Susquehanna Valley Section

April 2009 Meeting

The three hundred and seventy-sixth meeting of the Susquehanna Valley Local Section will be held on Wednesday, 8 April 2009 at Susquehanna University in Selinsgrove, PA. The meeting begins at 7:30 p.m. and will be held in Fisher Science Hall room 316. The meeting will be preceded by a dinner at BJ's Steak & Rib House. The guest speaker, Dr. Erin Sheets (from the Department of Chemistry at Penn State University), will deliver a presentation entitled "Life as a lipid: rafts, dynamics & interactions".

Directions: see below.

Reception and Dinner: 5:30 p.m., at BJ's Steak & Rib House. Ordering will be from the menu. If you are interested in attending the dinner please RSVP to Geneive Henry at henry@susqu.edu or 570-372-4222 by 4:00 p.m. on Monday, 6 April 2008.

Meeting and Presentation: 7:30 p.m. in 316 Fisher Science Hall. Brief Local Section announcements will be followed by our guest presentation.

Life as a lipid: rafts, dynamics and interactions

The molecular ordering of the lipids within a biomembrane can profoundly change the local biophysical properties, such as lateral and rotational diffusion, permeability, and fluidity, and these properties, in turn, may affect protein or enzyme activity, transient compartmentalization, and trafficking of vesicular compartments. We are studying various aspects of these properties in living cells and biomimetic membranes using quantitative fluorescence microscopy and spectroscopy. Specialized nanodomains (or "rafts") within the plasma membranes of mast cells (immune cells) have been implicated in facilitating the allergic response; however they have not yet been observed directly in living cells. We have developed a quantitative optical approach toward the elusive goal of visualizing the spatial and temporal dynamics of these nanodomains with specific signaling molecules. By exploiting the nanoscale sensitivity of fluorescence lifetime and fluorescence polarization anisotropy, we can probe membrane nanodomain dynamics below optical resolution. This experimental approach should be directly applicable to any signaling pathway that may be dependent upon local membrane ordering. We are also investigating the role of proteins (annexin) in inducing local structural changes within the membrane. Finally we are studying the dynamics of vesicles diffusing close to biomimetic membranes as a model for endo- and exocytosis using fluorescence correlation spectroscopy.

Dr. Erin Sheets received her BA in Chemistry from Juniata College in Huntingdon PA. She then went to the University of North Carolina at Chapel Hill where she learned about membrane biophysics and cell biology, and fluorescence microscopy from Nancy Thompson and Ken Jacobson. For her doctoral research, Erin used single particle tracking to follow the dynamics of lipid-anchored proteins and glycolipids in the plasma membranes of living cells. After she received her PhD in Chemistry in 1997, Erin moved to Cornell University to work on immunoreceptor signaling and cholesterol-rich membrane domains with Barbara Baird and David Holowka. She has been at the Department of Chemistry at Penn State University since 2002, where she has built a multidisciplinary research program that is directed toward understanding the molecular interactions and dynamics occurring both within and between biomembranes both in vivo and in vitro. In 2006, she was awarded the Young Alumni Achievement Award from Juniata College for her work in membrane biophysics.

Directions to the University:

From Route I-80 West: Take the Danville exit, 224. Take route 54 east to route 11 south towards Selinsgrove. Continue left on route 11/15 south (continue as directed below from route 11/15).
From Route I-80 East: Take the Lewisburg exit, 210A. Take route 15 south towards Selinsgrove. Turn right onto route 11/15 south(continue as directed below from route 11/15).

Route 11/15 south becomes Market Street. Turn right onto W. Pine Street. West Pine Street becomes University Avenue. Follow the campus map to visitor parking.

View directions and a campus map.

Directions to BJ's Steak & Rib House: visit the map page to help find your way to 17 North Market Street Selinsgrove, Pennsylania.