SSBD:database

Detail of Fig1A_MbCD_withoutEGF_1

Miri Takayama, Sakura Maeda, Daisuke Watanabe, Kazutoshi Takebayashi, Michio Hiroshima, Masahiro Ueda (2024) Cholesterol suppresses spontaneous activation of EGFR-mediated signal transduction., Biochemical and biophysical research communications, Volume 704, pp. 149673

Published in 2024 Feb 12 (Electronic publication in Feb. 12, 2024, midnight )

• doi: 10.1016/j.bbrc.2024.149673
• pmid: 38401305
  

(Abstract) Epidermal growth factor receptor (EGFR)-mediated signal transduction controls cell growth and proliferation. The signaling pathway is regulated so that it is activated only by external EGF stimuli, but the mechanisms that prevent EGF-independent spontaneous activation of EGFR-mediated signaling are unknown. Here we report cholesterol depletion activates EGFR-mediated signaling without EGF. We applied automated single-molecule imaging to EGFR and characterized the lateral diffusion and cluster formation on cholesterol-depleted and cholesterol-supplemented membranes. In cells in which cholesterol was depleted by methyl-beta-cyclodextrin (MbetaCD) treatment, EGFR exhibited a reduction in lateral diffusion, an acceleration of cluster formation, and autophosphorylation without EGF. Concurrently, extracellular signal-regulated kinase (ERK), which is regulated by EGFR-mediated signaling, exhibited phosphorylation and nuclear translocation without EGF. These cholesterol depletion-induced changes were similar, albeit less efficient, to those that occurred with EGF stimulation in normal cells without MbetaCD, indicating the spontaneous activation of EGFR signaling. The exogenous supplementation of cholesterol suppressed the MbetaCD-induced spontaneous activation of EGFR and ERK nuclear translocation. Single-molecule imaging of EGFR in a large number of cells revealed cell-to-cell heterogeneity, with a sub-population showing a high ability for spontaneous activation. These results provide evidence that EGFR-mediated signaling is properly regulated by cholesterol metabolism to prevent uncontrolled spontaneous activation.