title: Sorting nexin 27 interacts with the Cytohesin associated scaffolding protein (CASP) in lymphocytes.
abstract: 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.
authors.affiliation: Department of Biology, Dalhousie University, Halifax, NS, Canada B3H 4J1.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: MacNeil
authors.forename: Marc
authors.initials: M
authors.lastname: Mansour
authors.forename: Bill
authors.initials: B
authors.lastname: Pohajdak
mesh_terms: D001665:Binding Sites; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D004705:Endocytosis / Q000502:physiology*; D011992:Endosomes / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D011485:Protein Binding; D058305:Sorting Nexins; D033921:Vesicular Transport Proteins / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; C513660:Cybr protein, mouse; D008565:Membrane Proteins; C500393:Snx27 protein, mouse; D058305:Sorting Nexins; D033921:Vesicular Transport Proteins