FIGURE 2.

Candidate proteins closely related to MBII-52 RNP. (A) Distribution of candidate proteins in a glycerol gradient of brain nuclear extract. The signal peak of Nucleolin and ELAVL1, as well as Fibrillarin, appeared in lighter fractions than that of MBII-52 Northern blotting, while Matrin-3 and SNRPA appeared in heavier fractions. (B) MBII-52 copurified with an antibody against each candidate from fractions 3–8. Notably, MBII-52 was copurified in association with Fibrillarin from fractions 5 and higher. U6 signal was shown in the right for background control. (C) Immunoprecipitation of Nucleolin and ELAVL1 from individual fractions. Both proteins did not coimmunoprecipitate with each other. NB, Northern blotting; WB, Western blotting.