Citation

  • Authors: Flores-Rodriguez, N., Kenwright, D. A., Chung, P. H., Harrison, A. W., Stefani, F., Waigh, T. A., Allan, V. J., Woodman, P. G.
  • Year: 2015
  • Journal: J Cell Sci 128 755-67
  • Applications: in vitro / siRNA / INTERFERin
  • Cell types:
    1. Name: HeLa
      Description: Human cervix epitheloid carcinoma cells
    2. Name: A549
      Description: Human lung carcinoma cells, type II pneumocytes
      Known as: A-549

Abstract

Endosomal sorting complexes required for transport (ESCRT)-0 sorts ubiquitylated EGFR within the early endosome so that the receptor can be incorporated into intralumenal vesicles. An important question is whether ESCRT-0 acts solely upon EGFR that has already entered the vacuolar early endosome (characterised by the presence of EEA1) or engages EGFR within earlier compartments. Here, we employ a suite of software to determine the localisation of ESCRT-0 at subpixel resolution and to perform particle-based colocalisation analysis with other endocytic markers. We demonstrate that although some of the ESCRT-0 subunit Hrs (also known as HGS) colocalises with the vacuolar early endosome marker EEA1, most localises to a population of peripheral EEA1-negative endosomes that act as intermediates in transporting EGFR from the cell surface to more central early endosomes. The peripheral Hrs-labelled endosomes are distinct from APPL1-containing endosomes, but co-label with the novel endocytic adaptor SNX15. In contrast to ESCRT-0, ESCRT-I is recruited to EGF-containing endosomes at later times as they move to more a central position, whereas ESCRT-III is also recruited more gradually. RNA silencing experiments show that both ESCRT-0 and ESCRT-I are important for the transit of EGF to EEA1 endosomes.

Go to