Publication Date:
2006-10-28
Description:
Large-conductance calcium- and voltage-activated potassium channels (BKCa) are dually activated by membrane depolarization and elevation of cytosolic calcium ions (Ca2+). Under normal cellular conditions, BKCa channel activation requires Ca2+ concentrations that typically occur in close proximity to Ca2+ sources. We show that BKCa channels affinity-purified from rat brain are assembled into macromolecular complexes with the voltage-gated calcium channels Cav1.2 (L-type), Cav2.1 (P/Q-type), and Cav2.2 (N-type). Heterologously expressed BKCa-Cav complexes reconstitute a functional "Ca2+ nanodomain" where Ca2+ influx through the Cav channel activates BKCa in the physiological voltage range with submillisecond kinetics. Complex formation with distinct Cav channels enables BKCa-mediated membrane hyperpolarization that controls neuronal firing pattern and release of hormones and transmitters in the central nervous system.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Berkefeld, Henrike -- Sailer, Claudia A -- Bildl, Wolfgang -- Rohde, Volker -- Thumfart, Jorg-Oliver -- Eble, Silke -- Klugbauer, Norbert -- Reisinger, Ellen -- Bischofberger, Josef -- Oliver, Dominik -- Knaus, Hans-Gunther -- Schulte, Uwe -- Fakler, Bernd -- New York, N.Y. -- Science. 2006 Oct 27;314(5799):615-20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Physiology, University of Freiburg, Hermann-Herder-Strasse 7, 79104 Freiburg, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17068255" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Animals
;
Brain Chemistry
;
CHO Cells
;
Calcium/*metabolism
;
Calcium Channels, L-Type/drug effects/isolation & purification/*metabolism
;
Calcium Channels, N-Type/drug effects/isolation & purification/*metabolism
;
Calcium Signaling
;
Chromaffin Cells/drug effects/metabolism
;
Cricetinae
;
Cricetulus
;
Egtazic Acid/analogs & derivatives/pharmacology
;
Large-Conductance Calcium-Activated Potassium Channels/drug effects/isolation &
;
purification/*metabolism
;
Membrane Potentials/drug effects
;
Molecular Sequence Data
;
Patch-Clamp Techniques
;
Potassium/*metabolism
;
Rats
;
*Signal Transduction
;
Transfection
;
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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