Membrane Shape Instability Induced by Protein Crowding.
Peripheral proteins can bend membranes through several different mechanisms, including scaffolding, wedging, oligomerization, and crowding. The crowding effect in particular has received considerable attention recently, in part because it is a colligative mechanism-implying that it could, in principle, be explored by any peripheral protein. Here we sought to clarify to what extent this mechanism is exploited by endocytic accessory proteins. We quantitatively investigate membrane curvature generation by means of a GUV shape stability assay. We found that the amount of crowding required to induce membrane curvature is correlated with membrane tension. Importantly, we also revealed that at the same membrane tension, the crowding mechanism requires far higher protein coverage to induce curvature changes compared to those observed for the endophilin BAR domain, serving here as an example of an endocytic accessory protein. Our results are important for the design of membrane-targeted biosensors as well as the understanding of mechanisms of biological membrane shaping.
Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania.
Zhiming
Z
Chen
Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Chemical Engineering, University of Pennsylvania, Philadelphia, Pennsylvania.
Ehsan
E
Atefi
Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania. Electronic address: baumgart@sas.upenn.edu.
Tobias
T
Baumgart
D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism*; D004705:Endocytosis; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D000072417:Protein Domains; D013314:Stress, Mechanical; D053835:Unilamellar Liposomes / Q000737:chemistry / Q000378:metabolism
D008565:Membrane Proteins; D053835:Unilamellar Liposomes