Transcription factor

Transcription Factor

A transcription factor (pronounced: tran-skrip-shun fak-tor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The function of transcription factors is to regulate - turn on and off - genes in order to ensure that they are expressed in the right cell at the right time and in the right amount throughout the life of the cell and the organism.

Etymology

The term "transcription factor" is derived from the process it regulates - transcription. In biology, transcription is the first step of gene expression, where a particular segment of DNA is copied into RNA by the enzyme RNA polymerase. The word "factor" is a general term for a component or agent that carries out a particular process or function.

Related Terms

Gene Expression: The process by which information from a gene is used in the synthesis of a functional gene product.
DNA: Deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
RNA: Ribonucleic acid, a nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins.
RNA Polymerase: An enzyme that is responsible for copying a DNA sequence into an RNA sequence, during the process of transcription.
Protein: A large molecule composed of one or more chains of amino acids in a specific order; the order is determined by the base sequence of nucleotides in the gene coding for the protein.