Deforming biological membranes: how the cytoskeleton affects a polymerizing fiber.
We give a theoretical treatment of the force exerted by a fluctuating membrane on a polymer rod tip, taking into account the effects of an underlying biological cytoskeleton by way of a simple harmonic dependence on displacement. We also consider theoretically and experimentally the dynamics of a growing fiber tip under the influence of such a fluctuation-induced membrane force, including the effects of an underlying cytoskeletal network. We compare our model with new experimental data for the growth of hemoglobin fibers within red blood cells, revealing a good agreement. We are also able to estimate the force and membrane/cytoskeletal displacement required to stall growth of, or buckle, a growing fiber. We discuss the significance of our results in a biological context, including how the properties of the membrane and cytoskeleton relate to the thermodynamics of rod polymerization.
Daniels
D R
DR
Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom. d.r.daniels@warwick.ac.uk
Wang
J C
JC
Briehl
R W
RW
Turner
M S
MS
D001703:Biophysics / Q000379:methods*; D002462:Cell Membrane; D002627:Chemistry, Physical / Q000379:methods*; D003599:Cytoskeleton / Q000737:chemistry / Q000378:metabolism*; D004910:Erythrocyte Membrane / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D006454:Hemoglobins / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D008560:Membrane Fluidity; D015233:Models, Statistical; D011108:Polymers / Q000737:chemistry*; D013816:Thermodynamics; D013997:Time Factors
D006454:Hemoglobins; D011108:Polymers