Figure 7.

Translational regulation in the PGE pathway of retrograde signaling needs the action of GUN1. A, Comparison of the polysome profiles upon Lin treatment with those of the untreated controls for RBCS and LHCA4 demonstrates that translational inhibition of HiToP PhANGs in gun1 in response to Lin treatment is compromised. The probe used does not distinguish between different isoforms of RBCS. B, Comparison of polysome profiles upon Lin treatment with those of the untreated controls for PSRP5 and RPL4 demonstrates that up-regulation of their translation in response to Lin treatment is compromised in gun1 (in that the shift to heavier gradient fractions does not occur; compare with Fig. 6). In both A and B, the three major polysome-containing fractions are boxed. The wedges above the blots indicate the increasing Suc concentration across the gradient. The ethidium bromide-stained rRNAs on the gels prior to blotting are also shown. For puromycin controls, see Supplemental Figure S5.