Estradiol induces membrane localization of the estrogen receptor and association with Shc in neurons

SCERBO, M.J.; GOROSITO, S.V.; GUTIERREZ, S.; MIR, F.; CISTERNAS, C.D.; CAEIRO, X.; TORRES, A.; CAMBIASSO, M.J.

Puerto Madryn

Congreso; XLVI Reunion Annual Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular; 2010

Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular (SAIB)

17-b estradiol (E2) has important physiological effects in central nervous system. Previous studies from our laboratory have demonstrated that E2 induces axonal growth on male hypothalamic neurons by a membrane-initiated mechanism involving Ca2+, PKC and ERK signaling. We have also found that ERá can be detected from the cell exterior as a biotinylated cell-surface protein. To corroborate the presence of ERá in the cell-surface of hypothalamic neurons we studied the membrane distribution of the receptor in intact cells by immuno-electron-microscopy. After 48 h of E2 treatment, male hypothalamic neurons were incubated with anti ERá, labeled with protein A-colloidal gold complex and processed for electron microscopy. Gold-particles adhered on the surface of the plasma membrane and attached to cytoplasmic vesicles membranes were observed, confirming that ERá is expressed on the cell-surface. We also analyze if ERá might mediate effects of E2 by direct association with the Shc adapter protein. We immunoprecipitated Shc protein and detected ERá on Western blots, and found that ERá is associated to Shc in control conditions. In the presence of E2 the amount of ERá co-immpunoprecipitated with Shc increases two folds. Together our results suggest that the cell-surface expressed ERá is associated to the adapter protein Shc constituting a possible linkage of rapid E2 action to MAPK activation.