Cloning and functional expression of human retinal Kir2.4, a pH-sensitive inwardly rectifying K+ channel

Citation
Ba. Hughes et al., Cloning and functional expression of human retinal Kir2.4, a pH-sensitive inwardly rectifying K+ channel, AM J P-CELL, 279(3), 2000, pp. C771-C784
Citations number
56
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY
ISSN journal
0363-6143 → ACNP
Volume
279
Issue
3
Year of publication
2000
Pages
C771 - C784
Database
ISI
SICI code
0363-6143(200009)279:3<C771:CAFEOH>2.0.ZU;2-J
Abstract
To identify novel potassium channel genes expressed in the retina, we scree ned a human retina cDNA library with an EST sequence showing partial homolo gy to inwardly rectifying potassium (Kir) channel genes. The isolated cDNA yielded a 2,961-base pair sequence with the predicted open reading frame sh owing strong homology to the rat Kir2.4 (rKir2.4). Northern analysis of mRN A from human and bovine tissues showed preferential expression of Kir2.4 in the neural retina. In situ hybridization to sections of monkey retina dete cted Kir2.4 transcript in most retinal neurons. Somatic hybridization analy sis and dual-color in situ hybridization to metaphase chromosomes mapped Ki r2.4 to human chromosome 19 q13.1-q13.3. Expression of human Kir2.4 cRNA in Xenopus oocytes generated strong, inwardly rectifying K+ currents that wer e enhanced by extracellular alkalinization. We conclude that human Kir2.4 e ncodes an inwardly rectifying K+ channel that is preferentially expressed i n the neural retina and that is sensitive to physiological changes in extra cellular pH.