Transcription factors bind to the promoters and allow RNA polymerase to act. The promoter is not transcribed itself. The common promoters, TATA and CAAT boxes, are found about 30 bp and 75 bp, respectively, upstream of the transcription initiation site. It is immediately 5' to the gene. The 5'-UT region is transcribed but not translated.
Translation takes place in the ribosome in the cytoplasm.
Although they are not represented in the resultant polypeptide, they may contain some regulatory sequences. The involvement of 3' UTR is well-documented in controlling male and female gametogenesis and in early embryonic development. Myotonic dystrophy is a disease caused by the expansion of the triplet repeats in the 3' UTR of a protein kinase gene. These are briefly described in the biotechnology section.