Potassium channels play a central role in cardiac and neuronal functions. Mutations of the human ether-a-go-go (hERG) potassium channel are causal to long QT syndrome. Many drugs that have been withdrawn from the market are due to the inhibitory effects on potassium channels such as hERG, thereby causing prolongation of the QT interval, which ultimately could lead to cardiac sudden death. The failure to express a membrane receptor on a cell surface represents one of the most common and well known mechanisms of action that are caused by genetic mutations in human diseases, including the Long QT syndrome. Although the sequence motifs that dominantly localize protein to intracellular compartments (e.g., ER retention or localization) have been studied extensively, little is known about either motifs or machinery that zipcode the plasma membrane expression of surface receptors. The proposed research is focused on the biogenesis of potassium channel using a combination of molecular, biochemical, and electrophysiological approaches. This proposal is aimed at addressing fundamental questions concerning potassium channel biogenesis. By achieving the proposed goals, much will be learned about the forward trafficking process. This information may provide a general principle concerning functional expression of membrane proteins, and important insights into the molecular basis of human diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM070959-04
Application #
7345485
Study Section
Biophysics of Synapses, Channels, and Transporters Study Section (BSCT)
Program Officer
Shapiro, Bert I
Project Start
2005-02-01
Project End
2010-01-31
Budget Start
2008-02-01
Budget End
2010-01-31
Support Year
4
Fiscal Year
2008
Total Cost
$295,452
Indirect Cost
Name
Johns Hopkins University
Department
Neurosciences
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
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Xiong, Qiaojie; Sun, Haiyan; Li, Min (2007) Zinc pyrithione-mediated activation of voltage-gated KCNQ potassium channels rescues epileptogenic mutants. Nat Chem Biol 3:287-96

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