Fig. 4.

Rbm3 associates with translating ribosomes in an RNA-independent manner. (A) A fraction of Rbm3 copurifies with rat brain ribosomes on sucrose gradients. A polysome-enriched fraction of rat brain was centrifuged through a linear 10–50% (wt/vol) sucrose gradient. The top of the gradient is on the left. (B) Ribosomal profile of a rat brain polysome-enriched fraction after treatment with RNase A. For both A and B, the distributions of Rbm3 and ribosomal protein L4 in the fractions of the gradient were analyzed by immunoblotting using anti-Rbm3 and anti-L4 antibodies, respectively.