HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 282, Issue 46, 33537-33544, November 16, 2007

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 282/46/33537    most recent M706162200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by García-Sáez, A. J. Articles by Schwille, P. Search for Related Content PubMed PubMed Citation Articles by García-Sáez, A. J. Articles by Schwille, P. Social Bookmarking                      What's this?

Effect of Line Tension on the Lateral Organization of Lipid Membranes^*

From the Biotechnologisches Zentrum der Techische Universität Dresden, 1307 Dresden, Germany

The principles of organization and functioning of cellular membranes are currently not well understood. The raft hypothesis suggests the existence of domains or rafts in cell membranes, which behave as protein and lipid platforms. They have a functional role in important cellular processes, like protein sorting or cell signaling, among others. Theoretical work suggests that the interfacial energy at the domain edge, also known as line tension, is a key parameter determining the distribution of domain sizes, but there is little evidence of how line tension affects membrane organization. We have investigated the effects of the line tension on the formation and stability of liquid ordered domains in model lipid bilayers with raft-like composition by means of time-lapse confocal microscopy coupled to atomic force microscopy. We varied the hydrophobic mismatch between the two phases, and consequently the line tension, by modifying the thickness of the disordered phase with phosphatidylcholines of different acyl chain length. The temperature of domain formation, the dynamics of domain growth, and the distribution of domain sizes depend strongly on the thickness difference between the domains and the surrounding membrane, which is related to line tension. When considering line tension calculated from a theoretical model, our results revealed a linear increase of the temperature of domain formation and domain growth rate with line tension. Domain budding was also shown to depend on height mismatch. Our experiments contribute significantly to our knowledge of the physical-chemical parameters that control membrane organization. Importantly, the general trends observed can be extended to cellular membranes.

Received for publication, July 26, 2007 , and in revised form, September 6, 2007.

^* This work was supported by a Marie Curie Intra-European Fellowship (to A. J. G. S.) within the sixth European Framework Program and Europäischen Fonds für regional Entwicklung (EFRE) Grant 4212/0402. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The on-line version of this article (available at http://www.jbc.org) contains supplemental data.

¹ To whom correspondence should be addressed: Tatzberg 47-51, 1307 Dresden, Germany. Tel.: 49-351-4634-0328; Fax: 49-351-4634-0342; E-mail: petra.schwille{at}biotec.tu-dresden.de.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				K. K. Halling, B. Ramstedt, J. H. Nystrom, J. P. Slotte, and T. K. M. Nyholm Cholesterol Interactions with Fluid-Phase Phospholipids: Effect on the Lateral Organization of the Bilayer Biophys. J., October 15, 2008; 95(8): 3861 - 3871. [Abstract] [Full Text] [PDF]

				P. Schon, A. J. Garcia-Saez, P. Malovrh, K. Bacia, G. Anderluh, and P. Schwille Equinatoxin II Permeabilizing Activity Depends on the Presence of Sphingomyelin and Lipid Phase Coexistence Biophys. J., July 15, 2008; 95(2): 691 - 698. [Abstract] [Full Text] [PDF]

				A. R. Honerkamp-Smith, P. Cicuta, M. D. Collins, S. L. Veatch, M. den Nijs, M. Schick, and S. L. Keller Line Tensions, Correlation Lengths, and Critical Exponents in Lipid Membranes Near Critical Points Biophys. J., July 1, 2008; 95(1): 236 - 246. [Abstract] [Full Text] [PDF]