Fig. 9. Co-immunoprecipitation of Stau2⁵⁹ with ribosomes. Cytoplasmic extracts from rat cortical neurons in culture were prepared and immunoprecipitated with (A) normal human serum (NHS) and anti-ribosomal protein P (P) or (B) pre-immune serum (PI) and rabbit polyclonal anti-Stau2 (Stau2) antibodies. Immunoprecipitates were analyzed by western blotting with anti-L7a, monoclonal anti-Stau2 and anti-P as indicated. Results similar to those in (A) were obtained when the immunoprecipitation was carried out with the anti-L7a antibodies (data not shown). (C) The Stau2 immunoprecipitates (as in B) were also analyzed by northern blotting for the presence of 18S rRNA (small ribosomal subunit). These experiments were performed three times with reproducible results.