Multimeric and differential binding of CIN85/CD2AP with two atypical proline-rich sequences from CD2 and Cbl-b*

Authors

  • M. Angeles Ceregido,

    1. Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, Spain
    2. Structural Biology Brussels, Vrije Universiteit Brussels, Belgium
    3. Molecular Recognition Unit, Department of Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
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  • Abel Garcia-Pino,

    1. Structural Biology Brussels, Vrije Universiteit Brussels, Belgium
    2. Molecular Recognition Unit, Department of Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
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  • Jose L. Ortega-Roldan,

    1. Department of Biochemistry, University of Oxford, UK
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  • Salvador Casares,

    1. Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, Spain
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  • Obdulio López Mayorga,

    1. Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, Spain
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  • Jeronimo Bravo,

    1. Instituto de Biomedicina de Valencia-CSIC, Spain
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  • Nico A. J. van Nuland,

    Corresponding author
    1. Structural Biology Brussels, Vrije Universiteit Brussels, Belgium
    2. Molecular Recognition Unit, Department of Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
    • Correspondence

      A. I. Azuaga, Department of Physical Chemistry, University of Granada, Avenida Fuentenueva, 18071 Granada, Spain

      Fax: +34 958 272879

      Tel: +34 958 249366

      E-mail: aiazuaga@ugr.es

      N. A. J. van Nuland, Department of Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050 Brussels, Belgium

      Fax: +32 2 6291962

      Tel: +32 2 6293553

      E-mail: nvnuland@vub.ac.be

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  • Ana I. Azuaga

    Corresponding author
    1. Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, Spain
    • Correspondence

      A. I. Azuaga, Department of Physical Chemistry, University of Granada, Avenida Fuentenueva, 18071 Granada, Spain

      Fax: +34 958 272879

      Tel: +34 958 249366

      E-mail: aiazuaga@ugr.es

      N. A. J. van Nuland, Department of Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050 Brussels, Belgium

      Fax: +32 2 6291962

      Tel: +32 2 6293553

      E-mail: nvnuland@vub.ac.be

    Search for more papers by this author

Abstract

The CD2AP (CD2-associated protein) and CIN85 (Cbl-interacting protein of 85 kDa) adaptor proteins each employ three Src homology 3 (SH3) domains to cluster protein partners and ensure efficient signal transduction and down-regulation of tyrosine kinase receptors. Using NMR, isothermal titration calorimetry and small-angle X-ray scattering methods, we have characterized several binding modes of the N-terminal SH3 domain (SH3A) of CD2AP and CIN85 with two natural atypical proline-rich regions in CD2 (cluster of differentiation 2) and Cbl-b (Casitas B-lineage lymphoma), and compared these data with previous studies and published crystal structures. Our experiments show that the CD2AP-SH3A domain forms a type II dimer with CD2 and both type I and type II dimeric complexes with Cbl-b. Like CD2AP, the CIN85-SH3A domain forms a type II complex with CD2, but a trimeric complex with Cbl-b, whereby the type I and II interactions take place at the same time. Together, these results explain how multiple interactions among similar SH3 domains and ligands produce a high degree of diversity in tyrosine kinase, cell adhesion or T-cell signaling pathways.

Structured digital abstract

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