title: Lipid Rafts Are Physiologic Membrane Microdomains Necessary for the Morphogenic and Developmental Functions of Glial Cell Line-Derived Neurotrophic Factor In Vivo.
abstract: Glial cell line-derived neurotrophic factor (GDNF) promotes PNS development and kidney morphogenesis via a receptor complex consisting of the glycerophosphatidylinositol (GPI)-anchored, ligand binding receptor GDNF family receptor α1 (GFRα1) and the receptor tyrosine kinase Ret. Although Ret signal transduction in vitro is augmented by translocation into lipid rafts via GFRα1, the existence and importance of lipid rafts in GDNF-Ret signaling under physiologic conditions is unresolved. A knock-in mouse was produced that replaced GFRα1 with GFRα1-TM, which contains a transmembrane (TM) domain instead of the GPI anchor. GFRα1-TM still binds GDNF and promotes Ret activation but does not translocate into rafts. In Gfrα1(TM/TM) mice, GFRα1-TM is expressed, trafficked, and processed at levels identical to GFRα1. Although Gfrα1(+/TM) mice are viable, Gfrα1(TM/TM) mice display bilateral renal agenesis, lack enteric neurons in the intestines, and have motor axon guidance deficits, similar to Gfrα1(-/-) mice. Therefore, the recruitment of Ret into lipid rafts by GFRα1 is required for the physiologic functions of GDNF in vertebrates. Significance statement: Membrane microdomains known as lipid rafts have been proposed to be unique subdomains in the plasma membrane that are critical for the signaling functions of multiple receptor complexes. Their existence and physiologic relevance has been debated. Based on in vitro studies, lipid rafts have been reported to be necessary for the function of the Glial cell line-derived neurotrophic factor (GDNF) family of neurotrophic factors. The receptor for GDNF comprises the lipid raft-resident, glycerophosphatidylinositol-anchored receptor GDNF family receptor α1 (GFRα1) and the receptor tyrosine kinase Ret. Here we demonstrate, using a knock-in mouse model in which GFRα1 is no longer located in lipid rafts, that the developmental functions of GDNF in the periphery require the translocation of the GDNF receptor complex into lipid rafts.
authors.affiliation: Department of Internal Medicine-Nephrology Division and.
authors.forename: Cynthia C
authors.initials: CC
authors.lastname: Tsui
authors.affiliation: Program in Cellular and Molecular Biology, University of Michigan School of Medicine, Ann Arbor, Michigan 48109, and Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan 48109.
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Gabreski
authors.affiliation: Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan 48109.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Hein
authors.affiliation: Program in Cellular and Molecular Biology, University of Michigan School of Medicine, Ann Arbor, Michigan 48109, and Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan 48109 pierchal@umich.edu.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Pierchala
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D004151:Dipeptides / Q000494:pharmacology; D004622:Embryo, Mammalian; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004963:Estrenes / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000235:genetics*; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors / Q000235:genetics; D051098:Glial Cell Line-Derived Neurotrophic Factors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D021962:Membrane Microdomains / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009024:Morphogenesis / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000166:cytology* / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects / Q000235:genetics; D011760:Pyrrolidinones / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D013116:Spinal Cord / Q000166:cytology; D017783:Superior Cervical Ganglion / Q000166:cytology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D004151:Dipeptides; D004791:Enzyme Inhibitors; D004963:Estrenes; C494987:GFRA1 protein, human; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D051098:Glial Cell Line-Derived Neurotrophic Factors; D006877:Hydroxamic Acids; C092152:N-((2-(hydroxyaminocarbonyl)methyl)-4-methylpentanoyl)-3-(2'-naphthyl)alanylalanine, 2-aminoethylamide; D011760:Pyrrolidinones; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D014446:Tyrosine 3-Monooxygenase; D000110:Acetylcholinesterase
keywords: GDNF; Ret; lipid raft; neurotrophic factor; spinal motor neuron; transgenic