The twain shall meet: channels, transporters and things between

Abstract

The Royal Society discussion meeting on ‘Membrane transport in flux: the ambiguous interface between channels and pumps’ took place on 19 and 20 May 2008 in London, UK, and was organized by F. Ashcroft, C. Miller and D. Gadsby. ![][1] For many years, studies of ion channels and transport proteins have bred distinct fields with divergent approaches, mindsets and methods. ‘Ion channelologists’ focused on gating and permeation, and mumbled about obscure kinetic schemes, whereas ‘transporterologists’ studied substrate coupling and transport kinetics, and mumbled about other obscure kinetic schemes. Practitioners of each field generally held their counterparts in low regard, given the obvious superiority and importance of their own proteins: channel fans despised transporters as deplorably slow ‘draught horses’, whereas transporter enthusiasts scoffed at channels for being simple holes that merely squander the meticulous work accomplished by pump molecules. In recent years, however, this has all begun to change: transporters and channels are converging mechanistically as members of both groups are found to share fundamental characteristics, even to the point that several molecular families of ‘mixed descent’ have been discovered. In recognition of this convergence, the Royal Society recently sponsored a discussion meeting in London, UK, to explore the increasingly blurry distinction between these classes of membrane protein, and to examine some molecules that occupy the boundary between channels and transporters. This meeting provided an unusual opportunity to explore in depth what makes a channel distinct from a transporter and, perhaps more importantly, what fundamental mechanistic features they share. It is to be hoped that these two groups of scientists will continue to find common ground and will now start to mumble to each other about obscure kinetic schemes. Here, we focus on a subset of talks that addressed the core issues of the conference: the detailed analysis of channel and transporter … [1]: /embed/graphic-1.gif