Figure 7: Post-transcriptional gene repression by Trim71.

(a) Tethering assays. Wild-type (upper panel) and DGCR8 KO (lower panel) ESCs were transfected with a Renilla luciferase, a firefly luciferase with or without MS2-binding sites in the 3′-UTR, and a plasmid expressing either MS2 protein or MS2-fusion, as indicated. Firefly/Renilla ratios were calculated. Relative luciferase activity represents the ratio of the reporter containing MS2-binding sites to the reporter lacking a site. Normalized signals for the MS2 control were set to 1 (b) Tethering assays in wild-type V6.5 ESCs were performed as in (a) except Rck, TNRC6B, or Trim71 not fused to MS2 (and hence not tethered to the firefly luciferase mRNA 3′-UTR). (c) Tethering assays in Hela cells performed as in (a) with the indicated Trim71 deletion MS2 fusion proteins. Normalized signals for the MS2 control were set to 1. Error bars represent mean +/−s.d. with n=3. The P-values are from two-tailed t-test result. NS = not significant. (d) Schematic representation of functional domains of Trim71.