Channelpedia

Kv6.1

Description: potassium voltage-gated channel, subfamily G, member 1
Gene: Kcng1
Alias: Kv6.1, kcng1, kh2, kcng, k13

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Introduction

Kv6.1, encoded by the gene KCNG1, is a member is a gamma subunit of the voltage-gated potassium channel, subfamily G. Kv6.1 is thought to be a delayed-rectifier type channels that may contribute to cardiac action potential repolarization. NCBI

Experimental data

Rat Kv6.1 gene in CHO host cells       datasheet

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15 °C
show 41 cells

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25 °C
show 92 cells

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35 °C
show 69 cells
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Gene

Species NCBI gene ID Chromosome Position
Human 3755 20 19451
Mouse 241794 2 21416
Rat 296395 3 32160
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Transcript

Species NCBI accession Length (nt)
Human NM_002237.4 2189
Mouse NM_001081134.2 4063
Rat NM_001106545.1 2745
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Protein Isoforms

Species Uniprot ID Length (aa)
Human Q9UIX4 513
Mouse A2BDX4 514
Rat D4AD53 514

Isoforms

Transcript
Length (nt)
Protein
Length (aa)
Variant
Isoform
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Post-Translational Modifications

PTM
Position
Type
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Structure

Kv6.1
Visual Representation of Kv6.1 Structure
Methodology for visual representation of structure available here

Comparisons of predicted amino acid sequences strongly indicate that both Kv5.1 and Kv6.1 are members of the Kv family [399], exhibiting hallmarks such as the conserved GYGD sequence in H5 [657], six hydrophobic transmembrane domains including the positively charged S4 [658],[659], and amino terminal Tl [8] or NA and Nn [399],[660] domains.

Kv6.1 predicted AlphaFold size

Species Area (Å2) Reference
Human 4650.40 source
Mouse 6288.75 source
Rat 6172.24 source

Methodology for AlphaFold size prediction and disclaimer are available here

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Kinetics

Heteromultimeric potassium channels may include alpha-subunits, such as Kv6.1, that are electrically silent when expressed alone, as is the case for the Kir2 subfamily [652], cyclic nucleotide gated channels [653], [654], [655] and perhaps the Kv4 subfamily [656].

KV6.1 Kinetics with Kv2

Kv5.1 kin

We previously showed that coexpression of Kv2.1 and Kv6.1 resulted in currents that deactivated extremely slowly upon depolarization [398]



Human Kv6.1/ Kv6.3/ Kv6.4 Expressed with human Kv2.1 in CHO-K1 Cells

Kv5.1 kin Currents were measured using whole cells patch clamp techniques. The cells were superfused with symmetrical high K+ solutions and depolarizing voltage steps were applied from the holding potential of -80 mV to potentials between -70 and +40 mV (10 mV increments)

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Expression and Distribution

EXPRESSION OF KV6.1

Unlike kH1, 2.4 kb of kH2 was expressed predominantly in the brain, placenta, and the skeletal muscle where it shared a differently spliced form of the kH2 mRNA, approximately 2.0 kb [1698]

Expression in heart

All three known members of the Kv4 family are expressed in the ferret heart, with Kv4.2 being the most abundant (P≤.01). The transcript of Kv5.1 was most common in the right atrium (46.4%) and rarest in the atrial septum (21.5%). Kv6.1 was less abundant. It was present in 28.4% of SA nodal cells and in <16% of cells in the other anatomic regions [1774]

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Function

Kv6.1 regulates the kinetics of Kv2.2 channels: It was much less effective in speeding inactivation at intermediate potentials than Kv5.1, had a slowing effect on inactivation at strong depolarizations, and had no effect on cumulative inactivation. Kv6.1 had profound effects on activation, including a negative shift of the steadystate activation curve and marked slowing of deactivation tail currents. [389]

Regulation of gating by electrically silent alpha-subunits, such as Kv6.1, is not restricted to the Kv2 subfamily. They interact with members of the Shal [651] and Kv3 (Shaw) [400] subfamilies as well.

Amino terminal portions of Kv6.1 were unable to form homomultimers but interacted specifically with amino termini of Kv2.1. Xenopus oocytes co-injected with Kv6.1 and Kv2.1 cRNAs exhibited a novel current with decreased rates of deactivation, decreased sensitivity to TEA block, and a hyperpolarizing shift of the half maximal activation potential when compared to Kv2.1. Our results indicate that Kv channel subfamilies can form heteromultimeric channels and, for the first time, suggest a possible functional role for the Kv6 subfamily.

References

312

Rettig J et al. Inactivation properties of voltage-gated K+ channels altered by presence of beta-subunit.
Nature, 1994 May 26 , 369 (289-94).

400

Salinas M et al. New modulatory alpha subunits for mammalian Shab K+ channels.
J. Biol. Chem., 1997 Sep 26 , 272 (24371-9).

649

Isacoff EY et al. Evidence for the formation of heteromultimeric potassium channels in Xenopus oocytes.
Nature, 1990 Jun 7 , 345 (530-4).

651

Jegla T et al. A novel subunit for shal K+ channels radically alters activation and inactivation.
J. Neurosci., 1997 Jan 1 , 17 (32-44).

652

Namba N et al. Kir2.2v: a possible negative regulator of the inwardly rectifying K+ channel Kir2.2.
FEBS Lett., 1996 May 20 , 386 (211-4).

653

Chen TY et al. A new subunit of the cyclic nucleotide-gated cation channel in retinal rods.
Nature, 1993 Apr 22 , 362 (764-7).

655

Bradley J et al. Heteromeric olfactory cyclic nucleotide-gated channels: a subunit that confers increased sensitivity to cAMP.
Proc. Natl. Acad. Sci. U.S.A., 1994 Sep 13 , 91 (8890-4).

658

Papazian DM et al. Alteration of voltage-dependence of Shaker potassium channel by mutations in the S4 sequence.
Nature, 1991 Jan 24 , 349 (305-10).

659

Liman ER et al. Voltage-sensing residues in the S4 region of a mammalian K+ channel.
Nature, 1991 Oct 24 , 353 (752-6).

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Credits

Contributors: Rajnish Ranjan, Michael Schartner, Katherine Johnston

To cite this page: [Contributors] Channelpedia https://channelpedia.epfl.ch/wikipages/19/ , accessed on 2024 Dec 21


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