FIG. 5.

Evaluation of the contribution of individual RRMs and hinge region of HuR to its stabilization effect. RNA blots showing stabilization effects of various truncated HuR mutants on decay of β-globin mRNA containing the c-fos ARE (BBB+ARE) (upper panels) and stabilization effect of intact HuR on decay of BBB+ARE mRNA or BFB mRNA, a hybrid message containing the c-fos protein-coding region determinant of instability (lower panels). RNA isolation, nonpolyadenylated [poly(A)⁻] RNA preparation, and time course experiments were carried out as described in the legend to Fig. 1. The control mRNA (α-globin/GAPDH) was expressed constitutively and served as an internal standard. The times given at the top of each blot correspond to hours after serum induction (S.I.).