Sorting Nexin 27 Interacts With the Cytohesin Associated Scaffolding Protein (CASP) in Lymphocytes

Biochem Biophys Res Commun. 2007 Aug 10;359(4):848-53. doi: 10.1016/j.bbrc.2007.05.162. Epub 2007 May 30.


CASP is a small cytokine-inducible protein, primarily expressed in hematopoetic cells, which associates with members of the Cytohesin/ARNO family of guanine nucleotide-exchange factors. Cytohesins activate ARFs, a group of GTPases involved in vesicular initiation. Functionally, CASP is an adaptor protein containing a PDZ domain, a coiled-coil, and a potential carboxy terminal PDZ-binding motif that we sought to characterize here. Using GST pulldowns and mass spectrometry we identified the novel interaction of CASP and sorting nexin 27 (SNX27). In lymphocytes, CASP's PDZ-binding motif interacts with the PDZ domain of SNX27. This protein is a unique member of the sorting nexin family of proteins, a group generally involved in the endocytic and intracellular sorting machinery. Endogenous SNX27 and CASP co-localize at the early endosomal compartment in lymphocytes and also in transfection studies. These results suggest that endosomal SNX27 may recruit CASP to orchestrate intracellular trafficking and/or signaling complexes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Carrier Proteins / metabolism*
  • Cell Line
  • Endocytosis / physiology*
  • Endosomes / metabolism*
  • Humans
  • Kidney / metabolism*
  • Lymphocytes / metabolism*
  • Membrane Proteins / metabolism*
  • Protein Binding
  • Sorting Nexins
  • Vesicular Transport Proteins / metabolism*


  • Carrier Proteins
  • Cybr protein, mouse
  • Membrane Proteins
  • Snx27 protein, mouse
  • Sorting Nexins
  • Vesicular Transport Proteins