Dilation of ion selectivity filters in cation channels

Trends Biochem Sci. 2024 Mar 20:S0968-0004(24)00049-5. doi: 10.1016/j.tibs.2024.02.004. Online ahead of print.ABSTRACTIon channels establish the voltage gradient across cellular membranes by providing aqueous pathways for ions to selectively diffuse down their concentration gradients. The selectivity of any given channel for its favored ions has conventionally been viewed as a stable property, and in many cation channels, it is determined by an ion-selectivity filter within the external end of the ion-permeation pathway. In several instances, including voltage-activated K+ (Kv) channels, ATP-activated P2X receptor channels, and transient receptor potential (TRP) channels, the ion-permeation pathways have been proposed to dilate in response to persistent activation, dynamically altering ion permeation. Here, we discuss evidence for dynamic ion selectivity, examples where ion selectivity filters exhibit structural plasticity, and opportunities to fill gaps in our current understanding.PMID:38514273 | DOI:10.1016/j.tibs.2024.02.004

Source: Trends in Biochemical Sciences - March 21, 2024 Category: Biochemistry Authors: Kate Huffer Xiao-Feng Tan Ana I Fern ández-Mariño Surbhi Dhingra Kenton J Swartz Source Type: research