title: pH dependence of the inwardly rectifying potassium channel, Kir5.1, and localization in renal tubular epithelia.
abstract: The physiological role of the inwardly rectifying potassium channel, Kir5.1, is poorly understood, as is the molecular identity of many renal potassium channels. In this study we have used Kir5.1-specific antibodies to reveal abundant expression of Kir5.1 in renal tubular epithelial cells, where Kir4.1 is also expressed. Moreover, we also show that Kir5.1/Kir4.1 heteromeric channel activity is extremely sensitive to inhibition by intracellular acidification and that this novel property is conferred predominantly by the Kir5.1 subunit. These findings suggest that Kir5.1/Kir4.1 heteromeric channels are likely to exist in vivo and implicate an important and novel functional role for the Kir5.1 subunit.
authors.affiliation: University Laboratory of Physiology, Parks Road, Oxford OX1 3PT, United Kingdom. stephen.tucker@physiol.ox.ac.uk
authors.forename: S J
authors.initials: SJ
authors.lastname: Tucker
authors.forename: P
authors.initials: P
authors.lastname: Imbrici
authors.forename: L
authors.initials: L
authors.lastname: Salvatore
authors.forename: M C
authors.initials: MC
authors.lastname: D'Adamo
authors.forename: M
authors.initials: M
authors.lastname: Pessia
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D004848:Epithelium / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry; D007684:Kidney Tubules / Q000378:metabolism*; D008969:Molecular Sequence Data; D015221:Potassium Channels / Q000378:metabolism*; D024661:Potassium Channels, Inwardly Rectifying; D051381:Rats
chemical_list: D017931:DNA Primers; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying