Jorgensen Jost

Learn More
We have isolated the mouse MyoD1 gene flanked by its promoter region by screening a genomic library with synthetic oligonucleotides. The structural gene is interrupted by two G + C rich introns. Transfection of the cloned gene inserted into an expression vector converts fibroblasts to myoblasts. Sequence analysis of about 650 bp of the 5' upstream region(More)
We show that in mouse myoblasts the MyoD1 promoter is highly stimulated by MyoD1 expression, suggesting that it is controlled by a positive feedback loop. Using deletion and mutation analyses, we identified the targets for MyoD1 promoter autoregulation as the two proximal E-boxes located close to the MyoD1 core promoter. Gel mobility shift competition(More)
A negative regulating protein (MDBP-2) from rooster liver nuclear extracts binds preferentially to a methylated promoter region 5'TTCACCTTmCGCTATGAGGGGGATCATACTGG3' of the avian vitellogenin II gene (Nucleic Acids Res. 19, 1029-1034, 1991). Treatment of adult and immature roosters with estradiol results in a 90% decrease in the binding activity of MDBP-2(More)
We have previously purified and characterized a 5-methylcytosine (5-MeC)-DNA glycosylase from 12 day old chick embryos [Jost,J.P. et al. (1995) J. Biol. Chem. 270, 9734-9739]. The activity of the purified enzyme is abolished upon treatment with proteinase K and ribonuclease A. RNA copurifies with 5-MeC-DNA glycosylase activity throughout all chromatographic(More)
We have previously shown that DNA demethylation by chick embryo 5-methylcytosine (5-MeC)-DNA glycosylase needs both protein and RNA. RNA from enzyme purified by SDS-PAGE was isolated and cloned. The clones have an insert ranging from 240 to 670 bp and contained on average one CpG per 14 bases. All six clones tested had different sequences and did not have(More)
We have constructed a stable cell line, human embryonal kidney 293M+, containing a lacZ reporter gene controlled by an in vitro methylated hormone-responsive enhancer. Methylation of the enhancer-promoter abolishes lacZ expression controlled by ponasterone A (an analogue of ecdysone). Ponasterone A-induced expression is restored by the short-chain fatty(More)
We have previously shown that in vivo estradiol-dependent dephosphorylation of MDBP-2-H1 (a member of the histone H1 family) correlates with the loss of in vitro preferential binding to methylated DNA. To study the effects of the phosphorylation/dephosphorylation of MDBP-2-H1 on the expression of the avian vitellogenin II gene, we optimised an in vitro(More)
In vitro transcription competition with oligonucleotides has shown that a down regulating factor can be displaced by a methylated oligonucleotide covering a specific region of the avian vitellogenin II gene promoter (Proc. Natl. Acad. Sci USA, (1990) 87, 3047-3051). Gel mobility shift and competition assays show that a protein binding preferentially to(More)
The expression of the serine protease inhibitor Protease nexin-1 (PN-1) is upregulated in glial cells following different types of lesion in the nervous system. A strong negative regulatory element has been shown by the missing nucleoside technique to be a CACGTG site (E-box) in the proximal part of the PN-1 promoter. The factor binding to this site is(More)