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Trends Pharmacol Sci. 2000 Nov;21(11):445-51.

Hinges, swivels and switches: the role of prolines in signalling via transmembrane alpha-helices.

Author information

1
Department of Biochemistry, University of Oxford, UK. mark@biop.ox.ac.uk

Abstract

Extracellular signals are transduced across membranes via conformational changes in the transmembrane domains (TMs) of ion channels and G-protein-coupled receptors (GPCRs). Experimental and simulation studies indicate that such conformational switches in transmembrane (alpha-helices can be generated by proline-containing motifs that form molecular hinges. Computational approaches tested on model channel-forming peptides (e.g. alamethicin) reveal functional mechanisms in gap-junction proteins (such as connexin) and voltage-gated K+ channels. Similarly, functionally important roles for proline-based switches in TM6 and TM7 were identified in GPCRs. However, hinges in transmembrane helices are not confined to proline-containing sequence motifs, as evidenced by a non-proline hinge in the M2 helix of the nicotinic acetylcholine receptor. This helix lines the pore and plays a key role in the gating of this channel.

PMID:
11121576
[Indexed for MEDLINE]

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