Undulations, steric interaction and cohesion of fluid membranes

Helfrich, W.; Servuss, R.M.

doi:10.1007/bf02452208

Cited by 504 publications

(472 citation statements)

References 23 publications

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“…This observation indicates that each individual motor experiences a force about half stall force (Ϸ2-3 pN) (32). Such an increase in force may result from an increase in membrane tension, likely caused by membrane extraction from GUVs (34). A high initial tension of the purified Golgi membrane could explain why phase I is not observed in this system.…”

Section: Discussionmentioning

confidence: 86%

A minimal system allowing tubulation with molecular motors pulling on giant liposomes

Roux

Cappello

Cartaud

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

289

219

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The elucidation of physical and molecular mechanisms by which a membrane tube is generated from a membrane reservoir is central to the understanding of the structure and dynamics of intracellular organelles and of transport intermediates in eukaryotic cells. Compelling evidence exists that molecular motors of the dynein and kinesin families are involved in the tubulation of organelles. Here, we show that lipid giant unilamellar vesicles (GUVs), to which kinesin molecules have been attached by means of small polystyrene beads, give rise to membrane tubes and to complex tubular networks when incubated in vitro with microtubules and ATP. Similar tubes and networks are obtained with GUVs made of purified Golgi lipids, as well as with Golgi membranes. No tube formation was observed when kinesins were directly bound to the GUV membrane, suggesting that it is critical to distribute the load on both lipids and motors by means of beads. A kinetic analysis shows that network growth occurs in two phases: a phase in which membrane-bound beads move at the same velocity than free beads, followed by a phase in which the tube growth rate decreases and strongly fluctuates. Our work demonstrates that the action of motors bound to a lipid bilayer is sufficient to generate membrane tubes and opens the way to well controlled experiments aimed at the understanding of basic mechanisms in intracellular transport.

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Section: Discussionmentioning

confidence: 86%

A minimal system allowing tubulation with molecular motors pulling on giant liposomes

Roux

Cappello

Cartaud

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

289

219

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“…Therefore, in some sense, the membrane "feels" the presence of a surface or another membrane less and there is a corresponding decrease in entropic repulsion. This effect was looked at by Helfrich and Servuss [25], who, within a mean-field theory, found that the entropic repulsion, between two membranes, decayed exponentially in h 2 in the tension-dominated regime. Such a result has also been confirmed by Evans [26] via a self-consistent mean-field method.…”

Section: Weakly Adhering Membranesmentioning

confidence: 96%

The Influence of Substrate Structure on Membrane Adhesion

Swain

Andelman

1999

Langmuir

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We consider a membrane both weakly and strongly adhering to a geometrically structured substrate. The interaction potential is assumed to be local, via the Deryagin approximation, and harmonic. Consequently, we can analytically describe a variety of different geometries: as well as randomly rough self-affine surfaces, smooth substrates interrupted by an isolated cylindrical pit, a single elongated trench or a periodic array of trenches are investigated. We present more general expressions for the adhesion energy and membrane configuration in Fourier space and find that, compared to planar surfaces, the adhesion energy decreases. We also highlight the possibility of overshoots occurring in the membrane profile and look at its degree of penetration into surface indentations.

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“…where Γ is the membrane tension corresponding to a deformed state [28]. In this model, membrane tension increases/decreases in response to the unfolding/folding of the "undulations" (thermal fluctuations) on the membrane.…”

mentioning

confidence: 99%

“…Ka [28]. Here K a is the bulk elastic modulus of the membrane, and the first and second terms on the RHS denote contributions from entropic and elastic stretching, respectively.…”

mentioning

confidence: 99%