| First Author | Luo H | Year | 2011 |
| Journal | J Biol Chem | Volume | 286 |
| Issue | 52 | Pages | 44976-87 |
| PubMed ID | 22069310 | Mgi Jnum | J:332362 |
| Mgi Id | MGI:6832579 | Doi | 10.1074/jbc.M111.316414 |
| Citation | Luo H, et al. (2011) Ephrinb1 and Ephrinb2 are associated with interleukin-7 receptor alpha and retard its internalization from the cell surface. J Biol Chem 286(52):44976-87 |
| abstractText | IL-7 plays vital roles in thymocyte development, T cell homeostasis, and the survival of these cells. IL-7 receptor alpha (IL-7Ralpha) on thymocytes and T cells is rapidly internalized upon IL-7 ligation. Ephrins (Efns) are cell surface molecules and ligands of the largest receptor kinase family, Eph kinases. We discovered that T cell-specific double gene knock-out (dKO) of Efnb1 and Efnb2 in mice led to reduced IL-7Ralpha expression in thymocytes and T cells, and that IL-7Ralpha down-regulation was accelerated in dKO CD4 cells upon IL-7 treatment. On the other hand, Efnb1 and Efnb2 overexpression on T cell lymphoma EL4 cells retarded IL-7Ralpha down-regulation. dKO T cells manifested compromised STAT5 activation and homeostatic proliferation, an IL-7-dependent process. Fluorescence resonance energy transfer and immunoprecipitation demonstrated that Efnb1 and Efnb2 interacted physically with IL-7Ralpha. Such interaction likely retarded IL-7Ralpha internalization, as Efnb1 and Efnb2 were not internalized. Therefore, we revealed a novel function of Efnb1 and Efnb2 in stabilizing IL-7Ralpha expression at the post-translational level, and a previously unknown modus operandi of Efnbs in the regulation of expression of other vital cell surface receptors. |
