A two-component protein condensate of the EGFR cytoplasmic tail and Grb2 regulates Ras activation by SOS at the membrane

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 119; no. 19; pp. 1 - 8
• Main Authors: Lin, Chun-Wei, Nocka, Laura M., Stinger, Brittany L., DeGrandchamp, Joseph B., Lew, L. J. Nugent, Alvarez, Steven, Phan, Henry T., Kondo, Yasushi, Kuriyan, John, Groves, Jay T.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 10.05.2022
• Subjects: Adaptor proteins; BASIC BIOLOGICAL SCIENCES; Biological Sciences; condensation phase transition; Crosslinking; EGFR; Epidermal growth factor; Epidermal growth factor receptors; ErbB Receptors - metabolism; GRB2 Adaptor Protein - metabolism; Grb2 protein; Growth factors; Guanine; Guanine nucleotide exchange factor; MAP kinase; membrane; Membrane proteins; Membranes; Mutation; Nucleotides; Phase transitions; Phosphorylation; Phosphotyrosine; Phosphotyrosine - metabolism; protein condensate; Proteins; Ras; Ras protein; Residues; Science & Technology - Other Topics; Signal Transduction; Substrates; protein condensate; membrane; Ras; condensation phase transition; EGFR
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.2122531119

We reconstitute a phosphotyrosine-mediated protein condensation phase transition of the ∼200 residue cytoplasmic tail of the epidermal growth factor receptor (EGFR) and the adaptor protein, Grb2, on a membrane surface. The phase transition depends on phosphorylation of the EGFR tail, which recruits Grb2, and crosslinking through a Grb2-Grb2 binding interface. The Grb2 Y160 residue plays a structurally critical role in the Grb2-Grb2 interaction, and phosphorylation or mutation of Y160 prevents EGFR:Grb2 condensation. By extending the reconstitution experiment to include the guanine nucleotide exchange factor, SOS, and its substrate Ras, we further find that the condensation state of the EGFR tail controls the ability of SOS, recruited via Grb2, to activate Ras. These results identify an EGFR:Grb2 protein condensation phase transition as a regulator of signal propagation from EGFR to the MAPK pathway.