Negative regulation of retrovirus expression in embryonal carcinoma cells mediated by an intragenic domain.
An intragenic region spanning the tRNA primer binding site of a Moloney murine leukemia virus recombinant retrovirus was found to restrict expression specifically in embryonal carcinoma (EC) cells. When the inhibitory domain was present, the levels of steady-state RNA synthesized from integrated recombinant templates in stable cotransformation assays were reduced 20-fold in EC cells but not in C2 myoblast cells. Transient-cotransfection assays showed that repression of a template containing the EC-specific inhibitory component was relieved by an excess of specific competitor DNA. In addition, repression mediated by the inhibitory component was orientation independent. This evidence demonstrates the presence of a saturable, trans-acting negative regulatory factor(s) in EC cells and suggests that the interaction of the factor(s) with the intragenic inhibitory component occurs at the DNA level.
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E. I. du Pont de Nemours and Company, Inc., Central Research and Development Department, Wilmington, Delaware 19898.
Sievert
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Scott
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D000818:Animals; D001483:Base Sequence; D001667:Binding, Competitive; D004279:DNA, Viral / Q000235:genetics*; D054278:Embryonal Carcinoma Stem Cells; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D008979:Moloney murine leukemia virus / Q000235:genetics; D014411:Neoplastic Stem Cells / Q000382:microbiology*; D011533:Proviruses / Q000235:genetics; D012315:RNA Caps; D012367:RNA, Viral / Q000096:biosynthesis*; D011995:Recombination, Genetic; D012190:Retroviridae / Q000235:genetics*; D014162:Transfection
D004279:DNA, Viral; D012315:RNA Caps; D012367:RNA, Viral