Premium
Modulation of the Two‐Pore Domain Potassium Channel TASK‐1 by Caveolin‐3
Author(s) -
Kang Chen,
Hu Keli
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.845.14
Subject(s) - hek 293 cells , transfection , western blot , microbiology and biotechnology , potassium channel , patch clamp , chemistry , biology , cell culture , neuroscience , electrophysiology , biophysics , gene , biochemistry , genetics
The two‐pore domain potassium channel TASK‐1 is strongly expressed in the heart and has been shown to regulate the resting membrane potential and action potential. Modulation of the TASK‐1 background current provides a mechanism for control of cellular excitability. However, little is known about the localization and regulation of TASK‐1 in the heart. The present study was designed to determine whether TASK‐1 is physically associated with and functionally modulated by caveolin‐3. Freshly isolated adult rat cardiomyocytes and HEK293T cells transfected with caveolin‐3 and TASK‐1 cDNA were used in the study. Western blot experiments confirmed that there was a strong expression of TASK‐1 in rat cardiomyocytes. Co‐immunoprecipitation analysis indicated that caveolin‐3 associated with TASK‐1. Co‐localization of TASK‐1 and caveolin‐3 was also confirmed by immunofluorescence microscopy. Functional studies with the patch‐clamp technique showed that the expression of caveolin‐3 in HEK293T cells decreased the recombinant TASK‐1 current density significantly when compared with HEK293T cells transfected with TASK‐1 plus empty vector (59.63 ± 8.10%, p<0.05, n=6‐10). However, caveolin‐3 expression did not affect the recombinant TASK‐1 expression in the cell peripheral region of HEK293T cells, indicating that TASK‐1 cell surface expression may not be affected by caveolin‐3. In summary, our study indicates that TASK‐1 is associated with caveolin‐3 and functionally regulated by caveolin‐3. These results point out a novel mechanism in the regulation of cardiac TASK‐1 channels.