Cloning and Functional Characterization of Novel Large Conductance Calcium-activated Potassium Channel β Subunits, hKCNMB3 and hKCNMB4*
- R. Brenner, T. Jegla, A. Wickenden, Yi Liu, R. Aldrich
- BiologyJournal of Biological Chemistry
- 3 March 2000
The cloning and characterization of two novel calcium-activated potassium channel β subunits that are enriched in the testis and brain are presented, and it is found that the different effects of the β subunit on some Hslo1 channel properties are calcium-dependent.
Effects of external cations and mutations in the pore region on C-type inactivation of Shaker potassium channels.
C-type inactivation is a process influenced by the ionic composition of the external milieu which strongly depends on the amino acid at position 449 in the pore region, and may help to explain the variability in inactivation kinetics observed in the various types of K channels.
Coupling between Voltage Sensor Activation, Ca2+ Binding and Channel Opening in Large Conductance (BK) Potassium Channels
This dual-allosteric mechanism can reproduce the steady-state behavior of mSlo1 over a wide range of conditions, with the assumption that activation of individual Ca2+ sensors or voltage sensors additively affect the energy of the C-O transition and that a weak interaction between Ca2+.
Shaker potassium channel gating. III: Evaluation of kinetic models for activation
Predictions of different classes of gating models involving identical conformational changes in each of four subunits were compared to the gating behavior of Shaker potassium channels without N-type inactivation to see if they could adequately account for the steady state and kinetic behavior of the channel.
Shaker potassium channel gating. II: Transitions in the activation pathway
The results were generally consistent with models involving a number of independent and identical transitions with a major exception that the first closing transition is slower than expected as indicated by tail current and OFF gating charge measurements.
Two types of inactivation in Shaker K+ channels: Effects of alterations in the carboxy-terminal region
Tetraethylammonium blockade distinguishes two inactivation mechanisms in voltage-activated K+ channels.
- K. L. Choi, R. Aldrich, G. Yellen
- BiologyProceedings of the National Academy of Sciences…
- 15 June 1991
It is reported that remnant inactivation must occur by a distinct mechanism from the rapid inactivation of the wild-type Shaker channel, which is sensitive only to intracellular application of tetraethylammonium.
Vasoregulation by the β1 subunit of the calcium-activated potassium channel
It is shown that targeted deletion of the gene for the β1 subunit leads to a decrease in the calcium sensitivity of BK channels, a reduction in functional coupling of calcium sparks to BK channel activation, and increases in arterial tone and blood pressure.
Local potassium signaling couples neuronal activity to vasodilation in the brain
The results support the concept of intercellular K+ channel–to–K+ channel signaling, through which neuronal activity in the form of an astrocytic Ca2+ signal is decoded by astroCytic BK channels, which locally release K+ into the perivascular space to activate SMC Kir channels and cause vasodilation.
International Union of Pharmacology. LII. Nomenclature and Molecular Relationships of Calcium-Activated Potassium Channels
- A. Wei, G. Gutman, R. Aldrich, K. Chandy, S. Grissmer, H. Wulff
- BiologyPharmacological Reviews
- 1 December 2005
The first cloned potassium channel gene was the Drosophila voltage-gated shaker channel, and this was rapidly followed by the identification of other potassium channel genes.