Abstract

Src is a protein tyrosine kinase commonly activated downstream of transmembrane receptors and plays key roles in cell growth, migration and survival signaling pathways. In conventional dendritic cells (cDCs), Src is involved in the activation of the non-enzymatic functions of indoleamine 2,3-dioxygenase 1 (IDO1), an immunoregulatory molecule endowed with both catalytic activity and signal transducing properties. Prompted by the discovery that the metabolite spermidine confers a tolerogenic phenotype on cDCs that is dependent on both the expression of IDO1 and the activity of Src kinase, we here investigated the spermidine mode of action. We found that spermidine directly binds Src in a previously unknown allosteric site located on the backside of the SH2 domain and thus acts as a positive allosteric modulator of the enzyme. Besides confirming that Src phosphorylates IDO1, here we showed that spermidine promotes the protein-protein interaction of Src with IDO1. Overall, this study may pave the way toward the design of allosteric modulators able to switch on/off the Src-mediated pathways, including those involving the immunoregulatory protein IDO1.

Data availability

All data generated or analyzed during this study are included in the manuscript and supporting file.Figure 1 - Source Data 1; Figure 1 - Source Data 2; Figure 1 - Figure supplement 1 - Source Data 3; Figure 2 - Source Data 4; Figure 2 - Figure supplement 1 - Source Data 5; Figure 2 - Figure supplement 2 - Source Data 6; Figure 3 - Source Data 7; Figure 3 - Source Data 8; Figure 3 - Source Data 9; Figure 3 - Source Data 10; Figure 3 - Source Data 11; Figure 3 - Figure supplement 1 - Source Data 12: contain the original blots used to generate the figures.

Article and author information

Author details

  1. Sofia Rossini

    Department of Medicine and Surgery, University of Perugia, Perugia, Italy
    Competing interests
    The authors declare that no competing interests exist.
  2. Marco Gagaro

    Department of Medicine and Surgery, University of Perugia, Perugia, Italy
    Competing interests
    The authors declare that no competing interests exist.
  3. Giulia Scalisi

    Department of Medicine and Surgery, University of Perugia, Perugia, Italy
    Competing interests
    The authors declare that no competing interests exist.
  4. Elisa Bianconi

    Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4597-8056
  5. Sara Ambrosino

    Department of Medicine and Surgery, University of Perugia, Perugia, Italy
    Competing interests
    The authors declare that no competing interests exist.
  6. Eleonora Panfili

    Department of Medicine and Surgery, University of Perugia, Perugia, Italy
    Competing interests
    The authors declare that no competing interests exist.
  7. Claudia Volpi

    Department of Medicine and Surgery, University of Perugia, Perugia, Italy
    Competing interests
    The authors declare that no competing interests exist.
  8. Ciriana Orabona

    Department of Medicine and Surgery, University of Perugia, Perugia, Italy
    Competing interests
    The authors declare that no competing interests exist.
  9. Antonio Macchiarulo

    Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
    Competing interests
    The authors declare that no competing interests exist.
  10. Francesca Fallarino

    Department of Medicine and Surgery, University of Perugia, Perugia, Italy
    Competing interests
    The authors declare that no competing interests exist.
  11. Giada Mondanelli

    Department of Medicine and Surgery, University of Perugia, Perugia, Italy
    For correspondence
    giada.mondanelli@unipg.it
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0798-0465

Funding

Università degli Studi di Perugia (Ricerca di base 2019)

  • Giada Mondanelli

Associazione italiana per la ricerca sul cancro (AIRC 2019-23084)

  • Claudia Volpi

Italian Ministry of Education, University, and Research (PRIN 2020L45ZW)

  • Ciriana Orabona

Università degli Studi di Perugia (Ricerca di base 2020)

  • Antonio Macchiarulo

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Copyright

© 2023, Rossini et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Sofia Rossini
  2. Marco Gagaro
  3. Giulia Scalisi
  4. Elisa Bianconi
  5. Sara Ambrosino
  6. Eleonora Panfili
  7. Claudia Volpi
  8. Ciriana Orabona
  9. Antonio Macchiarulo
  10. Francesca Fallarino
  11. Giada Mondanelli
(2023)
A back-door insights into the modulation of Src kinase activity by the polyamine spermidine
eLife 12:e85872.
https://doi.org/10.7554/eLife.85872

Share this article

https://doi.org/10.7554/eLife.85872

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