positive regulation of DNA-templated transcription

Definition

Target type: biologicalprocess

Any process that activates or increases the frequency, rate or extent of cellular DNA-templated transcription. [GOC:go_curators, GOC:txnOH]

Positive regulation of DNA-templated transcription is a fundamental biological process that controls the rate at which genes are transcribed into messenger RNA (mRNA), which in turn dictates the level of protein production. This intricate process involves a complex interplay of regulatory elements, including transcription factors, enhancers, and chromatin modifications.

**Transcription Factors:** These proteins bind to specific DNA sequences known as promoters located upstream of genes. They act as molecular switches, either activating or repressing transcription. Activator proteins recruit other proteins that assist in assembling the transcription machinery, while repressor proteins block the assembly process.

**Enhancers:** These DNA sequences can be located far away from the gene they regulate and enhance transcription by interacting with promoters through DNA looping. They act as docking sites for transcription factors and co-activators, further promoting transcription initiation.

**Chromatin Modifications:** The DNA in eukaryotic cells is packaged into a complex structure called chromatin, which can be either open (euchromatin) or closed (heterochromatin). Euchromatin allows for easier access of transcription factors to DNA, whereas heterochromatin restricts access. Modifications to histones, proteins that package DNA, can influence chromatin structure and thus affect transcription.

**Steps Involved in Positive Regulation:**

1. **Binding of Transcription Factors:** Transcription factors bind to their specific DNA sequences within the promoter and enhancer regions.
2. **Recruitment of Co-activators:** Transcription factors and enhancers recruit co-activators, which further enhance transcription initiation.
3. **Chromatin Remodeling:** Co-activators can remodel chromatin, opening up the DNA structure and allowing for easier access of the transcription machinery.
4. **Assembly of the Transcription Pre-initiation Complex (PIC):** The PIC is a complex of proteins, including RNA polymerase II, which is responsible for synthesizing mRNA.
5. **Initiation of Transcription:** Once the PIC is assembled, RNA polymerase II begins transcribing the gene into mRNA.

**Factors Influencing Positive Regulation:**

* **Cellular Signaling:** External signals, such as hormones, growth factors, and stress, can activate signaling pathways that ultimately regulate gene expression.
* **Developmental Stage:** The expression of genes often changes during development, reflecting the need for different proteins at different stages.
* **Environmental Factors:** Environmental cues, such as temperature and nutrient availability, can also influence transcription.

Positive regulation of DNA-templated transcription is an essential process for maintaining cellular homeostasis, responding to environmental cues, and driving development. It is a highly regulated process, ensuring that genes are expressed at the right time and in the right amount to meet the needs of the cell and the organism.'
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Proteins (160)

Compounds (3,944)