Basolateral Endocytic Recycling Requires RAB-10 and AMPH-1 Mediated Recruitment of RAB-5 GAP TBC-2 to Endosomes

PLoS Genet. 2015 Sep 22;11(9):e1005514. doi: 10.1371/journal.pgen.1005514. eCollection 2015.

Abstract

The small GTPase RAB-5/Rab5 is a master regulator of the early endosome, required for a myriad of coordinated activities, including the degradation and recycling of internalized cargo. Here we focused on the recycling function of the early endosome and the regulation of RAB-5 by GAP protein TBC-2 in the basolateral C. elegans intestine. We demonstrate that downstream basolateral recycling regulators, GTPase RAB-10/Rab10 and BAR domain protein AMPH-1/Amphiphysin, bind to TBC-2 and help to recruit it to endosomes. In the absence of RAB-10 or AMPH-1 binding to TBC-2, RAB-5 membrane association is abnormally high and recycling cargo is trapped in early endosomes. Furthermore, the loss of TBC-2 or AMPH-1 leads to abnormally high spatial overlap of RAB-5 and RAB-10. Taken together our results indicate that RAB-10 and AMPH-1 mediated down-regulation of RAB-5 is an important step in recycling, required for cargo exit from early endosomes and regulation of early endosome-recycling endosome interactions.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans Proteins / genetics*
  • Caenorhabditis elegans Proteins / metabolism
  • Endocytosis / genetics
  • Endosomes / genetics
  • Endosomes / metabolism
  • GTPase-Activating Proteins / genetics*
  • GTPase-Activating Proteins / metabolism
  • Gene Expression Regulation / genetics
  • Intestinal Mucosa / metabolism
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism
  • Protein Transport / genetics
  • RNA Interference
  • Vesicular Transport Proteins / genetics*
  • Vesicular Transport Proteins / metabolism
  • rab GTP-Binding Proteins / genetics*
  • rab GTP-Binding Proteins / metabolism

Substances

  • Caenorhabditis elegans Proteins
  • GTPase-Activating Proteins
  • Nerve Tissue Proteins
  • Rab-5 protein, C elegans
  • TBC-2 protein, C elegans
  • Vesicular Transport Proteins
  • amphiphysin
  • RAB-10 protein, C elegans
  • rab GTP-Binding Proteins