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Expression of Epithelial sodium channel ENaC is regulated by posttranscriptional mechanisms
Author(s) -
Perlewitz Andrea,
Nafz Benno,
Skalweit Angela,
Fähling Michael,
Persson Pontus Börje,
Thiele Bernd Joachim
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.998.8
Subject(s) - epithelial sodium channel , rna , untranslated region , microbiology and biotechnology , messenger rna , hek 293 cells , translation (biology) , chemistry , gene expression , biology , rna binding protein , sodium channel , biochemistry , gene , sodium , organic chemistry
Epithelial sodium channel ENaC is essential in the regulation of sodium homeostasis for instance in the distal nephron and is involved in physiological processes like blood pressure control. Functional ENaC channels consist of three autonomously expressed subunits a, b and g. Their expression has been studied so far especially on the transcriptional and posttranslational level. The aim of this study was to elucidate posttranscriptional mechanisms, in particular the role of untranslated regions (UTR) and their interaction with RNA‐binding proteins (RNA‐BP) for stability and translational efficiency of ENaC mRNAs. As a model we used kidney cell lines mpkCCD and HEK293 cultivated under the action of known regulators of ENaC expression, e.g. aldosterone and vasopressin. Regulative potential of UTRs was investigated by luciferase‐reportergene‐assays, RNA/protein interaction by UV‐crosslinking‐assays and identification and functional characterization of candidate RNA‐BPs by RNA‐affinity‐chromatography, MALDI‐TOF‐MS, polysome gradient analysis and co‐transfection experiments. Our results show that posttranscriptional mechanisms are involved in the regulation of all three subunits under hormonal stimulation, but in particular in gENaC.