Fig. 3.

Mutation of PBE motifs in 3′UTR causes reversal of PUM2- but not PUM1-mediated repression of SIAH1 mRNA. a Schematic diagram of the luciferase constructs used. Grey-shaded boxes refer to mutated motifs (−PBE2 and −PBE1 consensus; PBE1, PBE2, PBE3, and PBE4). b Effects of PUM1 and PUM2 overexpression on reporter luciferase construct carrying wild-type (WT) or (MUT) lacking six PBE/PBEs-like in SIAH1 full-length 3′UTR. Derepression of the SIAH1 3′UTR reporter carrying mutated PBE occurs only under PUM2 overexpression. c Effects of PUM2, NANOS3, or PUM2/NANOS3 overexpression on luciferase reporter carrying wild-type or mutated full-length SIAH1 3′UTR (****P < 0.001). Error bars denote standard deviation (n = 9). Luminescence values (RLU relative luciferase units) are presented as % of the RLU of the sample transfected with reporter construct only which was set to 100%. Renilla luciferase values were normalized using firefly luciferase measurements