Differential compartmentalization and distinct functions of GABAB receptor variants

Réjan Vigot, Samuel Barbieri, Hans Bräuner-Osborne, Rostislav Turecek, Ryuichi Shigemoto, Yan-Ping Zhang, Rafael Luján, Laura H Jacobson, Barbara Biermann, Jean-Marc Fritschy, Claire-Marie Vacher, Matthias Müller, Gilles Sansig, Nicole Guetg, John F Cryan, Klemens Kaupmann, Martin Gassmann, Thomas G Oertner, Bernhard Bettler

    229 Citationer (Scopus)

    Abstract

    GABAB receptors are the G protein-coupled receptors for the main inhibitory neurotransmitter in the brain, gamma-aminobutyric acid (GABA). Molecular diversity in the GABAB system arises from the GABAB1a and GABAB1b subunit isoforms that solely differ in their ectodomains by a pair of sushi repeats that is unique to GABAB1a. Using a combined genetic, physiological, and morphological approach, we now demonstrate that GABAB1 isoforms localize to distinct synaptic sites and convey separate functions in vivo. At hippocampal CA3-to-CA1 synapses, GABAB1a assembles heteroreceptors inhibiting glutamate release, while predominantly GABAB1b mediates postsynaptic inhibition. Electron microscopy reveals a synaptic distribution of GABAB1 isoforms that agrees with the observed functional differences. Transfected CA3 neurons selectively express GABAB1a in distal axons, suggesting that the sushi repeats, a conserved protein interaction motif, specify heteroreceptor localization. The constitutive absence of GABAB1a but not GABAB1b results in impaired synaptic plasticity and hippocampus-dependent memory, emphasizing molecular differences in synaptic GABAB functions.
    OriginalsprogEngelsk
    TidsskriftNeuron
    Vol/bind50
    Udgave nummer4
    Sider (fra-til)589-601
    ISSN0896-6273
    DOI
    StatusUdgivet - 18 maj 2006

    Fingeraftryk

    Dyk ned i forskningsemnerne om 'Differential compartmentalization and distinct functions of GABAB receptor variants'. Sammen danner de et unikt fingeraftryk.

    Citationsformater