Bulletin of the American Physical Society
2007 APS March Meeting
Volume 52, Number 1
Monday–Friday, March 5–9, 2007; Denver, Colorado
Session X5: Elasticity of Biological Membranes: From Physical Principles to Biological Processes |
Hide Abstracts |
Sponsoring Units: DBP Chair: Ranjan Mukhopadhyay, Clark University Room: Colorado Convention Center Korbel 1A-1B |
Friday, March 9, 2007 8:00AM - 8:36AM |
X5.00001: Biophysical studies of biological membranes Invited Speaker: |
Friday, March 9, 2007 8:36AM - 9:12AM |
X5.00002: The Beginning of the Ends: A Curvature-Mediated Mechanism for Localization of Lipids to Bacterial Poles Invited Speaker: In the past decade, intracellular fluorescence microscopy has fashioned a new appreciation for the diversity of ways in which proteins organize and segregate on bacterial membranes. Though some targeting anchors are known, cellular symmetry breaking ultimately requires molecular components that self-organize. We propose a novel equilibrium mechanism, based on the two-dimensional curvature of the membrane, for spontaneous lipid targeting to the poles and division site of rod-shaped bacterial cells. If one of the membrane components has a large intrinsic curvature, the geometrical constraint of the plasma membrane by the more rigid bacterial cell wall counteracts the attractive interaction between like lipids and leads to microphase separation. We find that the resulting clusters of high-curvature lipids are large enough to spontaneously and stably localize to the two cell poles and septal regions, and could have similar utility to lipid rafts as a stage for targeting proteins involved in a wide variety of biological processes. Recent evidence of localization of the phospholipid cardiolipin to the poles of bacterial cells suggests that protein targeting may depend on the membrane's heterogeneous lipid content. More generally, aggregates of lipids, proteins, and lipid-protein complexes may localize in response to features of cell geometry incapable of localizing individual molecules. [Preview Abstract] |
Friday, March 9, 2007 9:12AM - 9:48AM |
X5.00003: Fundamental physical mechanisms of membrane phase separation Invited Speaker: |
Friday, March 9, 2007 9:48AM - 10:24AM |
X5.00004: Membrane mechanics of nuclear division in yeast Invited Speaker: |
Friday, March 9, 2007 10:24AM - 11:00AM |
X5.00005: Fusion, Fission, and Membrane Microdomains Invited Speaker: In biology, curvature of intracellular membranes plays a key role in defining compartments to organize the interior of a cell and in creating the optimal shapes of organelles for function. We have studied how membrane curvature plays a crucial role in determining the energetics of membrane fusion in a number of systems. How the proteins that catalyze membrane fusion in cellular secretion and in viral fusion will be discussed in detail. Newer work on the role of proteins in the budding of viruses during assembly will be presented. The assembly of viruses also requires a concentration of viral protein components in the membrane. Recent experiments on cells expressing the influenza hemagglutinin show a clustering of proteins at many length scales. The dependence on cell cholesterol of this clustering (microdomain formation) will also be discussed. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700