Functional expression of the rat heart I Na+ channel isoform Demonstration of properties characteristic of native cardiac Na+ channels

[摘要]

We describe the expression of functional Na⁺ channel in Xenopus oocytes injected with cRNA transcribed from the rat heart 1 cDNA clone. The expressed rat heart 1 Na⁺ currents show kinetic properties and resistance to tetrodotoxin and saxitoxin which are characteristic of native cardiac Na⁺ currents. The primary amino acid sequence of the rat heart 1 α-subunit is therefore sufficient for expression of of tetrodotoxin resistance, and the rat heart 1 clone is likely to account for the tetrodotoxin-resistant phenotype of cardiac and denervated skeletal muscle.

[学科分类] 生物化学/生物物理

[关键词] Na+ channel;cDNA expression;Xenopus oocyte;Na+ current;Tetrodotoxin;Saxitoxin;TTX;tetrodotoxin;STX;saxitoxin;I Na;sodium current;TTX-S;TTX-sensitive;TTX-R;TTX-resistant;RH-I;rat heart I Na + channel