Genomic and functional characteristics of novel human pancreatic 2P domain K+ channels

C Girard, F Duprat, C Terrenoire, N Tinel… - Biochemical and …, 2001 - Elsevier
C Girard, F Duprat, C Terrenoire, N Tinel, M Fosset, G Romey, M Lazdunski, F Lesage
Biochemical and biophysical research communications, 2001Elsevier
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 Ba2+, quinine, quinidine, chloroform, halothane, and isoflurane but are not affected by
TEA, 4-AP, Cs+, arachidonic acid, hypertonic solutions, agents activating protein kinases C …
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 Ba2+, 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 Ca2+ concentrations, and by activation of Gi and Gq 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.
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