Dual clathrin and adhesion signaling systems regulate growth factor receptor activation

Abstract

The crosstalk between growth factor and adhesion receptors is key for cell growth and migration. In pathological settings, these receptors are drivers of cancer. Yet, how growth and adhesion signals are spatially organized and integrated is poorly understood. Here we use quantitative fluorescence and electron microscopy to reveal a mechanism where flat clathrin lattices partition and activate growth factor signals via a coordinated response that involves crosstalk between epidermal growth factor receptor (EGFR) and the adhesion receptor {beta}5-integrin. We show that ligand-activated EGFR, Grb2, Src, and {beta}5-integrin are captured by clathrin coated-structures at the plasma membrane. Clathrin structures dramatically grow in response to ligand activation into large flat plaques and provide a signaling platform that link EGFR and {beta}5-integrin through Src-mediated phosphorylation. Disrupting this EGFR/Src/{beta}5-integrin axis prevents both clathrin plaque growth and receptor signaling. Our study reveals a reciprocal regulation of clathrin lattices and two different receptor systems to enhance cell growth factor signaling. These findings have broad implications for the control of growth factor receptors, mechanotransduction, and endocytosis.