| Structural highlights
Disease
[KCNQ1_HUMAN] Defects in KCNQ1 are the cause of long QT syndrome type 1 (LQT1) [MIM:192500]; also known as Romano-Ward syndrome (RWS). Long QT syndromes are heart disorders characterized by a prolonged QT interval on the ECG and polymorphic ventricular arrhythmias. They cause syncope and sudden death in response to exercise or emotional stress. LQT1 inheritance is an autosomal dominant.[1] [2] [3] [4] [5] [6] [7] [:][8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] Defects in KCNQ1 are the cause of Jervell and Lange-Nielsen syndrome type 1 (JLNS1) [MIM:220400]. JLNS1 is an autosomal recessive disorder characterized by congenital deafness, prolongation of the QT interval, syncopal attacks due to ventricular arrhythmias, and a high risk of sudden death.[28] [29] [30] Defects in KCNQ1 are the cause of familial atrial fibrillation type 3 (ATFB3) [MIM:607554]. Atrial fibrillation is a common disorder of cardiac rhythm that is hereditary in a small subgroup of patients. It is characterized by disorganized atrial electrical activity and ineffective atrial contraction promoting blood stasis in the atria and reduces ventricular filling. It can result in palpitations, syncope, thromboembolic stroke, and congestive heart failure.[31] Defects in KCNQ1 are the cause of short QT syndrome type 2 (SQT2) [MIM:609621]. Short QT syndromes are heart disorders characterized by idiopathic persistently and uniformly short QT interval on ECG in the absence of structural heart disease in affected individuals. They cause syncope and sudden death.[32]
Function
[KCNQ1_HUMAN] Probably important in cardiac repolarization. Associates with KCNE1 (MinK) to form the I(Ks) cardiac potassium current. Elicits a rapidly activating, potassium-selective outward current. Muscarinic agonist oxotremorine-M strongly suppresses KCNQ1/KCNE1 current in CHO cells in which cloned KCNQ1/KCNE1 channels were coexpressed with M1 muscarinic receptors. May associate also with KCNE3 (MiRP2) to form the potassium channel that is important for cyclic AMP-stimulated intestinal secretion of chloride ions, which is reduced in cystic fibrosis and pathologically stimulated in cholera and other forms of secretory diarrhea.
Publication Abstract from PubMed
Coiled-coils are widespread protein-protein interaction motifs typified by the heptad repeat (abcdefg)(n) in which 'a' and 'd' positions are hydrophobic residues. While identification of likely coiled-coil sequences is robust, prediction of strand order remains elusive. We present the X-ray crystal structure of a short form (residues 583-611), 'Q1-short', of the coiled-coil assembly specificity domain from the voltage-gated potassium channel Kv7.1 (KCNQ1) determined at 1.7 A resolution. Q1-short lacks one and half heptads present in a previously studied tetrameric coiled-coil construct, Kv7.1 585-621, 'Q1-long'. Surprisingly, Q1-short crystallizes as a trimer. In solution, Q1-short self-assembles more poorly than Q1-long and depends on an R-h-x-x-h-E motif common to trimeric coiled-coils. Addition of native sequences that include 'a' and 'd' positions C-terminal to Q1-short overrides the R-h-x-x-h-E motif influence and changes assembly state from a weakly associated trimer to a strongly associated tetramer. These data provide a striking example of a naturally occurring amino sequence that exhibits context-dependent folding into different oligomerization states, a three-stranded versus a four-stranded coiled-coil. The results emphasize the degenerate nature of coiled-coil energy landscapes in which small changes can have drastic effects on oligomerization. Discovery of these properties in an ion channel assembly domain and prevalence of the R-h-x-x-h-E motif in coiled-coil assembly domains of a number of different channels that are thought to function as tetrameric assemblies raises the possibility that such sequence features may be important for facilitating the assembly of intermediates en route to the final native state.
Crystal structure of a trimeric form of the K(V)7.1 (KCNQ1) A domain Tail coiled-coil reveals structural plasticity and context dependent changes in a putative coiled-coil trimerization motif.,Xu Q, Minor DL Jr Protein Sci. 2009 Aug 19. PMID:19693805[33]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
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- ↑ Itoh T, Tanaka T, Nagai R, Kikuchi K, Ogawa S, Okada S, Yamagata S, Yano K, Yazaki Y, Nakamura Y. Genomic organization and mutational analysis of KVLQT1, a gene responsible for familial long QT syndrome. Hum Genet. 1998 Sep;103(3):290-4. PMID:9799083
- ↑ Neyroud N, Richard P, Vignier N, Donger C, Denjoy I, Demay L, Shkolnikova M, Pesce R, Chevalier P, Hainque B, Coumel P, Schwartz K, Guicheney P. Genomic organization of the KCNQ1 K+ channel gene and identification of C-terminal mutations in the long-QT syndrome. Circ Res. 1999 Feb 19;84(3):290-7. PMID:10024302
- ↑ Wang Q, Curran ME, Splawski I, Burn TC, Millholland JM, VanRaay TJ, Shen J, Timothy KW, Vincent GM, de Jager T, Schwartz PJ, Toubin JA, Moss AJ, Atkinson DL, Landes GM, Connors TD, Keating MT. Positional cloning of a novel potassium channel gene: KVLQT1 mutations cause cardiac arrhythmias. Nat Genet. 1996 Jan;12(1):17-23. PMID:8528244 doi:http://dx.doi.org/10.1038/ng0196-17
- ↑ Shalaby FY, Levesque PC, Yang WP, Little WA, Conder ML, Jenkins-West T, Blanar MA. Dominant-negative KvLQT1 mutations underlie the LQT1 form of long QT syndrome. Circulation. 1997 Sep 16;96(6):1733-6. PMID:9323054
- ↑ Russell MW, Dick M 2nd, Collins FS, Brody LC. KVLQT1 mutations in three families with familial or sporadic long QT syndrome. Hum Mol Genet. 1996 Sep;5(9):1319-24. PMID:8872472
- ↑ de Jager T, Corbett CH, Badenhorst JC, Brink PA, Corfield VA. Evidence of a long QT founder gene with varying phenotypic expression in South African families. J Med Genet. 1996 Jul;33(7):567-73. PMID:8818942
- ↑ Tanaka T, Nagai R, Tomoike H, Takata S, Yano K, Yabuta K, Haneda N, Nakano O, Shibata A, Sawayama T, Kasai H, Yazaki Y, Nakamura Y. Four novel KVLQT1 and four novel HERG mutations in familial long-QT syndrome. Circulation. 1997 Feb 4;95(3):565-7. PMID:9024139
- ↑ Donger C, Denjoy I, Berthet M, Neyroud N, Cruaud C, Bennaceur M, Chivoret G, Schwartz K, Coumel P, Guicheney P. KVLQT1 C-terminal missense mutation causes a forme fruste long-QT syndrome. Circulation. 1997 Nov 4;96(9):2778-81. PMID:9386136
- ↑ van den Berg MH, Wilde AA, Robles de Medina EO, Meyer H, Geelen JL, Jongbloed RJ, Wellens HJ, Geraedts JP. The long QT syndrome: a novel missense mutation in the S6 region of the KVLQT1 gene. Hum Genet. 1997 Sep;100(3-4):356-61. PMID:9272155
- ↑ Wollnik B, Schroeder BC, Kubisch C, Esperer HD, Wieacker P, Jentsch TJ. Pathophysiological mechanisms of dominant and recessive KVLQT1 K+ channel mutations found in inherited cardiac arrhythmias. Hum Mol Genet. 1997 Oct;6(11):1943-9. PMID:9302275
- ↑ Li H, Chen Q, Moss AJ, Robinson J, Goytia V, Perry JC, Vincent GM, Priori SG, Lehmann MH, Denfield SW, Duff D, Kaine S, Shimizu W, Schwartz PJ, Wang Q, Towbin JA. New mutations in the KVLQT1 potassium channel that cause long-QT syndrome. Circulation. 1998 Apr 7;97(13):1264-9. PMID:9570196
- ↑ Priori SG, Schwartz PJ, Napolitano C, Bianchi L, Dennis A, De Fusco M, Brown AM, Casari G. A recessive variant of the Romano-Ward long-QT syndrome? Circulation. 1998 Jun 23;97(24):2420-5. PMID:9641694
- ↑ Splawski I, Shen J, Timothy KW, Vincent GM, Lehmann MH, Keating MT. Genomic structure of three long QT syndrome genes: KVLQT1, HERG, and KCNE1. Genomics. 1998 Jul 1;51(1):86-97. PMID:9693036 doi:S0888-7543(98)95361-7
- ↑ Saarinen K, Swan H, Kainulainen K, Toivonen L, Viitasalo M, Kontula K. Molecular genetics of the long QT syndrome: two novel mutations of the KVLQT1 gene and phenotypic expression of the mutant gene in a large kindred. Hum Mutat. 1998;11(2):158-65. PMID:9482580 doi:<158::AID-HUMU9>3.0.CO;2-F 10.1002/(SICI)1098-1004(1998)11:2<158::AID-HUMU9>3.0.CO;2-F
- ↑ Ackerman MJ, Schroeder JJ, Berry R, Schaid DJ, Porter CJ, Michels VV, Thibodeau SN. A novel mutation in KVLQT1 is the molecular basis of inherited long QT syndrome in a near-drowning patient's family. Pediatr Res. 1998 Aug;44(2):148-53. PMID:9702906
- ↑ Denjoy I, Lupoglazoff JM, Donger C, Berthet M, Richard P, Neyroud N, Villain E, Lucet V, Coumel P, Guicheney P. [Congenital long QT syndrome. The value of genetics in prognostic evaluation] Arch Mal Coeur Vaiss. 1999 May;92(5):557-63. PMID:10367071
- ↑ Priori SG, Napolitano C, Schwartz PJ. Low penetrance in the long-QT syndrome: clinical impact. Circulation. 1999 Feb 2;99(4):529-33. PMID:9927399
- ↑ Larsen LA, Fosdal I, Andersen PS, Kanters JK, Vuust J, Wettrell G, Christiansen M. Recessive Romano-Ward syndrome associated with compound heterozygosity for two mutations in the KVLQT1 gene. Eur J Hum Genet. 1999 Sep;7(6):724-8. PMID:10482963 doi:10.1038/sj.ejhg.5200323
- ↑ Jongbloed RJ, Wilde AA, Geelen JL, Doevendans P, Schaap C, Van Langen I, van Tintelen JP, Cobben JM, Beaufort-Krol GC, Geraedts JP, Smeets HJ. Novel KCNQ1 and HERG missense mutations in Dutch long-QT families. Hum Mutat. 1999;13(4):301-10. PMID:10220144 doi:<301::AID-HUMU7>3.0.CO;2-V 10.1002/(SICI)1098-1004(1999)13:4<301::AID-HUMU7>3.0.CO;2-V
- ↑ Larsen LA, Christiansen M, Vuust J, Andersen PS. High-throughput single-strand conformation polymorphism analysis by automated capillary electrophoresis: robust multiplex analysis and pattern-based identification of allelic variants. Hum Mutat. 1999;13(4):318-27. PMID:10220146 doi:<318::AID-HUMU9>3.0.CO;2-F 10.1002/(SICI)1098-1004(1999)13:4<318::AID-HUMU9>3.0.CO;2-F
- ↑ Franqueza L, Lin M, Shen J, Splawski I, Keating MT, Sanguinetti MC. Long QT syndrome-associated mutations in the S4-S5 linker of KvLQT1 potassium channels modify gating and interaction with minK subunits. J Biol Chem. 1999 Jul 23;274(30):21063-70. PMID:10409658
- ↑ Chouabe C, Neyroud N, Richard P, Denjoy I, Hainque B, Romey G, Drici MD, Guicheney P, Barhanin J. Novel mutations in KvLQT1 that affect Iks activation through interactions with Isk. Cardiovasc Res. 2000 Mar;45(4):971-80. PMID:10728423
- ↑ Splawski I, Shen J, Timothy KW, Lehmann MH, Priori S, Robinson JL, Moss AJ, Schwartz PJ, Towbin JA, Vincent GM, Keating MT. Spectrum of mutations in long-QT syndrome genes. KVLQT1, HERG, SCN5A, KCNE1, and KCNE2. Circulation. 2000 Sep 5;102(10):1178-85. PMID:10973849
- ↑ Tester DJ, Will ML, Haglund CM, Ackerman MJ. Compendium of cardiac channel mutations in 541 consecutive unrelated patients referred for long QT syndrome genetic testing. Heart Rhythm. 2005 May;2(5):507-17. PMID:15840476 doi:10.1016/j.hrthm.2005.01.020
- ↑ Thomas D, Khalil M, Alter M, Schweizer PA, Karle CA, Wimmer AB, Licka M, Katus HA, Koenen M, Ulmer HE, Zehelein J. Biophysical characterization of KCNQ1 P320 mutations linked to long QT syndrome 1. J Mol Cell Cardiol. 2010 Jan;48(1):230-7. doi: 10.1016/j.yjmcc.2009.06.009. Epub , 2009 Jun 21. PMID:19540844 doi:10.1016/j.yjmcc.2009.06.009
- ↑ Aidery P, Kisselbach J, Schweizer PA, Becker R, Katus HA, Thomas D. Biophysical properties of mutant KCNQ1 S277L channels linked to hereditary long QT syndrome with phenotypic variability. Biochim Biophys Acta. 2011 Apr;1812(4):488-94. doi: 10.1016/j.bbadis.2011.01.008., Epub 2011 Jan 15. PMID:21241800 doi:10.1016/j.bbadis.2011.01.008
- ↑ Chouabe C, Neyroud N, Richard P, Denjoy I, Hainque B, Romey G, Drici MD, Guicheney P, Barhanin J. Novel mutations in KvLQT1 that affect Iks activation through interactions with Isk. Cardiovasc Res. 2000 Mar;45(4):971-80. PMID:10728423
- ↑ Neyroud N, Denjoy I, Donger C, Gary F, Villain E, Leenhardt A, Benali K, Schwartz K, Coumel P, Guicheney P. Heterozygous mutation in the pore of potassium channel gene KvLQT1 causes an apparently normal phenotype in long QT syndrome. Eur J Hum Genet. 1998 Mar-Apr;6(2):129-33. PMID:9781056 doi:10.1038/sj.ejhg.5200165
- ↑ Mohammad-Panah R, Demolombe S, Neyroud N, Guicheney P, Kyndt F, van den Hoff M, Baro I, Escande D. Mutations in a dominant-negative isoform correlate with phenotype in inherited cardiac arrhythmias. Am J Hum Genet. 1999 Apr;64(4):1015-23. PMID:10090886
- ↑ Chen YH, Xu SJ, Bendahhou S, Wang XL, Wang Y, Xu WY, Jin HW, Sun H, Su XY, Zhuang QN, Yang YQ, Li YB, Liu Y, Xu HJ, Li XF, Ma N, Mou CP, Chen Z, Barhanin J, Huang W. KCNQ1 gain-of-function mutation in familial atrial fibrillation. Science. 2003 Jan 10;299(5604):251-4. PMID:12522251 doi:10.1126/science.1077771
- ↑ Bellocq C, van Ginneken AC, Bezzina CR, Alders M, Escande D, Mannens MM, Baro I, Wilde AA. Mutation in the KCNQ1 gene leading to the short QT-interval syndrome. Circulation. 2004 May 25;109(20):2394-7. PMID:15159330 doi:10.1161/01.CIR.0000130409.72142.FE
- ↑ Xu Q, Minor DL Jr. Crystal structure of a trimeric form of the K(V)7.1 (KCNQ1) A domain Tail coiled-coil reveals structural plasticity and context dependent changes in a putative coiled-coil trimerization motif. Protein Sci. 2009 Aug 19. PMID:19693805 doi:10.1002/pro.224
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