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Identification of CNK3 in the Aldosterone‐regulated ENaC Regulatory Complex
Author(s) -
Ziera Tim,
Koo Eric,
Soundararajan Rama,
Pearce David
Publication year - 2011
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.25.1_supplement.950.1
Subject(s) - epithelial sodium channel , aldosterone , pdz domain , sgk1 , microbiology and biotechnology , immunoprecipitation , chemistry , enhancer , biology , phosphorylation , transcription factor , sodium , gene , endocrinology , biochemistry , organic chemistry
Members of the Connector Enhancer of KSR (CNK) family of proteins possess multiple protein interaction domains, and have been proposed to function as scaffolds possibly assisting various interactions in a multiple signaling cascade. Mammalian CNK3 is an aldosterone‐induced protein that is essential for the activity of the epithelial sodium channel (ENaC). We have shown earlier that ENaC surface expression and activity are regulated by the ENaC‐regulatory complex, GILZ1 and SGK1 are important aldosterone‐induced components thereof. The present study examines the role of CNK3 in GILZ1/SGK1‐mediated ENaC stimulation. Co‐immunoprecipitation experiments revealed specific physical interactions of CNK3 with both GILZ1 and SGK1 in an aldosterone‐dependent manner. GILZ1 markedly enhances the interaction of CNK3 with SGK1, and also augments CNK3 multimerization, an attribute that has been shown to be critical for protein scaffolding of other larger PDZ domain‐containing proteins. The present study suggests that CNK3 is an important component of the aldosterone‐regulated ENaC regulatory complex.