Transcription response elements

We have proposed a mechanism by which lL-1 exerts its deleterious effects on islet function and viability (Fig. 11 Corbett et al., 1992). In this proposed mechanism, lL-1 is released by macrophages during the initial stages of islet infiltration. IL-1 binds to a specific IL-1 receptors on the /3 cell activating a tyrosine kinase. Tyrosine kinase phosphorylation stimulates second messengers to induce the expression of c-/os, c-jun, the activation of NF-xB, and possibly other early transcriptional regulators. These early-immediate transcriptional response elements may activate or stimulate the expression of inducible nitric oxide... 

More subtle modes of action are also possible since the response to hormone receptor binding is complex and could be affected by chemical interference with receptor-related proteins, DNA methylation or histone acetylation. Dioxin (TCDD), for example, reduces the ability of the oestrogen-receptor complex to bind to the oestrogen response element of DNA, reducing gene transcription. ... 

One such hypotheses submits that most antidepressants enhance the expression of cyclo-AMP response element binding protein (CREB), which is a transcription factor that after phosphorylation binds to cyclo-AMP response elements localized in the promoter region of many genes including that coding for brain... 

CREB stands for cyclic-AMP response element (CRE) binding protein and is a transcription factor. When phosphorylated by cyclic AMP- and cyclic GMP-dependent Protein Kinases or other protein kinases it binds to gene promoters that contain a specific binding site. After binding, the respective transcription activity is modulated. 

DNA response elements are generally found a short distance upstream of promoters in selected genes. They are specific for selective transcription factors and... 

Peroxisome Proliferator-Activated Receptors. Figure 3 Transcription of PPAR target genes. A schematic representation of the transcription of PPAR-regulated genes in the absence (a) and presence (b) of PPAR ligand. Abbreviations PPAR-RE, peroxisome proliferator-activated receptor-response element RNA Pol II, RNA polymerase II TATA-BP, TATA-binding protein. 

Regulatory regions are transcriptional control sequences, which consist of promoters, response elements, enhancers and possibly silencers, located upstream of the start site of transcription. The overall effect on gene transcription is a sum of the contributions of these elements and the activities of proteins recruited to these sites. Promoters are located immediately upstream of the start site and initiate transcription. They often contain tissue- or cell-specific elements if the gene is not ubiquitously expressed. Enhancers are positive regulatory elements which function independently of orientation and distance from the genes they regulate. 

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