Endoplasmic reticulum sorting and kinesin-1 command the targeting of Axonal GABAB receptors
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Archivos
Fecha
2012-08
Autores
Valdés, V.
Valenzuela, J.
Salas, D.
Jaureguiberry-Bravo, M.
Otero, C.
Thiede, C.
Schmidt, C.
Couve, A.
Profesor/a Guía
Facultad/escuela
Idioma
en
Título de la revista
ISSN de la revista
Título del volumen
Editor
Public Library of Science (PLoS)
Nombre de Curso
Licencia CC
Attribution 2.0 Generic (CC BY 2.0)
Licencia CC
https://plos.org/open-science/open-access/
Resumen
In neuronal cells the intracellular trafficking machinery controls the availability of neurotransmitter receptors at the plasma membrane, which is a critical determinant of synaptic strength. Metabotropic γ amino-butyric acid (GABA) type B receptors (GABABRs) are neurotransmitter receptors that modulate synaptic transmission by mediating the slow and prolonged responses to GABA. GABABRs are obligatory heteromers constituted by two subunits, GABABR1 and GABABR2. GABABR1a and GABABR1b are the most abundant subunit variants. GABABR1b is located in the somatodendritic domain whereas GABABR1a is additionally targeted to the axon. Sushi domains located at the N-terminus of GABABR1a constitute the only difference between both variants and are necessary and sufficient for axonal targeting. The precise targeting machinery and the organelles involved in sorting and transport have not been described. Here we demonstrate that GABABRs require the Golgi apparatus for plasma membrane delivery but that axonal sorting and targeting of GABABR1a operate in a pre-Golgi compartment. In the axon GABABR1a subunits are enriched in the endoplasmic reticulum (ER), and their dynamic behavior and colocalization with other secretory organelles like the ER-to-Golgi intermediate compartment (ERGIC) suggest that they employ a local secretory route. The transport of axonal GABABR1a is microtubule-dependent and kinesin-1, a molecular motor of the kinesin family, determines axonal localization. Considering that progression of GABABRs through the secretory pathway is regulated by an ER retention motif our data contribute to understand the role of the axonal ER in non-canonical sorting and targeting of neurotransmitter receptors.
Notas
Indexación: Scopus
Palabras clave
4 Aminobutyric Acid B Receptor, Baclofen, Animals, brain nerve cell, cell compartmentalization, cellular distribution, controlled study, endoplasmic reticulum
Citación
PLoS ONE, Volume 7, Issue 827, August 2012, Article number e44168
DOI
10.1371/journal.pone.0044168