Disease relevance of Kcnk4

• By using reverse transcription-polymerase chain reaction, we found that TREK-1 and TREK-2 mRNA had no obvious changes in cortex after ischemia, while TRAAK mRNA was significantly increased by 70% after 30 days [1].
• To determine the gene expression level of the lipid-sensitive mechano-gated 2P domain K(+) channels in rat cortex and hippocampus after chronic cerebral ischemia, TREK-1, TREK-2 and TRAAK were detected in rats at 3 and 30 days after permanent bilateral carotid artery ligation (BCAL) [1].

High impact information on Kcnk4

• Its amino acid sequence shares 54% identity with that of TASK-1, but less than 30% with those of TASK-2 and other tandem pore K(+) channels (TWIK, TREK, TRAAK) [2].
• At 37 degrees C, TREK-1, TREK-2 and TRAAK were sensitive to arachidonic acid, pH and membrane stretch in both cell-attached and inside-out patches [3].
• We studied the temperature-sensitivity of TREK-2 and TRAAK in COS-7 cells and in neuronal cells [3].
• One K(+) channel was activated by application of pressure, arachidonic acid and alkaline pH(i), and showed single-channel kinetics indistinguishable from those of TRAAK [4].
• RT-PCR revealed message for the following AA-sensitive K(2P) channels in rat MCA: tandem of P domains in weak inward rectifier K+ (TWIK-2), TWIK-related K+ (TREK-1 and TREK-2), TWIK-related AA-stimulated K+ (TRAAK), and TWIK-related halothane-inhibited K+ (THIK-1) channels [5].

Biological context of Kcnk4

• In hippocampus, the gene expressions of TREK-1 and TRAAK were increased markedly at 3 days (97% and 87%, respectively) and 30 days (63% and 47%, respectively) after ischemia [1].
• Axonal transport of TREK and TRAAK potassium channels in rat sciatic nerves [6].
• mRNAs encoded by genes for the lipid-sensitive mechano-gated K(+) channels TREK-1, TREK-2, and TRAAK were detected in rat brain at different life-cycle stages: 18-day embryos, postnatal days 1, 7, 28, and 60 (adulthood). mRNA expression of TREK-1 or TREK-2 showed no appreciable changes during the development of cortex and hippocampus [7].

Anatomical context of Kcnk4

• In the present study, we investigated the immunohistochemical localization of two-pore K(+)-channels TASK-1, TASK-2, TASK-3 and TRAAK in the rat carotid body [8].
• Intrinsic nerve cell bodies were also strongly positive for TASK-1, TASK-2 and TRAAK, but negative for TASK-3 [8].
• TRAAK immunoreactivity was observed in the chief cells of the aortic body as well as these of the carotid body, but not in the paraganglionic cells in the sympathetic (superior cervical and stellate) ganglia [9].
• In the present study, we investigated the immunohistochemical localization of the two-pore K+ channels, TASK-3 and TRAAK, in paraganglionic cells within the superior cervical ganglion, stellate ganglion, and aortic body in comparison with membrane channels in chief cells of the carotid body [9].
• We report that in cultured rat type-1 cortical astrocytes, exposure to 10 microM AA activates an open rectifier K(+) channel, which exhibits many similarities with TREK/TRAAK members of the two-pore-domain K(+) channel family KCNK [10].

Associations of Kcnk4 with chemical compounds

• Furthermore, inhibition of Ba(2+) and/or Gd(3+) sensitive two-pore K(+) channels (i.e. TREK-1 and TRAAK) was insufficient to account for cold transduction in HT(cool) or LT(cool) neurons [11].
• The genes (TWIK-1, TWIK-2, TASK-1, TASK-2, TASK-3, TREK-1, TREK-2, TRAAK and KCNK6) were quantified, relative to glyceraldehyde-3-phosphate dehydrogenase (GADPH), in all four chambers of adult rat hearts and in the ventricles of embryonic rat hearts [12].

References