Kv6.1
Description: potassium voltage-gated channel, subfamily G, member 1 Gene: Kcng1 Synonyms: Kv6.1, kcng1, kh2, kcng, k13
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].
Experimental data
Rat Kv6.1 gene in CHO host cell datasheet |
||
Click for details ![]() 15 °C |
Click for details ![]() 25 °C |
Click for details ![]() 35 °C |
Gene
Transcript
Acc No | Sequence | Length | Source | |
---|---|---|---|---|
NM_001106545 | n/A | n/A | NCBI | |
NM_001081134 | n/A | n/A | NCBI | |
NM_002237 | n/A | n/A | NCBI |
Ontology
Accession | Name | Definition | Evidence | |||||||
---|---|---|---|---|---|---|---|---|---|---|
GO:0008076 | voltage-gated potassium channel complex | A protein complex that forms a transmembrane channel through which potassium ions may cross a cell membrane in response to changes in membrane potential. | IEA | |||||||
GO:0016020 | membrane | Double layer of lipid molecules that encloses all cells, and, in eukaryotes, many organelles; may be a single or double lipid bilayer; also includes associated proteins. | IEA |
Interaction
Protein
Structure
The sparsely populated Kv channel subfamilies Kv5 and Kv6 each contain one member, Kv5.1 and Kv6.1 (see Chandy, K.G. and Gutman, G.A. (1995) In: (R.A. North, ed.), Handbook of Receptors and Channels. Ligand- and Voltage- Gated Ion Channels. CRC Press, Ann Arbor, MI, pp. 1-71) referred to as IK8 and K13, [399]. No function has yet been demonstrated for either of these proteins alone [399]. 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.
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]
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.
KV6.1 Kinetics with Kv2
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
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)
Model
References
649
Isacoff EY
et al.
Evidence for the formation of heteromultimeric potassium channels in Xenopus oocytes.
Nature,
1990
Jun
7
, 345 (530-4).
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).
Jegla T
et al.
A novel subunit for shal K+ channels radically alters activation and inactivation.
J. Neurosci.,
1997
Jan
1
, 17 (32-44).
Salinas M
et al.
New modulatory alpha subunits for mammalian Shab K+ channels.
J. Biol. Chem.,
1997
Sep
26
, 272 (24371-9).
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).
Chen TY
et al.
A new subunit of the cyclic nucleotide-gated cation channel in retinal rods.
Nature,
1993
Apr
22
, 362 (764-7).
Liman ER
et al.
A second subunit of the olfactory cyclic nucleotide-gated channel confers high sensitivity to cAMP.
Neuron,
1994
Sep
, 13 (611-21).
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).
656
Biel M
et al.
Molecular cloning and expression of the Modulatory subunit of the cyclic nucleotide-gated cation channel.
J. Biol. Chem.,
1996
Mar
15
, 271 (6349-55).
Haug T
et al.
Regulation of K+ flow by a ring of negative charges in the outer pore of BKCa channels. Part I: Aspartate 292 modulates K+ conduction by external surface charge effect.
J. Gen. Physiol.,
2004
Aug
, 124 (173-84).
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).
Liman ER
et al.
Voltage-sensing residues in the S4 region of a mammalian K+ channel.
Nature,
1991
Oct
24
, 353 (752-6).
Xu J
et al.
Assembly of voltage-gated potassium channels. Conserved hydrophilic motifs determine subfamily-specific interactions between the alpha-subunits.
J. Biol. Chem.,
1995
Oct
20
, 270 (24761-8).
399
Post MA
et al.
Kv2.1 and electrically silent Kv6.1 potassium channel subunits combine and express a novel current.
FEBS Lett.,
1996
Dec
9
, 399 (177-82).
Kramer JW
et al.
Modulation of potassium channel gating by coexpression of Kv2.1 with regulatory Kv5.1 or Kv6.1 alpha-subunits.
Am. J. Physiol.,
1998
Jun
, 274 (C1501-10).
Brahmajothi MV
et al.
In situ hybridization reveals extensive diversity of K+ channel mRNA in isolated ferret cardiac myocytes.
Circ. Res.,
1996
Jun
, 78 (1083-9).
Credits
Contributors: Rajnish Ranjan, Michael Schartner
To cite this page: [Contributors] Channelpedia https://channelpedia.epfl.ch/ionchannels/19/ , accessed on [date]