Iron-inducible transcription of a malic enzyme gene (also reputed to be ap65-1) in Trichomonas vaginalis was previously shown to involve a Myb1 repressor and a Myb2 activator, each of which may preferentially select two closely spaced promoter sites, MRE-1/MRE-2r, which comprises overlapping promoter elements, and MRE-2f. In the present study, an iron-inducible approximately 32-kDa Myb3 nuclear...

Expression of the cytokine interleukin-6 (IL-6) by skeletal muscle is hugely increased in response to a single bout of endurance exercise, and this appears to be mediated by increases in intracellular calcium. We examined the effects of endurance exercise on IL-6 mRNA levels and promoter activity in skeletal muscle in vivo, and the role of the calcium-activated calcineurin signaling pathway on ...

conclusions the mutation ratio difference between genotypes b and c in children was higher than that of adults and several combined mutations were exclusively detected in children with chronic hbv genotype c infection associated with higher viral load. objectives the aim of this study was to assess the mutation profiles of bcp and precore regions in different hbv genotypes in chronically infect...

SUMMARY The early ultrastructural changes induced by the tumor promoter 12-O-tetradecanoyl-phorbol-l3-acetate in mouse epi dermis previously transformed by treatment with an initiating dose of 7,1 2-dimethylbenz(a)anthracene are described and compared with those in the basal cells of papillomas and carcinoma that appear later after repeated promoter treat ment. Groups of cells with fine structu...

Repression of basal transcription of a 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) responsive 25-hydroxyvitamin D3-24-hydroxylase (CYP24) promoter construct as observed in kidney cells in the absence of ligand and this repression was dependent on a functional vitamin D response element (VDRE). Basal repression was also seen with a construct where a consensus DR-3-type VDRE was fused to the thymidin...

Thyroid hormone receptor (TR) can act as both a transcriptional activator and a silencer. Optimal activation by TR requires synergism with activator(s) bound to the promoter (promoter proximal activator). It is thought that liganded TR either helps to recruit preinitiation complexes (PIC) to the promoter or activates the PIC already recruited. However, the studies analyzing the TR action on the...

The enzyme cyclooxygenase (COX)-1 is constitutive whereas COX-2 is regulated in virtually all tissues. To assess whether this dogma holds true in the pancreatic islet, we examined basal and interleukin (IL)-1-regulated expression of COX-2 in HIT-T15 cells, Syrian hamster and human islets, and other Syrian hamster tissues. We found that COX-2, and not COX-1, gene expression is dominant in pancre...

Nuclear thyroid hormone receptors (TRs) act as ligand-dependent activators, but paradoxically unliganded TRs can increase transcription of promoters containing negative response elements (nTRE), and hormone binding represses this activation. The rat growth hormone (GH) promoter contains a positive TRE and a nTRE. Ligand-dependent negative regulation mediated by the nTRE could play an important ...

FOXP3 is playing an essential role for T regulatory cells and is involved in the molecular mechanisms controlling immune tolerance. Although the biological relevance of this transcription factor is well documented, the pathways responsible for its induction are still unclear. The current study reveals structure and function of the human FOXP3 promoter, revealing essential molecular mechanisms o...