KCNH1

Last updated

KCNH1
Available structures
PDB Ortholog search: PDBe RCSB
Identifiers
Aliases KCNH1 , EAG, EAG1, Kv10.1, h-eag, TMBTS, ZLS1, hEAG1, potassium voltage-gated channel subfamily H member 1, hEAG
External IDs OMIM: 603305; MGI: 1341721; HomoloGene: 68242; GeneCards: KCNH1; OMA:KCNH1 - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_002238
NM_172362

NM_001038607
NM_010600

RefSeq (protein)

NP_002229
NP_758872

NP_001033696
NP_034730

Location (UCSC) Chr 1: 210.68 – 211.13 Mb Chr 1: 191.87 – 192.19 Mb
PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Potassium voltage-gated channel subfamily H member 1 (KV10.1, EAG1) is a protein that in humans is encoded by the KCNH1 gene. [5] [6] [7] Mutations in KCNH1 cause genetic epilepsy and developmental encephalopathies, and aberant expression is associated with tumor progression.

Contents

Function

Expression of KCNH1 is predominantly restricted to the adult central nervous system. [8] The KCNH1 gene encodes a homotetrameric highly-conserved voltage-gated potassium channel (KV10.1) thought to be responsible for reestablishing the membrane potential of excitatory neurons in response to high frequency firing. [9]

KV10.1 is a non-inactivating delayed rectifier potassium channel. Like other voltage-gated potassium ion channels, opening of the KV10.1 channel pore is triggered by membrane depolarisation, which results in an outward flow of potassium ions to rectify the baseline membrane potential. KV10.1 is slow to open when triggered and does not undergo an inactivation state after closing.

Structurally, KV10.1 is composed of four identical subunits that are each 989 residues long (111.4 kDa). Each subunit is composed of a PAS domain, transmembrane voltage-sensing and pore domains, a C-linker, and an intracellular cyclic nucleotide-binding homology domain. Alternative splicing of this gene results in two transcript variants encoding distinct isoforms that differ by the inclusion or exclusion of 27 amino acids between the S3 and S4 helices of the voltage-sensing domain. [7]

KCNH1 expression is activated at the onset of myoblast differentiation and known to play roles in the cell cycle and cell proliferation. [10]

Pathologies

Gabbett and colleagues described Temple–Baraitser syndrome (TBS) in 2008, naming the condition after English clinical geneticists Profs Karen Temple and Michael Baraitser. [11] TBS is categorized by intellectual disabilities, epilepsy, atypical facial features, and aplasia of the nails.

It was later demonstrated that de novo missense mutations in the KCNH1 gene cause deleterious gain of function in the voltage-gated potassium channel, resulting in TBS. [12] Patients with de novo mutations in KCNH1 were found to be affected by epilepsy, while children born with germline mutations from mosaic probands were affected by TBS. [12] This provides further evidence of the role that genetic mosaicism plays in the etiology of neurological disorders. Type 1 Zimmermann–Laband syndrome was later found to be caused by similar missense mutations in KCNH1. [13] This has led some researchers to believe that type 1 Zimmermann-Laband and Temple-Baraitser syndromes are different manifestations of the same disorder. [14] [15]

Overexpression of KCNH1 may confer a growth advantage to cancer cells and favor tumor cell proliferation, as KCNH1 overexpression has been observed in 70% of solid tumors. [16]

Interactions

KCNH1 has been shown to interact with KCNB1 [17] and is inhibited by the highly-conserved secondary messenger calmodulin in the presence of calcium.

See also

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000143473 Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000058248 Ensembl, May 2017
  3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. Occhiodoro T, Bernheim L, Liu JH, Bijlenga P, Sinnreich M, Bader CR, et al. (August 1998). "Cloning of a human ether-a-go-go potassium channel expressed in myoblasts at the onset of fusion". FEBS Letters. 434 (1–2): 177–182. Bibcode:1998FEBSL.434..177O. doi: 10.1016/S0014-5793(98)00973-9 . PMID   9738473.
  6. Gutman GA, Chandy KG, Grissmer S, Lazdunski M, McKinnon D, Pardo LA, et al. (December 2005). "International Union of Pharmacology. LIII. Nomenclature and molecular relationships of voltage-gated potassium channels". Pharmacological Reviews. 57 (4): 473–508. doi:10.1124/pr.57.4.10. PMID   16382104. S2CID   219195192.
  7. 1 2 "Entrez Gene: KCNH1 potassium voltage-gated channel, subfamily H (eag-related), member 1".
  8. "603305 - Potassium channel, voltage-gated; subfamily H, member 1; KCNH1". Online Mendelian Inheritance in Man (OMIM).
  9. Schmidt H, Farsi Z, Barrantes-Freer A, Rubio ME, Ufartes R, Eilers J, et al. (2015). "KV10.1 opposes activity-dependent increase in Ca2+ influx into the presynaptic terminal of the parallel fibre–Purkinje cell synapse". The Journal of Physiology. 593 (1): 181–196. doi:10.1113/jphysiol.2014.281600. ISSN   1469-7793. PMC   4293062 . PMID   25556795.
  10. del Camino D, Sánchez A, Alves F, Brüggemann A, Beckh S, Stühmer W, et al. (1999-10-15). "Oncogenic potential of EAG K+ channels". The EMBO Journal. 18 (20): 5540–5547. doi:10.1093/emboj/18.20.5540. ISSN   0261-4189. PMC   1171622 . PMID   10523298.
  11. Gabbett MT, Clark RC, McGaughran JM (February 2008). "A second case of severe mental retardation and absent nails of hallux and pollex (Temple-Baraitser syndrome)". American Journal of Medical Genetics. Part A. 146A (4): 450–452. doi:10.1002/ajmg.a.32129. PMID   18203178. S2CID   2532859.
  12. 1 2 Simons C, Rash LD, Crawford J, Ma L, Cristofori-Armstrong B, Miller D, et al. (January 2015). "Mutations in the voltage-gated potassium channel gene KCNH1 cause Temple-Baraitser syndrome and epilepsy". Nature Genetics. 47 (1): 73–77. doi:10.1038/ng.3153. PMID   25420144. S2CID   52799681.
  13. Kortüm F, Caputo V, Bauer CK, Stella L, Ciolfi A, Alawi M, et al. (June 2015). "Mutations in KCNH1 and ATP6V1B2 cause Zimmermann-Laband syndrome". Nature Genetics. 47 (6): 661–667. doi:10.1038/ng.3282. hdl: 2108/118197 . PMID   25915598. S2CID   12060592.
  14. Mégarbané A, Al-Ali R, Choucair N, Lek M, Wang E, Ladjimi M, et al. (June 2016). "Temple-Baraitser Syndrome and Zimmermann-Laband Syndrome: one clinical entity?". BMC Medical Genetics. 17 (1) 42. doi: 10.1186/s12881-016-0304-4 . PMC   4901505 . PMID   27282200.
  15. Bramswig NC, Ockeloen CW, Czeschik JC, van Essen AJ, Pfundt R, Smeitink J, et al. (October 2015). "'Splitting versus lumping': Temple-Baraitser and Zimmermann-Laband Syndromes". Human Genetics. 134 (10): 1089–1097. doi:10.1007/s00439-015-1590-1. PMID   26264464. S2CID   14238362.
  16. Tomczak AP, Zahed F, Stühmer W, Pardo LA, Urrego D (2014-03-19). "Potassium channels in cell cycle and cell proliferation". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 369 (1638): 20130094. doi:10.1098/rstb.2013.0094. PMC   3917348 . PMID   24493742.
  17. Ottschytsch N, Raes A, Van Hoorick D, Snyders DJ (June 2002). "Obligatory heterotetramerization of three previously uncharacterized Kv channel alpha-subunits identified in the human genome". Proceedings of the National Academy of Sciences of the United States of America. 99 (12): 7986–7991. Bibcode:2002PNAS...99.7986O. doi: 10.1073/pnas.122617999 . PMC   123007 . PMID   12060745.

Further reading

This article incorporates text from the United States National Library of Medicine, which is in the public domain.