Impairment of GABAB receptor dimer by endogenous 14-3-3ζ in chronic pain conditions.

Sophie Laffray, Rabia Bouali-Benazzouz, Marie-Amélie Papon, Alexandre Favereaux, Yang Jiang, Tina Holm, Corentin Spriet, Pascal Desbarats, Pascal Fossat, Yves Le Feuvre, Marion Decossas, Laurent Héliot, Ulo Langel, Frédéric Nagy, Marc Landry
The EMBO Journal. 2012-06-12; 31(15): 3239-3251
DOI: 10.1038/emboj.2012.161

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In the central nervous system, the inhibitory GABAB receptor is the archetype of heterodimeric G protein-coupled receptors (GPCRs). However, the regulation of GABAB dimerization, and more generally of GPCR oligomerization, remains largely unknown. We propose a novel mechanism for inhibition of GPCR activity through de-dimerization in pathological conditions. We show here that 14-3-3ζ, a GABAB1-binding protein, dissociates the GABAB heterodimer, resulting in the impairment of GABAB signalling in spinal neurons. In the dorsal spinal cord of neuropathic rats, 14-3-3ζ is overexpressed and weakens GABAB inhibition. Using anti-14-3-3ζ siRNA or competing peptides disrupts 14-3-3ζ/GABAB1 interaction and restores functional GABAB heterodimers in the dorsal horn. Importantly, both strategies greatly enhance the anti-nociceptive effect of intrathecal Baclofen in neuropathic rats. Taken together, our data provide the first example of endogenous regulation of a GPCR oligomeric state and demonstrate its functional impact on the pathophysiological process of neuropathic pain sensitization.


Auteurs Bordeaux Neurocampus