What is an enhancer and an enhancer RNA?

[Ashtar V]

What is an enhancer?

What is an enhancer RNA? Is it mRNA transcript of an enhancer sequence?

[Y Soun]

an enhancer is a short (50–1500 bp) region of DNA that can be bound by proteins (activators) to increase the likelihood that transcription of a particular gene will occur. These proteins are usually referred to as transcription factors. Enhancers are cis-acting. They can be located up to 1 Mbp (1,000,000 bp) away from the gene, upstream or downstream from the start site. There are hundreds of thousands of enhancers in the human genome. They are found in both prokaryotes and eukaryotes.

Ref: Enhancer (genetics) – Wikipedia

Enhancer RNAs (eRNAs) represent a class of relatively long non-coding RNA molecules (50-2000 nucleotides) transcribed from the DNA sequence of enhancer regions. They are not mRNAs. The expression of a given eRNA correlates with the activity of its corresponding enhancer in target genes. Increasing evidence suggests that eRNAs actively play a role in transcriptional regulation. Their mechanisms of action remain unclear.

Ref: Enhancer RNA – Wikipedia

 

 

[Fazil Hussein]

Enhancers are non-coding DNA sequences that act as control switches for our genes. They sit far away from the genes they regulate, sometimes even on different chromosomes! Their job is to tell RNA polymerase, the enzyme that makes RNA copies of genes, to get to work and crank out more mRNA from a specific gene.
magine enhancers as the conductors of a gene expression orchestra. They don’t play the instruments themselves (code for protein), but they coordinate the timing and intensity of which genes are expressed, influencing how cells behave and develop.

In 2010, scientists discovered a surprising twist: enhancers can also produce their own RNA molecules called enhancer RNAs (eRNAs). Unlike mRNAs that code for proteins, eRNAs are non-coding.
But here’s the interesting part: eRNA production is linked to enhancer activity. When an enhancer is turned on and boosting gene expression, it tends to produce more eRNA. This suggests that eRNAs might play a role in the whole gene expression dance.
However, unlike mRNA transcripts of genes, eRNAs are not directly translated into proteins. They work in more subtle ways, influencing gene expression through different mechanisms:

Looping DNA: eRNAs can form loops in the DNA, bringing enhancers closer to their target genes for more efficient activation.

Modifying chromatin: eRNAs can recruit proteins that change the packaging of DNA, making it easier for RNA polymerase to access the gene.

Interacting with proteins: eRNAs can directly interact with proteins involved in gene expression, influencing their activity or recruiting them to specific genes.

So, are eRNAs mRNA transcripts of enhancer sequences? Not quite. eRNAs are not translated into proteins, and their sequences can be different from the actual enhancer DNA due to splicing and other processing steps. They’re more like messengers or signals that reflect enhancer activity and play a role in regulating gene expression in their own unique way.
The field of eRNA research is still young, but it’s already offering exciting insights into the complex world of gene regulation. Understanding how these molecules work could lead to new therapeutic approaches for diseases caused by gene expression errors.

Source: Bard

[Author]

Posts