treadmilling filaments.
Unregulated polymer assembly typically leads to exponential length distributions. In living cells, though, the length distribution of cytoskeletal filaments often shows a sharp maximum at a finite value. We discuss a simple mechanism for length regulation that is based on generating an effectively length-dependent disassembly rate by locally acting cytoskeletal proteins. We analyze steady-state distributions by stochastic simulations and develop a method to analytically characterize the typical filament length. We find three different types of behavior: (1) unbounded filament growth, (2) exponential distributions and (3) unimodal distributions, which can be very sharp with a standard deviation much smaller than the mean filament length. We discuss possible implications of our results for subcellular processes.
Erlenkämper
C
C
Theoretische Physik, Universität des Saarlandes, Postfach 151150, 66041 Saarbrücken, Germany. cerly@lusi.uni-sb.de
Kruse
K
K
D003598:Cytoskeletal Proteins / Q000378:metabolism*; D003599:Cytoskeleton / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D013269:Stochastic Processes
D003598:Cytoskeletal Proteins