NAChR cation-permeable channel

The open channel has in most cases a selective permeability, allowing a restricted class of ions to flow,for example Na+, K+, Ca++ or Cl- and, accordingly, these channels are called Na+-channels, K+-channels, Ca -channels and Cr-channels. In contrast, cation-permeable channels with little selectivity reject all anions but discriminate little among small cations. Little is known about the structures and functions of these non-selective cation channels [1], and so far only one of them, the nicotinic acetylcholine receptor (nAChR, see Nicotinic Receptors), has been characterized in depth [2, 3]. The nAChR is a ligand-gated channel (see below) that does not select well among cations the channel is even permeable to choline, glycine ethylester and tris buffer cations. A number of other plasma... 

Nicotinic acetylcholine receptors (nAChRs) are a family of ligand-gated ion channels that are found in abundance at the neuromuscular junction, and are widely distributed throughout the central and peripheral nervous systems. They comprise five subunit proteins that combine to form a cation permeable pore at the cell surface. In neuronal tissues, multiple nAChR subtypes may be assembled from a diverse array of subunits (a2-a9 32-p4) and their... 

The well-studied nicotinic acetylcholine receptors of vertebrates usually consist of two a and three non-a subunits, but a9 forms a heteromer with alO with a stoichiometry of two a9 and three alO subunits when expressed in Xenopus oocytes [8]. Also, a7, a8, and a9 subunits can form functional homomers in the oocyte expression system [9-11], The cation-permeable ion channels of nAChRs open in response to binding of ACh. Most neonicotinoids are agonists of native... 

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