CALCIUM-ACTIVATED POTASSIUM CHANNELS - REGULATION BY CALCIUM

被引:233
作者
MCMANUS, OB
机构
[1] Department of Membrane Biochemistry and Biophysics, Merck Institute for Therapeutic Research, Rahway, 07065, New Jersey
关键词
CALCIUM-ACTIVATED POTASSIUM CHANNEL; POTASSIUM CHANNEL; ION CHANNEL; CHANNEL GATING;
D O I
10.1007/BF00785810
中图分类号
Q6 [生物物理学];
学科分类号
071011 ;
摘要
A wide variety of calcium-activated K channels has been described and can be conveniently separated into three classes based on differences in single-channel conductance, voltage dependence of channel opening, and sensitivity to blockers. Large-conductance calcium-activated K channels typically require micromolar concentrations of calcium to open, and their sensitivity to calcium increases with membrane depolarization, suggesting that they may be involved in repolarization events. Small-conductance calcium-activated K channels are generally more sensitive to calcium at negative membrane potentials, but their sensitivity to calcium is independent of membrane potential, suggesting that they may be involved in regulating membrane properties near the resting potential. Intermediate-conductance calcium-activated K channels are a loosely defined group, where membership is determined because a channel does not fit in either of the other two groups. Within each broad group, variations in calcium sensitivity and single-channel conductance have been observed, suggesting that there may be families of closely related calcium-activated K channels. Kinetic studies of the gating of calcium-activated potassium channels have revealed some basic features of the mechanisms involved in activation of these channels by calcium, including the number of calcium ions participating in channel opening, the number of major conformations of the channels involved in the gating process, and the number of transition pathways between open and closed states. Methods of analysis have been developed that may allow identification of models that give accurate descriptions of the gating of these channels. Although such kinetic models are likely to be oversimplifications of the behavior of a large macromolecule, these models may provide some insight into the mechanisms that control the gating of the channel, and are subject to falsification by new data.
引用
收藏
页码:537 / 560
页数:24
相关论文
共 109 条
[51]   CHARACTERIZATION OF A CA-DEPENDENT MAXI K-CHANNEL IN THE APICAL MEMBRANE OF A CULTURED RENAL EPITHELIUM (JTC-12.P3) [J].
KOLB, HA ;
BROWN, CDA ;
MURER, H .
JOURNAL OF MEMBRANE BIOLOGY, 1986, 92 (03) :207-215
[52]   STATISTICAL DISCRIMINATION OF FRACTAL AND MARKOV-MODELS OF SINGLE-CHANNEL GATING [J].
KORN, SJ ;
HORN, R .
BIOPHYSICAL JOURNAL, 1988, 54 (05) :871-877
[53]   EFFECTS OF INTRACELLULAR PH ON CALCIUM-ACTIVATED POTASSIUM CHANNELS IN RABBIT TRACHEAL SMOOTH-MUSCLE [J].
KUME, H ;
TAKAGI, K ;
SATAKE, T ;
TOKUNO, H ;
TOMITA, T .
JOURNAL OF PHYSIOLOGY-LONDON, 1990, 424 :445-457
[54]   PROPERTIES OF 2 CALCIUM-ACTIVATED HYPERPOLARIZATIONS IN RAT HIPPOCAMPAL-NEURONS [J].
LANCASTER, B ;
NICOLL, RA .
JOURNAL OF PHYSIOLOGY-LONDON, 1987, 389 :187-203
[55]   TETRAETHYLAMMONIUM BLOCKADE OF APAMIN-SENSITIVE AND INSENSITIVE CA-2+-ACTIVATED K+ CHANNELS IN A PITUITARY CELL-LINE [J].
LANG, DG ;
RITCHIE, AK .
JOURNAL OF PHYSIOLOGY-LONDON, 1990, 425 :117-132
[56]   LARGE AND SMALL CONDUCTANCE CALCIUM-ACTIVATED POTASSIUM CHANNELS IN THE GH3 ANTERIOR-PITUITARY CELL-LINE [J].
LANG, DG ;
RITCHIE, AK .
PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY, 1987, 410 (06) :614-622
[57]   RECONSTITUTION IN PLANAR LIPID BILAYERS OF A CA-2+-DEPENDENT K+ CHANNEL FROM TRANSVERSE TUBULE MEMBRANES ISOLATED FROM RABBIT SKELETAL-MUSCLE [J].
LATORRE, R ;
VERGARA, C ;
HIDALGO, C .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES, 1982, 79 (03) :805-809
[58]   VARIETIES OF CALCIUM-ACTIVATED POTASSIUM CHANNELS [J].
LATORRE, R ;
OBERHAUSER, A ;
LABARCA, P ;
ALVAREZ, O .
ANNUAL REVIEW OF PHYSIOLOGY, 1989, 51 :385-399
[60]   FUNCTIONAL MODIFICATION OF A CA-2+-ACTIVATED K+ CHANNEL BY TRIMETHYLOXONIUM [J].
MACKINNON, R ;
MILLER, C .
BIOCHEMISTRY, 1989, 28 (20) :8087-8092