| Structural highlights
Function
GBRB2_HUMAN Component of the heteropentameric receptor for GABA, the major inhibitory neurotransmitter in the vertebrate brain. Functions also as histamine receptor and mediates cellular responses to histamine. Functions as receptor for diazepines and various anesthetics, such as pentobarbital; these are bound at a separate allosteric effector binding site. Functions as ligand-gated chloride channel.[1] [2]
Publication Abstract from PubMed
Autoantibodies targeting neuronal membrane proteins can cause encephalitis, seizures, and severe behavioral abnormalities. While antibodies for several neuronal targets have been identified, structural details on how they regulate function are unknown. Here we determined cryo-electron microscopy structures of antibodies derived from an encephalitis patient bound to the gamma-aminobutyric acid type A (GABA(A)) receptor. These antibodies induced severe encephalitis by directly inhibiting GABA(A) function, resulting in nervous-system hyperexcitability. The structures reveal mechanisms of GABA(A) inhibition and pathology. One antibody directly competes with a neurotransmitter and locks the receptor in a resting-like state. The second antibody targets the subunit interface involved in binding benzodiazepines and antagonizes diazepam potentiation. We identify key residues in these antibodies involved in specificity and affinity and confirm structure-based hypotheses for functional effects using electrophysiology. Together these studies define mechanisms of direct functional antagonism of neurotransmission underlying autoimmune encephalitis in a human patient.
Structural mechanisms of GABA(A) receptor autoimmune encephalitis.,Noviello CM, Kreye J, Teng J, Pruss H, Hibbs RE Cell. 2022 Jul 7;185(14):2469-2477.e13. doi: 10.1016/j.cell.2022.06.025. PMID:35803245[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Zhao C, Xu Z, Wang F, Chen J, Ng SK, Wong PW, Yu Z, Pun FW, Ren L, Lo WS, Tsang SY, Xue H. Alternative-splicing in the exon-10 region of GABA(A) receptor beta(2) subunit gene: relationships between novel isoforms and psychotic disorders. PLoS One. 2009 Sep 18;4(9):e6977. doi: 10.1371/journal.pone.0006977. PMID:19763268 doi:http://dx.doi.org/10.1371/journal.pone.0006977
- ↑ Hadingham KL, Wingrove PB, Wafford KA, Bain C, Kemp JA, Palmer KJ, Wilson AW, Wilcox AS, Sikela JM, Ragan CI, et al.. Role of the beta subunit in determining the pharmacology of human gamma-aminobutyric acid type A receptors. Mol Pharmacol. 1993 Dec;44(6):1211-8. PMID:8264558
- ↑ Noviello CM, Kreye J, Teng J, Prüss H, Hibbs RE. Structural mechanisms of GABA(A) receptor autoimmune encephalitis. Cell. 2022 Jul 7;185(14):2469-2477.e13. PMID:35803245 doi:10.1016/j.cell.2022.06.025
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