User Visitor Login
/images/graph_sv_i.gif
English only
EPFL > FSV > BBP > Channelpedia
Ion channels
References
Reports
SEARCH IN WIKI
Logged in as a Visitor.

Kv9.2

potassium voltage-gated channel, delayed-rectifier, subfamily S, member 2
Synonyms: Kv9.2 kcns2. Symbol: Kcns2

Introductions


KV9.2 is member 2 of subfamily S of potassium voltage-gated delayed-rectifier channels, encoded by the gene KCNS2.

Voltage-gated potassium channels form the largest and most diversified class of ion channels and are present in both excitable and nonexcitable cells. Their main functions are associated with the regulation of the resting membrane potential and the control of the shape and frequency of action potentials. The alpha subunits are of 2 types: those that are functional by themselves and those that are electrically silent but capable of modulating the activity of specific functional alpha subunits. The protein encoded by this gene is not functional by itself but can form heteromultimers with member 1 and with member 2 (and possibly other members) of the Shab-related subfamily of potassium voltage-gated channel proteins. This gene belongs to the S subfamily of the potassium channel family. [606]

(http://www.ncbi.nlm.nih.gov/pubmed?Db=gene&Cmd=retrieve&dopt=fullreport&listuids=3787)

Genes


In contrast to the genes in the other subfamilies, members of the Kv8 and Kv9 subfamilies have been found to be incapable of forming functional channels when expressed either in oocytes or cell lines. Moreover, these mammalian genes appear to have no Drosophila homologs. [402]

Kcns2 : potassium voltage-gated channel, delayed-rectifier, subfamily S, member 2

RGD ID Chromosome Position Species
621525 7 70249013-70280172 Rat
732195 15 34767136-34772092 Mouse
1342899 8 99439250-99443025 Human

Transcripts


Acc No Sequence Length Source
NM_023966 NCBI
NM_181317 NCBI
NM_020697 NCBI

Ontologies


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:0016021 integral to membrane Penetrating at least one phospholipid bilayer of a membrane. May also refer to the state of being buried in the bilayer with no exposure outside the bilayer. When used to describe a protein, indicates that all or part of the peptide sequence is embedded in the membrane. IEA
GO:0005886 plasma membrane The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins. 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

Interactions


Kv2.1 and Kv2.2

Kv9.1 and Kv9.2 colocalized with Kv2.1 and/or Kv2.2 α subunits in several regions of the brain and alters the Kv2's kinetics as well [400]

Proteins


Structures


Structure of Kv9.2 ion Channel

The ORFs of Kv9.1 and Kv9.2 encode proteins of 497 and 477 amino acids, respectively, with a calculated molecular mass of 54.9 and 54.3 kDa (Fig. 1 A). Protein sequences reveal that all the structural characteristics of outward rectifier voltage-gated K+ channel α subunits (Kv) are conserved in Kv9.1 and Kv9.2, i.e. six putative transmembrane segments (S1 to S6), a transmembrane region (S4) showing five positively charged amino acids and a conserved pore-forming region (named H5 or P domain). As indicated in Fig. 1 A, Kv9.1 and Kv9.2 subunits contain several putative phosphorylation sites located in the cytoplasmic regions for protein kinase C, cAMP-dependent protein kinase, Ca2+-calmodulin kinase II, casein kinase II, and tyrosine kinase. No N-glycosylation sequence was detected [400]

Kv9.1 and Kv9.2 are neuronal modulatory alpha subunits that define a structural family designated as Kv9. They modulate Kv2.alpha subunits but have no functional activity by themselves. [400]

Distributions


Expressions


Kv9.2 Expressed Exclusively in the Brain

Northern blot analysis presented in Fig.2 shows that Kv9.1 and Kv9.2 mRNAs are expressed only in the brain. Specific probes detected two transcripts for Kv9.1 with an estimated size of 2.2 and 2.7 kb and one for Kv9.2 of approximately 5.3 kb. No expression was observed in heart, spleen, lung, liver, skeletal muscle, kidney, or testis [4000]

Inferior Colliculus

Kv9.1 and Kv9.2, two known members of the Kv9 subfamily, appear to be expressed diffusely in cells of the inferior colliculus [400].

Functionals


K+ channel functions are included in very diverse processes such as neuronal integration, cardiac pacemaking, muscle contraction, and hormone secretion in excitable cells [735], as well as in cell proliferation, cell volume regulation, and lymphocyte differentiation [736].

Kv9.1 and Kv9.2 modulate Kv2.alpha subunits but have no functional activity by themselves [400]. I.e., the kinetics of activation and the voltage-dependence of Kv2.1 currents are altered by such co-expression with Kv9.1 [402].

Kinetics


Kinetics of Kv9.2 with Kv2 Family

Kv1.1 structure The time constant of activation of Kv2.1 was not modified by Kv9.1 but it was slightly increased by Kv9.2. No variation of the intensity of the remaining Kv2.1 current after a 9-s inactivation was recorded in the presence of Kv9.1 and Kv9.2. The image bellow shows that the normalized Kv2.2 currents are only slightly modified by Kv9.1 and Kv9.2. The time constant of activation of Kv2.2 was slightly decreased by Kv9.1 and not modified by Kv9.2 [400].

Models


References


[400 : 9305895]
[606 : 16382104]
[402 : 10962170]
[735 : 20670831]
[736 : 7612237]
[737 : 8271269]
[738 : 8038378]
[733 : 8361540]
[734 : 8361541]
[740 : 7748553]
[742 : 7556617]
[743 : 8816716]
[739 : 7538310]
[741 : 2317379]

Credits


Editor : Admin.

Contributors : Rajnish Ranjan, Michael Schartner

To cite : [Editor], [Contributors]. Accessed on [Date] Channelpedia , http://channelpedia.epfl.ch/ionchannels/31