| Autor: |
Mikel M. Arbulo-Echevarria, Inmaculada Vico-Barranco, Isaac Narbona-Sánchez, Francisco García-Cózar, Arkadiusz Miazek, Enrique Aguado |
| Jazyk: |
angličtina |
| Rok vydání: |
2020 |
| Předmět: |
|
| Zdroj: |
Frontiers in Cell and Developmental Biology, Vol 8 (2020) |
| Druh dokumentu: |
article |
| ISSN: |
2296-634X |
| DOI: |
10.3389/fcell.2020.561503 |
| Popis: |
The adaptor LAT plays a crucial role in the transduction of signals coming from the TCR/CD3 complex. Phosphorylation of some of its tyrosines generates recruitment sites for other cytosolic signaling molecules. Tyrosine 132 in human LAT is essential for PLC-γ activation and calcium influx generation. It has been recently reported that a conserved glycine residue preceding tyrosine 132 decreases its phosphorylation kinetics, which constitutes a mechanism for ligand discrimination. Here we confirm that a LAT mutant in which glycine 131 has been substituted by an aspartate (LATG131D) increases phosphorylation of Tyr132, PLC-γ activation and calcium influx generation. Interestingly, the LATG131D mutant has a slower protein turnover while being equally sensitive to Fas-mediated protein cleavage by caspases. Moreover, J.CaM2 cells expressing LATG131D secrete greater amounts of interleukin-2 (IL-2) in response to CD3/CD28 engagement. However, despite this increased IL-2 secretion, J.CaM2 cells expressing the LATG131D mutant are more sensitive to inhibition of IL-2 production by pre-treatment with anti-CD3, which points to a possible role of this residue in the generation of anergy. Our results suggest that the increased kinetics of LAT Tyr132 phosphorylation could contribute to the establishment of T cell anergy, and thus constitutes an earliest known intracellular event responsible for the induction of peripheral tolerance. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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