Abstract
Hepatocyte nuclear factor 4 (HNF4) was first identified as a DNA binding activity in rat liver nuclear extracts. Protein purification had then led to the cDNA cloning of rat HNF4, which was found to be an orphan member of the nuclear receptor superfamily. Binding sites for this factor were identified in many tissue-specifically expressed genes, and the protein was found to be essential for early embryonic development in the mouse. We have now isolated cDNAs encoding the human homolog of the rat and mouse HNF4 splice variant HNF4 alpha 2, as well as a previously unknown splice variant of this protein, which we called HNF alpha 4. More importantly, we also cloned a novel HNF4 subtype (HNF4 gamma) derived from a different gene and showed that the genes encoding HNF 4 alpha and HNF4 gamma are located on human chromosomes 20 and 8, respectively. Northern (RNA) blot analysis revealed that HNF4 GAMMA is expressed in the kidney, pancreas, small intestine, testis, and colon but not in the liver, while HNF4 alpha RNA was found in all of these tissues. By cotransfection experiments in C2 and HeLa cells, we showed that HNF4 gamma is significantly less active than HNF4 alpha 2 and that the novel HNF4 alpha splice variant HNF4 alpha 4 has no detectable transactivation potential. Therefore, the differential expression of distinct HNF4 proteins may play a key role in the differential transcriptional regulation of HNF4-dependent genes.
Full Text
The Full Text of this article is available as a PDF (417.0 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Avraham K. B., Prezioso V. R., Chen W. S., Lai E., Sladek F. M., Zhong W., Darnell J. E., Jr, Jenkins N. A., Copeland N. G. Murine chromosomal location of four hepatocyte-enriched transcription factors: HNF-3 alpha, HNF-3 beta, HNF-3 gamma, and HNF-4. Genomics. 1992 Jun;13(2):264–268. doi: 10.1016/0888-7543(92)90241-j. [DOI] [PubMed] [Google Scholar]
- Chartier F. L., Bossu J. P., Laudet V., Fruchart J. C., Laine B. Cloning and sequencing of cDNAs encoding the human hepatocyte nuclear factor 4 indicate the presence of two isoforms in human liver. Gene. 1994 Sep 30;147(2):269–272. doi: 10.1016/0378-1119(94)90079-5. [DOI] [PubMed] [Google Scholar]
- Chen W. S., Manova K., Weinstein D. C., Duncan S. A., Plump A. S., Prezioso V. R., Bachvarova R. F., Darnell J. E., Jr Disruption of the HNF-4 gene, expressed in visceral endoderm, leads to cell death in embryonic ectoderm and impaired gastrulation of mouse embryos. Genes Dev. 1994 Oct 15;8(20):2466–2477. doi: 10.1101/gad.8.20.2466. [DOI] [PubMed] [Google Scholar]
- Clairmont A., Ebert T., Weber H., Zoidl C., Eickelmann P., Schulz W. A., Sies H., Ryffel G. U. Lowered amounts of the tissue-specific transcription factor LFB1 (HNF1) correlate with decreased levels of glutathione S-transferase alpha messenger RNA in human renal cell carcinoma. Cancer Res. 1994 Mar 1;54(5):1319–1323. [PubMed] [Google Scholar]
- Costa R. H., Grayson D. R., Darnell J. E., Jr Multiple hepatocyte-enriched nuclear factors function in the regulation of transthyretin and alpha 1-antitrypsin genes. Mol Cell Biol. 1989 Apr;9(4):1415–1425. doi: 10.1128/mcb.9.4.1415. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Deschatrette J., Moore E. E., Dubois M., Weiss M. C. Dedifferentiated variants of a rat hepatoma:reversion analysis. Cell. 1980 Apr;19(4):1043–1051. doi: 10.1016/0092-8674(80)90095-1. [DOI] [PubMed] [Google Scholar]
- Drewes T., Clairmont A., Klein-Hitpass L., Ryffel G. U. Estrogen-inducible derivatives of hepatocyte nuclear factor-4, hepatocyte nuclear factor-3 and liver factor B1 are differently affected by pure and partial antiestrogens. Eur J Biochem. 1994 Oct 1;225(1):441–448. doi: 10.1111/j.1432-1033.1994.00441.x. [DOI] [PubMed] [Google Scholar]
- Hata S., Inoue T., Kosuga K., Nakashima T., Tsukamoto T., Osumi T. Identification of two splice isoforms of mRNA for mouse hepatocyte nuclear factor 4 (HNF-4). Biochim Biophys Acta. 1995 Jan 2;1260(1):55–61. doi: 10.1016/0167-4781(94)00177-5. [DOI] [PubMed] [Google Scholar]
- Kastner P., Krust A., Turcotte B., Stropp U., Tora L., Gronemeyer H., Chambon P. Two distinct estrogen-regulated promoters generate transcripts encoding the two functionally different human progesterone receptor forms A and B. EMBO J. 1990 May;9(5):1603–1614. doi: 10.1002/j.1460-2075.1990.tb08280.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kuo C. J., Conley P. B., Chen L., Sladek F. M., Darnell J. E., Jr, Crabtree G. R. A transcriptional hierarchy involved in mammalian cell-type specification. Nature. 1992 Jan 30;355(6359):457–461. doi: 10.1038/355457a0. [DOI] [PubMed] [Google Scholar]
- Lai E., Darnell J. E., Jr Transcriptional control in hepatocytes: a window on development. Trends Biochem Sci. 1991 Nov;16(11):427–430. doi: 10.1016/0968-0004(91)90169-v. [DOI] [PubMed] [Google Scholar]
- Miquerol L., Lopez S., Cartier N., Tulliez M., Raymondjean M., Kahn A. Expression of the L-type pyruvate kinase gene and the hepatocyte nuclear factor 4 transcription factor in exocrine and endocrine pancreas. J Biol Chem. 1994 Mar 25;269(12):8944–8951. [PubMed] [Google Scholar]
- Nordeen S. K. Luciferase reporter gene vectors for analysis of promoters and enhancers. Biotechniques. 1988 May;6(5):454–458. [PubMed] [Google Scholar]
- Schorpp M., Kugler W., Wagner U., Ryffel G. U. Hepatocyte-specific promoter element HP1 of the Xenopus albumin gene interacts with transcriptional factors of mammalian hepatocytes. J Mol Biol. 1988 Jul 20;202(2):307–320. doi: 10.1016/0022-2836(88)90460-3. [DOI] [PubMed] [Google Scholar]
- Sladek F. M., Darnell J. E. Mechanisms of liver-specific gene expression. Curr Opin Genet Dev. 1992 Apr;2(2):256–259. doi: 10.1016/s0959-437x(05)80282-5. [DOI] [PubMed] [Google Scholar]
- Sladek F. M., Zhong W. M., Lai E., Darnell J. E., Jr Liver-enriched transcription factor HNF-4 is a novel member of the steroid hormone receptor superfamily. Genes Dev. 1990 Dec;4(12B):2353–2365. doi: 10.1101/gad.4.12b.2353. [DOI] [PubMed] [Google Scholar]
- Sucov H. M., Evans R. M. Retinoic acid and retinoic acid receptors in development. Mol Neurobiol. 1995 Apr-Jun;10(2-3):169–184. doi: 10.1007/BF02740674. [DOI] [PubMed] [Google Scholar]
- Taraviras S., Monaghan A. P., Schütz G., Kelsey G. Characterization of the mouse HNF-4 gene and its expression during mouse embryogenesis. Mech Dev. 1994 Nov;48(2):67–79. doi: 10.1016/0925-4773(94)90017-5. [DOI] [PubMed] [Google Scholar]
- Tian J. M., Schibler U. Tissue-specific expression of the gene encoding hepatocyte nuclear factor 1 may involve hepatocyte nuclear factor 4. Genes Dev. 1991 Dec;5(12A):2225–2234. doi: 10.1101/gad.5.12a.2225. [DOI] [PubMed] [Google Scholar]
- Tronche F., Yaniv M. HNF1, a homeoprotein member of the hepatic transcription regulatory network. Bioessays. 1992 Sep;14(9):579–587. doi: 10.1002/bies.950140902. [DOI] [PubMed] [Google Scholar]
- Xanthopoulos K. G., Mirkovitch J. Gene regulation in rodent hepatocytes during development, differentiation and disease. Eur J Biochem. 1993 Sep 1;216(2):353–360. doi: 10.1111/j.1432-1033.1993.tb18152.x. [DOI] [PubMed] [Google Scholar]
- Zapp D., Bartkowski S., Holewa B., Zoidl C., Klein-Hitpass L., Ryffel G. U. Elements and factors involved in tissue-specific and embryonic expression of the liver transcription factor LFB1 in Xenopus laevis. Mol Cell Biol. 1993 Oct;13(10):6416–6426. doi: 10.1128/mcb.13.10.6416. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhong W., Mirkovitch J., Darnell J. E., Jr Tissue-specific regulation of mouse hepatocyte nuclear factor 4 expression. Mol Cell Biol. 1994 Nov;14(11):7276–7284. doi: 10.1128/mcb.14.11.7276. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhong W., Sladek F. M., Darnell J. E., Jr The expression pattern of a Drosophila homolog to the mouse transcription factor HNF-4 suggests a determinative role in gut formation. EMBO J. 1993 Feb;12(2):537–544. doi: 10.1002/j.1460-2075.1993.tb05685.x. [DOI] [PMC free article] [PubMed] [Google Scholar]