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BP: Fachverband Biologische Physik
BP 4: Statistical Physics of Biological Systems II (joint BP, DY)
BP 4.8: Vortrag
Montag, 22. März 2010, 16:15–16:30, H45
Long-range protein coupling mediated by critical low-energy modes of tubular lipid membranes — Sylvain Monnier1,3, Sergei B. Rochal2, •Andrea Parmeggiani3, and Vladimir L. Lorman1 — 1LPTA, CNRS, University of Montpellier II, 34095 Montpellier, France — 2Physical Department, South Federal University, 344090 Rostov-on-Don, Russia — 3DIMNP, CNRS, University of Montpellier II, 34095 Montpellier, France
Tubular lipid membranes (TLMs) are nanoscopic cylindrical assemblies that play a fundamental role in many intracellular and intercellular processes like protein trafficking, signaling and organelle morphogenesis. TLMs can be generated by a sum of mechano-chemical actions, ranging from mechanical forces produced by motor proteins pulling at one TLM-end up to the specific chemical activity of membrane proteins.
We develop a theory of TLM instabilities under longitudinal force and pressure difference constraints. Two qualitatively different critical low-energy modes are shown to define the stability domain boundaries. The analysis allows to introduce a new framework describing TLM-protein coupling, adsorbed protein-protein interaction and protein cluster nucleation on a TLM. In particular, bare TLM mechanical instabilities strongly influence protein-TLM coupling and protein desorption from the TLM. Model predictions can be directly tested in experiments involving nanomechanical devices extracting TLM over a large spectrum of mechanochemical conditions.