L2 - Pre-transcriptional gene regulation: Transcription factors & the role of oestrogen

Question 1

Define a transcription factor

Answer 1

A molecule that must bind to the promoter region of a chromosome in order for the gene to be transcribed

Question 2

Where is the promoter region in relation to the gene?

Answer 2

The promoter region is UPSTREAM of the gene

Question 3

When is RNA polymerase activated for gene transcription?

Answer 3

Only when specific transcription factors bind to the gene’s promoter

Question 4

Describe the 5 stages of the role of oestrogen in initiating transcription

Answer 4

1) Oestrogen diffuses through the plasma membrane of the target cell & diffuses through the nuclear pore, into the nucleus.
2) In the nucleus, it attaches to an ERα (alpha) oestrogen receptor that is contained within a protein complex.
3) This causes the oestrogen receptor to change shape and leave the protein complex that inhibits its action.
4) The oestrogen receptor can now attach to the promoter region of a target gene.
5) It attracts other cofactors to bind with it. This enables RNA polymerase to transcribe the target gene.