Figure 7. Pab 1801 puncta and PBs are simultaneously induced by different strategies.

A, B, U2OS cells were treated with two different combinations of arsenite and puromycin: 250 µM arsenite +100 µg/ml puromycin (1× induction) and 500 µM arsenite +250 µg/ml puromycin (2× induction). A, The average number of PBs per cell increased from 4 in control cells to 14 in treated cells, as evaluated in 100 cells from duplicate experiments for each treatment. Induced PBs were stained with the Pab 1801 in all cases. An example of the 2× induction is shown in Ars+Puro panel. B, the size of Dcp1a-foci and Pab 1801 foci increased at the same rate and in a dose-dependent manner. Median values of more than 100 foci size for each treatment were plotted. C, overexpression of the translational repressor Smaug 1 also provoked 1801 foci induction. U2OS cells were transfected with Smaug 1-ECFP and number of foci per cell and foci size were analized in transfected (T) and neighbouring non-transfected cells (NT). The average number of PBs per cell increased from 5 in non-transfected cells to 55 in transfected cells, as evaluated in 100 hundred cells of each condition. In all cases PBs were stained with the 1801 antibody. The foci size increased more than twice, as evaluated for both 1801 and Rck/p54 in 200 non-transfected foci and 750 Smaug1-ECFP transfected foci. Bars, 10 µm.