2014
Long-QT mutation p.K557E-Kv7.1: dominant-negative suppression of I-Ks, but preserved cAMP-dependent up-regulation
SPÄTJENS, Roel L.H.M.G., Markéta BÉBAROVÁ, Sandrine R.M. SEYEN, Viola LENTINK, Roselie J. JONGBLOED et. al.Základní údaje
Originální název
Long-QT mutation p.K557E-Kv7.1: dominant-negative suppression of I-Ks, but preserved cAMP-dependent up-regulation
Autoři
SPÄTJENS, Roel L.H.M.G. (528 Nizozemské království), Markéta BÉBAROVÁ (203 Česká republika, garant, domácí), Sandrine R.M. SEYEN (528 Nizozemské království), Viola LENTINK (528 Nizozemské království), Roselie J. JONGBLOED (528 Nizozemské království), Yvonne H.J.M. ARENS (528 Nizozemské království), Jordi HEIJMAN (276 Německo) a Paul G.A. VOLDERS (528 Nizozemské království)
Vydání
Cardiovascular Research, Netherlands, Elsevier Science B.V. 2014, 0008-6363
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
30201 Cardiac and Cardiovascular systems
Stát vydavatele
Velká Británie a Severní Irsko
Utajení
není předmětem státního či obchodního tajemství
Impakt faktor
Impact factor: 5.940
Kód RIV
RIV/00216224:14110/14:00076953
Organizační jednotka
Lékařská fakulta
UT WoS
000343317000022
Klíčová slova anglicky
Long-QT syndrome type 1; I-Ks; Potassium channel; Adrenergic regulation; KCNQ1
Štítky
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 28. 11. 2014 13:53, Ing. Mgr. Věra Pospíšilíková
Anotace
V originále
Aims Mutations in KCNQ1, encoding for Kv7.1, the alpha-subunit of the I-Ks channel, cause long-QT syndrome type 1, potentially predisposing patients to ventricular tachyarrhythmias and sudden cardiac death, in particular, during elevated sympathetic tone. Here, we aim at characterizing the p.Lys557Glu (K557E) Kv7.1 mutation, identified in a Dutch kindred, at baseline and during (mimicked) increased adrenergic tone. Methods and results K557E carriers had moderate QTc prolongation that augmented significantly during exercise. I-Ks characteristics were determined after co-expressing Kv7.1-wild-type (WT) and/or K557E with minK and Yotiao in Chinese hamster ovary cells. K557E caused I-Ks loss of function with slowing of the activation kinetics, acceleration of deactivation kinetics, and a rightward shift of voltage-dependent activation. Together, these contributed to a dominant-negative reduction in I-Ks density. Confocal microscopy and western blot indicated that trafficking of K557E channels was not impaired. Stimulation of WT I-Ks by 3'-5'-cyclic adenosine monophosphate (cAMP) generated strong current up-regulation that was preserved for K557E in both hetero- and homozygosis. Accumulation of I-Ks at fast rates occurred both in WT and in K557E, but was blunted in the latter. In a computational model, K557E showed a loss of action potential shortening during beta-adrenergic stimulation, in accordance with the lack of QT shortening during exercise in patients. Conclusion K557E causes I-Ks loss of function with reduced fast rate-dependent current accumulation. cAMP-dependent stimulation of mutant I-Ks is preserved, but incapable of fully compensating for the baseline current reduction, explaining the long QT intervals at baseline and the abnormal QT accommodation during exercise in affected patients.