Figure 5.

TIA-1 and TIAR act in a redundant manner. (A) Northern blots showing sucrose gradient polysome profiles of the rpL32-β-globin 5′TOP mRNA reporter in HeLa cells treated with the siRNA targeting TIA-1 and TIAR (TIA-1/R) or a control siRNA targeting Luciferase (Ctrl). Cells were subjected to 2 h of amino acid starvation prior to polysome fractionation. “Add-back” indicates cotransfected “siRNA-resistant” expression plasmid encoding TIA-1, TIA-1 RBD, or TIA-1 PRD. (B) Same as A, but adding back exogenous TIAR instead of TIA-1. (C) Schematic of TIA-1 showing the RNA-binding RRM domains (RBDs) and the PRD (white box).