"The rat alpha7 nicotinic acetylcholine receptor (nAChR) can undergo rapid onset of desensitization; however, the mechanisms of desensitization are largely unknown.
The contribution of a tryptophan (W) residue at position 55 of the rat alpha7 nAChR subunit, which lies within the beta2 strand, was studied by mutating it to other hydrophobic and/or aromatic amino acids, followed by voltage-clamp experiments in Xenopus oocytes.
When mutated to alanine, the alpha7-W55A nAChR desensitized more slowly, and recovered from desensitization more rapidly, than wildtype alpha7 nAChRs.
The contribution of desensitization was validated by kinetic modelling. ..." Reference: Gay EA, Giniatullin R, Skorinkin A, Yakel JL (2008) Aromatic residues at position 55 of rat alpha7 nicotinic acetylcholine receptors are critical for maintaining rapid desensitization. J Physiol 586:1105-15 [PubMed] |