Journal Article

Threshold‐controlled ubiquitination of the EGFR directs receptor fate

Pascolutti, Roberta, Cuomo, Alessandro, Capuani, Fabrizio, Bianchi, Fabrizio, Verhoef, Lisette G G C, Bonaldi, Tiziana, Ciliberto, Andrea, Polo, Simona, Sigismund, Sara, Algisi, Veronica, Nappo, Gilda, Maspero, Elena, Di Fiore, Pier Paolo, Conte, Alexia, Argenzio, Elisabetta

2013

Overview

How the cell converts graded signals into threshold‐activated responses is a question of great biological relevance. Here, we uncover a nonlinear modality of epidermal growth factor receptor (EGFR)‐activated signal transduction, by demonstrating that the ubiquitination of the EGFR at the PM is threshold controlled. The ubiquitination threshold is mechanistically determined by the cooperative recruitment of the E3 ligase Cbl, in complex with Grb2, to the EGFR. This, in turn, is dependent on the simultaneous presence of two phosphotyrosines, pY1045 and either one of pY1068 or pY1086, on the same EGFR moiety. The dose–response curve of EGFR ubiquitination correlate precisely with the non‐clathrin endocytosis (NCE) mode of EGFR internalization. Finally, EGFR‐NCE mechanistically depends on EGFR ubiquitination, as the two events can be simultaneously re‐engineered on a phosphorylation/ubiquitination‐incompetent EGFR backbone. Since NCE controls the degradation of the EGFR, our findings have implications for how the cell responds to increasing levels of EGFR signalling, by varying the balance of receptor signalling and degradation/attenuation. The amount of EGF present for binding to its receptor governs an on–off switch of EGFR ubiquitination and hence ligand‐controlled non‐clathrin‐mediated endocytosis and EGFR degradation.

• Publisher: Nature Publishing Group UK,John Wiley & Sons, Ltd,Springer Nature B.V,Nature Publishing Group
• Subject: Animals / Binding sites / CHO Cells / Cricetinae / Cricetulus / EGFR / EMBO20 / EMBO37 / Endocytosis / Endocytosis - physiology / Epidermal growth factor / GRB2 Adaptor Protein - genetics / GRB2 Adaptor Protein - metabolism / HeLa Cells / Humans / Membranes / Molecular biology / Proteolysis / Proto-Oncogene Proteins c-cbl - genetics / Proto-Oncogene Proteins c-cbl - metabolism / Receptor, Epidermal Growth Factor - genetics / Receptor, Epidermal Growth Factor - metabolism / Signal transduction / ubiquitination / Ubiquitination - physiology