Abstract
The homeodomain containing thyroid transcription factor 1 (TTF-1) is a lung- and thyroid-enriched protein implicated in the regulation of a number of pulmonary specific genes. Within the lung TTF-1 is expressed within the epithelial cells. Although the molecular mechanisms that govern this tight cell-type-specific distribution are unclear, transient transfection studies have suggested that tissue specificity is conferred in part by regions of the proximal promoter. Further studies have shown that two functionally important regions (BS1 and BS2) are sites for activation of the TTF-1 gene by the homeodomain protein HoxB3, raising the possibility that Hox proteins might function in the regulation of TTF-1 in vivo. The different cellular distributions of the two proteins within the lung suggest, however, that proteins distinct from HoxB3 might be the mediators of expression through these sites. In the present study we have used gel-mobility-shift experiments to show that in a pulmonary adenocarcinoma cell line (NCI-H441) that expresses TTF-1, the same single protein binds to both of these sites. The binding of this protein is competed for specifically by the addition of oligonucleotides containing a range of octamer-binding sites but not by a variety of non-related binding sites. Using specific antiserum we have identified this protein as being the ubiquitously expressed POU-domain protein Oct-1. Reverse transcriptase-PCR performed with degenerated primers suggests that Oct-1 is the major POU-domain-containing protein expressed in H441 cells. These results suggest that BS1 and BS2 are functional octamer sites and might therefore be implicated in the basal rather than the tissue-restricted expression of the TTF-1 gene.
Full Text
The Full Text of this article is available as a PDF (247.7 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bingle C. D., Gitlin J. D. Identification of hepatocyte nuclear factor-3 binding sites in the Clara cell secretory protein gene. Biochem J. 1993 Oct 1;295(Pt 1):227–232. doi: 10.1042/bj2950227. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bingle C. D., Gowan S. Molecular cloning of the forkhead transcription factor HNF-3 alpha from a human pulmonary adenocarcinoma cell line. Biochim Biophys Acta. 1996 Jun 3;1307(1):17–20. doi: 10.1016/0167-4781(96)00058-9. [DOI] [PubMed] [Google Scholar]
- Bingle C. D., Hackett B. P., Moxley M., Longmore W., Gitlin J. D. Role of hepatocyte nuclear factor-3 alpha and hepatocyte nuclear factor-3 beta in Clara cell secretory protein gene expression in the bronchiolar epithelium. Biochem J. 1995 May 15;308(Pt 1):197–202. doi: 10.1042/bj3080197. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bohinski R. J., Di Lauro R., Whitsett J. A. The lung-specific surfactant protein B gene promoter is a target for thyroid transcription factor 1 and hepatocyte nuclear factor 3, indicating common factors for organ-specific gene expression along the foregut axis. Mol Cell Biol. 1994 Sep;14(9):5671–5681. doi: 10.1128/mcb.14.9.5671. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bruno M. A., Bohinski R. J., Carter J. E., Foss K. A., Whitsett J. A. Structure and function of the mouse surfactant protein B gene. Am J Physiol. 1995 Mar;268(3 Pt 1):L381–L389. doi: 10.1152/ajplung.1995.268.3.L381. [DOI] [PubMed] [Google Scholar]
- Bruno M. D., Bohinski R. J., Huelsman K. M., Whitsett J. A., Korfhagen T. R. Lung cell-specific expression of the murine surfactant protein A (SP-A) gene is mediated by interactions between the SP-A promoter and thyroid transcription factor-1. J Biol Chem. 1995 Mar 24;270(12):6531–6536. doi: 10.1074/jbc.270.12.6531. [DOI] [PubMed] [Google Scholar]
- Dennig J., Hagen G., Beato M., Suske G. Members of the Sp transcription factor family control transcription from the uteroglobin promoter. J Biol Chem. 1995 May 26;270(21):12737–12744. doi: 10.1074/jbc.270.21.12737. [DOI] [PubMed] [Google Scholar]
- Fleming R. E., Whitman I. P., Gitlin J. D. Induction of ceruloplasmin gene expression in rat lung during inflammation and hyperoxia. Am J Physiol. 1991 Feb;260(2 Pt 1):L68–L74. doi: 10.1152/ajplung.1991.260.2.L68. [DOI] [PubMed] [Google Scholar]
- Gstaiger M., Knoepfel L., Georgiev O., Schaffner W., Hovens C. M. A B-cell coactivator of octamer-binding transcription factors. Nature. 1995 Jan 26;373(6512):360–362. doi: 10.1038/373360a0. [DOI] [PubMed] [Google Scholar]
- Guazzi S., Lonigro R., Pintonello L., Boncinelli E., Di Lauro R., Mavilio F. The thyroid transcription factor-1 gene is a candidate target for regulation by Hox proteins. EMBO J. 1994 Jul 15;13(14):3339–3347. doi: 10.1002/j.1460-2075.1994.tb06636.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Guazzi S., Price M., De Felice M., Damante G., Mattei M. G., Di Lauro R. Thyroid nuclear factor 1 (TTF-1) contains a homeodomain and displays a novel DNA binding specificity. EMBO J. 1990 Nov;9(11):3631–3639. doi: 10.1002/j.1460-2075.1990.tb07574.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hagen G., Müller S., Beato M., Suske G. Sp1-mediated transcriptional activation is repressed by Sp3. EMBO J. 1994 Aug 15;13(16):3843–3851. doi: 10.1002/j.1460-2075.1994.tb06695.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hapgood J., Cuthill S., Söderkvist P., Wilhelmsson A., Pongratz I., Tukey R. H., Johnson E. F., Gustafsson J. A., Poellinger L. Liver cells contain constitutive DNase I-hypersensitive sites at the xenobiotic response elements 1 and 2 (XRE1 and -2) of the rat cytochrome P-450IA1 gene and a constitutive, nuclear XRE-binding factor that is distinct from the dioxin receptor. Mol Cell Biol. 1991 Sep;11(9):4314–4323. doi: 10.1128/mcb.11.9.4314. [DOI] [PMC free article] [PubMed] [Google Scholar]
- He X., Treacy M. N., Simmons D. M., Ingraham H. A., Swanson L. W., Rosenfeld M. G. Expression of a large family of POU-domain regulatory genes in mammalian brain development. Nature. 1989 Jul 6;340(6228):35–41. doi: 10.1038/340035a0. [DOI] [PubMed] [Google Scholar]
- Herr W., Sturm R. A., Clerc R. G., Corcoran L. M., Baltimore D., Sharp P. A., Ingraham H. A., Rosenfeld M. G., Finney M., Ruvkun G. The POU domain: a large conserved region in the mammalian pit-1, oct-1, oct-2, and Caenorhabditis elegans unc-86 gene products. Genes Dev. 1988 Dec;2(12A):1513–1516. doi: 10.1101/gad.2.12a.1513. [DOI] [PubMed] [Google Scholar]
- Ikeda K., Clark J. C., Shaw-White J. R., Stahlman M. T., Boutell C. J., Whitsett J. A. Gene structure and expression of human thyroid transcription factor-1 in respiratory epithelial cells. J Biol Chem. 1995 Apr 7;270(14):8108–8114. doi: 10.1074/jbc.270.14.8108. [DOI] [PubMed] [Google Scholar]
- Kimura S., Hara Y., Pineau T., Fernandez-Salguero P., Fox C. H., Ward J. M., Gonzalez F. J. The T/ebp null mouse: thyroid-specific enhancer-binding protein is essential for the organogenesis of the thyroid, lung, ventral forebrain, and pituitary. Genes Dev. 1996 Jan 1;10(1):60–69. doi: 10.1101/gad.10.1.60. [DOI] [PubMed] [Google Scholar]
- Lazzaro D., Price M., de Felice M., Di Lauro R. The transcription factor TTF-1 is expressed at the onset of thyroid and lung morphogenesis and in restricted regions of the foetal brain. Development. 1991 Dec;113(4):1093–1104. doi: 10.1242/dev.113.4.1093. [DOI] [PubMed] [Google Scholar]
- Lillycrop K. A., Dent C. L., Wheatley S. C., Beech M. N., Ninkina N. N., Wood J. N., Latchman D. S. The octamer-binding protein Oct-2 represses HSV immediate-early genes in cell lines derived from latently infectable sensory neurons. Neuron. 1991 Sep;7(3):381–390. doi: 10.1016/0896-6273(91)90290-g. [DOI] [PubMed] [Google Scholar]
- Minoo P., Hamdan H., Bu D., Warburton D., Stepanik P., deLemos R. TTF-1 regulates lung epithelial morphogenesis. Dev Biol. 1995 Dec;172(2):694–698. doi: 10.1006/dbio.1995.8080. [DOI] [PubMed] [Google Scholar]
- Mizuno K., Gonzalez F. J., Kimura S. Thyroid-specific enhancer-binding protein (T/EBP): cDNA cloning, functional characterization, and structural identity with thyroid transcription factor TTF-1. Mol Cell Biol. 1991 Oct;11(10):4927–4933. doi: 10.1128/mcb.11.10.4927. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nakshatri H., Nakshatri P., Currie R. A. Interaction of Oct-1 with TFIIB. Implications for a novel response elicited through the proximal octamer site of the lipoprotein lipase promoter. J Biol Chem. 1995 Aug 18;270(33):19613–19623. doi: 10.1074/jbc.270.33.19613. [DOI] [PubMed] [Google Scholar]
- Oguchi H., Pan Y. T., Kimura S. The complete nucleotide sequence of the mouse thyroid-specific enhancer-binding protein (T/EBP) gene: extensive identity of the deduced amino acid sequence with the human protein. Biochim Biophys Acta. 1995 Apr 4;1261(2):304–306. doi: 10.1016/0167-4781(95)00033-d. [DOI] [PubMed] [Google Scholar]
- Price M., Lazzaro D., Pohl T., Mattei M. G., Rüther U., Olivo J. C., Duboule D., Di Lauro R. Regional expression of the homeobox gene Nkx-2.2 in the developing mammalian forebrain. Neuron. 1992 Feb;8(2):241–255. doi: 10.1016/0896-6273(92)90291-k. [DOI] [PubMed] [Google Scholar]
- Sawaya P. L., Stripp B. R., Whitsett J. A., Luse D. S. The lung-specific CC10 gene is regulated by transcription factors from the AP-1, octamer, and hepatocyte nuclear factor 3 families. Mol Cell Biol. 1993 Jul;13(7):3860–3871. doi: 10.1128/mcb.13.7.3860. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schreiber E., Himmelmann A., Malipiero U., Tobler A., Stahel R., Fontana A. Human small cell lung cancer expresses the octamer DNA-binding and nervous system-specific transcription factor N-Oct 3 (brain-2). Cancer Res. 1992 Nov 1;52(21):6121–6124. [PubMed] [Google Scholar]
- Schreiber E., Matthias P., Müller M. M., Schaffner W. Rapid detection of octamer binding proteins with 'mini-extracts', prepared from a small number of cells. Nucleic Acids Res. 1989 Aug 11;17(15):6419–6419. doi: 10.1093/nar/17.15.6419. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Strubin M., Newell J. W., Matthias P. OBF-1, a novel B cell-specific coactivator that stimulates immunoglobulin promoter activity through association with octamer-binding proteins. Cell. 1995 Feb 10;80(3):497–506. doi: 10.1016/0092-8674(95)90500-6. [DOI] [PubMed] [Google Scholar]
- Suske G., Lorenz W., Klug J., Gazdar A. F., Beato M. Elements of the rabbit uteroglobin promoter mediating its transcription in epithelial cells from the endometrium and lung. Gene Expr. 1992;2(4):339–352. [PMC free article] [PubMed] [Google Scholar]
- Toonen R. F., Gowan S., Bingle C. D. The lung enriched transcription factor TTF-1 and the ubiquitously expressed proteins Sp1 and Sp3 interact with elements located in the minimal promoter of the rat Clara cell secretory protein gene. Biochem J. 1996 Jun 1;316(Pt 2):467–473. doi: 10.1042/bj3160467. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Venkatesh V. C., Planer B. C., Schwartz M., Vanderbilt J. N., White R. T., Ballard P. L. Characterization of the promoter of human pulmonary surfactant protein B gene. Am J Physiol. 1995 Apr;268(4 Pt 1):L674–L682. doi: 10.1152/ajplung.1995.268.4.L674. [DOI] [PubMed] [Google Scholar]
- White R. T., Damm D., Miller J., Spratt K., Schilling J., Hawgood S., Benson B., Cordell B. Isolation and characterization of the human pulmonary surfactant apoprotein gene. 1985 Sep 26-Oct 2Nature. 317(6035):361–363. doi: 10.1038/317361a0. [DOI] [PubMed] [Google Scholar]