transcription coactivator activity

Definition

Target type: molecularfunction

A transcription coregulator activity that activates or increases the transcription of specific gene sets via binding to a DNA-bound DNA-binding transcription factor, either on its own or as part of a complex. Coactivators often act by altering chromatin structure and modifications. For example, one class of transcription coactivators modifies chromatin structure through covalent modification of histones. A second class remodels the conformation of chromatin in an ATP-dependent fashion. A third class modulates interactions of DNA-bound DNA-binding transcription factors with other transcription coregulators. A fourth class of coactivator activity is the bridging of a DNA-binding transcription factor to the general (basal) transcription machinery. The Mediator complex, which bridges sequence-specific DNA binding transcription factors and RNA polymerase, is also a transcription coactivator. [GOC:txnOH-2018, PMID:10213677, PMID:16858867]

Transcription coactivator activity is a crucial molecular function in gene regulation. It involves proteins, known as coactivators, that enhance the activity of transcription factors, which are proteins that bind to DNA and regulate the initiation of gene transcription. Coactivators play a vital role in facilitating the assembly of the transcriptional machinery, a complex of proteins that transcribes DNA into RNA. They achieve this through various mechanisms, including:

1. **Chromatin Remodeling:** Coactivators can interact with chromatin remodeling complexes, which alter the structure of chromatin, making DNA more accessible to transcription factors. This accessibility is essential for the initiation of transcription.

2. **Histone Modifications:** Coactivators can recruit enzymes that modify histones, the proteins that package DNA into chromatin. These modifications, such as acetylation and methylation, can influence the accessibility of DNA and the recruitment of other transcription factors.

3. **Mediator Complex Interaction:** Many coactivators interact with the Mediator complex, a large protein complex that acts as a bridge between transcription factors and RNA polymerase II, the enzyme responsible for transcribing DNA into RNA. This interaction helps to stabilize the transcriptional machinery and enhance the efficiency of transcription initiation.

4. **Recruitment of Other Factors:** Coactivators can also recruit other proteins involved in transcription, such as general transcription factors, which are essential for the assembly of the pre-initiation complex.

5. **Signal Integration:** Coactivators can integrate signals from various signaling pathways, allowing cells to respond to different environmental stimuli and regulate gene expression accordingly.

In summary, transcription coactivators are essential for the proper regulation of gene expression by facilitating the assembly and function of the transcriptional machinery. They contribute to chromatin remodeling, histone modifications, Mediator complex interaction, recruitment of other transcription factors, and signal integration, all of which are critical for the accurate and efficient transcription of genes.'
"

Proteins (44)

Compounds (624)