Difference between revisions of "Part:BBa K2100033"

Revision as of 05:24, 19 October 2016

pEXPR pERE3:TALER14

pEREx3 is a synthetic mammalian promoter that responds to estrogen receptor activated by estradiol (E2). pEREx3 consists of three repeats of the estrogen response element (ERE) with the sequence 5′-GGTCAnnnTGACC-3 upstream of a minimal promoter (minCMV). We interspaced these elements with 22 randomly selected bases in between, the same spacing between TREs in the TRE promoter. This design choice was made because when an ERE is not properly oriented, it has trouble interacting with ERα and polymerases. Since we wanted to decrease the probability of helical turns inhibiting the transcriptional activity of promoters, we modeled the spacing after the TRE promoter.

In endometrial cells, estrogen receptors facilitate the cell's response to estrogen, initiating the proliferative phase of the menstrual cycle. Mechanistically, estrogen diffuses through the cell membrane and binds to the ligand binding domain of the ER. The DNA-binding domain of the estrogen receptor becomes exposed. The receptor then relocalizes to the nucleus from the cytoplasm, recruits co-activators, and acts as a transcription factor for the TALER14 gene. TALER14 is an engineered repressor from TAL effectors, amino acids which have corresponding DNA target sites. When transcribed, TALER14 represses the DNA sequences found on the pTALER14 promoter with the help of the corepressor VP16-Gal4.

Sequence and Features