TY - JOUR
T1 - HERG channel dysfunction in human long QT syndrome. Intracellular transport and functional defects
AU - Zhou, Zhengfeng
AU - Gong, Qiuming
AU - Epstein, Miles L.
AU - January, Craig T.
PY - 1998/8/14
Y1 - 1998/8/14
N2 - Mutations in HERG are associated with human chromosome 7-linked congenital long QT (LQT-2) syndrome. We used electrophysiological, biochemical, and immunohistochemical methods to study the molecular mechanisms of HERG channel dysfunction caused by LQT-2 mutations. Wild type HERG and LQT-2 mutations were studied by stable and transient expression in HEK 293 cells. We found that some mutations (Y611H and V822M) caused defects in biosynthetic processing of HERG channels with the protein retained in the endoplasmic reticulum. Other mutations (1593R and G628S) were processed similarly to wild type HERG protein, but these mutations did not produce functional channels. In contrast, the T474I mutation expressed HERG current but with altered gating properties. These findings suggest that the loss of HERG channel function in LQT-2 mutations is caused by multiple mechanisms including abnormal channel processing, the generation of nonfunctional channels, and altered channel gating.
AB - Mutations in HERG are associated with human chromosome 7-linked congenital long QT (LQT-2) syndrome. We used electrophysiological, biochemical, and immunohistochemical methods to study the molecular mechanisms of HERG channel dysfunction caused by LQT-2 mutations. Wild type HERG and LQT-2 mutations were studied by stable and transient expression in HEK 293 cells. We found that some mutations (Y611H and V822M) caused defects in biosynthetic processing of HERG channels with the protein retained in the endoplasmic reticulum. Other mutations (1593R and G628S) were processed similarly to wild type HERG protein, but these mutations did not produce functional channels. In contrast, the T474I mutation expressed HERG current but with altered gating properties. These findings suggest that the loss of HERG channel function in LQT-2 mutations is caused by multiple mechanisms including abnormal channel processing, the generation of nonfunctional channels, and altered channel gating.
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U2 - 10.1074/jbc.273.33.21061
DO - 10.1074/jbc.273.33.21061
M3 - Article
C2 - 9694858
AN - SCOPUS:0032516934
SN - 0021-9258
VL - 273
SP - 21061
EP - 21066
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 33
ER -