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An essential role of cortactin in regulation of ENaC
Author(s) -
Ilatovskaya Daria,
Vinnakota Kalyan C,
Pavlov Tengis S,
Staruschenko Alexander
Publication year - 2010
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.24.1_supplement.606.2
Subject(s) - cortactin , epithelial sodium channel , microbiology and biotechnology , phosphorylation , immunoprecipitation , chemistry , actin , mutant , biology , biochemistry , cytoskeleton , sodium , gene , cell , organic chemistry
Epithelial Na + Channel (ENaC) is critical for maintenance of sodium balance. Cortactin is a key signaling protein for many cellular processes, including direct interaction with F‐actin. In this study we have addressed the role of cortactin in mediating regulation of ENaC. As assessed by Western blotting, cortactin is highly expressed in mpkCCD c14 , M‐1 and MDCK cells. Immunohistochemistry analysis showed localization of cortactin in the cortical collecting duct in Sprague‐Dawley rat kidneys. Co‐immunoprecipitation analysis revealed that cortactin directly interacts with ENaC subunits when co‐expressed in CHO cells. We have supported these data with fluorescent microscopy co‐localization approach and fluorescence correlation spectroscopy analysis. Coexpression of cortactin with ENaC decreased channel's activity as measured by patch‐clamp. Surprisingly, cortactin's dynamin‐binding Src homology 3 domain is not required for ENaC regulation. Similarly cortactin mutants with deleted phosphorylation domain, or lacking ability to bind F‐actin decrease ENaC current. However cortactin mutant unable to bind Arp2/3 complex does not influence ENaC activity. Thus, we conclude that cortactin decreases ENaC activity via Arp2/3 complex. Supported by AHA and ASN.