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.
Tang
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Department of CNS Research, Lederle Laboratories, American Cyanamid Co., Pearl River, NY 10965.
Yang
X C
XC
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