title: Imaging local sphingomyelin-rich domains in the plasma membrane using specific probes and advanced microscopy.
abstract: Sphingomyelin (SM) is one of the major lipids in the mammalian plasma membrane. Multiple lines of evidence suggest that SM plays at least two functional roles in the cell, as a reservoir of lipid second messengers and as a platform for signaling molecules. To understand the molecular organization and dynamics of the SM-rich membrane domains, new approaches have been developed utilizing newly characterized specific SM-binding probes and state-of-the-art microscopy techniques. The toxic protein from the sea anemone, equinatoxin II, has been characterized as a specific probe for SM. The cytolytic protein from the earthworm, lysenin, has also been used as a SM-specific probe for the analysis of the heterogeneity of SM-rich membrane domains. Recently, using a non-toxic form of lysenin, we showed the spatial and temporal localization of SM in the plasma membrane by confocal and super-resolution microscopy. New microscopy techniques have also been introduced by other groups to help visualize membrane lipid domains. Here we review the most recent studies on imaging the SM-rich domains in biological membranes. This article is part of a Special Issue entitled New Frontiers in Sphingolipid Biology.
authors.affiliation: Lipid Biology Laboratory, RIKEN, Wako, Saitama, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Abe
authors.affiliation: Lipid Biology Laboratory, RIKEN, Wako, Saitama, Japan; INSERM U1060, Université Lyon1, INSA Lyon, Villeurbanne, France. Electronic address: kobayasi@riken.jp.
authors.forename: Toshihide
authors.initials: T
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D006801:Humans; D021962:Membrane Microdomains / Q000378:metabolism*; D008853:Microscopy / Q000379:methods*; D015335:Molecular Probes; D013109:Sphingomyelins / Q000378:metabolism*
chemical_list: D015335:Molecular Probes; D013109:Sphingomyelins
keywords: Equinatoxin II; Lysenin; Sphingomyelin-binding toxin; Super-resolution microscopy