EHBP-1 Functions With RAB-10 During Endocytic Recycling in Caenorhabditis Elegans

Mol Biol Cell. 2010 Aug 15;21(16):2930-43. doi: 10.1091/mbc.E10-02-0149. Epub 2010 Jun 23.

Abstract

Caenorhabditis elegans RAB-10 functions in endocytic recycling in polarized cells, regulating basolateral cargo transport in the intestinal epithelia and postsynaptic cargo transport in interneurons. A similar role was found for mammalian Rab10 in MDCK cells, suggesting that a conserved mechanism regulates these related pathways in metazoans. In a yeast two-hybrid screen for binding partners of RAB-10 we identified EHBP-1, a calponin homology domain (CH) protein, whose mammalian homolog Ehbp1 was previously shown to function during endocytic transport of GLUT4 in adipocytes. In vivo we find that EHBP-1-GFP colocalizes with RFP-RAB-10 on endosomal structures of the intestine and interneurons and that ehbp-1 loss-of-function mutants share with rab-10 mutants specific endosome morphology and cargo localization defects. We also show that loss of EHBP-1 disrupts transport of membrane proteins to the plasma membrane of the nonpolarized germline cells, a defect that can be phenocopied by codepletion of RAB-10 and its closest paralog RAB-8. These results indicate that RAB-10 and EHBP-1 function together in many cell types and suggests that there are differences in the level of redundancy among Rab family members in polarized versus nonpolarized cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Amino Acid Sequence
  • Animals
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Endocytosis / genetics
  • Endocytosis / physiology*
  • Endosomes / metabolism
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • Protein Binding
  • Protein Transport
  • RNA Interference
  • Receptors, AMPA / genetics
  • Receptors, AMPA / metabolism
  • Sequence Homology, Amino Acid
  • Two-Hybrid System Techniques
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / metabolism*
  • rab GTP-Binding Proteins / genetics
  • rab GTP-Binding Proteins / metabolism*

Substances

  • Caenorhabditis elegans Proteins
  • EHBP-1 protein, C elegans
  • Receptors, AMPA
  • Vesicular Transport Proteins
  • glr-1 protein, C elegans
  • Green Fluorescent Proteins
  • Adenosine Triphosphate
  • RAB-10 protein, C elegans
  • rab GTP-Binding Proteins