Wednesday Colloquium: Dr. Sarah Veatch, University of Michigan, Ann Arbor  Add To Calendar

  • Date(s): Wednesday, 4/29 3:00 PM to Wednesday, 4/29 4:00 PM
  • Speaker: Dr. Sarah Veatch
  • Host: Ursula Perez-Salas
  • Campus Address: 138 SES (Science and Engineering South)

Title: Phases and fluctuations in biological membranes
Abstract: The thermodynamic properties of plasma membrane lipids play a vital role in many functions that initiate at the mammalian cell surface.  Some functions are thought to occur, at least in part, because plasma membrane lipids have a tendency to separate into two distinct liquid phases. We propose that these lipid mediated functions occur because plasma membrane composition is tuned close to a miscibility critical point at physiological temperature.  This hypothesis is supported by our observations of micron-sized and dynamic critical composition fluctuations in isolated plasma membranes near room temperature.  In this talk, I will discuss our ongoing efforts to probe for the existence and consequences of criticality in the plasma membranes of intact cells.  These recent efforts include using quantitative super-resolution fluorescence localization microscopy to monitor the organization of plasma membrane proteins in B cell lymphocytes, both in resting cells and in cells stimulated with multivalent antigen against the B cell receptor.  We also have identified a range of membrane perturbations, including n-alcohols, which alter both the magnitude of fluctuations in isolated vesicles.  These perturbations of membrane structure are also well characterized general anesthetics, and I will present some preliminary evidence suggesting that some aspects of anesthetic function can be attributed to lipid heterogeneity.

Colloq flyer 4-29 Veatch