title: Rapid hop diffusion of a G-protein-coupled receptor in the plasma membrane as revealed by single-molecule techniques.
abstract: Diffusion of a G-protein coupled receptor, mu-opioid receptor (muOR), in the plasma membrane was tracked by single-fluorescent molecule video imaging and high-speed single-particle tracking. At variance with a previous publication, where gold-tagged muOR was found to be totally confined within a domain, which in turn underwent very slow diffusion itself, we found that muOR undergoes rapid hop diffusion over membrane compartments (210-nm and 730-nm nested double compartments in the case of normal rat kidney cell line), which are likely delimited by the actin-based membrane-skeleton "fence or corrals" and its associated transmembrane protein "pickets", at a rate comparable to that for transferrin receptor (every 45 and 760 ms on average, respectively), suggesting that the fence and picket models may also be applicable to G-protein coupled receptors. Further, we found that strong confinement of gold-labeled muOR could be induced by the prolonged on-ice preincubation of the gold probe with the cells, showing that this procedure should be avoided in future single-particle tracking experiments. Based on the dense, long trajectories of muOR obtained by high-speed single-particle tracking, the membrane compartments apposed and adjoined to each other could be defined that are delimited by rather straight boundaries, consistent with the involvement of actin filaments in membrane compartmentalization.
authors.affiliation: Kusumi Membrane Organizer Project, Exploratory Research for Advanced Technology Organization, Department of Biological Science and Institute for Advanced Research, Nagoya University, Nagoya 464-8602, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Suzuki
authors.forename: Ken
authors.initials: K
authors.lastname: Ritchie
authors.forename: Eriko
authors.initials: E
authors.lastname: Kajikawa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fujiwara
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kusumi
mesh_terms: D000199:Actins / Q000737:chemistry; D000818:Animals; D001703:Biophysics / Q000379:methods*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry; D016466:CHO Cells; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism* / Q000502:physiology*; D003102:Colloids / Q000737:chemistry; D006224:Cricetinae; D004058:Diffusion; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D018715:Microscopy, Video; D008954:Models, Biological; D008958:Models, Molecular; D015233:Models, Statistical; D051381:Rats; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry*; D013696:Temperature; D013844:Thiazoles / Q000737:chemistry; D053778:Thiazolidines; D013997:Time Factors
chemical_list: D000199:Actins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D003102:Colloids; D008565:Membrane Proteins; D043562:Receptors, G-Protein-Coupled; D013844:Thiazoles; D053778:Thiazolidines; D049452:Green Fluorescent Proteins; C037068:latrunculin B