Structural mechanisms of GABAA receptor autoimmune encephalitis

Colleen M. Noviello, Jakob Kreye, Jinfeng Teng, Harald Prüss, Ryan E. Hibbs

Research output: Contribution to journalArticlepeer-review

Abstract

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 γ-aminobutyric acid type A (GABAA) receptor. These antibodies induced severe encephalitis by directly inhibiting GABAA function, resulting in nervous-system hyperexcitability. The structures reveal mechanisms of GABAA 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.

Original languageEnglish (US)
Pages (from-to)2469-2477.e13
JournalCell
Volume185
Issue number14
DOIs
StatePublished - Jul 7 2022

Keywords

  • autoimmune disease
  • cryo-electron microscopy
  • Cys-loop receptor
  • encephalitis
  • GABA receptor

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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