Fluorescence STED nanoscopy reveals insights of lipid interactions with the nicotinic acetylcholine receptor

C. EGGELING; D. MACHADO ANDRADE; H. TA; V. MUELLER; BORRONI M.V.; BARRANTES, F.J.

Buenos Aires

Conferencia; Synapses and dendritic spines in health and disease; 2012

International Society for Neurochemistry

Lipid-protein interactions are considered to play a functional role in a whole range of membrane-associated processes. However, their direct and non-invasive observation in living cells is impeded by the resolution limit of >200 nm of a conventional far-field optical microscope. With the superior spatial resolution of STED nanoscopy with effective focal spot sizes down to 20?30 nm in living cells, it is now possible to directly resolve such interactions [1]. The combination of STED nanoscopy with tools such as fluorescence correlation spectroscopy (FCS) allows the disclosure of complex nanoscopic dynamic processes. By performing FCS measurements in focal spots tuned to a diameter of down to 30 nm, we have obtained new details of molecular membrane dynamics [1]. Unlike fluorescent phosphoglycerolipids, both fluorescent sphingolipids and certain proteins, including the nicotinic acetylcholine receptor, are transiently (~10 ms) trapped in cholesterol-mediated molecular complexes of nanoscale dimensions. These interactions are distinct for different lipids and proteins and may play an important role in cellular functionality [2]. Here we use STED-FCS to gain new insights into the interaction of certain phosphoglycerolipids with the nicotinic acetylcholine receptor in the plasma membrane of living cells. References [1] C Eggeling Nature (2009), 457, 1159; C Ringemann? New J Physics (2009) 11, 103054. [2] V Mueller? Biophys J (2011) 101, 1651.