Selective Regulation of Clathrin-Mediated Epidermal Growth Factor Receptor Signaling and Endocytosis by Phospholipase C and Calcium

Mol Biol Cell. 2017 Oct 15;28(21):2802-2818. doi: 10.1091/mbc.E16-12-0871. Epub 2017 Aug 16.

Abstract

Clathrin-mediated endocytosis is a major regulator of cell-surface protein internalization. Clathrin and other proteins assemble into small invaginating structures at the plasma membrane termed clathrin-coated pits (CCPs) that mediate vesicle formation. In addition, epidermal growth factor receptor (EGFR) signaling is regulated by its accumulation within CCPs. Given the diversity of proteins regulated by clathrin-mediated endocytosis, how this process may distinctly regulate specific receptors is a key question. We examined the selective regulation of clathrin-dependent EGFR signaling and endocytosis. We find that perturbations of phospholipase Cγ1 (PLCγ1), Ca2+, or protein kinase C (PKC) impair clathrin-mediated endocytosis of EGFR, the formation of CCPs harboring EGFR, and EGFR signaling. Each of these manipulations was without effect on the clathrin-mediated endocytosis of transferrin receptor (TfR). EGFR and TfR were recruited to largely distinct clathrin structures. In addition to control of initiation and assembly of CCPs, EGF stimulation also elicited a Ca2+- and PKC-dependent reduction in synaptojanin1 recruitment to clathrin structures, indicating broad control of CCP assembly by Ca2+ signals. Hence EGFR elicits PLCγ1-calcium signals to facilitate formation of a subset of CCPs, thus modulating its own signaling and endocytosis. This provides evidence for the versatility of CCPs to control diverse cellular processes.

MeSH terms

  • Calcium / metabolism
  • Cell Line
  • Cell Membrane / metabolism
  • Clathrin / metabolism
  • Clathrin-Coated Vesicles / metabolism
  • Coated Pits, Cell-Membrane / metabolism
  • Endocytosis / physiology*
  • Epidermal Growth Factor / metabolism
  • ErbB Receptors / genetics
  • ErbB Receptors / metabolism*
  • Humans
  • Receptors, Transferrin / metabolism
  • Retinal Pigment Epithelium
  • Signal Transduction
  • Type C Phospholipases / metabolism*

Substances

  • Clathrin
  • Receptors, Transferrin
  • Epidermal Growth Factor
  • EGFR protein, human
  • ErbB Receptors
  • Type C Phospholipases
  • Calcium