It takes two to tango: PROPPINs use two phosphoinositide-binding sites

Autophagy. 2013 Jan;9(1):106-7. doi: 10.4161/auto.22400. Epub 2012 Oct 15.


PROPPINs are a family of PtdIns3P and PtdIns(3,5)P 2-binding proteins. The crystal structure now unravels the presence of two distinct phosphoinositide-binding sites at the circumference of the seven bladed β-propeller. Mutagenesis analysis of the binding sites shows that both are required for normal membrane association and autophagic activities. We identified a set of evolutionarily conserved basic and polar residues within both binding pockets, which are crucial for phosphoinositide binding. We expect that membrane association of PROPPINs is further stabilized by membrane insertions and interactions with other proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Carrier Proteins / chemistry*
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Crystallography, X-Ray
  • Fungal Proteins / chemistry*
  • Fungal Proteins / metabolism*
  • Kluyveromyces / metabolism
  • Models, Molecular
  • Mutagenesis
  • Phosphatidylinositol Phosphates / genetics
  • Phosphatidylinositol Phosphates / metabolism
  • Phosphatidylinositols / genetics
  • Phosphatidylinositols / metabolism*
  • Protein Conformation
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*


  • Carrier Proteins
  • Fungal Proteins
  • Phosphatidylinositol Phosphates
  • Phosphatidylinositols
  • Saccharomyces cerevisiae Proteins
  • phosphatidylinositol 3,5-diphosphate
  • phosphatidylinositol 3-phosphate