Voltage gated channel

Capsaicin receptor" agonists capsaicin, resmiferatoxin II, Via voltage-gated channels maitotoxm ( ) OH ... 

At this time, more then thirty channel DNAs have been cloned and characterized from various sources, predominantly from Drosophila melanogaster, mouse, rat and human cDNA/genomic libraries [6-31]. Inspection of the derived primary K channel protein sequences indicates that voltage-gated channels belong to a... 

Structure and biophysical properties of cloned voltage-gated channels... 

Historically the Shaker (Sh) K channel was the first K channel which was cloned and characterized [6-10]. Subsequently many more channel cDNAs and genes have been isolated and studied. Yet Sh channels remained in the forefront of channel research. The study of Sh channel mutants has provided the most thorough insight into structure-function relationships of K channels to date. I will first discuss in this chapter the primary sequences of voltage-gated channels. I will only use a few selected examples for discussion. As of this time, so many related K channel protein sequences have been published that it is not feasible to discuss all of them. Subsequently, I will describe in detail the present knowledge about functional K" " channel domains which are implicated in activation, inactivation and selectivity of the channel. 

Chang, K.T., Berg, D.K. Voltage-gated channels block nicotinic regulation of CREB phosphorylation and gene expression in neurons. Neuron. 32 855, 2001. 

Increases in the concentration of calcium in the cytosol provides a signal that can initiate muscle contraction, vision, and other signaling pathways. The response depends on the cell type. In muscle, a transient rise in the cytosolic calcium levels (from opening calcium channels in the sarcoplasmic reticulum) causes contraction. This signaling in contraction is a direct consequence of electrical activation of the voltage-gated channel. 

Guy, H. R. and Conti, F. Pursuing the structure and function of voltage-gated channels. Trends Neurosci. 13, 201-206, 1990. 

Ca2+ enters cells via a number of plasma membrane channels which belong to three families (Figure 11.2) (i) voltage-gated channels (ii) ligand-gated channels and (iii) capacitative, or store-operated channels (SOCs). 

Figure 11.2 The Ca2+ influx channels of the plasma membrane, (a) A voltage-gated channel—the membrane topography of the al-subunit, which forms the channel proper, (b) Membrane topography of TRP channels, homologous to the SOC channels, (c) Membrane topography of the ligand-gated glutamate NMDA receptor. (From Carafoli, 2005. Reproduced with permission from Blackwell...

Figure 4.3 Sequence alignment of hERG and other representative l<+ channels alignments of the pore helix, selectivity filter and inner helices. The inner helix of KcsA corresponds with S6 of the other l<+ channels shown here, which are all voltage-gated channels. hERG residues close to the selectivity filter and on S6 implicated in drug...

---