title: Monitoring endosomal trafficking of the g protein-coupled receptor somatostatin receptor 3.
abstract: Endocytic trafficking of G protein-coupled receptors (GPCRs) regulates the number of cell surface receptors available for activation by agonists and serves as one mechanism that controls the intensity and duration of signaling. Deregulation of GPCR-mediated signaling pathways results in a multitude of diseases, and thus extensive efforts have been directed toward understanding the pathways and molecular events that regulate endocytic trafficking of these receptors. The general paradigms associated with internalization and recycling, as well as many of the key regulators involved in endosomal trafficking of GPCRs have been identified. This knowledge provides goalposts to facilitate the analysis of endosomal pathways traversed by previously uncharacterized GPCRs. Some of the most informative markers associated with GPCR transit are the Rab members of the Ras-related family of small GTPases. Individual Rabs show high selectivity for distinct endosomal compartments, and thus colocalization of a GPCR with a particular Rab informs on the internalization pathway traversed by the receptor. Progress in our knowledge of endosomal trafficking of GPCRs has been achieved through advances in our ability to tag GPCRs and Rabs with fluorescent proteins and perform live cell imaging of multiple fluorophores, allowing real-time observation of receptor trafficking between subcellular compartments in a cell culture model.
authors.affiliation: Department of Cell Biology, Emory University, Atlanta, Georgia, USA.
authors.forename: Cristy
authors.initials: C
authors.lastname: Tower-Gilchrist
authors.affiliation: Department of Biology, Birmingham-Southern College, Birmingham, Alabama, USA.
authors.forename: Melanie L
authors.initials: ML
authors.lastname: Styers
authors.affiliation: Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Bradley K
authors.initials: BK
authors.lastname: Yoder
authors.affiliation: Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Nicolas F
authors.initials: NF
authors.lastname: Berbari
authors.affiliation: Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA. Electronic address: esztul@uab.edu.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Sztul
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D011992:Endosomes / Q000378:metabolism* / Q000648:ultrastructure; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005456:Fluorescent Dyes; D015870:Gene Expression; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007685:Kidney Tubules, Collecting / Q000166:cytology / Q000378:metabolism; D051379:Mice; D018613:Microscopy, Confocal; D057054:Molecular Imaging; D009154:Mutation; D021381:Protein Transport; D017481:Receptors, Somatostatin / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D059008:Time-Lapse Imaging; D014162:Transfection; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020695:rab4 GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020696:rab5 GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D000090802:rab7 GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins
chemical_list: D005456:Fluorescent Dyes; D049452:Green Fluorescent Proteins; D017481:Receptors, Somatostatin; D011993:Recombinant Fusion Proteins; D020691:rab GTP-Binding Proteins; D020695:rab4 GTP-Binding Proteins; D020696:rab5 GTP-Binding Proteins; D000090802:rab7 GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C485184:enhanced green fluorescent protein; C103631:somatostatin receptor 3
keywords: Endosomal trafficking; Epitope tag; Fluorescent proteins; G protein-coupled receptor (GPCR); Live cell imaging; Rab GTPases; Somatostatin receptor 3