Date of Award
Master of Science (MS)
Estrogen has two receptor proteins, estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ). ERα can undergo multiple post-transcriptional modifications (PTMs); however, relatively little is known about the function and regulation of any of the PTMs that ERα can potentially undergo, especially in vivo. In total, 19 phosphorylation sites have been identified in ERα thus far, and most sites contain a Ser-Pro motif. Different pathways are responsible for the phosphorylation of different sites. These pathways include mitogen-activated protein kinase (MAPK) signaling, IkappaB kinase complex alpha (IKKα), cyclin-dependent kinase 7 (CDK7), a subunit of transcription factor II H, protein kinase B (PKB), glycogen synthesis kinase-3 beta (GSK3β), mammalian target of rapamycin (mTOR/p70S6K), ribosomal s6 kinase (Rsk), and casein kinase II. Here, phosphorylation of three sites between resting and activated human T cells are compared. T cells were purified and total proteins were extracted from both resting and activated T cells. Changes in ERα were investigated via immunoprecipitation and Western blot. The amount of phosphorylation at each site was compared between resting and activated T cells, and the amount of phosphorylated receptor was adjusted to the total ERα in each sample. The results for a sample size of ten indicated that when ERα is at 100%, Ser 104/106 resting T cells are 89.30% and active are 92.00%, Ser 118 resting T cells are 80.08% and activated are 87.54%, and Ser 167 resting T cells are 86.44% and activated are 78.35%. Statistical analysis revealed the results were significant for both resting and activated T cell for ERα Ser 118 and Ser 167, but not for Ser 104/106 in those same conditions. These results provide a baseline for studying the phosphorylation changes in SLE patients. It is known that the MAPK-ERK1/2 pathway is abnormal in SLE; therefore, it is hypothesized there will be a decrease in phosphorylation in activated T cells compared with control.
Meneely, Samantha, "Changes in Estrogen Receptor Alpha (ERα) Phosphorylation in Human T Cells" (2015). Electronic Thesis Collection. Paper 26.