Decoding EGFR ligand bias through an endocytic organelle platform

Jendrisek, G.; Mesa, D.; Freddi, S.; Miloro, G.; Tordonato, C.; Benvenuto, A. F.; Quarto, M.; Caputo, M.; Raimondi, A.; Caldieri, G.; Barbieri, E.; Pelicci, S.; Faretta, M.; Malabarba, M. G.; Chianese, D.; Begnozzi, F.; Pinton, P.; Bonora, M.; Di Fiore, P. P.; Sigismund, S.

doi:10.64898/2026.08.03.742496

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bioRxiv · 10.64898/2026.08.03.742496

Decoding EGFR ligand bias through an endocytic organelle platform

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Abstract

How growth factor receptors decode ligand identity into distinct cellular responses remains a fundamental question in cell signaling. Here, we identify a receptor-proximal mechanism that links ligand-specific EGFR activation to distinct endocytic and biological outputs. We show that EGF, but not TGF, selectively engages a RAC1-PLC{gamma}2-IP3R signaling axis that supports EGFR non-clathrin endocytosis (NCE). PLC{gamma}2, but not PLC{gamma}1, localizes to RTN3-dependent PM-ER contact sites, where it generates localized Ca{superscript 2} signals required for completion of NCE, mitochondrial activation and cell motility. This specificity requires the RAC-binding interface of PLC{gamma}2 and is associated with RAC1-dependent formation of CTxB-positive PM regions, indicating that spatial organization contributes to signaling specificity. TGF fails to efficiently assemble the EGFR-associated organelle platform and instead favors clathrin-dependent EGFR uptake, prolonged proliferative signaling, greater organoid yield, and reduced migration compared with EGF. Together, our findings identify the RAC1-PLC{gamma}2 axis as the key determinant that decodes EGFR ligand bias by coupling receptor trafficking to the metabolic program that supports cell migration.

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Jendrisek, G., Mesa, D., Freddi, S., Miloro, G., Tordonato, C., Benvenuto, A. F., Quarto, M., Caputo, M., Raimondi, A., Caldieri, G., Barbieri, E., Pelicci, S., Faretta, M., Malabarba, M. G., Chianese, D., Begnozzi, F., Pinton, P., Bonora, M., Di Fiore, P. P., Sigismund, S.. 2026-08-04. Decoding EGFR ligand bias through an endocytic organelle platform. https://doi.org/10.64898/2026.08.03.742496

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