Title : Structure and functional interaction of the extracellular
domain of human GABA(B)
receptor GBR2
Abstract :
- Inhibitory neurotransmission is mediated primarily by GABA
- The metabotropic GABA(B) receptor is a G protein-coupled receptor central to mammalian brain function
- Malfunction of GABA(B) receptor has been implicated in several neurological disorders
- GABA(B) receptor functions as a heterodimeric assembly of GBR1 and GBR2 subunits , where GBR1 is responsible for ligand-binding and GBR2 is responsible for G protein coupling
- Here we demonstrate that the GBR2 ectodomain directly interacts with the GBR1 ectodomain to increase agonist affinity by selectively stabilizing the agonist-bound conformation of GBR1
- We present the crystal structure of the GBR2 ectodomain , which reveals a polar heterodimeric interface
- We also identify specific heterodimer contacts from both subunits , and GBR1 residues involved in ligand recognition
- Lastly, our structural and functional data indicate that the GBR2 ectodomain adopts a constitutively open conformation, suggesting a structural asymmetry in the active state of GABA(B) receptor that is unique to the GABAergic system
Output (sent_index, trigger,
protein,
sugar,
site):
Output(Part-Of) (sent_index,
protein,
site):
- 0. GBR2, domain
- 5. GBR2, ectodomain
- 6. structure of the GBR2, ectodomain
- 7. subunits, residues
- 8. GBR2, ectodomain
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):