Figure 5. DRBD3-associated transcripts remain bound in stress conditions.

(A) Association of DRBD3-regulated mRNAs was assayed by quantitative RT-PCR after immunoprecipitation of DRBD3 ribonucleoprotein complexes using anti-DRBD3 antiserum from normally grown (control) or stressed trypanosomes. Fold-enrichment of target transcripts was calculated after comparing to mock immunoprecipitations carried out using normal rabbit serum and normalizing to the 7SL RNA. Experiments were done at least four times. (B) Total levels of AATP11 and PT-X in control or stressed cells were visualized by Northern blot analysis using specific radioactive probes [19]. RNA samples were extracted from cells starved during 3 hours in PBS or incubated in the presence of 50 µM sodium arsenite for 1–4 hours.