The rat albumin gene promoter is appropriately regulated in transient but not in stable transfections.

AUTOR(ES)

Berland, R

RESUMO

The tissue-specific expression of the liver-specific rat albumin gene promoter was examined after transfer to various hepatic and non-hepatic cell lines. A 402 base pair sequence from the albumin gene 5' flank enabled a fused reporter chloramphenicol acetyltransferase gene to be expressed in rat hepatoma cell lines but not in fibroblast lines or dedifferentiated hepatoma cells. However, when this same construct was analyzed in permanently transfected cell populations, it was expressed equally well in differentiated and dedifferentiated hepatoma cells and in two of three fibroblast lines tested. The inappropriate expression of the albumin promoter was also seen using the HSV tk gene and the E. coli gpt gene as reporters, and when assayed by colony formation in HAT medium (tk gene) or by S1 protection of transcripts in cotransfected populations (tk and gpt genes). These results show that gene regulatory elements can behave differently in transient vs. stable transfections, and suggest that chromosomal integration can provide long range positive influences on gene expression.

Documentos Relacionados

• Albumin gene expression is down-regulated by albumin or macromolecule infusion in the rat.
• Determinants of rat albumin promoter tissue specificity analyzed by an improved transient expression system.
• The Saccharomyces cerevisiae DNA repair gene RAD2 is regulated in meiosis but not during the mitotic cell cycle.
• c-Ha-ras down regulates the alpha-fetoprotein gene but not the albumin gene in human hepatoma cells.
• The Bacillus thuringiensis PlcR-Regulated Gene inhA2 Is Necessary, but Not Sufficient, for Virulence