Genetic and functional linkage of Kir5.1 and Kir2.1 channel subunits.
We have identified several cDNAs for the human Kir5.1 subunit of inwardly rectifying K(+) channels. Alternative splicing of exon 3 and the usage of two alternative polyadenylation sites contribute to cDNA diversity. The hKir5.1 gene KCNJ16 is assigned to chromosomal region 17q23.1-24.2, and is separated by only 34 kb from the hKir2.1 gene (KCNJ2). In the brain, Kir5.1 mRNA is restricted to the evolutionary older parts of the hindbrain, midbrain and diencephalon and overlaps with Kir2.1 in the superior/inferior colliculus and the pontine region. In the kidney Kir5.1 and Kir2.1 are colocalized in the proximal tubule. When expressed in Xenopus oocytes, Kir5.1 is efficiently targeted to the cell surface and forms electrically silent channels together with Kir2.1, thus negatively controlling Kir2.1 channel activity in native cells.
Institute for Normal and Pathological Physiology, University of Marburg, Germany.
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Derst
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Karschin
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Wischmeyer
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Hirsch
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Preisig-Müller
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Rajan
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Engel
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Grzeschik
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Daut
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Karschin
D017398:Alternative Splicing / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D002478:Cells, Cultured; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics; D008040:Genetic Linkage; D006801:Humans; D007668:Kidney / Q000378:metabolism; D008969:Molecular Sequence Data; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D009928:Organ Specificity; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000235:genetics* / Q000378:metabolism; D024661:Potassium Channels, Inwardly Rectifying; D021122:Protein Subunits; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014162:Transfection; D014981:Xenopus
D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D021122:Protein Subunits; D012333:RNA, Messenger