Mutation in F64 position of GABAAR alpha subunit affects the receptor gating

• Autorzy: Czyzewska M.M. , Szczot M. , Kisiel M. , Mozrzymas J. W.
• Języki publikacji: EN

Abstrakty

EN

GABAA receptor (GABAAR) is a pentamer, formed by 2α, 2β and γ subunit. GABA binding site is localized at the interface between α and β subunits. Our aim was to characterize how mutation localized at the binding pocket (α1F64) influences agonist binding and conformational transitions between bound receptor states (gating). We used patchclamp technique with ultrafast perfusion system and HEK 293 cells expressing native or mutated GABAARs. All mutations (α1F64C/L/A) right-shifted the dose-dependent curve and accelerated current deactivation, indicating impairment of binding. Reduction of fast desensitization, which in the case of α1F64C was complete, indicates changes in gating. Moreover, the mutation decreased the maximum open channel probability, a key feature of receptor gating. Experiments performed with different agonists confirmed mutation-induced changes in the channel’s opening/closing transitions (gating). Quantitative analysis based on model simulations indicated that this mutation mostly affected the channel state which precedes opening and is interpreted as a macromolecule destabilization (“priming” or “flipping”) following agonist binding, whereas desensitization or efficacy are affected to a smaller extent. Our data thus suggest that mutation of α1F64 residue affects the “transition wave” from binding sites to the channel gate.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2013
• Tom: 73
• Numer: Suppl.1
• Opis fizyczny: p.58

Twórcy

autor

Czyzewska M.M.

• Department of Biophysics, Laboratory of Neuroscience, Wroclaw Medical University, Wroclaw, Poland

autor

Szczot M.

• Department of Biophysics, Laboratory of Neuroscience, Wroclaw Medical University, Wroclaw, Poland

autor

Kisiel M.

• Department of Biophysics, Laboratory of Neuroscience, Wroclaw Medical University, Wroclaw, Poland

autor

Mozrzymas J. W.

• Department of Biophysics, Laboratory of Neuroscience, Wroclaw Medical University, Wroclaw, Poland