RILP interacts with VPS22 and VPS36 of ESCRT-II and regulates their membrane recruitment

Biochem Biophys Res Commun. 2006 Nov 17;350(2):413-23. doi: 10.1016/j.bbrc.2006.09.064. Epub 2006 Sep 25.

Abstract

RILP is emerging as a key regulator of late endocytic pathway by functioning as a downstream effector of activated Rab7 and Rab34, while ESCRT-I-->ESCRT-II-->ESCRT-III machinery acts in sorting proteins to the multivesicular body (MVB) initiated at the early/sorting endosome. We show here that the early machinery is integrated with the late machinery through a novel regulatory loop in which RILP interacts with VPS22 and VPS36 of ESCRT-II to mediate their membrane recruitment. The N-terminal and C-terminal half of RILP mediate interaction with VPS22 and VPS36, respectively. Overexpression of RILP leads to enlarged and clustered MVBs marked by lysobisphosphatidic acid (LBPA). In addition, RILP or its C-terminal fragment causes a retardation of sorting internalized EGF to the degradation route at the level of sorting endosomes marked by EEA1. We propose that RILP-->ESCRT-II serves as a regulatory/feedback loop to govern the coordination of early and late parts of the endocytic pathway.

MeSH terms

  • Adaptor Proteins, Signal Transducing / chemistry
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Binding Sites
  • Cytoplasm / chemistry
  • Endocytosis
  • Endosomes / metabolism*
  • Endosomes / ultrastructure
  • Epidermal Growth Factor / metabolism
  • HeLa Cells
  • Humans
  • Intracellular Membranes / metabolism*

Substances

  • Adaptor Proteins, Signal Transducing
  • Epidermal Growth Factor