Channelpedia

PubMed 7926018


Referenced in Channelpedia wiki pages of: none

Automatically associated channels: Kir1.1 , Kir2.1 , Kir2.2 , Kir2.3 , Kir3.1 , Kir3.2 , Kir3.3 , Kir6.2 , Kv1.4



Title: Cloning provides evidence for a family of inward rectifier and G-protein coupled K+ channels in the brain.

Authors: F Lesage, F Duprat, M Fink, E Guillemare, T Coppola, M Lazdunski, J P Hugnot

Journal, date & volume: FEBS Lett., 1994 Oct 10 , 353, 37-42

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/7926018


Abstract
MbIRK3, mbGIRK2 and mbGIRK3 K+ channels cDNAs have been cloned from adult mouse brain. These cDNAs encode polypeptides of 445, 414 and 376 amino acids, respectively, which display the hallmarks of inward rectifier K+ channels, i.e. two hydrophobic membrane-spanning domains M1 and M2 and a pore-forming domain H5. MbIRK3 shows around 65% amino acid identity with IRK1 and rbIRK2 and only 50% with ROMK1 and GIRK1. On the other hand, mbGIRK2 and mbGIRK3 are more similar to GIRK1 (60%) than to ROMK1 and IRK1 (50%). Northern blot analysis reveals that these three novel clones are mainly expressed in the brain. Xenopus oocytes injected with mbIRK3 and mbGIRK2 cRNAs display inward rectifier K(+)-selective currents very similar to IRK1 and GIRK1, respectively. As expected from the sequence homology, mbGIRK2 cRNA directs the expression of G-protein coupled inward rectifier K+ channels which has been observed through their functional coupling with co-expressed delta-opioid receptors. These results provide the first evidence that the GIRK family, as the IRK family, is composed of multiple genes with members specifically expressed in the nervous system.