Cloning a novel human brain inward rectifier potassium channel and its functional expression in Xenopus oocytes.
We have cloned a novel inward rectifier K+ channel (hIRK2) from a human frontal cortex cDNA library. The amino acid sequence of hIRK2 shares 60% and 40% identity with the mouse IRK1 and the rat ROMK1 channels, respectively. Xenopus oocytes injected with hIRK2 cRNA showed an inwardly rectifying K+ current that had a prominent 'N-shape' I-V curve and was blocked by extracellular Ba2+. The hIRK2 channel has two unique features: (a) an 18 amino acid insertion between the first transmembrane region and the pore, and (b) restricted mRNA distribution found only in human brain and heart.
Department of CNS Research, Lederle Laboratories, American Cyanamid Co., Pearl River, NY 10965.
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001923:Brain Chemistry; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000302:isolation & purification; D005260:Female; D015870:Gene Expression; D018014:Gene Transfer Techniques; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism*; D015221:Potassium Channels / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D016415:Sequence Alignment; D017421:Sequence Analysis; D014018:Tissue Distribution; D014981:Xenopus
D018076:DNA, Complementary; D015221:Potassium Channels; D012333:RNA, Messenger