Site-specific anti-c-erb A antibodies recognizing native thyroid hormone receptors: their use to detect the expression and localization of alpha and beta c-erb A proteins in rat liver.

AbstractThe cell-specific expression and tissue distribution of c-erbA proteins α and β is still unknown. To address this problem, we prepared anti-peptide antibodies directed against epitopes of human (h) c-erbA, specific for the α or β form of thyroid hormone receptors. The cDNAs coding for h c-erbA β1, α1 and α2 were transcribed and the mRNAs were translated in vitro in the presence of 35S-methionine, and then their reactivity with the antisera was evaluated. The antiserum anti-β 62–81 immunoprecipitated only the β1 receptor. The antiserum anti-α 144–162 determined precipitation of both α1 and α2 proteins but not of the β1 receptor. Anti-α2 431–451 produced a selective precipitation of α2, and had no effect on α1 or β1 receptor. In order to study the interaction of the antibodies with native T3 receptor we evaluated the binding of antibodies to rat liver T3 receptors by Sephacryl S300 chromatography: both antisera anti-β 62–81 and anti-α 144–162 caused a partial shift of the labeled T3–receptor complex...