Two Types Of Neuronal Death Model The Mechanism Of - Loss Of K +-mediated Apoptosis And Glutamate-induced Death

The voltage-gated potassium (Kv) channels are a group of channels which participate in the excitable activities of neurons. The T1 domain, which is conserved in Kv channels, plays an important role in channel assembly and subunit tetramerization. Recent evidences have shown that the apoptosis of cortical neurons induced by serum deprivation or by staurosporine was associated with loss of total intracellular K+. Attenuating outward K+ current with TEA, a specific blocker of potassium channels, or elevated extracellular K+ reduced the neuronal apoptosis. Protein kinase A(PKA) is an important kinase for cell survival. In our lab, A conserved sequence possibly phosphorylated by PKA was found in the T1 domain of Kv channels and two antibodies(1505IV and 1505pV) were generated by immunizing rabbits with the corresponding unphosphorylated and phosphorylated(ser229 in Kv1.4) peptides. I found that the molecular weight(MW) of the proteins identified specifically by the two antibodies were 100kD and 120kD. I have overexpressed Kv1.4 in HEK293 cells,stimulated the cells with the PKA activator forskolin and found that Kv1.4 was phosphorylated. In addition that proteins with the same MW were recognized by 1505IV and commercial Kv1.4 antibodies, we concluded that in neurons 1505IV and 1505pV recognized unphosphorylated and phosphorylated Kv1.4, respectively. I have also constructed Kv1.4S229A and Kv1.2S84A mutant plasmids, which can be used for further experiments.