Autor: |
Hui Guo, Guilin Qiao, Haiyan Ying, Zhenping Li, Yixia Zhao, Yanran Liang, Lifen Yang, Stanley Lipkowitz, Josef M. Penninger, Wallace Y. Langdon, Jian Zhang |
Jazyk: |
angličtina |
Rok vydání: |
2012 |
Předmět: |
|
Zdroj: |
Cell Reports, Vol 1, Iss 5, Pp 472-482 (2012) |
Druh dokumentu: |
article |
ISSN: |
2211-1247 |
DOI: |
10.1016/j.celrep.2012.04.008 |
Popis: |
E3 ubiquitin ligase Cbl-b plays a crucial role in T cell activation and tolerance induction. However, the molecular mechanism by which Cbl-b inhibits T cell activation remains unclear. Here, we report that Cbl-b does not inhibit PI3K but rather suppresses TCR/CD28-induced inactivation of Pten. The elevated Akt activity in Cbl-b−/− T cells is therefore due to heightened Pten inactivation. Suppression of Pten inactivation in T cells by Cbl-b is achieved by impeding the association of Pten with Nedd4, which targets Pten K13 for K63-linked polyubiquitination. Consistent with this finding, introducing Nedd4 deficiency into Cbl-b−/− mice abrogates hyper-T cell responses caused by the loss of Cbl-b. Hence, our data demonstrate that Cbl-b inhibits T cell activation by suppressing Pten inactivation independently of its ubiquitin ligase activity. |
Databáze: |
Directory of Open Access Journals |
Externí odkaz: |
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