scholarly journals Hepatocyte nuclear factor 6: organization and chromosomal assignment of the rat gene and characterization of its promoter

1998 ◽  
Vol 334 (3) ◽  
pp. 565-569 ◽  
Author(s):  
Mojgan RASTEGAR ◽  
Claude SZPIRER ◽  
Guy G. ROUSSEAU ◽  
Frédéric P. LEMAIGRE
Keyword(s):  
Amino Acids ◽  
Dna Binding ◽  
Transcription Initiation ◽  
Initiation Site ◽  
Transcription Initiation Site ◽  
Chromosomal Assignment ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Specific Expression ◽  
Exon 2

Hepatocyte nuclear factor 6 (HNF-6) is the prototype of a family of tissue-specific transcription factors characterized by a bipartite DNA-binding domain consisting of a single cut domain and a novel type of homeodomain. We have previously cloned rat cDNA species coding for two isoforms, HNF-6α (465 residues) and β (491 residues), which differ only by the length of the spacer between the two DNA-binding domains. We have now localized the rat Hnf6 gene to chromosome 8q24–q31 by Southern blotting of DNA from somatic cell hybrids and by fluorescence in situhybridization. Cloning and sequencing of the rat gene showed that the two HNF-6 isoforms are generated by alternative splicing of three exons that are more than 10 kb apart from each other. Exon 1 codes for the N-terminal part and the cut domain, exon 2 codes for the 26 HNF-6β-specific amino acids, and exon 3 codes for the homeodomain and the C-terminal amino acids. The transcription initiation site was mapped by ribonuclease protection and 5´ rapid amplification of cDNA ends. Transfection experiments showed that promoter activity was contained within 0.75 kb upstream of the transcription initiation site. This activity was detected by the transfection of liver-derived HepG2 cells, but not of Rat-1 fibroblasts, suggesting that the promoter is sufficient to confer liver-specific expression.

scholarly journals Initiation binding repressor, a factor that binds to the transcription initiation site of the histone h5 gene, is a glycosylated member of a family of cell growth regulators [corrected].

1995 ◽  
Vol 15 (12) ◽  
pp. 6670-6685 ◽  
Author(s):  
A Gómez-Cuadrado ◽  
M Martín ◽  
M Noël ◽  
A Ruiz-Carrillo
Keyword(s):  
Dna Binding ◽  
Transcription Initiation ◽  
Direct Repeat ◽  
Initiation Site ◽  
Transcription Initiation Site ◽  
Nuclear Targeting ◽  
Dimerization Domain ◽  
Localization Signal ◽  
Molecular Aspects ◽  
Histone H5

Initiation binding repressor [corrected] (IBR) is a chicken erythrocyte factor (apparent molecular mass, 70 to 73 kDa) that binds to the sequences spanning the transcription initiation site of the histone h5 gene, repressing its transcription. A variety of other cells, including transformed erythroid precursors, do not have IBR but a factor referred to as IBF (68 to 70 kDa) that recognizes the same IBR sites. We have cloned the IBR cDNA and studied the relationship of IBR and IBF. IBR is a 503-amino-acid-long acidic protein which is 99.0% identical to the recently reported human NRF-1/alpha-Pal factor and highly related to the invertebrate transcription factors P3A2 and erected wing gene product (EWG). We present evidence that IBR and IBF are most likely identical proteins, differing in their degree of glycosylation. We have analyzed several molecular aspects of IBR/F and shown that the factor associates as stable homodimers and that the dimer is the relevant DNA-binding species. The evolutionarily conserved N-terminal half of IBR/F harbors the DNA-binding/dimerization domain (outer limits, 127 to 283), one or several casein kinase II sites (37 to 67), and a bipartite nuclear localization signal (89 to 106) which appears to be necessary for nuclear targeting. Binding site selection revealed that the alternating RCGCRYGCGY consensus constitutes high-affinity IBR/F binding sites and that the direct-repeat palindrome TGCGCATGCGCA is the optimal site. A survey of genes potentially regulated by this family of factors primarily revealed genes involved in growth-related metabolism.

The restricted promoter activity of the liver transcription factor hepatocyte nuclear factor 3 beta involves a cell-specific factor and positive autoactivation

1992 ◽  
Vol 12 (2) ◽  
pp. 552-562
Author(s):  
L Pani ◽  
X B Quian ◽  
D Clevidence ◽  
R H Costa
Keyword(s):  
Transcription Factor ◽  
Promoter Activity ◽  
Binding Activity ◽  
Specific Factor ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Cell Type ◽  
Specific Expression ◽  
Cell Type Specific Expression ◽  
Cell Type Specific

The transcription factor hepatocyte nuclear factor 3 (HNF-3) is involved in the coordinate expression of several liver genes. HNF-3 DNA binding activity is composed of three different liver proteins which recognize the same DNA site. The HNF-3 proteins (designated alpha, beta, and gamma) possess homology in the DNA binding domain and in several additional regions. To understand the cell-type-specific expression of HNF-3 beta, we have defined the regulatory sequences that elicit hepatoma-specific expression. Promoter activity requires -134 bp of HNF-3 beta proximal sequences and binds four nuclear proteins, including two ubiquitous factors. One of these promoter sites interacts with a novel cell-specific factor, LF-H3 beta, whose binding activity correlates with the HNF-3 beta tissue expression pattern. Furthermore, there is a binding site for the HNF-3 protein within its own promoter, suggesting that an autoactivation mechanism is involved in the establishment of HNF-3 beta expression. We propose that both the LF-H3 beta and HNF-3 sites play an important role in the cell-type-specific expression of the HNF-3 beta transcription factor.

Identification of upstream and intragenic regulatory elements that confer cell-type-restricted and differentiation-specific expression on the muscle creatine kinase gene

1988 ◽  
Vol 8 (7) ◽  
pp. 2896-2909 ◽  
Author(s):  
E A Sternberg ◽  
G Spizz ◽  
W M Perry ◽  
D Vizard ◽  
T Weil ◽  
...  
Keyword(s):  
Transcription Initiation ◽  
Regulatory Element ◽  
Simian Virus 40 ◽  
Muscle Cells ◽  
Regulatory Elements ◽  
Initiation Site ◽  
Simian Virus ◽  
Cell Type ◽  
Specific Expression ◽  
Developing Muscle

Terminal differentiation of skeletal myoblasts is accompanied by induction of a series of tissue-specific gene products, which includes the muscle isoenzyme of creatine kinase (MCK). To begin to define the sequences and signals involved in MCK regulation in developing muscle cells, the mouse MCK gene has been isolated. Sequence analysis of 4,147 bases of DNA surrounding the transcription initiation site revealed several interesting structural features, some of which are common to other muscle-specific genes and to cellular and viral enhancers. To test for sequences required for regulated expression, a region upstream of the MCK gene from -4800 to +1 base pairs, relative to the transcription initiation site, was linked to the coding sequences of the bacterial chloramphenicol acetyltransferase (CAT) gene. Introduction of this MCK-CAT fusion gene into C2 muscle cells resulted in high-level expression of CAT activity in differentiated myotubes and no detectable expression in proliferating undifferentiated myoblasts or in nonmyogenic cell lines. Deletion mutagenesis of sequences between -4800 and the transcription start site showed that the region between -1351 and -1050 was sufficient to confer cell type-specific and developmentally regulated expression on the MCK promoter. This upstream regulatory element functioned independently of position, orientation, or distance from the promoter and therefore exhibited the properties of a classical enhancer. This upstream enhancer also was able to confer muscle-specific regulation on the simian virus 40 promoter, although it exhibited a 3- to 5-fold preference for its own promoter. In contrast to the cell type- and differentiation-specific expression of the upstream enhancer, the MCK promoter was able to function in myoblasts and myotubes and in nonmyogenic cell lines when combined with the simian virus 40 enhancer. An additional positive regulatory element was identified within the first intron of the MCK gene. Like the upstream enhancer, this intragenic element functioned independently of position, orientation, and distance with respect to the MCK promoter and was active in differentiated myotubes but not in myoblasts. These results demonstrate that expression of the MCK gene in developing muscle cells is controlled by complex interactions among multiple upstream and intragenic regulatory elements that are functional only in the appropriate cellular context.

Tissue-specific regulation of mouse hepatocyte nuclear factor 4 expression

1994 ◽  
Vol 14 (11) ◽  
pp. 7276-7284
Author(s):  
W Zhong ◽  
J Mirkovitch ◽  
J E Darnell
Keyword(s):  
Transcription Factor ◽  
Transgenic Mice ◽  
Transient Transfection ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Distal Enhancer ◽  
Specific Expression ◽  
Tissue Specific ◽  
Hypersensitive Sites ◽  
Hepatocyte Nuclear Factor 4

Hepatocyte nuclear factor 4 (HNF-4) is a liver-enriched transcription factor and a member of the steroid hormone receptor superfamily. HNF-4 is required for the hepatoma-specific expression of HNF-1 alpha, another liver-enriched transcription factor, suggesting the early participation of HNF-4 in development. To prepare for further study of HNF-4 in development, the tissue-specific expression of the mouse HNF-4 gene was studied by analyzing the promoter region for required DNA elements. DNase-hypersensitive sites in the gene in liver and kidney tissues were found in regions both distal and proximal to the RNA start that were absent in tissues in which HNF-4 expression did not occur. By use of reporter constructs in transient-transfection assays and with transgenic mice, a region sufficient to drive liver-specific expression of HNF-4 was identified. While an HNF-1 binding site between bp -98 and -68 played an important role in the hepatoma-specific promoter activity of HNF-4 in transient-transfection assays, it was not sufficient for the liver-specific expression of a reporter gene in transgenic mice. Distal enhancer elements indicated by the presence of DNase I-hypersensitive sites at kb -5.5 and -6.5, while not functional in transient-transfection assays, were required for the correct expression of the mouse HNF-4 gene in animals.

Identification of the transcription initiation site of the asexually expressed rRNA genes of the malaria parasite Plasmodium berghei

1999 ◽  
Vol 99 (2) ◽  
pp. 193-205 ◽  
Author(s):  
Rosalina M.L. van Spaendonk ◽  
Glenn A. McConkey ◽  
Jai Ramesar ◽  
Andrei Gabrielian ◽  
Thomas F. McCutchan ◽  
...  
Keyword(s):  
Plasmodium Berghei ◽  
Transcription Initiation ◽  
Malaria Parasite ◽  
Initiation Site ◽  
Transcription Initiation Site ◽  
Rrna Genes ◽  
Parasite Plasmodium
Sign in / Sign up

Export Citation Format

Share Document