GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:10692449

From GONUTS
Jump to: navigation, search
Citation

Brenner, R, Jegla, TJ, Wickenden, A, Liu, Y and Aldrich, RW (2000) Cloning and functional characterization of novel large conductance calcium-activated potassium channel beta subunits, hKCNMB3 and hKCNMB4. J. Biol. Chem. 275:6453-61

Abstract

We present the cloning and characterization of two novel calcium-activated potassium channel beta subunits, hKCNMB3 and hKCNMB4, that are enriched in the testis and brain, respectively. We compare and contrast the steady state and kinetic properties of these beta subunits with the previously cloned mouse beta1 (mKCNMB1) and the human beta2 subunit (hKCNMB2). Once inactivation is removed, we find that hKCNMB2 has properties similar to mKCNMB1. hKCNMB2 slows Hslo1 channel gating and shifts the current-voltage relationship to more negative potentials. hKCNMB3 and hKCNMB4 have distinct effects on slo currents not observed with mKCNMB1 and hKCNMB2. Although we found that hKCNMB3 does interact with Hslo channels, its effects on Hslo1 channel properties were slight, increasing Hslo1 activation rates. In contrast, hKCNMB4 slows Hslo1 gating kinetics, and modulates the apparent calcium sensitivity of Hslo1. We found that the different effects of the beta subunits on some Hslo1 channel properties are calcium-dependent. mKCNMB1 and hKCNMB2 slow activation at 1 microM but not at 10 microM free calcium concentrations. hKCNMB4 decreases Hslo1 channel openings at low calcium concentrations but increases channel openings at high calcium concentrations. These results suggest that beta subunits in diverse tissue types fine-tune slo channel properties to the needs of a particular cell.

Links

PubMed

Keywords

Amino Acid Sequence; Brain/metabolism; Calcium/pharmacology; Cloning, Molecular; Humans; Ion Channel Gating; Kinetics; Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; Large-Conductance Calcium-Activated Potassium Channel beta Subunits; Large-Conductance Calcium-Activated Potassium Channels; Male; Molecular Sequence Data; Nerve Tissue Proteins/chemistry; Patch-Clamp Techniques; Potassium Channels/chemistry; Potassium Channels/genetics; Potassium Channels, Calcium-Activated; RNA, Messenger/metabolism; Sequence Alignment; Testis/metabolism

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

HUMAN:KCMA1

enables

GO:0005515: protein binding

ECO:0000353: physical interaction evidence used in manual assertion

UniProtKB:Q86W47

F

Seeded From UniProt

complete

HUMAN:KCMB4

involved_in

GO:0007268: chemical synaptic transmission

ECO:0000304: author statement supported by traceable reference used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB4

involved_in

GO:0006813: potassium ion transport

ECO:0000304: author statement supported by traceable reference used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB4

enables

GO:0015269: calcium-activated potassium channel activity

ECO:0000314: direct assay evidence used in manual assertion

F

Seeded From UniProt

complete

HUMAN:KCMB4

enables

GO:0005515: protein binding

ECO:0000353: physical interaction evidence used in manual assertion

UniProtKB:Q12791

F

Seeded From UniProt

complete

HUMAN:KCMB4

involved_in

GO:0019229: regulation of vasoconstriction

ECO:0000304: author statement supported by traceable reference used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB4

involved_in

GO:0019228: neuronal action potential

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB4

part_of

GO:0008076: voltage-gated potassium channel complex

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

HUMAN:KCMB4

located_in

GO:0005887: integral component of plasma membrane

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

HUMAN:KCMB4

involved_in

GO:0006813: potassium ion transport

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB4

involved_in

GO:0005513: detection of calcium ion

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB4

involved_in

GO:0001508: action potential

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB4

involved_in

GO:0046928: regulation of neurotransmitter secretion

ECO:0000304: author statement supported by traceable reference used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB3

enables

GO:0015269: calcium-activated potassium channel activity

ECO:0000314: direct assay evidence used in manual assertion

F

Seeded From UniProt

complete

HUMAN:KCMB3

involved_in

GO:0019228: neuronal action potential

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB3

part_of

GO:0008076: voltage-gated potassium channel complex

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

HUMAN:KCMB3

located_in

GO:0005887: integral component of plasma membrane

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

HUMAN:KCMB3

involved_in

GO:0006813: potassium ion transport

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB3

involved_in

GO:0005513: detection of calcium ion

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB3

involved_in

GO:0001508: action potential

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB2

enables

GO:0015269: calcium-activated potassium channel activity

ECO:0000314: direct assay evidence used in manual assertion

F

Seeded From UniProt

complete

HUMAN:KCMB2

involved_in

GO:0019229: regulation of vasoconstriction

ECO:0000304: author statement supported by traceable reference used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB2

involved_in

GO:0019228: neuronal action potential

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB2

part_of

GO:0008076: voltage-gated potassium channel complex

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

HUMAN:KCMB2

located_in

GO:0005887: integral component of plasma membrane

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

HUMAN:KCMB2

involved_in

GO:0006813: potassium ion transport

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB2

involved_in

GO:0005513: detection of calcium ion

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:KCMB2

involved_in

GO:0001508: action potential

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete


See also

References

See Help:References for how to manage references in GONUTS.