Phosphorylated EGFR Dimers Are Not Sufficient to Activate Ras

Samantha I Liang; Bettina van Lengerich; Kelsie Eichel; Minkwon Cha; David M Patterson; Tae-Young Yoon; Mark von Zastrow; Natalia Jura; Zev J Gartner

doi:10.1016/j.celrep.2018.02.031

Phosphorylated EGFR Dimers Are Not Sufficient to Activate Ras

Cell Rep. 2018 Mar 6;22(10):2593-2600. doi: 10.1016/j.celrep.2018.02.031.

Authors

Samantha I Liang¹, Bettina van Lengerich², Kelsie Eichel³, Minkwon Cha⁴, David M Patterson⁵, Tae-Young Yoon⁶, Mark von Zastrow⁷, Natalia Jura⁸, Zev J Gartner⁹

Affiliations

¹ Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA; Program in Biochemistry and Molecular Biology, University of California, San Francisco, San Francisco, CA, USA.
² Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA.
³ Program in Biochemistry and Molecular Biology, University of California, San Francisco, San Francisco, CA, USA; Department of Psychiatry, University of California, San Francisco, San Francisco, CA, USA.
⁴ Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea; Center for Nanomedicine, Institute for Basic Science (IBS), Yonsei University, Seoul 30722, South Korea; Yonsei-IBS Institute, Yonsei University, Seoul 30722, South Korea.
⁵ Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA.
⁶ Center for Nanomedicine, Institute for Basic Science (IBS), Yonsei University, Seoul 30722, South Korea; Yonsei-IBS Institute, Yonsei University, Seoul 30722, South Korea; Department of Biological Sciences, Seoul National University, Seoul 08826, South Korea.
⁷ Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA; Department of Psychiatry, University of California, San Francisco, San Francisco, CA, USA.
⁸ Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA. Electronic address: natalia.jura@ucsf.edu.
⁹ Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA; Chan Zuckerberg Biohub, University of California, San Francisco, San Francisco, CA, USA; Center for Cellular Construction, University of California, San Francisco, San Francisco, CA, USA. Electronic address: zev.gartner@ucsf.edu.

Abstract

Growth factor binding to EGFR drives conformational changes that promote homodimerization and transphosphorylation, followed by adaptor recruitment, oligomerization, and signaling through Ras. Whether specific receptor conformations and oligomerization states are necessary for efficient activation of Ras is unclear. We therefore evaluated the sufficiency of a phosphorylated EGFR dimer to activate Ras without growth factor by developing a chemical-genetic strategy to crosslink and "trap" full-length EGFR homodimers on cells. Trapped dimers become phosphorylated and recruit adaptor proteins at stoichiometry equivalent to that of EGF-stimulated receptors. Surprisingly, these phosphorylated dimers do not activate Ras, Erk, or Akt. In the absence of EGF, phosphorylated dimers do not further oligomerize or reorganize on cell membranes. These results suggest that a phosphorylated EGFR dimer loaded with core signaling adapters is not sufficient to activate Ras and that EGFR ligands contribute to conformational changes or receptor dynamics necessary for oligomerization and efficient signal propagation through the SOS-Ras-MAPK pathway.

Keywords: EGFR nanoclusters; EGFR signaling; Ras-MAPK signaling; chemical-genetic dimerization; spatial reorganization.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Clathrin-Coated Vesicles / drug effects
Clathrin-Coated Vesicles / metabolism
Cross-Linking Reagents / chemistry
Cross-Linking Reagents / metabolism
Epidermal Growth Factor / pharmacology
ErbB Receptors / chemistry
ErbB Receptors / metabolism*
HEK293 Cells
Humans
Ligands
Phosphorylation / drug effects
Phosphotyrosine / metabolism
Protein Conformation
Protein Multimerization*
Signal Transduction / drug effects
ras Proteins / metabolism*

Substances

Cross-Linking Reagents
Ligands
Phosphotyrosine
Epidermal Growth Factor
ErbB Receptors
ras Proteins

Abstract

Publication types

MeSH terms

Substances

Grants and funding