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Effects of nitric oxide donors on hIK1 cell surface expression
Author(s) -
O'Rourke Kellie Leatha,
Jones Heather Marie
Publication year - 2009
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.23.1_supplement.998.21
Subject(s) - hek 293 cells , endocytosis , microbiology and biotechnology , nitric oxide , chemistry , cell , endocytic cycle , cell growth , transfection , viability assay , biochemistry , biology , organic chemistry , gene
The human intermediate conductance ion channel, hIK1, is a calcium (Ca 2+ ) activated potassium (K + ) channel that has a variety of roles in physiological functions. These functions include cancer development, cell volume regulation, cell growth and cell proliferation. Nitric oxide (NO) is a signaling molecule increased by activation of nitric oxide synthase. Treatment of hIK1 transfected HEK cells with NO‐donors, SNAP and PAP‐NONOate, showed increased hIK1 protein expression levels. Additionally, cell surface immunoprecipitation experiments demonstrated increased levels of hIK1 at the cell surface with NO‐donor treatment. Cell surface expression of hIK1 in untreated HEK cells was evaluated using biotin ligase labeled cells which were treated with strepavidin‐Alexa 488 and detected using confocal microscopy. Channels in untreated HEK cells were rapidly endocytosed and, following a one hour incubation, a majority of the channel was located within endocytic vesicles. Treatment with the NO donors increased cell surface expression of hIK1 after one hour and a decrease in the amount of channel located in endocytic vesicles. These results suggest that NO may regulate hIK1 endocytosis and lead to an increase expression of active channel at the cell surface.