A Kir2.1 gain-of-function mutation underlies familial atrial fibrillation.
The inward rectifier K(+) channel Kir2.1 mediates the potassium I(K1) current in the heart. It is encoded by KCNJ2 gene that has been linked to Andersen's syndrome. Recently, strong evidences showed that Kir2.1 channels were associated with mouse atrial fibrillation (AF), therefore we hypothesized that KCNJ2 was associated with familial AF. Thirty Chinese AF kindreds were evaluated for mutations in KCNJ2 gene. A valine-to-isoleucine mutation at position 93 (V93I) of Kir2.1 was found in all affected members in one kindred. This valine and its flanking sequence is highly conserved in Kir2.1 proteins among different species. Functional analysis of the V93I mutant demonstrated a gain-of-function consequence on the Kir2.1 current. This effect is opposed to the loss-of-function effect of previously reported mutations in Andersen's syndrome. Kir2.1 V93I mutation may play a role in initiating and/or maintaining AF by increasing the activity of the inward rectifier K(+) channel.
Xia
Min
M
Institute of Medical Genetics, Tongji University, Shanghai, China.
Jin
Qingfeng
Q
Bendahhou
Saïd
S
He
Yusong
Y
Larroque
Marie-Madeleine
MM
Chen
Yiping
Y
Zhou
Qinshu
Q
Yang
Yiqing
Y
Liu
Yi
Y
Liu
Ban
B
Zhu
Qian
Q
Zhou
Yanting
Y
Lin
Jie
J
Liang
Bo
B
Li
Li
L
Dong
Xiongjian
X
Pan
Zhiwen
Z
Wang
Rongrong
R
Wan
Haiying
H
Qiu
Weiqin
W
Xu
Wenyuan
W
Eurlings
Petra
P
Barhanin
Jacques
J
Chen
Yihan
Y
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D000818:Animals; D001281:Atrial Fibrillation / Q000235:genetics*; D019556:COS Cells; D002460:Cell Line; D017124:Conserved Sequence; D004247:DNA / Q000737:chemistry; D004252:DNA Mutational Analysis; D004594:Electrophysiology; D005192:Family Health; D005260:Female; D006325:Heart Atria / Q000378:metabolism; D006801:Humans; D007532:Isoleucine / Q000737:chemistry; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D024661:Potassium Channels, Inwardly Rectifying / Q000235:genetics*; D011487:Protein Conformation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014162:Transfection; D014633:Valine / Q000737:chemistry
C489457:KCNJ2 protein, human; D024661:Potassium Channels, Inwardly Rectifying; D007532:Isoleucine; D004247:DNA; D014633:Valine