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Publication Abstract from PubMed

The alpha7 nicotinic acetylcholine receptor is a pentameric ligand-gated ion channel that plays an important role in cholinergic signaling throughout the nervous system. Its unique physiological characteristics and implications in neurological disorders and inflammation make it a promising but challenging therapeutic target. Positive allosteric modulators overcome limitations of traditional alpha7 agonists, but their potentiation mechanisms remain unclear. Here, we present high-resolution structures of alpha7-modulator complexes, revealing partially overlapping binding sites but varying conformational states. Structure-guided functional and computational tests suggest that differences in modulator activity arise from the stable rotation of a channel gating residue out of the pore. We extend the study using a time-resolved cryoelectron microscopy (cryo-EM) approach to reveal asymmetric state transitions for this homomeric channel and also find that a modulator with allosteric agonist activity exploits a distinct channel-gating mechanism. These results define mechanisms of alpha7 allosteric modulation and activation with implications across the pentameric receptor superfamily.

Structural mechanisms of alpha7 nicotinic receptor allosteric modulation and activation.,Burke SM, Avstrikova M, Noviello CM, Mukhtasimova N, Changeux JP, Thakur GA, Sine SM, Cecchini M, Hibbs RE Cell. 2024 Feb 29;187(5):1160-1176.e21. doi: 10.1016/j.cell.2024.01.032. Epub , 2024 Feb 20. PMID:38382524^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.