Figure 3: MEX-3C’s E3 ubiquitin-ligase activity regulates deadenylation.

(a) Schematic of deadenylation assay. (b) Deadenylation time course. Strep-MEX-3C pull-downs were incubated with a 5′-fluorescein-labelled specific RNA substrate (Flc-5′-UCUAAAUA20) to assay the deadenylation activity of CNOT7 over the indicated time points. Degradation of 5′-fluorescein-labelled RNA substrate was visualized by denaturing polyacrylamide gel electrophoresis. Right panel shows loading controls for the assay. (c) Quantification of the substrate's fluorescence intensity remaining after deadenylation reaction. Results are expressed as mean±s.d. of three independent experiments. *P<0.05 and **P<0.01, both versus WT of the same time point; unpaired Student’s t-test. IB, immunoblot.