Expression of TASK-1, a pH-sensitive twin-pore domain K(+) channel, in rat myocytes.
We have investigated the expression of TASK-1, a pH-sensitive, twin-pore domain K(+) channel in the rat heart. A mammalian cell line of Chinese hamster ovary cells (CHO), transfected with a plasmid containing mouse TASK-1, demonstrated the specificity of the anti-TASK-1 antibody. TASK-1 expression in cardiac tissue was initially demonstrated by Western blot and then localized by immunofluorescence. In single rat ventricular myocytes, strong staining of the TASK-1 protein was located at the intercalated disks and across the cell in a striated pattern, corresponding to the transverse axial tubular network (T tubules). In contrast, single rat atrial myocytes were stained at the intercalated disks with a weak punctate, striated pattern corresponding to underdeveloped T tubules. Also, formamide was used to induce the detubulation of ventricular myocytes, which enabled confirmation that TASK-1 protein expression occurs in T tubules. Consistent with this, RT-PCR revealed the expression of TASK-1 mRNA in total RNA from both the ventricles and atria. In this study, we conclusively demonstrated that TASK-1 protein and mRNA were expressed in rat atrial and ventricular tissue. The extensive distribution of TASK-1 shown to exist within myocyte membranes may provide a potential future target for antiarrhythmic drugs.
Jones
Sandra A
SA
School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom. s.a.jones@leeds.ac.uk
Morton
Michael J
MJ
Hunter
Malcolm
M
Boyett
Mark R
MR
D000818:Animals; D000918:Antibody Specificity; D015153:Blotting, Western; D016466:CHO Cells; D002469:Cell Separation; D006224:Cricetinae; D005455:Fluorescent Antibody Technique; D006325:Heart Atria / Q000166:cytology / Q000378:metabolism; D006352:Heart Ventricles / Q000166:cytology / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D009419:Nerve Tissue Proteins; D015221:Potassium Channels / Q000096:biosynthesis* / Q000235:genetics; D024683:Potassium Channels, Tandem Pore Domain; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014909:Wheat Germ Agglutinins
D009419:Nerve Tissue Proteins; D015221:Potassium Channels; D024683:Potassium Channels, Tandem Pore Domain; D012333:RNA, Messenger; D014909:Wheat Germ Agglutinins; C420132:potassium channel subfamily K member 3