Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
J Neurosci
2004 Jun 16;2424:5585-91. doi: 10.1523/JNEUROSCI.1296-04.2004.
Show Gene links
Show Anatomy links
Ligand-dependent activation of Slo family channels is defined by interchangeable cytosolic domains.
Xia XM
,
Zhang X
,
Lingle CJ
.
???displayArticle.abstract???
Large-conductance Ca2+- and voltage-regulated K+ channels (Slo1 BK-type) are controlled by two physiological stimuli, membrane voltage and cytosolic Ca2+. Regulation by voltage is similar to that in voltage-dependent K+ channels, arising from positively charged amino acids primarily within the S4 transmembrane helices. The basis for regulation by Ca2+ remains controversial. One viewpoint suggests that the extensive cytosolic C terminus contains the Ca2+ regulatory machinery, whereas another suggests that the pore-forming module contains the Ca2+-sensing elements. To address this issue, we take advantage of another Slo family member, the pH-regulated homolog Slo3. We reason that if the ligand-sensing apparatus is uniquely associated with a particular domain (either the pore or the cytosolic domain), exchange of those domains between Slo1 and Slo3 should result in exchange of ligand dependence in association with the key domain. The results show that the Slo3 cytosolic module confers pH-dependent regulation on the Slo1 pore module, whereas the Slo1 cytosolic module confers Ca2+-dependent regulation on the Slo3 pore module. Thus, ligand-specific regulation is defined by interchangeable cytosolic regulatory modules.
Adelman,
Calcium-activated potassium channels expressed from cloned complementary DNAs.
1992,
Pubmed
,
Xenbase
Avdonin,
Stimulatory action of internal protons on Slo1 BK channels.
2003,
Pubmed
Bao,
Mapping the BKCa channel's "Ca2+ bowl": side-chains essential for Ca2+ sensing.
2004,
Pubmed
,
Xenbase
Bao,
Elimination of the BK(Ca) channel's high-affinity Ca(2+) sensitivity.
2002,
Pubmed
,
Xenbase
Barrett,
Properties of single calcium-activated potassium channels in cultured rat muscle.
1982,
Pubmed
Bhattacharjee,
Slick (Slo2.1), a rapidly-gating sodium-activated potassium channel inhibited by ATP.
2003,
Pubmed
,
Xenbase
Bian,
Ca2+-binding activity of a COOH-terminal fragment of the Drosophila BK channel involved in Ca2+-dependent activation.
2001,
Pubmed
Brelidze,
Protons block BK channels by competitive inhibition with K+ and contribute to the limits of unitary currents at high voltages.
2004,
Pubmed
,
Xenbase
Butler,
mSlo, a complex mouse gene encoding "maxi" calcium-activated potassium channels.
1993,
Pubmed
,
Xenbase
Cox,
Role of the beta1 subunit in large-conductance Ca(2+)-activated K(+) channel gating energetics. Mechanisms of enhanced Ca(2+) sensitivity.
2000,
Pubmed
,
Xenbase
Cox,
Allosteric gating of a large conductance Ca-activated K+ channel.
1997,
Pubmed
,
Xenbase
Cui,
Allosteric linkage between voltage and Ca(2+)-dependent activation of BK-type mslo1 K(+) channels.
2000,
Pubmed
Cui,
Intrinsic voltage dependence and Ca2+ regulation of mslo large conductance Ca-activated K+ channels.
1997,
Pubmed
,
Xenbase
Díaz,
Role of the S4 segment in a voltage-dependent calcium-sensitive potassium (hSlo) channel.
1998,
Pubmed
,
Xenbase
Hamill,
Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches.
1981,
Pubmed
Horrigan,
Allosteric voltage gating of potassium channels I. Mslo ionic currents in the absence of Ca(2+).
1999,
Pubmed
,
Xenbase
Horrigan,
Coupling between voltage sensor activation, Ca2+ binding and channel opening in large conductance (BK) potassium channels.
2002,
Pubmed
,
Xenbase
Jiang,
Crystal structure and mechanism of a calcium-gated potassium channel.
2002,
Pubmed
Jiang,
Structure of the RCK domain from the E. coli K+ channel and demonstration of its presence in the human BK channel.
2001,
Pubmed
,
Xenbase
Joiner,
Formation of intermediate-conductance calcium-activated potassium channels by interaction of Slack and Slo subunits.
1998,
Pubmed
Lingle,
Inactivation of BK channels mediated by the NH(2) terminus of the beta3b auxiliary subunit involves a two-step mechanism: possible separation of binding and blockade.
2001,
Pubmed
,
Xenbase
Magleby,
Gating mechanism of BK (Slo1) channels: so near, yet so far.
2003,
Pubmed
Moczydlowski,
Gating kinetics of Ca2+-activated K+ channels from rat muscle incorporated into planar lipid bilayers. Evidence for two voltage-dependent Ca2+ binding reactions.
1983,
Pubmed
Moss,
Gating and conductance properties of BK channels are modulated by the S9-S10 tail domain of the alpha subunit. A study of mSlo1 and mSlo3 wild-type and chimeric channels.
2001,
Pubmed
,
Xenbase
Piskorowski,
Calcium activation of BK(Ca) potassium channels lacking the calcium bowl and RCK domains.
2002,
Pubmed
,
Xenbase
Rothberg,
Gating kinetics of single large-conductance Ca2+-activated K+ channels in high Ca2+ suggest a two-tiered allosteric gating mechanism.
1999,
Pubmed
Schreiber,
Slo3, a novel pH-sensitive K+ channel from mammalian spermatocytes.
1998,
Pubmed
Schreiber,
Transplantable sites confer calcium sensitivity to BK channels.
1999,
Pubmed
,
Xenbase
Schreiber,
A novel calcium-sensing domain in the BK channel.
1997,
Pubmed
,
Xenbase
Shi,
Mechanism of magnesium activation of calcium-activated potassium channels.
2002,
Pubmed
Wei,
Calcium sensitivity of BK-type KCa channels determined by a separable domain.
1994,
Pubmed
Xia,
Molecular basis for the inactivation of Ca2+- and voltage-dependent BK channels in adrenal chromaffin cells and rat insulinoma tumor cells.
1999,
Pubmed
,
Xenbase
Xia,
Multiple regulatory sites in large-conductance calcium-activated potassium channels.
2002,
Pubmed
Yuan,
SLO-2, a K+ channel with an unusual Cl- dependence.
2000,
Pubmed
Yuan,
The sodium-activated potassium channel is encoded by a member of the Slo gene family.
2003,
Pubmed
,
Xenbase
Zeng,
Redox-sensitive extracellular gates formed by auxiliary beta subunits of calcium-activated potassium channels.
2003,
Pubmed
Zhang,
Allosteric regulation of BK channel gating by Ca(2+) and Mg(2+) through a nonselective, low affinity divalent cation site.
2001,
Pubmed
,
Xenbase
