IL-7-induced phosphorylation of the adaptor Crk-like and other targets
- Cell Signal. 2018 Jul:47:131-141. doi: 10.1016/j.cellsig.2018.03.008.
- 1. Cancer and Inflammation Program, CCR, NCI, NIH, Bldg 560, Frederick, MD 21702, USA. Electronic address: [email protected].
- 2. Molecular Targets Laboratory, FCRDC, Bldg 560, Frederick, MD 21702, USA. Electronic address: [email protected].
- 3. Cancer and Inflammation Program, CCR, NCI, NIH, Bldg 560, Frederick, MD 21702, USA. Electronic address: [email protected].
- 4. Cancer and Inflammation Program, CCR, NCI, NIH, Bldg 560, Frederick, MD 21702, USA. Electronic address: [email protected].
- 5. Cancer and Inflammation Program, CCR, NCI, NIH, Bldg 560, Frederick, MD 21702, USA. Electronic address: [email protected].
- 6. Laboratory of Experimental Medicine, FCRDC, Bldg 560, Frederick, MD 21702, USA. Electronic address: [email protected].
- 7. Dulbecco Telethon Institute, IRCCS-Istituto di Ricerche Farmacologiche M. Negri, via La Masa 19, 20156 Milano, Italy.
- 8. Department of Medicine and Aging Sciences, University of Chieti-Pescara, via dei Vestini, 66013 Chieti, Italy. Electronic address: [email protected].
- 9. Center for Cancer Research, NIH, Bethesda, MD 20892, USA. Electronic address: [email protected].
- 10. Department of Clinical and Medical Sciences, Marche Polytechnic University, via Tronto 10, 60100 Ancona, Italy. Electronic address: [email protected].
- 11. Dulbecco Telethon Institute, IRCCS-Istituto di Ricerche Farmacologiche M. Negri, via La Masa 19, 20156 Milano, Italy. Electronic address: [email protected].
- 12. Cancer and Inflammation Program, CCR, NCI, NIH, Bldg 560, Frederick, MD 21702, USA. Electronic address: [email protected].
IL-7 is required for T cell differentiation and mature T cell homeostasis and promotes pro-B cell proliferation and survival. Tyrosine phosphorylation plays a central role in IL-7 signaling. We identified by two-dimensional electrophoresis followed by anti-phosphotyrosine immunoblotting and mass spectrometry sixteen tyrosine phosphorylated proteins from the IL-7-dependent cell line D1. IL-7 stimulation induced the phosphorylation of the proteins STI1, ATIC and hnRNPH, involved in pathways related to survival, proliferation and gene expression, respectively, and increased the phosphorylation of CrkL, a member of a family of adaptors including the highly homologous Crk isoforms CrkII and CrkI, important in multiple signaling pathways. We observed an increased phosphorylation of CrkL in murine pro-B cells and in murine and human T cells. In addition, IL-7 increased the association of CrkL with the transcription factor STAT5, essential for IL-7 pro-survival activity. The selective tyrosine kinase inhibitor Imatinib. counteracted the IL-7 pro-survival effect in D1 cells and decreased CrkL phosphorylation. These data suggested that CrkL could play a pro-survival role in IL-7-mediated signaling. We observed that pro-B cells also expressed, in addition to CrkL, the Crk isoforms CrkII and CrkI and therefore utilized pro-B cells conditionally deficient in all three to evaluate the role of these proteins. The observation that the IL-7 pro-survival effect was reduced in Crk/CrkL conditionally-deficient pro-B cells further pointed to a pro-survival role of these adaptors. To further evaluate the role of these proteins, gene expression studies were performed in Crk/CrkL conditionally-deficient pro-B cells. IL-7 decreased the transcription of the receptor LAIR1, which inhibits B cell proliferation, in a Crk/CrkL-dependent manner, suggesting that the Crk family of proteins may promote pro-B cell proliferation. Our data contribute to the understanding of IL-7 signaling and suggest the involvement of Crk family proteins in pathways promoting survival and proliferation.