Expression of thermosensitive two-pore domain K+ channels in human keratinocytes cell line HaCaT cells.
Recent studies have shown that keratinocytes can sense temperature via thermo-transient receptor potential (TRP) channels. It is not known whether other thermosensitive ion channels such as TREK-1, TREK-2 and TRAAK (TREKs/TRAAK) that are members of the two-pore domain K(+) (K(2P)) channel family are expressed in human keratinocytes. Here, we identified the expression of TREKs/TRAAK in human keratinocytes-derived cell line HaCaT cells using RT-PCR, immunocytochemistry, Western blot analysis and patch-clamp technique. RT-PCR showed that all six K(2P) channels tested (TASK-1, TASK-3, TREK-1, TREK-2, TRAAK and TASK-2) were expressed in HaCaT cells, as well as in skin and dorsal root ganglion (DRG) of rat. The expression of TREKs/TRAAK mRNA identified by RT-PCR was further studied at the protein level. Using anti-TREK-1, -TREK-2 and -TRAAK, bands of approximately 46, approximately 60 and approximately 43 kDa, respectively, were observed at plasma membrane of HaCaT cells. Immunostaining also showed that TREK-1, TREK-2 and TRAAK were expressed in all area of cells including plasma membrane. Whole-cell K(+) currents recorded from HaCaT cells were activated by arachidonic acid and heat. These results suggest that TREKs/TRAAK channels could act as thermosensors in human keratinocytes.
Kang
Dawon
D
Medical Research Center for Neural Dysfunction and Department of Physiology, College of Medicine and Institute of Health Sciences, Gyeongsang National University, Jinju, Korea.
Kim
Sung-Hee
SH
Hwang
Eun-Mi
EM
Kwon
Oh-Sang
OS
Yang
Hae-Young
HY
Kim
Eun-Sook
ES
Choi
Tae Hyun
TH
Park
Jae-Yong
JY
Hong
Seong-Geun
SG
Han
Jaehee
J
D016718:Arachidonic Acid; D015153:Blotting, Western; D002460:Cell Line; D004594:Electrophysiology; D006358:Hot Temperature; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000378:metabolism*; D024683:Potassium Channels, Tandem Pore Domain / Q000378:metabolism*; D012881:Skin Temperature / Q000502:physiology*
D024683:Potassium Channels, Tandem Pore Domain; D016718:Arachidonic Acid