Figure 8.

mTORC1 interplay in mRNA decapping through interaction with Edc4: The schematic diagram (Edc4 box) shows that mTORC1 interacted with Edc4 to keep its expression at the basal level by inhibiting Edc4 through serine phosphorylation (white bold arrow). This hyper-phosphorylated Edc4 was then no longer available for mRNA decapping activity in the mRNA decay process. Treatment of cells with rapamycin led to the inhibition of mTORC1 kinase activity, resulting in Edc4 dephosphorylation. This dephosphorylated Edc4 probably leads to activation of the decapping machinery and increased mRNA degradation.