Publication Date:
1991-11-01
Description:
Voltage-dependent ion channels respond to changes in the membrane potential by means of charged voltage sensors intrinsic to the channel protein. Changes in transmembrane potential cause movement of these charged residues, which results in conformational changes in the channel. Movements of the charged sensors can be detected as currents known as gating currents. Measurement of the gating currents of the Drosophila Shaker potassium channel indicates that the charge on the voltage sensor of the channels is progressively immobilized by prolonged depolarizations. The charge is not immobilized in a mutant of the channel that lacks inactivation. These results show that the region of the molecule responsible for inactivation interacts, directly or indirectly, with the voltage sensor to prevent the return of the charge to its original position. The gating transitions between closed states of the channel appear not to be independent, suggesting that the channel subunits interact during activation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bezanilla, F -- Perozo, E -- Papazian, D M -- Stefani, E -- GM30376/GM/NIGMS NIH HHS/ -- GM43459/GM/NIGMS NIH HHS/ -- HL37044/HL/NHLBI NIH HHS/ -- R01 GM043459/GM/NIGMS NIH HHS/ -- R01 GM043459-09/GM/NIGMS NIH HHS/ -- R01 GM043459-10/GM/NIGMS NIH HHS/ -- R01 GM043459-11/GM/NIGMS NIH HHS/ -- R01 GM043459-12/GM/NIGMS NIH HHS/ -- R01 GM043459-13/GM/NIGMS NIH HHS/ -- R01 GM043459-14/GM/NIGMS NIH HHS/ -- R01 GM043459-15/GM/NIGMS NIH HHS/ -- R01 GM043459-15S1/GM/NIGMS NIH HHS/ -- R01 GM043459-16/GM/NIGMS NIH HHS/ -- R01 GM043459-17/GM/NIGMS NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1991 Nov 1;254(5032):679-83.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology, UCLA School of Medicine 90024.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1948047" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Animals
;
Drosophila/physiology
;
*Ion Channel Gating/drug effects
;
Kinetics
;
Mutagenesis, Site-Directed
;
Oocytes/drug effects/physiology
;
Potassium Channels/drug effects/genetics/*physiology
;
Tetraethylammonium
;
Tetraethylammonium Compounds/pharmacology
;
Xenopus
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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