Issue No. 16

Voltage-gated calcium (Ca_V) channels play a major role in the normal functioning and pathophysiology of neurons and other excitable cells. Their role includes supply of Ca²⁺ for transmitter release, regulation of excitability by activation of Ca²⁺-dependent currents and activation of other Ca²⁺-dependent processes, including control of gene expression. Since Ca²⁺ entry regulates so many cellular processes, the correct trafficking and localization of Ca_V channels is of great importance for the normal functioning of cells.

Recently, mutations in a number of genes, causing disease in humans and mice, have been implicated in the context of voltage dependent ion channels and termed

TRP channels are a large family (20 genes) of plasma membrane, non-selective cationic channels that are either specifically or ubiquitously expressed in excitable and non excitable cells. These proteins are divided into three main subfamilies on the basis of sequence homology; TRPC, TRPV and TRPM1 (see Table). Like the K_V channel family, the TRP family can also form heteromers consisting of different members of the same subfamily. Their non-selective cationic nature makes them depolarizing agents, while their calcium permeability makes them as transducers leading to [Ca²⁺]_in elevation. However, there are many different gating mechanism and/or modulating agents that activate and inactivate different members of this channel family (for reviews see^2,3).

The pacemaker current is a hyperpolarization-activated, cation-selective, inward current that modulates the firing rate of cardiac and neuronal pacemaker cells1. …

The first of the distinctive family of two transmembrane domain inward rectifier K+ channels to be cloned was ROMK11, now …

Cyclic nucleotide gated (CNG) channels are non-selective cation channels facilitating the influx of Na+ and Ca2+ ions, with their opening …

The ether-a-go-go gene (EAG) family is a relative novel group of K+– channels, which belong to an increasing number of …

The KV4 subfamily of voltage dependent K+ channels is the mammalian parallel of the Drosophila Shal K+ channel. These currents …