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Gene trapping uncovers gender‐specific mechanisms for upstream stimulatory factors 1 and 2 in angiotensinogen expression
Author(s) -
Park Sungmi,
Liu Xuebo,
Davis Deborah R.,
Sigmund Curt D.
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.lb507
Subject(s) - gene knockdown , chromatin immunoprecipitation , microbiology and biotechnology , electrophoretic mobility shift assay , biology , gene , transcription (linguistics) , messenger rna , gene expression , transcription factor , promoter , genetics , linguistics , philosophy
A single‐nucleotide polymorphism (C/A) located within an E‐box sequence at the −20 position of the human angiotensinogen (AGT) promoter may regulate AGT transcriptional activation through differential recruitment of the transcription factors Upstream Stimulatory Factor (USF) 1 and 2. To study the contribution of USF1 vs USF2 binding to AGT gene expression, mice carrying a (−20C) human AGT transgene (hAGT) were bred with mice harboring a USF1 gene trap designed to knockdown USF1 expression [USF1Gt (XG830) Byg]. USF1 mRNA was significantly reduced in liver (9±1%), perigenital adipose (16±3%), kidney (17±1%), and brain (34±2%) in double‐transgenic mice of both genders. This decrease was confirmed by electrophoretic mobility shift assay. Quantitative chromatin immunoprecipitation (ChIP) analyses revealed a decrease in USF1 binding (2.2±0.6 vs. 0.9±0.1 fold of IgG) with retention of USF2 binding (7.2±0.4 vs. 5.9±0.5 fold of IgG) at the hAGT promoter in the liver of male liver. Surprisingly, hAGT expression was reduced in liver of female (45±6%) but not male mice (113%±3%). Treatment of USF1 knockdown males with intravenous adenoviral shRNA targeting USF2 resulted in reduced expression of USF1, USF2 and hAGT protein. In conclusion, both USF1 and USF2 are essential for AGT transcriptional regulation, and distinct gender‐specific mechanisms are involved in the activities of these transcription factors in vivo.