Genomic and functional characteristics of novel human pancreatic 2P domain K(+) channels.
We isolated three novel 2P domain K(+) channel subunits from human. The first two subunits, TALK-1 and TALK-2, are distantly related to TASK-2. Their genes form a tight cluster of 25 kb on chromosome 6p21.1-p21.2. The corresponding channels produce quasi-instantaneous and non-inactivating currents that are activated at alkaline pHs. These currents are sensitive to Ba(2+), quinine, quinidine, chloroform, halothane, and isoflurane but are not affected by TEA, 4-AP, Cs(+), arachidonic acid, hypertonic solutions, agents activating protein kinases C and A, changes of internal Ca(2+) concentrations, and by activation of G(i) and G(q) proteins. TALK-1 is exclusively expressed in the pancreas. TALK-2 is mainly expressed in the pancreas, but is also expressed at a lower level in liver, placenta, heart, and lung. We also cloned a third subunit, named hTHIK-2 which is present in many tissues with high levels again in the pancreas but which could not be functionally expressed.
Institut de Pharmacologie Moléculaire et Cellulaire, CNRS-UMR 6097, 660 route des Lucioles, Valbonne, Sophia Antipolis, 06560, France.
C
C
Girard
F
F
Duprat
C
C
Terrenoire
N
N
Tinel
M
M
Fosset
G
G
Romey
M
M
Lazdunski
F
F
Lesage
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D003001:Cloning, Molecular; D017931:DNA Primers; D006801:Humans; D008969:Molecular Sequence Data; D010179:Pancreas / Q000378:metabolism*; D015221:Potassium Channels / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D014981:Xenopus
D017931:DNA Primers; D015221:Potassium Channels