Regulation of membrane trafficking and organ separation by the NEVERSHED ARF-GAP protein

Development. 2009 Jun;136(11):1909-18. doi: 10.1242/dev.033605.


Cell separation, or abscission, is a highly specialized process in plants that facilitates remodeling of their architecture and reproductive success. Because few genes are known to be essential for organ abscission, we conducted a screen for mutations that alter floral organ shedding in Arabidopsis. Nine recessive mutations that block shedding were found to disrupt the function of an ADP-ribosylation factor-GTPase-activating protein (ARF-GAP) we have named NEVERSHED (NEV). As predicted by its homology to the yeast Age2 ARF-GAP and transcriptional profile, NEV influences other aspects of plant development, including fruit growth. Co-localization experiments carried out with NEV-specific antiserum and a set of plant endomembrane markers revealed that NEV localizes to the trans-Golgi network and endosomes in Arabidopsis root epidermal cells. Interestingly, transmission electron micrographs of abscission zone regions from wild-type and nev flowers reveal defects in the structure of the Golgi apparatus and extensive accumulation of vesicles adjacent to the cell walls. Our results suggest that NEV ARF-GAP activity at the trans-Golgi network and distinct endosomal compartments is required for the proper trafficking of cargo molecules required for cell separation.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / physiology*
  • Arabidopsis / ultrastructure
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / physiology*
  • Biological Transport
  • Endosomes / physiology*
  • Flowers / physiology*
  • Flowers / ultrastructure
  • GTPase-Activating Proteins / genetics
  • GTPase-Activating Proteins / physiology*
  • Golgi Apparatus / physiology*
  • Golgi Apparatus / ultrastructure
  • Intracellular Membranes / metabolism
  • Molecular Sequence Data
  • Mutation


  • Arabidopsis Proteins
  • GTPase-Activating Proteins
  • NEV protein, Arabidopsis