The Winged Helix Transcriptional Activator HFH-3 Is Expressed in the Distal Tubules of Embryonic and Adult Mouse Kidney*
Abstract
The hepatocyte nuclear factor-3 (HNF-3)/fork head homolog (HFH) proteins are an extensive family of transcription factors, which share homology in the winged helix DNA binding domain. Members of the HFH/winged helix family have been implicated in cell fate determination during pattern formation, in organogenesis, and in cell-type-specific gene expression. In this study we isolated a full-length HFH-3 cDNA clone from a human kidney library which encoded a 351-amino acid protein containing a centrally located winged helix DNA binding domain. We demonstrate that HFH-3 is a potent transcriptional activator requiring 138 C-terminal residues for activity. We used in situ hybridization to demonstrate that HFH-3 expression is restricted to the epithelium of the renal distal convoluted tubules. We determined the HFH-3 DNA binding consensus sequence by in vitro DNA binding site selection using recombinant HFH-3 protein and used this consensus sequence to identify putative HFH-3 target genes expressed there. These putative HFH-3 target genes include the Na/K-ATPase, Na/H and anion exchangers, E-cadherin, and mineralocorticoid receptor genes as well as genes for the transcription factors HNF-1, vHNF-1, and HNF-4.
Footnotes
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↵* This work was supported in part by Public Health Service Grant R01 GM43241-07 from the NIGMS, National Institutes of Health and grants from the Council for Tobacco Research and the American Heart Association.The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EMBL Data Bank with accession number(s) L13203.
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↵‡ Current address: Panduit Corp., 17301 Ridgeland Ave., Tinley Park, IL 60477.
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↵§ Established Investigator of the American Heart Association/Bristol-Myers Squibb. To whom correspondence should be addressed: Dept. of Biochemistry (M/C 536), College of Medicine, University of Illinois, 1819 W. Polk St., Chicago, IL 60612-7334. Tel.: 312-996-0474; Fax: 312-413-0364; E-mail: robcosta{at}uic.edu.
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↵1 The abbreviations used are: HNF, hepatocyte nuclear factor; HFH, fork head homolog; PCR, polymerase chain reaction; GST, glutathione S-transferase; EMSA, electrophoretic mobility shift assay; CAT, chloramphenicol acetyltransferase; CMV, cytomegalovirus.
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- Received March 7, 1997.
- Revision received March 21, 1997.
