The activation of transcription factor subunits is the first step of gene expression, in which a particular segment of DNA is copied into RNA (mRNA) by the enzyme RNA polymerases. Transcription factors, unites and elongations can be RNA and DNA nucleic acids, base pairs of nucleotides . Converting from DNA to RNA is made by enzymatic reactions. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, anti-parallel RNA strand called a primary transcript. Transcriptions are key functions in signal transduction pathways. Signaling ligand binding transcription factors play an important role in transduction cascades.
