title: Localization of the glycine transporter GLYT1 in glutamatergic synaptic vesicles.
abstract: We have previously shown the presence of the glycine transporter GLYT1 in glutamatergic terminals of the rat brain. In this study we present immunohistochemical and biochemical evidence indicating that GLYT1 is expressed not only at the plasma membrane of glutamatergic neurons, but also at synaptic vesicles. Confocal microscopy, immunoblots analysis of a highly purified synaptic vesicle fraction and immunoisolation of synaptic vesicles with anti-synaptophysin antibodies strongly suggested the presence of GLYT1 in synaptic vesicles. Moreover, direct observation with the electron microscope of purified vesicles immunoreacted with anti-GLYT1 and colloidal gold demonstrated that about 40% of the small vesicles of the purified vesicle fraction contained GLYT1. Double labeling for GLYT1 and synaptophysin of this vesicular fraction revealed that more of ninety percent of them were synaptic vesicles. Moreover, a significant part of the GLYT1 containing vesicles (86%) also contained the vesicular glutamate transporter vGLUT1, suggesting a functional role of GLYT1 in a subpopulation of glutamatergic vesicles.
authors.affiliation: Centro de Biología Molecular "Severo Ochoa" and Departamento de Biología Molecular, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Cubelos
authors.affiliation: Centro de Biología Molecular "Severo Ochoa" and Departamento de Biología Molecular, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Leite
authors.affiliation: Centro de Biología Molecular "Severo Ochoa" and Departamento de Biología Molecular, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Cecilio
authors.initials: C
authors.lastname: Giménez
authors.affiliation: Centro de Biología Molecular "Severo Ochoa" and Departamento de Biología Molecular, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III, Madrid, Spain. Electronic address: fzafra@cbm.uam.es.
authors.forename: Francisco
authors.initials: F
authors.lastname: Zafra
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D018698:Glutamic Acid / Q000502:physiology*; D050487:Glycine Plasma Membrane Transport Proteins / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013572:Synaptic Vesicles / Q000378:metabolism* / Q000648:ultrastructure; D050598:Vesicular Glutamate Transport Protein 1 / Q000378:metabolism
chemical_list: D050487:Glycine Plasma Membrane Transport Proteins; C493466:Slc17a7 protein, rat; C493266:Slc6a9 protein, rat; D050598:Vesicular Glutamate Transport Protein 1; D018698:Glutamic Acid
keywords: GLYT1; Glutamate; Glycine; Synaptic vesicles; Transporter