Structural Analysis of Estrogen Receptors: Interaction between Estrogen Receptors and Cav-1 within the Caveolae
Document Type
Article
Publication Date
2018
Digital Object Identifier (DOI)
https://doi.org/10.1093/biolre/ioy188
Abstract
Pregnancy is a physiologic state of substantially elevated estrogen biosynthesis that maintains vasodilator production by uterine artery endothelial cells (P-UAECs) and thus uterine perfusion. Estrogen receptors (ER-α and ER-β; ESR1 and ESR2) stimulate nongenomic rapid vasodilatory responses partly through activation of endothelial nitric oxide synthase (eNOS). Rapid estrogenic responses are initiated by the ∼4% ESRs localized to the plasmalemma of endothelial cells. Caveolin-1 (Cav-1) interactions within the caveolae are theorized to influence estrogenic effects mediated by both ESRs. Hypothesis: Both ESR1 and ESR2 display similar spatial partitioning between the plasmalemma and nucleus of UAECs and have similar interactions with Cav-1 at the plasmalemma. Using transmission electron microscopy, we observed numerous caveolae structures in UAECs, while immunogold labeling and subcellular fractionations identified ESR1 and ESR2 in three subcellular locations: membrane, cytosol, and nucleus. Bioinformatics approaches to analyze ESR1 and ESR2 transmembrane domains identified no regions that facilitate ESR interaction with plasmalemma. However, sucrose density centrifugation and Cav-1 immunoisolation columns uniquely demonstrated very high protein–protein association only between ESR1, but not ESR2, with Cav-1. These data demonstrate (1) both ESRs localize to the plasmalemma, cytosol and nucleus; (2) neither ESR1 nor ESR2 contain a classic region that crosses the plasmalemma to facilitate attachment; and (3) ESR1, but not ESR2, can be detected in the caveolar subcellular domain demonstrating ESR1 is the only ESR bound in close proximity to Cav-1 and eNOS within this microdomain. Lack of protein–protein interaction between Cav-1 and ESR2 demonstrates a novel independent association of these proteins at the plasmalemma.
Was this content written or created while at USF?
Yes
Citation / Publisher Attribution
Biology of Reproduction, v. 100, issue 2, p. 495-504
Scholar Commons Citation
Pastore, Mayra B.; Landeros, Rosalina Villalon; Chen, Dong-bao; and Magness, Ronald R., "Structural Analysis of Estrogen Receptors: Interaction between Estrogen Receptors and Cav-1 within the Caveolae" (2018). Obstetrics & Gynecology Faculty Publications. 30.
https://digitalcommons.usf.edu/obg_facpub/30
