A PH domain within OCRL bridges clathrin-mediated membrane trafficking to phosphoinositide metabolism

EMBO J. 2009 Jul 8;28(13):1831-42. doi: 10.1038/emboj.2009.155. Epub 2009 Jun 18.


OCRL, whose mutations are responsible for Lowe syndrome and Dent disease, and INPP5B are two similar proteins comprising a central inositol 5-phosphatase domain followed by an ASH and a RhoGAP-like domain. Their divergent NH2-terminal portions remain uncharacterized. We show that the NH2-terminal region of OCRL, but not of INPP5B, binds clathrin heavy chain. OCRL, which in contrast to INPP5B visits late stage endocytic clathrin-coated pits, was earlier shown to contain another binding site for clathrin in its COOH-terminal region. NMR structure determination further reveals that despite their primary sequence dissimilarity, the NH2-terminal portions of both OCRL and INPP5B contain a PH domain. The novel clathrin-binding site in OCRL maps to an unusual clathrin-box motif located in a loop of the PH domain, whose mutations reduce recruitment efficiency of OCRL to coated pits. These findings suggest an evolutionary pressure for a specialized function of OCRL in bridging phosphoinositide metabolism to clathrin-dependent membrane trafficking.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Clathrin / chemistry
  • Clathrin / metabolism*
  • Coated Vesicles / metabolism
  • Coated Vesicles / ultrastructure
  • Endocytosis
  • HeLa Cells
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Mutation
  • Nuclear Magnetic Resonance, Biomolecular
  • Phosphatidylinositols / metabolism
  • Phospholipids
  • Phosphoric Monoester Hydrolases / chemistry*
  • Phosphoric Monoester Hydrolases / genetics
  • Phosphoric Monoester Hydrolases / metabolism*
  • Protein Conformation
  • Protein Structure, Tertiary
  • Rats
  • Sequence Alignment


  • Clathrin
  • Phosphatidylinositols
  • Phospholipids
  • Phosphoric Monoester Hydrolases
  • OCRL protein, human
  • phosphoinositide 5-phosphatase

Associated data

  • PDB/2KIE
  • PDB/2KIG