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Rhodopsin is spatially heterogeneously distributed in rod outer segment disk membranes
Author(s) -
Buzhynskyy Nikolay,
Salesse Christian,
Scheuring Simon
Publication year - 2011
Publication title -
journal of molecular recognition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.401
H-Index - 79
eISSN - 1099-1352
pISSN - 0952-3499
DOI - 10.1002/jmr.1086
Subject(s) - rhodopsin , peripherin , biophysics , membrane , transducin , lipid bilayer , crystallography , biology , membrane protein , chemistry , retinal , biochemistry , gene
The visual photoreception takes place in the retina, where specialized rod and cone photoreceptor cells are located. The rod outer segments contain a stack of 500–2,000 sealed membrane disks. Rhodopsin is the visual pigment located in rod outer segment disks, it is a member of the G‐protein‐coupled receptor (GPCR) superfamily, an important group of membrane proteins responsible for the majority of physiological responses to stimuli such as light, hormones, peptides, etc. Alongside rhodopsin, peripherin/Rom proteins located in the disk rims are thought to be responsible for disk morphology. Here we describe the supramolecular structure of rod outer segment disk membranes and the spatial organization of rhodopsin and peripherin/Rom molecules. Using atomic force microscopy operated in physiological buffer solution, we found that rhodopsin is loosely packed in the central region of the disks, in average about 26 000 molecules covering approximately one third of the disk surface. Peripherin/Rom proteins form dense assemblies in the rim region. A protein‐free lipid bilayer girdle separates the rhodopsin and peripherin/Rom domains. The described supramolecular assembly of rhodospin, peripherin/Rom and lipids in native rod outer segment disks is consistent with the functional requirements of photoreception. Copyright © 2011 John Wiley & Sons, Ltd.