Molecular cloning and expression of a human heart inward rectifier potassium channel

  • Neuroreport. 1994 Dec 20;5(18):2501-5. doi: 10.1097/00001756-199412000-00024.
K F Raab-Graham  1 ,  C M Radeke ,  C A Vandenberg
Affiliations
  • 1. Department of Biological Sciences, University of California, Santa Barbara 93106.
PMID: 7696590 DOI: 10.1097/00001756-199412000-00024
Abstract

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.