Evidence for a sorting endosome in Arabidopsis root cells

Plant J. 2008 Jan;53(2):237-47. doi: 10.1111/j.1365-313X.2007.03338.x. Epub 2007 Nov 12.


In eukaryotic cells, the endocytic and secretory pathways are key players in several physiological processes. These pathways are largely inter-connected in animal and yeast cells through organelles named sorting endosomes. Sorting endosomes are multi-vesicular compartments that redirect proteins towards various destinations, such as the lysosomes or vacuoles for degradation, the trans-Golgi network for retrograde transport and the plasma membrane for recycling. In contrast, cross-talk between the endocytic and secretory pathways has not been clearly established in plants, especially in terms of cargo protein trafficking. Here we show by co-localization analyses that endosomes labelled with the AtSORTING NEXIN1 (AtSNX1) protein overlap with the pre-vacuolar compartment in Arabidopsis root cells. In addition, alteration of the routing functions of AtSNX1 endosomes by drug treatments leads to mis-routing of endocytic and secretory cargo proteins. Based on these results, we propose that the AtSNX1 endosomal compartment represents a sorting endosome in root cells, and that this specialized organelle is conserved throughout eukaryotes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / physiology*
  • Arabidopsis Proteins / metabolism
  • Cell Membrane / metabolism
  • Cytoplasmic Vesicles / physiology
  • Endocytosis
  • Endosomes / physiology*
  • Membrane Proteins / metabolism*
  • Plant Roots / physiology*
  • Plant Roots / ultrastructure
  • Protein Transport / physiology
  • Vesicular Transport Proteins / metabolism*
  • trans-Golgi Network / physiology


  • Arabidopsis Proteins
  • Membrane Proteins
  • Vesicular Transport Proteins