An ATP-sensitive potassium channel (or KATP channel) is a type of potassium channel that is gated by intracellular nucleotides, ATP and ADP. ATP-sensitive potassium channels are composed of Kir6.x-type subunits and sulfonylurea receptor (SUR) subunits, along with additional components. KATP channels are found in the plasma membrane; however some may also be found on subcellular membranes. These latter classes of KATP channels can be classified as being either sarcolemmal ("sarcKATP"), mitochondrial ("mitoKATP"), or nuclear ("nucKATP").
Discovery and structure
KATP channels were first identified in cardiac myocytes by the Akinori Noma group in Japan. They have also been found in pancreas where they control insulin secretion, but are in fact widely distributed in plasma membranes. SarcKATP are composed of eight protein subunits (octamer). Four of these are members of the inward-rectifier potassium ion channel family Kir6.x (either Kir6.1 or Kir6.2), while the other four are sulfonylurea receptors (SUR1, SUR2A, and SUR2B). The Kir subunits have two transmembrane spans and form the channel’s pore. The SUR subunits have three additional transmembrane domains, and contain two nucleotide-binding domains on the cytoplasmic side. These allow for nucleotide-mediated regulation of the potassium channel, and are critical in its roles as a sensor of metabolic status. These SUR subunits are also sensitive to sulfonylureas, MgATP, and some other pharmacological channel openers. While all sarcKATP are constructed of eight subunits in this 4:4 ratio, their precise composition varies with tissue type.
In the field of cell biology, potassium channels are the most widely distributed type of ion channel and are found in virtually all living organisms. They form potassium-selective pores that span cell membranes. Furthermore potassium channels are found in most cell types and control a wide variety of cell functions.
Function
Potassium channels function to conduct potassium ions down their electrochemical gradient, doing so both rapidly (up to the diffusion rate of K+ ions in bulk water) and selectively (excluding, most notably, sodium despite the sub-angstrom difference in ionic radius). Biologically, these channels act to set or reset the resting potential in many cells. In excitable cells, such as neurons, the delayed counterflow of potassium ions shapes the action potential.
By contributing to the regulation of the action potential duration in cardiac muscle, malfunction of potassium channels may cause life-threatening arrhythmias. Potassium channels may also be involved in maintaining vascular tone.
QLS-111 is a novel formulation based on an ATP-sensitive potassium (KATP) channel modulator platform, designed to lower IOP by relaxing the vessels in vascular and vascular-like tissues distal to the ...
... by activating KATP channels in mitochondria to restore mitochondrial function ... UNI-494 is a novel nicotinamide ester derivative and a selective ATP-sensitive mitochondrial potassium channel activator.
Officials say someone accessed Wallace's radio channel ... The sensors are known as adenosine triphosphate-sensitive potassium channels. Adenosine triphosphate, or ATP, is an energy source that all living cells need to survive.
Officials say someone accessed Wallace's radio channel ... The sensors are known as adenosine triphosphate-sensitive potassium channels. Adenosine triphosphate, or ATP, is an energy source that all living cells need to survive.
The company’s lead platform is based on the use of adenosine triphosphate (ATP)-sensitive potassium (K ATP ) channel modulators to affect the tone of vascular and vascular-like tissues for ophthalmic use.
LOS ALTOS, Calif., Oct. 26, 2022 (GLOBE NEWSWIRE) -- Unicycive Therapeutics, Inc. (Nasdaq... UNI-494 is a mitochondrial ATP sensitive potassium (mitoKATP) channel activator that is in development for the treatment of AKI ... The panel will feature Ravindra L.
DUBLIN--(BUSINESS WIRE)--Aug 8, 2022-- ... Nicorandil is an anti-anginal drug that both relieves angina symptoms and improves the prognosis of coronary artery disease, with both nitrate-like effects and ATP-sensitive potassium channel-opening effects ... .
The Eagle-Tribune
04 Mar 2024
The Eagle-Tribune
04 Mar 2024