FIGURE 4.

Tethered Xenopus CAF1 homologs repressed translation of a nonadenylated luciferase mRNA, while not destabilizing the mRNA. A, top panel, the relative translation of luciferase activity in response to each protein was quantified as the ratio of firefly to Renilla luciferase activity. The firefly luciferase mRNA contained three MS2-binding sites in the 3′-UTR and no poly(A) tail. The values were normalized to the ratio of luciferase activity without an MS2 fusion protein expressed. The error bars were derived from analysis of four sets of four oocytes within the same experiment. Bottom panel, lysates equivalent to two oocytes were loaded in each lane and analyzed by Western blotting with α-HA-11 and α-actin. B, lanes 1–7 indicate the stability of the reporter mRNAs when tethered to each protein. The reporter mRNA with and without a poly(A) tail are indicated. Blots show rRNA below each panel used as a loading control. Lane 8 shows signal from an uninjected oocyte. Lane 9 shows the reporter RNA before injection.