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  • The EMBO Journal (2002) 21, 5985 - 5995
  • doi:10.1093/emboj/cdf602

Dynamic interaction of CD2 with the GYF and the SH3 domain of compartmentalized effector molecules

Christian Freund1, Ronald Kühne2, Hailin Yang3, Sunghyouk Park4, Ellis L. Reinherz3 and Gerhard Wagner4

  1. Protein Engineering Group, Forschungsinstitut für Molekulare Pharmakologie and Freie Universität Berlin, Robert-Rössle-Strasse 10, D-13125 Berlin, Germany
  2. Molecular Modeling Group, Forschungsinstitut für Molekulare Pharmakologie and Freie Universität Berlin, Robert-Rössle-Strasse 10, D-13125 Berlin, Germany
  3. Laboratory of Immunobiology, Dana Farber Cancer Institute and Department of Medicine Boston, MA 02115, USA
  4. Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA

Correspondence to:

Christian Freund, E-mail: freund@fmp-berlin.de

Gerhard Wagner, E-mail: wagner@hms.harvard.edu

Received 5 July 2002; Accepted 23 September 2002; Revised 3 September 2002

Intracellular protein interaction domains are essential for eukaryotic signaling. In T cells, the CD2BP2 adaptor binds two membrane-proximal proline-rich motifs in the CD2 cytoplasmic tail via its GYF domain, thereby regulating interleukin-2 production. Here we present the structure of the GYF domain in complex with a CD2 tail peptide. Unlike SH3 domains, which use two surface pockets to accommodate proline residues of ligands, the GYF domain employs phylogenetically conserved hydrophobic residues to create a single interaction surface. NMR analysis shows that the Fyn but not the Lck tyrosine kinase SH3 domain competes with CD2BP2 GYF-domain binding to the same CD2 proline-rich sequence in vitro. To test the in vivo significance of this competition, we used co-immunoprecipitation experiments and found that CD2BP2 is the ligand of the membrane-proximal proline-rich tandem repeat of CD2 in detergent- soluble membrane compartments, but is replaced by Fyn SH3 after CD2 is translocated into lipid rafts upon CD2 ectodomain clustering. This unveils the mechanism of a switch of CD2 function due to an extracellular mitogenic signal.

  • Keywords:

    • CD2,
    • GYF domain,
    • lipid rafts,
    • NMR,
    • SH3 domain