DNA-binding peptides from rat liver and Novikoff hepatoma cells: quantitative level and possible biochemical differences

1983 ◽  
Vol 9 (3) ◽  
pp. 169-174 ◽  
Author(s):  
G. L. Gianfranceschi ◽  
D. Barra ◽  
S. Coderoni ◽  
M. Paparelli ◽  
F. Venanzi ◽  
...  
Keyword(s):  
Dna Binding ◽  
Rat Liver ◽  
Hepatoma Cells ◽  
Novikoff Hepatoma ◽  
Quantitative Level ◽  
Binding Peptides

scholarly journals cDNA cloning and expression of rat homeobox gene, Hex, and functional characterization of the protein

1999 ◽  
Vol 339 (1) ◽  
pp. 111-117 ◽  
Author(s):  
Takashi TANAKA ◽  
Tetsuya INAZU ◽  
Kazuya YAMADA ◽  
Zaw MYINT ◽  
Vincent W. KENG ◽  
...  
Keyword(s):  
Dna Binding ◽  
Binding Site ◽  
Rat Liver ◽  
Functional Characterization ◽  
Homeobox Gene ◽  
Hepatoma Cells ◽  
Cloning And Expression ◽  
Expression Vectors ◽  
Luciferase Reporter ◽  
Cdna Clones

We isolated two cDNA clones of rat Hex, a homeobox protein, studied its expression in rat liver and various cells, and characterized the protein. The levels of Hex mRNA were only slightly increased in liver of rats refed with a high-carbohydrate diet or after partial hepatectomy. Whereas the expression of Hex mRNA was detected in hepatocytes isolated from adult rat liver and also in highly differentiated hepatoma cells, no Hex mRNA was detected in poorly differentiated hepatoma cells. Hex mRNA was also detected in liver from embryo aged 15 days. Expression of Hex was increased in F9 cells during differentiation into visceral endoderm cells by treatment with retinoic acid. This stimulation occurred prior to an increase in the level of α-fetoprotein mRNA. When fusion-protein expression vectors of GAL4 DNA-binding domain and Hex were co-transfected with luciferase reporter plasmid, with or without five copies of the GAL4-binding site, into HepG2 cells, the luciferase activities were decreased in concentration- and GAL4-binding site-dependent manners. This repression did not require the presence of the homeodomain, which is located between the amino acid residues 137 and 196. Its repression domain was mapped between the residues 45 and 136 in the proline-rich N-terminal region. In addition, the homeodomain was responsible for DNA-binding of Hex. These results indicate that Hex functions as a transcriptional repressor and may be involved in the differentiation and/or maintenance of the differentiated state in hepatocytes.

Poly(A)-mRNA deprimerones in rat liver and Novikoff hepatoma cells

1980 ◽  
Vol 6 (2) ◽  
pp. 89-94 ◽  
Author(s):  
M. Hiliar ◽  
J. Przyjemski ◽  
Z. Stolzmann
Keyword(s):  
Rat Liver ◽  
Hepatoma Cells ◽  
Novikoff Hepatoma

scholarly journals Repression of the albumin gene in Novikoff hepatoma cells.

1982 ◽  
Vol 2 (3) ◽  
pp. 258-266 ◽  
Author(s):  
Y G Capetanaki ◽  
C N Flytzanis ◽  
A Alonso
Keyword(s):  
Rat Liver ◽  
Cdna Probe ◽  
Hepatoma Cells ◽  
In Vitro Translation ◽  
Specific Gene ◽  
Transcriptional Level ◽  
Novikoff Hepatoma ◽  
Albumin Gene ◽  
Albumin Mrna

Novikoff hepatoma cells have lost their capacity to synthesize albumin. As a first approach to study the mechanisms underlying this event, in vitro translation in a reticulocyte system was performed using total polyadenylated mRNA from rat liver and Novikoff hepatoma cells. Immunoprecipitation of the in vitro translation products with albumin-specific antibody revealed a total lack of albumin synthesis in Novikoff hepatoma, suggesting the absence of functional albumin mRNA in these cells. Titration experiments using as probe albumin cDNA cloned in pBR322 plasmid demonstrated the absence of albumin-specific sequences in both polysomal and nuclear polyadenylated and total RNA from Novikoff cells. This albumin recombinant plasmid was obtained by screening a rat liver cDNA library with albumin [32P]cDNA reverse transcribed from immuno-precipitated mRNA. The presence of an albumin-specific gene insert was documented with translation assays as well as by restriction mapping. Repression of the albumin gene at the transcriptional level was further demonstrated by RNA blotting experiments using the cloned albumin cDNA probe. Genomic DNA blots using the cloned albumin cDNA as probe did not reveal any large-scale deletions, insertions, or rearrangements in the albumin gene, suggesting that the processes involved in the suppression of albumin mRNA synthesis do not involve extensive genomic rearrangements.

Repression of the albumin gene in Novikoff hepatoma cells

1982 ◽  
Vol 2 (3) ◽  
pp. 258-266
Author(s):  
Y G Capetanaki ◽  
C N Flytzanis ◽  
A Alonso
Keyword(s):  
Rat Liver ◽  
Cdna Probe ◽  
Hepatoma Cells ◽  
In Vitro Translation ◽  
Specific Gene ◽  
Transcriptional Level ◽  
Novikoff Hepatoma ◽  
Albumin Gene ◽  
Albumin Mrna

Novikoff hepatoma cells have lost their capacity to synthesize albumin. As a first approach to study the mechanisms underlying this event, in vitro translation in a reticulocyte system was performed using total polyadenylated mRNA from rat liver and Novikoff hepatoma cells. Immunoprecipitation of the in vitro translation products with albumin-specific antibody revealed a total lack of albumin synthesis in Novikoff hepatoma, suggesting the absence of functional albumin mRNA in these cells. Titration experiments using as probe albumin cDNA cloned in pBR322 plasmid demonstrated the absence of albumin-specific sequences in both polysomal and nuclear polyadenylated and total RNA from Novikoff cells. This albumin recombinant plasmid was obtained by screening a rat liver cDNA library with albumin [32P]cDNA reverse transcribed from immuno-precipitated mRNA. The presence of an albumin-specific gene insert was documented with translation assays as well as by restriction mapping. Repression of the albumin gene at the transcriptional level was further demonstrated by RNA blotting experiments using the cloned albumin cDNA probe. Genomic DNA blots using the cloned albumin cDNA as probe did not reveal any large-scale deletions, insertions, or rearrangements in the albumin gene, suggesting that the processes involved in the suppression of albumin mRNA synthesis do not involve extensive genomic rearrangements.

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