Skip to main content
. 2007 Oct 29;28(1):40–49. doi: 10.1128/MCB.01298-07

FIG. 2.

FIG. 2.

PSF, p54nrb, GRSF-1, and YB-1 stimulate myc IRESs in vitro. (A) Schematic representation of the dicistronic reporter constructs pRF and pRIRESF, where pRIRESF contains the c-myc (pRMF), L-myc (pRLsF), N-myc (pRNF), BAG-1 (pRBF), or Apaf-1 (pRAF) 5′ UTRs inserted into the vector pRF and fused in frame with the firefly luciferase gene. SV40 prom, simian virus 40 promoter; luc, luciferase. (B and C) In vitro translation reactions in reticulocyte lysates primed with 100 ng of capped pRIRESF RNA and 50 to 200 ng of PSF, p54nrb, GRSF-1, YB-1, or PTB (see Fig. S1 in the supplemental material) show that these proteins can stimulate IRES activity from these dicistronic plasmids, albeit to different extents. The greatest effects were observed with the addition of YB-1 and p54nrb. IRES activity is expressed as a ratio of the downstream cistron to the upstream cistron (firefly/Renilla luciferase). All experiments were performed in triplicate on three independent occasions.