Decreased estrogenic stimulation of RNA polymerase II in aged rat uteri is apparently due to reduced nuclear binding of receptor-estradiol complexes.
The maximum ability of receptor-estradiol complexes to activate RNA polymerase II and bind to nuclear acceptor sites is reduced 40-50% in senescent rat uteri. A precise, linear stoichiometric relationship exists between acceptor site occupancy and polymerase activity, and this relationship is not altered with aging. Thus, reduced ability of estrogen to stimulate RNA polymerase II in aged rat uteri appears to be due to deficits in binding of receptor-estradiol complexes to nuclear acceptor sites.
D000375:Aging; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D004789:Enzyme Activation; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D012319:RNA Polymerase II / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D011960:Receptors, Estrogen / Q000378:metabolism*; D014599:Uterus / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism
D011960:Receptors, Estrogen; D004958:Estradiol; D012319:RNA Polymerase II