Voltage sensor ring in a native structure of a membrane-embedded potassium channel
نویسندگان
چکیده
منابع مشابه
Membrane insertion of a potassium-channel voltage sensor.
The mechanism of voltage gating in K+ channels is controversial. The paddle model posits that highly charged voltage-sensor domains move relatively freely across the lipid bilayer in response to membrane depolarization; competing models picture the charged S4 voltage-sensor helix as being shielded from lipid contact by other parts of the protein. We measured the apparent free energy of membrane...
متن کاملMolecular mechanism of voltage sensor movements in a potassium channel.
Voltage-gated potassium channels are six-transmembrane (S1-S6) proteins that form a central pore domain (4 x S5-S6) surrounded by four voltage sensor domains (S1-S4), which detect changes in membrane voltage and control pore opening. Upon depolarization, the S4 segments move outward carrying charged residues across the membrane field, thereby leading to the opening of the pore. The mechanism of...
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The four arginine-rich S4 helices of a voltage-gated channel move outward through the membrane in response to depolarization, opening and closing gates to generate a transient ionic current. Coupling of voltage sensing to gating was originally thought to operate with the S4s moving independently from an inward/resting to an outward/activated conformation, so that when all four S4s are activated...
متن کاملAn evidence for a potassium channel in endoplasmic reticulum based on single channel recording in bilayer lipid membrane
Introduction Numerous studies have demonstrated the presence of potassium selective channels in membranes internal organelles. These channels are essential to a large variety of cellular processes including intracellular 2+ a signaling, protein recycling, charge neutralization and cell protection. In contrast to the sarcoplasmic reticulum + here potassium channels have been clearly ...
متن کاملHow Does a Voltage Sensor Interact with a Lipid Bilayer? Simulations of a Potassium Channel Domain
The nature of voltage sensing by voltage-activated ion channels is a key problem in membrane protein structural biology. The way in which the voltage-sensor (VS) domain interacts with its membrane environment remains unclear. In particular, the known structures of Kv channels do not readily explain how a positively charged S4 helix is able to stably span a lipid bilayer. Extended (2 x 50 ns) mo...
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ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 2013
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.1218203110