Regulatory elements:

Several transcription factors bind to control  sequences  regulatory   elements within  a few  hundred  base  pairs  of the  protein-coding gene being regulated. Positive control elements which lie upstream of the gene, commonly within 200 bp of the  transcriptional begin site, are frequently known as UREs (upstream regulatory elements) and function to increase the transcriptional activity of the gene well above in which of the basal promoter.  Some of these components, for instance the SP1 box and the CAAT box, are found in the promoters of several eukaryotic protein-coding genes; indeed genes frequently have various copies of one or both components. The SP1 box has the core sequence GGGCGG and binds transcription factor  SP1  that  then  interacts  with  common  transcription  factor TFIID . In comparing  some upstream regulatory  elements  are related  only with  a few specific  genes  and are responsible  for limiting  the transcription  of those genes  to certain  tissues  or in response  to certain  stimuli  like as steroid hormones. For instance, steroid hormones control metabolism through entering the goal cell and binding to specific steroid hormone receptors in the cytoplasm. The binding of hormone releases the receptor from an inhibitor protein that generally keeps the receptor in the cytoplasm. 

The hormone-receptor difficult, now free of dimerizes, inhibitor and travels to the nucleus where it binds to a transcriptional control element, known as a hormone response element in the promoters of target genes. Then, such as other transcription factors the bound hormone-receptor complex interacts with the transcription initiation complex to increase the rate of transcription of the gene. The conclusion  is a hormone-specific transcription of a subset of genes in goal cells which  contain  the  appropriate steroid hormone receptor. At this time, the hormone receptor is itself a transcription factor which is activated through binding the hormone ligand. Accepts steroid hormones, polypeptide hormones like as insulin and cytokines, do not enter the goal cell but alternatively bind to protein receptors located at the cell surface. The binding reaction switches a cascade of protein activations, frequently including protein phosphorylation, that relay the signal inside the cell signal transduction. Again the response  should be in which specific transcription factors are activated and stimulate the transcription of selected genes, but here the activation  is mediated through the signal transduction pathway and does not include direct binding of the cytokine or hormone to the transcription factor. Several additional instance of transcriptional activation of specific genes by transcription factors exist in eukaryotes.