First Author | Jang IK | Year | 2010 |
Journal | Proc Natl Acad Sci U S A | Volume | 107 |
Issue | 23 | Pages | 10620-5 |
PubMed ID | 20498059 | Mgi Jnum | J:161294 |
Mgi Id | MGI:4457961 | Doi | 10.1073/pnas.0905039107 |
Citation | Jang IK, et al. (2010) Grb2 functions at the top of the T-cell antigen receptor-induced tyrosine kinase cascade to control thymic selection. Proc Natl Acad Sci U S A 107(23):10620-5 |
abstractText | Grb2 is an adaptor molecule that mediates Ras-MAPK activation induced by various receptors. Here we show that conditional ablation of Grb2 in thymocytes severely impairs both thymic positive and negative selections. Strikingly, the mutation attenuates T-cell antigen receptor (TCR) proximal signaling, including tyrosine phosphorylation of multiple signaling proteins and Ca(2+) influx. The defective TCR signaling can be attributed to a marked impairment in Lck activation. Ectopic expression of a mutant Grb2 composed of the central SH2 and the C-terminal SH3 domains in Grb2(-/-) thymocytes fully restores thymocyte development. Thus, Grb2 plays a pivotal role in both thymic positive and negative selection. It amplifies TCR signaling at the top end of the tyrosine phosphorylation cascade via a scaffolding function. |