Wangzhen Shen

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OBJECTIVE Rapid stimulation causes electrical remodeling in the intact atrium, with shortening of action potential duration (APD), down-regulation of L-type Ca2+ currents (I(Ca,L)), and increased vulnerability to atrial fibrillation (AF). The essential elements required for this process are currently unknown. We tested the hypothesis that rapid stimulation(More)
CO2 chemoreception may be related to modulation of inward rectifier K+ channels (Kir channels) in brainstem neurons. Kir4.1 is expressed predominantly in the brainstem and inhibited during hypercapnia. Although the homomeric Kir4.1 only responds to severe intracellular acidification, coexpression of Kir4.1 with Kir5.1 greatly enhances channel sensitivities(More)
With a worldwide incidence as high as 6.7% of children, febrile seizures are one of the most common reasons for seeking pediatric care, but the mechanisms underlying generation of febrile seizures are poorly understood. Febrile seizures have been suspected to have a genetic basis, and recently, mutations in GABAA receptor and sodium channel genes have been(More)
Approximately one-third of human genetic diseases are caused by premature translation-termination codon (PTC)-generating mutations. These mutations in sodium channel and GABA(A) receptor genes have been associated with idiopathic generalized epilepsies, but the cellular consequences of the PTCs on the mutant channel subunit biogenesis and function are(More)
Activation of protein kinase A (PKA) increases Na+ current derived from the human cardiac Na+ channel, hH1, in a slow, nonsaturable manner. This effect is prevented by compounds that disrupt plasma membrane recycling, implying enhanced trafficking of channels to the cell membrane as the mechanism responsible for Na+ current potentiation. To investigate the(More)
OBJECTIVE Na(+) current derived from expression of the principal cardiac Na(+) channel, Na(v)1.5, is increased by activation of protein kinase A (PKA). This effect is blocked by inhibitors of cell membrane recycling, or removal of a cytoplasmic endoplasmic reticulum (ER) retention motif, suggesting that PKA stimulation increases trafficking of cardiac Na(+)(More)
A GABA(A) receptor alpha1 subunit epilepsy mutation (alpha1(A322D)) introduces a negatively charged aspartate residue into the hydrophobic M3 transmembrane domain of the alpha1 subunit. We reported previously that heterologous expression of alpha1(A322D)beta2gamma2 receptors in mammalian cells resulted in reduced total and surface alpha1 subunit protein.(More)
Epileptic encephalopathies are a devastating group of severe childhood onset epilepsies with medication-resistant seizures and poor developmental outcomes. Many epileptic encephalopathies have a genetic aetiology and are often associated with de novo mutations in genes mediating synaptic transmission, including GABAA receptor subunit genes. Recently, we(More)
Mutations in GABAA receptor subunit genes are frequently associated with epilepsy, and nonsense mutations in GABRG2 are associated with several epilepsy syndromes including childhood absence epilepsy, generalized tonic clonic seizures and the epileptic encephalopathy, Dravet syndrome. The molecular basis for the phenotypic heterogeneity of mutations is(More)
We identified a de novo missense mutation, P302L, in the γ-aminobutyric acid type A (GABAA) receptor γ2 subunit gene GABRG2 in a patient with Dravet syndrome using targeted next-generation sequencing. The mutation was in the cytoplasmic portion of the transmembrane segment M2 of the γ2 subunit that faces the pore lumen. GABAA receptor α1 and β3 subunits(More)