dna - Transcription factor binding site located in intron

I have noticed that some TF binding sites are located in the introns of the genes.

I am puzzled about whether the TF only binds to DNA in the initiation stage of transcription and will detach during transcription. (I am thinking if the TF bind to the sense strand, it will block the PoLII for transcription, thus they should be removed.)

Many thanks in advance.

Answer

As Armatus said TF can remain bound without an effect.

There are some alternative explanations:

1. Promoters need not be always upstream to the Transcription Start Site (TSS). There are promoters called Downstream Promoter Elements that are actually downstream to TSS.


2. There can be alternate TSS within the introns


3. TF bound to intron may regulate elongation or splicing rather than initiation. [Elongation can also be regulated especially when a gene is poised for expression. RNApolymerase stalling is a well known phenomenon and is affected by epigenetic marks. Since splicing happens co-transcriptionally there can be DNA marks that affect the process. Although it has not been shown whether such a thing happens, but Intron-Exon boundaries are known to have a distinct nucleosomal pattern.{1, 2, 3}]