scholarly journals Thermodynamics of ion binding and occupancy in potassium channels

2021 ◽  
Author(s):  
Zhifeng Jing ◽  
Joshua A. Rackers ◽  
Lawrence Pratt ◽  
Chengwen Liu ◽  
Susan B. Rempe ◽  
...  
Keyword(s):  
Potassium Channels ◽  
Ion Binding ◽  
Cellular Functions ◽  
Ion Conduction

Potassium channels modulate various cellular functions through efficient and selective conduction of K+ ions. The mechanism of ion conduction in potassium channels has recently emerged as a topic of debate....

scholarly journals The conduction pathway of potassium channels is water free under physiological conditions

2019 ◽  
Vol 5 (7) ◽  
pp. eaaw6756 ◽  
Author(s):  
Carl Öster ◽  
Kitty Hendriks ◽  
Wojciech Kopec ◽  
Veniamin Chevelkov ◽  
Chaowei Shi ◽  
...  
Keyword(s):  
Potassium Channels ◽  
Direct Contact ◽  
Selectivity Filter ◽  
Water Molecules ◽  
Potassium Ions ◽  
Ion Conduction ◽  
Physiological Conditions ◽  
Conduction Pathway ◽  
Fundamental Process ◽  
Dynamics Simulations

Ion conduction through potassium channels is a fundamental process of life. On the basis of crystallographic data, it was originally proposed that potassium ions and water molecules are transported through the selectivity filter in an alternating arrangement, suggesting a “water-mediated” knock-on mechanism. Later on, this view was challenged by results from molecular dynamics simulations that revealed a “direct” knock-on mechanism where ions are in direct contact. Using solid-state nuclear magnetic resonance techniques tailored to characterize the interaction between water molecules and the ion channel, we show here that the selectivity filter of a potassium channel is free of water under physiological conditions. Our results are fully consistent with the direct knock-on mechanism of ion conduction but contradict the previously proposed water-mediated knock-on mechanism.

scholarly journals Mechanistic Pathways of ATP Sensitive Potassium Channels Referring to Cardio-Protective Effects and Cellular Functions

Drug Research ◽  
2019 ◽  
Vol 69 (07) ◽  
pp. 365-373
Author(s):  
Vishal Kumar Vishwakarma ◽  
Prabhat Kumar Upadhyay ◽  
Hridaya Shanker Chaurasiya ◽  
Ritesh Kumar Srivasatav ◽  
Tarique Mahmood Ansari ◽  
...  
Keyword(s):  
Heart Rate ◽  
Potassium Channels ◽  
Calcium Release ◽  
High Heat ◽  
High Heart Rate ◽  
Protective Effects ◽  
Cellular Functions ◽  
Cell Functions ◽  
Ischemic Reperfusion ◽  
Cardio Protection

AbstractA study of potassium channels correlates the fundamentals of mechanistic pathways and various physiological functions. The knowledge of these pathways provides the background, how to determine unit cell functions and to affect cardio protection. ATP sensitive potassium channels adjust excitability of membrane and functions as per metabolic status of cell. A lot of energy consumption primarily occurred in skeletal muscles which also express high number of potassium channels. The increase in calcium release and high heat production is occurred due to loss of potassium channels. Such type of mediations determines metabolic changes and energy required in the dissipation. IPC reduces infarct size in anesthetized mice. In ischemic-reperfusion, pressure in left ventricle was watched while contractile power recovery did not happen. It was seen that elements of intact potassium channel are fundamental for Ischemic preconditioning (IPC). If more prominent is enactment of potassium channels and their cardiologic effects create high heart rate. All the more as of late, it has been suggested that mitochondrial ATP sensitive potassium channels are critical as closing stage effectors which trigger IPC as opposed to sarcolemmal potassium channels. Nevertheless, the importance of the potassium channels reconsidered in cardio-protection in present findings. These discoveries recommend that potassium channels in the adjusting ischemic-reperfusion damage in mice. The heart rate of the mouse occurred during ischemia; enhance watchful extrapolation applied to larger warm blooded animals.

scholarly journals Two-pore-domain potassium channels: regulators of many cellular functions

2015 ◽  
Vol 467 (5) ◽  
pp. 865-866 ◽  
Author(s):  
Thomas Budde ◽  
Jürgen Daut ◽  
Armin Kurtz ◽  
Hans-Christian Pape
Keyword(s):  
Potassium Channels ◽  
Cellular Functions ◽  
Pore Domain

Physical and functional interaction between integrins and hERG potassium channels

2004 ◽  
Vol 32 (5) ◽  
pp. 826-827 ◽  
Author(s):  
A. Arcangeli ◽  
A. Becchetti ◽  
A. Cherubini ◽  
O. Crociani ◽  
P. Defilippi ◽  
...  
Keyword(s):  
Potassium Channels ◽  
Cell Types ◽  
Integrin Subunit ◽  
Channel Activity ◽  
Cellular Functions ◽  
Human Neuroblastoma ◽  
Intracellular Signals ◽  
Osteoclastic Differentiation ◽  
Herg Channels ◽  
Determining Factor

Integrins are adhesion receptors capable of transmitting intracellular signals that regulate many different cellular functions. Among integrin-mediated signals, the activation of ion channels can be included. We demonstrated that a long-lasting activation of hERG (human ether-a-go-go-related gene) potassium channels occurs in both human neuroblastoma and leukaemia cells after the activation of the β1 integrin subunit. This activation is apparently a determining factor inducing neurite extension and osteoclastic differentiation in both the cell types. More recently, we provided evidences that β1 integrins and hERG channels co-precipitate in both the cell types. Preliminary results suggest that a macromolecular signalling complex indeed occurs between integrins and the hERG1 protein and that hERG channel activity can modulate integrin downstream signalling.

scholarly journals Ion Conduction through C-Type Inactivated Shaker Channels

1997 ◽  
Vol 110 (5) ◽  
pp. 539-550 ◽  
Author(s):  
John G. Starkus ◽  
Lioba Kuschel ◽  
Martin D. Rayner ◽  
Stefan H. Heinemann
Keyword(s):  
Potassium Channels ◽  
Xenopus Oocytes ◽  
Ion Selectivity ◽  
Complete Removal ◽  
Ion Conduction ◽  
Internal Solution ◽  
Shaker Channels ◽  
Na Ions ◽  
Shaker Potassium Channels ◽  
Inside Out

C-type inactivation of Shaker potassium channels involves entry into a state (or states) in which the inactivated channels appear nonconducting in physiological solutions. However, when Shaker channels, from which fast N-type inactivation has been removed by NH2-terminal deletions, are expressed in Xenopus oocytes and evaluated in inside-out patches, complete removal of K+ ions from the internal solution exposes conduction of Na+ and Li+ in C-type inactivated conformational states. The present paper uses this observation to investigate the properties of ion conduction through C-type inactivated channel states, and demonstrates that both activation and deactivation can occur in C-type states, although with slower than normal kinetics. Channels in the C-type states appear “inactivated” (i.e., nonconducting) in physiological solutions due to the summation of two separate effects: first, internal K+ ions prevent Na+ ions from permeating through the channel; second, C-type inactivation greatly reduces the permeability of K+ relative to the permeability of Na+, thus altering the ion selectivity of the channel.

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