title: New insights into the organization of plasma membrane and its role in signal transduction.
abstract: Plasma membranes have heterogeneous structures for efficient signal transduction, required to perform cell functions. Recent evidence indicates that the heterogeneous structures are produced by (1) compartmentalization by actin-based membrane skeleton, (2) raft domains, (3) receptor-receptor interactions, and (4) the binding of receptors to cytoskeletal proteins. This chapter provides an overview of recent studies on diffusion, clustering, raft association, actin binding, and signal transduction of membrane receptors, especially glycosylphosphatidylinositol (GPI)-anchored receptors. Studies on diffusion of GPI-anchored receptors suggest that rafts may be small and/or short-lived in plasma membranes. In steady state conditions, GPI-anchored receptors form transient homodimers, which may represent the "standby state" for the stable homodimers and oligomers upon ligation. Furthermore, It is proposed that upon ligation, the binding of GPI-anchored receptor clusters to cytoskeletal actin filaments produces a platform for downstream signaling, and that the pulse-like signaling easily maintains the stability of the overall signaling activity.
authors.affiliation: Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Kyoto, Japan; National Centre for Biological Sciences (NCBS)/Institute for Stem Cell Biology and Regenerative Medicine (inStem), Bangalore, India.
authors.forename: Kenichi G N
authors.initials: KG
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D006801:Humans; D021962:Membrane Microdomains / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D008565:Membrane Proteins
keywords: Actin; Clusters; Cytoskeleton; Diffusion; GPI-anchored proteins; Rafts; Signaling; Single-molecule imaging