I have a biological question(s) for ya'll involving enhancers.
1.) Enhancers work by being the binding sites for TFs. But how does this increase transcription? (Especially when enhancers can be extremely far away from the gene they control.)
2.) Enhancers can become methylated. When they do, does this usually prevent transcription factor binding? And if it does prevent the binding, how does this affect the role of the TF and gene expression.
EDIT: Here's what I found.
It seems that enhancers can be far away from the gene they act upon, but the binding of TF via their DNA-binding domain can cause looping of DNA to help them reach the promoter region of the gene of interest. Thus, increasing the rate of gene expression.
On the reverse, methylation can sometimes be seen to act as silencing of gene expression. So, if our enhancer region is methylated, this may prevent TF binding and the enhancer from increasing gene expression.
BONUS: Methylation in promoters can also cause silencing by preventing RNA polymerase II, and the required proteins (ect) from carrying transcription.
If anybody wants to add (or correct anything, let me know!)