Characterization of the structure and regulation of the murine gene encoding gut-enriched Krüppel-like factor (Krüppel-like factor 4).
Gut-enriched Krüppel-like factor (GKLF, KLF4) is an epithelial-specific transcription factor whose expression is associated with growth arrest. In order to understand the mechanisms regulating expression of the gene encoding GKLF, we isolated a genomic clone containing murine GKLF. The gene spans 5.3 kb and contains four exons. A major start site of transcription was mapped to an adenine residue 601 nt 5' of the translation initiation codon. An additional 1 kb of the 5'-flanking region was sequenced and found to contain multiple cis -elements homologous to the binding sites of several established transcription factors including Sp1, AP-1, Cdx, GATA, and USF. In particular, three closely spaced GC-boxes 5' of the TATA box resemble the established binding site for GKLF. DNase I protection and electrophoretic mobility shift assays verified that recombinant GKLF bound to each of the three GC-boxes. In co-transfection experiments, GKLF transactivated a reporter gene linked to the GKLF 1 kb 5'-flanking region, as did Sp1, Sp3 and Cdx-2. Mutations of one or both of the first and second GC-boxes in the promoter resulted in diminished transactivation by GKLF. These results demonstrate that the 5'-flanking sequence of the mouse GKLF gene functions as a promoter and is subject to autoregulation by its own gene product.
Mahatan
C S
CS
Department of Medicine, The Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
Kaestner
K H
KH
Geiman
D E
DE
Yang
V W
VW
D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D019556:COS Cells; D006224:Cricetinae; D018983:DNA Footprinting; D004268:DNA-Binding Proteins; D005786:Gene Expression Regulation; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics*; D015533:Transcriptional Activation; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D011994:Recombinant Proteins; D014157:Transcription Factors