pPREx3 is a synthetic mammalian promoter that responds to estrogen receptor activated by medoxyprogesterone (MPA). pPREx3 consists of three repeats of the progesterone response element (PRE) consensus sequence upstream of a minimal promoter (minCMV).
In endometrial cells, progesterone receptors facilitate the cell's response to progesterone, initiating the secretory phase of the menstrual cycle. Mechanistically, progesterone diffuses through the cell membrane and binds to the ligand binding domain of the PgR-beta isoform. The DNA-binding domain of the progesterone receptor becomes exposed. The receptor then relocalizes to the nucleus from the cytoplasm, recruits co-activators, and acts as a transcription factor. There are two isoforms of the progesterone receptor, PgR alpha and PgR beta. In the context of our project, we are working with PgR beta.
Our team tested different possible variations of an estrogen-responsive promoter by varying the amount of progesterone response elements (PREs) present for the activated PgR complex to bind to. This particular construct contains three progesterone responsive elements with the sequence 5′-G/A G G/T AC A/G TGGTGTTCT-3′. We interspaced these elements with 22 randomly selected bases in between, the same spacing between TREs in the TRE promoter. Since we wanted to decrease the probability of helical turns inhibiting the transcriptional activity of promoters, we modeled the spacing after the TRE promoter.
Sequence and Features
- 10Illegal EcoRI site found at 211
- 12Illegal EcoRI site found at 211
- 21Illegal EcoRI site found at 211
- 23Illegal EcoRI site found at 211
- 25Illegal EcoRI site found at 211
- 1000Illegal BsaI site found at 7
Illegal BsaI.rc site found at 225
Illegal EcoRI site found at 211