Fig. 7: A proposed model of TTP-mediated rapid deadenylation via multivalent interactions with CCR4–NOT and PABPC1.

Schematic model illustrating how TTP exploits multivalent interactions with two key regulatory effectors of mRNA fate — CCR4–NOT and PABPC1. Short segments within TTP’s intrinsically disordered C-terminal region (red rectangles) serve as docking sites that scaffold these effectors and direct rapid, transcript-specific deadenylation. Phosphorylation of TTP (red “lollipop” symbols) promotes high-affinity binding to PABPC1, displacing PABPC1 from the poly(A) tail and thereby clearing access for CCR4–NOT to engage the tail and catalyze efficient deadenylation. Prepared in Affinity Designer 2.