Nontargeted global deregulation of termination. (A) Effect of release factor knockdown on MuLV readthrough efficiency. Rat2 cells silenced for eRF1 (Rat2 eRF1-shRNA), eRF3 (Rat2 eRF3-shRNA), and a negative control (Rat2 sh0) were transfected with pDluc-TMV, pDluc-MuLV, pDluc-S1GC-NMR1, or pDluc-S1GC-NMR3, and 24 h later, lysates were prepared and assayed for Renilla and firefly luciferase. (B) Effect of gentamicin on MuLV readthrough efficiency. 293T cells were transfected with pDluc-MuLV, pDluc-S1GC, pDluc-S1GC-NMR1, and pDluc-S1GC-NMR3 in the absence or presence of gentamicin (750 μg/ml) and assayed for Renilla and firefly luciferase 24 h later.