Cloning and functional expression of HH-IRK1 in Xenopus oocytes revealed a strongly inwardly rectifying K+ channel with a single-channel conductance of 30 pS, mapped to human chromosome 17.
The cloning and characterization of the human heart inward rectifier potassium channel (HH-IRK1) provides foundational knowledge for understanding cardiac electrophysiology.
We have isolated a cDNA encoding an inwardly rectifying K+ channel (HH-IRK1) from human heart. The cDNA codes for a 427-amino acid protein, with two putative transmembrane domains and an H5 region. The primary structure of HH-IRK1 is homologous to that of the IRK1 channel cloned from a mouse macrophage-like cell line. Functional expression in Xenopus oocytes showed that HH-IRK1 is a K+ channel with strong inward rectification, blocked by extracellular Ba2+ and Cs+, and with a single-channel conductance of 30 pS. Northern analysis showed HH-IRK1 transcripts in human heart, brain, skeletal muscle, placenta, lung and kidney. HH-IRK1 was mapped to human chromosome 17.
Raab‐Graham et al. (Thu,) reported a other. Molecular cloning and expression of HH-IRK1 was evaluated on Functional expression and characterization of HH-IRK1. Cloning and functional expression of HH-IRK1 in Xenopus oocytes revealed a strongly inwardly rectifying K+ channel with a single-channel conductance of 30 pS, mapped to human chromosome 17.