Epitope-dependent localization of XXXX receptor-alpha, but not -beta, in en face arterial endothelium.

@entity172 @entity7605 @entity53 @entity12209 @entity35
Rapid, nongenomic effects of @entity53 (E(2)) in endothelial cells are postulated to arise from membrane-associated @entity172 receptors (ERs), which have not been visualized in vascular tissue. To identify membrane ERs, we used multiple site-directed @entity7605 or @entity12209 antibodies to label en face @entity35 cerebral and coronary arterial endothelia. Western blots revealed a novel 55-kDa @entity7605 isoform. Three-dimensional images of cells labeled with these antibodies and markers for the nucleus and caveolin-1 were acquired with a wide-field microscope, deconvolved, and numerically analyzed. We found @entity7605 in the nucleus and cell periphery, where one-third colocalized with caveolin-1. The receptor location was dependent on the epitope of the antibody. Human ovarian surface epithelium produced similar results; but in @entity35 myometrium, the distribution was epitope independent and nuclear. @entity12209 distribution was predominantly intranuclear and epitope independent. A small amount of @entity7605 colocalized with @entity12209 within the nucleus. The results were identical in both arterial preparations and insensitive to E(2). We postulate that the different @entity7605 conformations at the membrane, in the nucleus, and between different cell types allow E(2) to trigger cell- and location-specific signaling cascades.
