Transcription factors visuals and great wiki explanation: **Transcription factor** In [molecular biology](https://en.wikipedia.org/wiki/Molecular_biology "Molecular biology"), a transcription factor (TF) (or sequence-specific DNA-binding factor) is a [protein](https://en.wikipedia.org/wiki/Protein "Protein") that controls the rate of [transcription](https://en.wikipedia.org/wiki/Transcription_(genetics) "Transcription (genetics)") of [genetic](https://en.wikipedia.org/wiki/Genetics "Genetics") information from [DNA](https://en.wikipedia.org/wiki/DNA "DNA") to [messenger RNA](https://en.wikipedia.org/wiki/Messenger_RNA "Messenger RNA"), by binding to a specific [DNA sequence](https://en.wikipedia.org/wiki/DNA_sequence "DNA sequence") The function of TFs is to regulate—turn on and off—genes in order to make sure that they are [expressed](https://en.wikipedia.org/wiki/Gene_expression "Gene expression") in the desired [cells](https://en.wikipedia.org/wiki/Cell_(biology) "Cell (biology)") at the right time and in the right amount throughout the life of the cell and the organism. Groups of TFs function in a coordinated fashion to direct [cell division](https://en.wikipedia.org/wiki/Cell_division "Cell division"), [cell growth](https://en.wikipedia.org/wiki/Cell_growth "Cell growth"), and [cell death](https://en.wikipedia.org/wiki/Cell_death "Cell death") throughout life; [cell migration](https://en.wikipedia.org/wiki/Cell_migration "Cell migration") and organization ([body plan](https://en.wikipedia.org/wiki/Body_plan "Body plan")) during embryonic development; and intermittently in response to signals from outside the cell, such as a [hormone](https://en.wikipedia.org/wiki/Hormone "Hormone"). There are 1500-1600 TFs in the [human genome](https://en.wikipedia.org/wiki/Human_genome "Human genome"). Transcription factors are members of the [proteome](https://en.wikipedia.org/wiki/Proteome "Proteome") as well as [regulome](https://en.wikipedia.org/wiki/Regulome "Regulome"). TFs work alone or with other proteins in a complex, by promoting (as an [activator](https://en.wikipedia.org/wiki/Activator_(genetics) "Activator (genetics)")), or blocking (as a [repressor](https://en.wikipedia.org/wiki/Repressor "Repressor")) the recruitment of [RNA polymerase](https://en.wikipedia.org/wiki/RNA_polymerase "RNA polymerase") (the enzyme that performs the [transcription](https://en.wikipedia.org/wiki/Transcription_(genetics) "Transcription (genetics)") of genetic information from DNA to RNA) to specific genes. A defining feature of TFs is that they contain at least one [DNA-binding domain](https://en.wikipedia.org/wiki/DNA-binding_domain "DNA-binding domain") (DBD), which attaches to a specific sequence of DNA adjacent to the genes that they regulate. TFs are grouped into classes based on their DBDs. Other proteins such as [coactivators](https://en.wikipedia.org/wiki/Coactivator_(genetics) "Coactivator (genetics)"), [chromatin remodelers](https://en.wikipedia.org/wiki/Chromatin_Structure_Remodeling_(RSC)_Complex "Chromatin Structure Remodeling (RSC) Complex"), [histone acetyltransferases](https://en.wikipedia.org/wiki/Histone_acetyltransferase "Histone acetyltransferase"), [histone deacetylases](https://en.wikipedia.org/wiki/Histone_deacetylase "Histone deacetylase"), [kinases](https://en.wikipedia.org/wiki/Kinase "Kinase"), and [methylases](https://en.wikipedia.org/wiki/Methylase "Methylase") are also essential to gene regulation, but lack DNA-binding domains, and therefore are not TFs. There are approximately 2800 proteins in the [human genome](https://en.wikipedia.org/wiki/Human_genome "Human genome") that contain DNA-binding domains, and 1600 of these are presumed to function as transcription factors,[[3]](https://en.wikipedia.org/wiki/Transcription_factor#cite_note-pmid15193307-3) though other studies indicate it to be a smaller number.[[14]](https://en.wikipedia.org/wiki/Transcription_factor#cite_note-14) Therefore, approximately 10% of genes in the genome code for transcription factors, which makes this family the single largest family of human proteins. Furthermore, genes are often flanked by several binding sites for distinct transcription factors, and efficient expression of each of these genes requires the cooperative action of several different transcription factors (see, for example, [hepatocyte nuclear factors](https://en.wikipedia.org/wiki/Hepatocyte_nuclear_factors#Function "Hepatocyte nuclear factors")). Hence, the combinatorial use of a subset of the approximately 2000 human transcription factors easily accounts for the unique regulation of each gene in the human genome during [development](https://en.wikipedia.org/wiki/Developmental_biology "Developmental biology"). Enhancer (genetics) In [genetics](https://en.wikipedia.org/wiki/Genetics "Genetics"), an **enhancer** is a short (50–1500 [bp](https://en.wikipedia.org/wiki/Base_pair "Base pair")) region of [DNA](https://en.wikipedia.org/wiki/DNA "DNA") that can be bound by [proteins](https://en.wikipedia.org/wiki/Protein "Protein") ([activators](https://en.wikipedia.org/wiki/Activator_(genetics) "Activator (genetics)")) to increase the likelihood that [transcription](https://en.wikipedia.org/wiki/Transcription_(genetics) "Transcription (genetics)") of a particular [gene](https://en.wikipedia.org/wiki/Gene "Gene") will occur. These proteins are usually referred to as [transcription factors](https://en.wikipedia.org/wiki/Transcription_factor "Transcription factor"). Enhancers are [_cis_-acting](https://en.wikipedia.org/wiki/Cis-regulatory_element "Cis-regulatory element"). They can be located up to 1 Mbp (1,000,000 bp) away from the gene, upstream or downstream from the start site.[[2]](https://en.wikipedia.org/wiki/Enhancer_(genetics)#cite_note-5questions-2)[[3]](https://en.wikipedia.org/wiki/Enhancer_(genetics)#cite_note-3) There are hundreds of thousands of enhancers in the human genome. --- Potential explore - [Transcription factors interact with RNA to regulate genes - PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC10529847/) ![[Index - Transcription Factors PMC10529847.png]]