Functional analysis of mutant IKs channels associated with long
QT syndrome type 1

a 2018

Functional analysis of mutant IKs channels associated with long QT syndrome type 1

BÉBAROVÁ, Markéta; Olga ŠVECOVÁ; Larisa BAIAZITOVA; Marcela POLICAROVÁ; Jan HOŠEK et al.

Základní údaje

Originální název

Functional analysis of mutant IKs channels associated with long QT syndrome type 1

Autoři

BÉBAROVÁ, Markéta ; Olga ŠVECOVÁ ; Larisa BAIAZITOVA; Marcela POLICAROVÁ; Jan HOŠEK a Tomáš NOVOTNÝ

Vydání

New Frontiers in Basic Cardiovascular Research: France - New EU Members, 2018

Další údaje

Jazyk

angličtina

Typ výsledku

Konferenční abstrakt

Stát vydavatele

Česká republika

Utajení

není předmětem státního či obchodního tajemství

Označené pro přenos do RIV

Organizační jednotka

Lékařská fakulta

Příznaky

Mezinárodní význam

Změněno: 26. 11. 2018 17:11, doc. MUDr. Markéta Bébarová, Ph.D.

Anotace

V originále

Long QT syndrome type 1 (LQT1) is an inherited arrhythmogenic syndrome caused by mostly heterozygous loss-of-function mutations in the KCNQ1 gene encoding structure of the alpha-subunit (Kv7.1 protein) of slow delayed rectifier potassium current (IKs), an important repolarizing current, especially during increased sympathetic stimulation. We aimed to analyse functional impact of two Kv7.1 mutations that have not been studied so far, namely P-loop mutation T309I and C-terminal mutation R562S. Measurements by the whole cell patch clamp technique were performed at 37degrees of C on wild-type (WT) and mutant human IKs channels transiently expressed on Chinese hamster ovary cells. Confocal microscopy was used to reveal cell localization of the channels. T309I mutation resulted in a complete loss of function due to absent cell membrane expression of the channels as proved by confocal microscopy. When WT and mutant subunits were coexpressed (1:1), haploinsufficiency character of the response was apparent with the average current at 0 mV decreased by about 55 %. A slight rightward shift and deceleration of activation of the current was also apparent. R562S mutation resulted at 0 mV in a decreased current (by about 49 %) with delayed and rightward shifted activation. Cotransfection of WT and R562S has not been tested so far. Our data revealed dysfunctional channels in both tested mutations. The dysfunction seemed to be mild in the case of R562S mutation. Hence, the pathogenic character of this mutation remains to be further proved.

Návaznosti

NV16-30571A, projekt VaV

Název: Klinický význam a elektrofyziologické zhodnocení mutace c.926C>T genu KCNQ1 (p.T309I) jako možné „founder mutation“ syndromu dlouhého intervalu QT

Citovat

BÉBAROVÁ, Markéta; Olga ŠVECOVÁ; Larisa BAIAZITOVA; Marcela POLICAROVÁ; Jan HOŠEK a Tomáš NOVOTNÝ. Functional analysis of mutant IKs channels associated with long QT syndrome type 1. In New Frontiers in Basic Cardiovascular Research: France - New EU Members. 2018.

@proceedings{1472416,
   author = {Bébarová, Markéta and Švecová, Olga and Baiazitova, Larisa and Policarová, Marcela and Hošek, Jan and Novotný, Tomáš},
   booktitle = {New Frontiers in Basic Cardiovascular Research: France - New EU Members},
   language = {eng},
   title = {Functional analysis of mutant IKs channels associated with long QT syndrome type 1},
   year = {2018}
}

TY  - CONF
ID  - 1472416
AU  - Bébarová, Markéta - Švecová, Olga - Baiazitova, Larisa - Policarová, Marcela - Hošek, Jan - Novotný, Tomáš
PY  - 2018
TI  - Functional analysis of mutant IKs channels associated with long QT syndrome type 1
N2  - Long QT syndrome type 1 (LQT1) is an inherited arrhythmogenic syndrome caused by mostly heterozygous loss-of-function mutations in the KCNQ1 gene encoding structure of the alpha-subunit (Kv7.1 protein) of slow delayed rectifier potassium current (IKs), an important repolarizing current, especially during increased sympathetic stimulation. We aimed to analyse functional impact of two Kv7.1 mutations that have not been studied so far, namely P-loop mutation T309I and C-terminal mutation R562S. Measurements by the whole cell patch clamp technique were performed at 37degrees of C on wild-type (WT) and mutant human IKs channels transiently expressed on Chinese hamster ovary cells. Confocal microscopy was used to reveal cell localization of the channels. T309I mutation resulted in a complete loss of function due to absent cell membrane expression of the channels as proved by confocal microscopy. When WT and mutant subunits were coexpressed (1:1), haploinsufficiency character of the response was apparent with the average current at 0 mV decreased by about 55 %. A slight rightward shift and deceleration of activation of the current was also apparent. R562S mutation resulted at 0 mV in a decreased current (by about 49 %) with delayed and rightward shifted activation. Cotransfection of WT and R562S has not been tested so far. Our data revealed dysfunctional channels in both tested mutations. The dysfunction seemed to be mild in the case of R562S mutation. Hence, the pathogenic character of this mutation remains to be further proved.
ER  -

BÉBAROVÁ, Markéta; Olga ŠVECOVÁ; Larisa BAIAZITOVA; Marcela POLICAROVÁ; Jan HOŠEK a Tomáš NOVOTNÝ. Functional analysis of mutant IKs channels associated with long QT syndrome type 1. In \textit{New Frontiers in Basic Cardiovascular Research: France - New EU Members}. 2018.

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