Clathrin-mediated Constitutive Endocytosis of PIN Auxin Efflux Carriers in Arabidopsis

Curr Biol. 2007 Mar 20;17(6):520-7. doi: 10.1016/j.cub.2007.01.052. Epub 2007 Feb 15.

Abstract

Endocytosis is an essential process by which eukaryotic cells internalize exogenous material or regulate signaling at the cell surface [1]. Different endocytic pathways are well established in yeast and animals; prominent among them is clathrin-dependent endocytosis [2, 3]. In plants, endocytosis is poorly defined, and no molecular mechanism for cargo internalization has been demonstrated so far [4, 5], although the internalization of receptor-ligand complexes at the plant plasma membrane has recently been shown [6]. Here we demonstrate by means of a green-to-red photoconvertible fluorescent reporter, EosFP [7], the constitutive endocytosis of PIN auxin efflux carriers [8] and their recycling to the plasma membrane. Using a plant clathrin-specific antibody, we show the presence of clathrin at different stages of coated-vesicle formation at the plasma membrane in Arabidopsis. Genetic interference with clathrin function inhibits PIN internalization and endocytosis in general. Furthermore, pharmacological interference with cargo recruitment into the clathrin pathway blocks internalization of PINs and other plasma-membrane proteins. Our data demonstrate that clathrin-dependent endocytosis is operational in plants and constitutes the predominant pathway for the internalization of numerous plasma-membrane-resident proteins including PIN auxin efflux carriers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / cytology
  • Arabidopsis / metabolism*
  • Arabidopsis / ultrastructure
  • Arabidopsis Proteins / analysis
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Cell Membrane / metabolism
  • Clathrin / analysis
  • Clathrin / antagonists & inhibitors
  • Clathrin-Coated Vesicles / metabolism*
  • Endocytosis / physiology*
  • Genes, Reporter
  • Indoleacetic Acids / metabolism*
  • Luminescent Proteins / analysis
  • Plant Roots / cytology
  • Plant Roots / metabolism
  • Plant Roots / ultrastructure
  • Protoplasts / metabolism
  • Recombinant Fusion Proteins / analysis

Substances

  • Arabidopsis Proteins
  • Clathrin
  • Indoleacetic Acids
  • Luminescent Proteins
  • PIN2 protein, Arabidopsis
  • Recombinant Fusion Proteins