Nicotinic acetylcholine receptor clusters localization on lipid domains of the plasmalemma

KAMERBEEK, C.B.; BORRONI, V.; PEDICONI, M.F.; BARRANTES, F.J.

Potrero de los Funes San Luis

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB); 2011

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

NICOTINIC ACETYLCHOLINE RECEPTOR CLUSTER LOCALIZATION ON LIPID DOMAINS OF THE PLASMALEMMA Kamerbeek CB; Borroni MV; Pediconi MF; Barrantes FJ Inst.of Biochem/UNESCO Chair Biophys. & Mol. Neurobiol., B. Blanca. E-mail: rtfjb1@criba.edu.ar In the present work we have attempted to establish whether there is a correlation between antibody-induced nicotinic acetylcholine receptor (AChR)-rich clusters and the physical state of the underlying cell membrane in living cells. For this purpose di-4-ANEPPDHQ, a fluorescent probe that differentiates liquid-ordered from liquid-disordered phases in model membranes was used in combination with labeling of the AChR in CHO-K1/A5, a clonal cell line expressing adult muscle-type AChR. The so-called generalized polarization (?GP?) of di-4-ANEPPDHQ was measured in regions of the cell-surface membrane associated with the AChR platforms clearly identified using conventional wide-field fluorescence microscopy. Under control conditions AChR clusters are roughly equally distributed among liquid-ordered and liquid-disordered domains. This distribution changes upon cyclodextrin-mediated cholesterol depletion or by Latrunculin disruption of the actin cytoskeleton. Association of AChR clusters with lipid domains with different biophysical properties may have consequences on AChR trafficking processes.