Characterization of nucleolar antigens of normal rat liver, regenerating rat liver, and Novikoff ascites hepatoma cells following in vitro translation of polyadenylic acid-containing messenger RNA

Abstract

Nucleolar antigens of normal rat liver, regenerating liver, and Novikoff ascites hepatoma cells were transplanted in vitro from polyadenylic acid-containing messenger RNAs isolated from the respective tissues and immunoprecipitated with specific antinucleolar antibodies and Protein A. By two-dimensional gel electrophoresis of the translation products, five antigens were detected in normal rat liver. The antigens detected in 18-hr regenerating rat liver were the same as those of normal rat liver when immunoprecipitated with the anti-liver nucleolar antibodies. In the Novikoff tumor, 11 antigens were detected with anti-Novikoff nucleolar antibodies. Of these, two were not found in either normal or regenerating liver. Four major antigens were detectable in both Novikoff hepatoma and regenerating liver messenger RNA translation products with anti-Novikoff nucleolar antibodies. Two antigens were found in normal and regenerating liver that were not found in Novikoff hepatoma. In agreement with previous results, these immunoprecipitation analyses provide further evidence that some nucleolar antigens are present in Novikoff hepatoma that are not found in either normal or regenerating rat liver.