Potassium Channels

Potassium channels are crucial regulators of membrane excitability. They control the frequency and shape of action potentials, regulate secretion of hormones and neurotransmitters and establish cell plasma membrane potential. This large family can be regulated by voltage, Ca2+, neurotransmitters and the signaling pathways that they stimulate. Structurally, potassium channels exist as tetramers and the pore forming entity is the α-subunit. There are more than 70 different genes encoding the K+ α-subunit in the human genome.

Targets
Literature
Ion Channel Data

The Proposed Structure of Voltage-Gated Potassium Channels


The figure below shows the proposed structure of voltage-gated potassium channels.

A single α subunit

A. A single α subunit showing the K+ ion selectivity signature motif 'T/SxxTxGYG' within the pore loop.

The general assembly of the K<sup>+</sup> channel

B. The general assembly of the K+ channel; composed of four, P loop-containing α-subunits arranged in a tetrameric fashion.

The table below summarizes the key characteristics of some potassium channels.

Literature for Potassium Channels

Cardiovascular

Cardiovascular Research Product Guide

A collection of over 250 products for cardiovascular research, the guide includes research tools for the study of:

  • Hypertension
  • Thrombosis and Hemostasis
  • Atherosclerosis
  • Myocardial Infarction
  • Ischemia/Reperfusion Injury
  • Arrhythmias
  • Heart Failure
Pain

Pain Research Product Guide

A collection of over 250 products for pain research, the guide includes research tools for the study of:

  • Nociception
  • Ion Channels
  • G-Protein-Coupled Receptors
  • Intracellular Signaling
Asthma

Asthma Poster

Asthma is one of the most common chronic diseases in the world, affecting over 300 million people. This poster highlights key pathways and new therapies used to treat the condition, including those currently in clinical development.

Pain

Pain Poster

Peripheral sensitization is the reduction in the threshold of excitability of sensory neurons that results in an augmented response to a given external stimulus. This poster outlines the excitatory and inhibitory signaling pathways involved in modulation of peripheral sensitization. The role of ion channels, GPCRs, neurotrophins, and cytokines in sensory neurons are also described.

Properties of Potassium Channels

Type Inward Rectifier ATP-Sensitive Voltage-Sensitive Ca2+-Activated
Subtype - - A-type Delayed rectifier Large conductance (maxi-K, BK) Small conductance (SK)
Effect of Ca2+ Insensitive Insensitive Insensitive Insensitive Variable High sensitivity
Effect of Voltage Strong, inward rectification Weak, inward rectification Sensitive Sensitive Sensitive Insensitive
Effect of ATP Insensitive Inhibits channel opening Insensitive Insensitive Insensitive Insensitive
Conductance (pS) 5-30 5-90 < 1-20 < 1-20 100-250 6-14

References

Robertson et al (1997) The real life of voltage-gated K+ channels: more than model behaviour. TiPS 18 474. Mathie et al (1998) Voltage-activated potassium channels in mammalian neurons and their block by novel pharmacological agents. Gen.Pharmacol. 30 13. Vergara et al (1998) Calcium-activated potassium channels. Curr.Opin.Neurobiol. 8 321.

.