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Antisense‐mediated post‐transcriptional silencing of SCN1B gene modulates sodium channel functional expression
Author(s) -
Baroni Debora,
Picco Cristiana,
Barbieri Raffaella,
Moran Oscar
Publication year - 2014
Publication title -
biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 85
eISSN - 1768-322X
pISSN - 0248-4900
DOI - 10.1111/boc.201300040
Subject(s) - sodium channel , biology , protein subunit , gene isoform , gene silencing , scn3a , microbiology and biotechnology , rna interference , gene expression , g alpha subunit , gene , biochemistry , chemistry , rna , sodium , organic chemistry
Background information Voltage‐dependent sodium channels are membrane proteins essential for cell excitability. They are composed by a pore‐forming α‐subunit and one or more β subunits. Nine α subunit and five β subunit isoforms have been identified in mammals: β1, its splice variant β1B, β2, β3 and β4. Although they do not form the ion channel pore, β subunits modulate both function as well as expression of sodium channels on cell membrane. Results To investigate the role of β1 subunit on the modulation of sodium channel expression, we silenced this auxiliary subunit with specific antisense oligonucleotides (ASONs) in two rat cell lines, the GH3 and the H9C2, from neuro‐ectoderm and cardiac myocyte origin, respectively. Treatment of cells with ASONs determined a reduction of about 50% of β1 subunit mRNA and protein expression in both cell lines. We found that this level of β1 subunit silencing resulted in an overall decrease of α subunit mRNA, protein expression and a decrease of sodium current density, without altering significantly the voltage‐dependent and kinetic properties of the currents. In GH3 cells, the β1 subunit silencing reduced the expression of Nav1.1, Nav1.3 and Nav1.6 isoforms, whereas the Nav 1.2 isoform expression remained unaltered. The expression of the only α subunit present in H9C2 cells, the Nav1.5, was also reduced by β1 subunit silencing. Conclusions These results indicate that the β1 subunit may exert an isoform‐specific fine‐tuned modulation of sodium channel expression.