scholarly journals Basal promoter of the rat connexin 32 gene: identification and characterization of an essential element and its DNA-binding protein.

1995 ◽  
Vol 15 (3) ◽  
pp. 1439-1445 ◽  
Author(s):  
S Bai ◽  
A Schoenfeld ◽  
A Pietrangelo ◽  
R D Burk
Keyword(s):  
Cell Lines ◽  
Rat Liver ◽  
Liver Tissue ◽  
Nuclear Protein ◽  
Hepatoma Cell ◽  
Essential Element ◽  
Connexin 32 ◽  
Mobility Shift ◽  
Preferential Expression ◽  
Hepatoma Cell Lines

The connexin 32 (Cx32) gene, a member of a multigene family, is expressed preferentially in the liver. The basal promoter complex of the rat Cx32 gene was previously localized to a 146-bp region (map positions [mp] -179 to -34) immediately upstream of the first exon. To investigate the biochemical factors contributing to the basal promoter activity, nuclear protein-DNA complexes within this region (mp -177 to -106) were investigated by using a DNA mobility shift assay. Three DNA-protein binding activities, termed Cx32-B1, Cx32-B2, and Cx32-B3, were identified with nuclear protein extracts from hepatoma cell lines, HuH7 and FAO-1. However, only Cx32-B2 binding activity was detected in nuclear protein extract from normal rat liver tissue. This activity was significantly more abundant in rat liver tissue than in hepatoma cell lines and tissues from various other organs. By using methylation interference footprinting, the Cx32-B2 complex was localized to the region between mp -152 and -127 and a DNA probe containing this region bound to a 60-kDa protein in rat liver nuclear extracts. Mutation of two nucleotides in the Cx32-B2 binding site abrogated the formation of the Cx32-B2 protein-DNA complex and significantly reduced the transcriptional activity of the Cx32 promoter. These results indicate that the Cx32-B2 complex is an essential component of the rat Cx32 basal promoter and is likely a major factor in the preferential expression of this gene in the liver.

Different Expression of Esterase Variants in Rat Hepatic and Hepatom a-Derived Cell Lines Detected by Electrophoresis

1995 ◽  
Vol 50 (9-10) ◽  
pp. 664-668 ◽  
Author(s):  
Adel S. Afify ◽  
Yoshimitsu Yamazaki ◽  
Yu-ichi Kageyama ◽  
Shiro Yusa ◽  
Yoshikatsu Ogawa ◽  
...  
Keyword(s):  
Cell Lines ◽  
Rat Liver ◽  
Hepatoma Cell ◽  
Polyacrylamide Gel Electrophoresis ◽  
Liver Homogenate ◽  
Normal Liver ◽  
Liver Parenchyma ◽  
Hepatoma Cell Lines ◽  
Normal Rat ◽  
Transformed Cell Lines

Abstract Esterases in nine rat hepatic and hepatoma-derived cell lines and normal rat liver homogenate were detected by polyacrylamide gel electrophoresis coupled with active staining with a-naphthyl acetate or butyrate as a substrate. The esterase band patterns of the non-cancerous and oncogene-transformed cell lines were alike, but different from those of hepatoma cell lines and normal rat liver homogenate. The former groups of cells might have completely lost the characteristics of rat liver parenchymal cells, or else they might have their origin at cells other than liver parenchyma. The esterase patterns of the hepatoma cell lines (e.g., McA-RH7777) and the normal rat liver highly resembled with each other, exemplifying the slight biochemical deviation of cancer from normal cells. However, two-dimensional electrophoretogram for the McA-RH7777 cell line showed a prominent esterase spot {p/ 6.0-Mr 110 kDa) that was lacking in the normal liver. This result indicates that there is invariably some change in esterase expression between the cancer cells and the normal liver cells

Molecular cloning of cDNA for rat argininosuccinate lyase and its expression in rat hepatoma cell lines

1986 ◽  
Vol 6 (5) ◽  
pp. 1722-1728
Author(s):  
M A Lambert ◽  
L R Simard ◽  
P N Ray ◽  
R R McInnes
Keyword(s):  
Cell Lines ◽  
Rat Liver ◽  
Transcriptional Activity ◽  
Hepatoma Cell ◽  
Cdna Clones ◽  
Argininosuccinate Lyase ◽  
Hepatoma Cell Lines ◽  
Liver Cdna Library ◽  
Nuclear Processing ◽  
Rat Hepatoma

Using antibody and plaque hybridization screening, we isolated rat argininosuccinate lyase (AS lyase) cDNA clones from a liver cDNA library prepared in the phage expression vector lambda gt11. Five overlapping cDNAs covering 1.7 kilobases of the estimated 2.0-kilobase AS lyase mRNA were characterized and confirmed as AS lyase sequences by hybrid selection. We examined the differential expression of AS lyase in rat liver and four rat hepatoma cell lines (7800C1, H4, HTC, and MH1C1). These cells exhibited a 60-fold range of AS lyase enzyme activity, with a direct correlation between activity, amount of AS lyase immunoreactive protein, and quantity of specific AS lyase mRNA. These observations suggest that the differences in AS lyase expression between rat liver and the hepatoma cell lines result from variations in AS lyase transcriptional activity or alterations in nuclear processing of AS lyase RNA.

scholarly journals Molecular cloning of cDNA for rat argininosuccinate lyase and its expression in rat hepatoma cell lines.

1986 ◽  
Vol 6 (5) ◽  
pp. 1722-1728 ◽  
Author(s):  
M A Lambert ◽  
L R Simard ◽  
P N Ray ◽  
R R McInnes
Keyword(s):  
Cell Lines ◽  
Rat Liver ◽  
Transcriptional Activity ◽  
Hepatoma Cell ◽  
Cdna Clones ◽  
Argininosuccinate Lyase ◽  
Hepatoma Cell Lines ◽  
Liver Cdna Library ◽  
Nuclear Processing ◽  
Rat Hepatoma

Using antibody and plaque hybridization screening, we isolated rat argininosuccinate lyase (AS lyase) cDNA clones from a liver cDNA library prepared in the phage expression vector lambda gt11. Five overlapping cDNAs covering 1.7 kilobases of the estimated 2.0-kilobase AS lyase mRNA were characterized and confirmed as AS lyase sequences by hybrid selection. We examined the differential expression of AS lyase in rat liver and four rat hepatoma cell lines (7800C1, H4, HTC, and MH1C1). These cells exhibited a 60-fold range of AS lyase enzyme activity, with a direct correlation between activity, amount of AS lyase immunoreactive protein, and quantity of specific AS lyase mRNA. These observations suggest that the differences in AS lyase expression between rat liver and the hepatoma cell lines result from variations in AS lyase transcriptional activity or alterations in nuclear processing of AS lyase RNA.

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