Role of transcriptional factors in regulating transcription

• For transcription to begin, the gene is switched on by transcriptional factors which move from the cytoplasm into the nucleus.
• Each transcriptional factor has a site that binds to specific base sequence of the DNA in the nucleus. When it binds, it causes the region of DNA to begin the process of transcription.
• Once transcription has begun, mRNA is produced and the information it carries is then translated into a polypeptide. This occurs when the transcriptional factor that binds to the DNA is active.
• When an inactive transcriptional factor binds to DNA, the gene is not expressed.
• If the binding site on the transcriptional factor is inactive, then it cannot cause transcription and polypeptide synthesis when it binds to DNA.