Figure 9.

The effect of TPA and RA + TPA on polyribosome association of VEGF mRNA is specific. Linear sucrose gradient fractionation was carried out as described in Fig. 8. The percentage of the VEGF mRNA (A) and β-actin mRNA (B) in the translationally inactive complexes (fractions 1–3), short polyribosomes (fraction 4), and large translating polyribosomes (fractions 5–7 and 8–10) were calculated and graphically displayed. In contrast to the altered distribution of VEGF mRNA on the gradient (A), neither TPA nor RA + TPA had any effect on polyribosome association on β-actin mRNA. *, Significant increase in percent of total VEGF mRNA in the indicated fractions compared with controls.