Tyrosine 319 in the interdomain B of ZAP-70 is a binding site for the Src homology 2 domain of Lck.
T-cell antigen receptor-induced signaling requires both ZAP-70 and Lck protein-tyrosine kinases. One essential function of Lck in this process is to phosphorylate ZAP-70 and up-regulate its catalytic activity. We have previously shown that after T-cell antigen receptor stimulation, Lck binds to ZAP-...
| Main Authors: | , , , , , , , |
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| Formato: | Journal article |
| Idioma: | English |
| Publicado em: |
1999
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| _version_ | 1826267601695670272 |
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| author | Pelosi, M Di Bartolo, V Mounier, V Mège, D Pascussi, J Dufour, E Blondel, A Acuto, O |
| author_facet | Pelosi, M Di Bartolo, V Mounier, V Mège, D Pascussi, J Dufour, E Blondel, A Acuto, O |
| author_sort | Pelosi, M |
| collection | OXFORD |
| description | T-cell antigen receptor-induced signaling requires both ZAP-70 and Lck protein-tyrosine kinases. One essential function of Lck in this process is to phosphorylate ZAP-70 and up-regulate its catalytic activity. We have previously shown that after T-cell antigen receptor stimulation, Lck binds to ZAP-70 via its Src homology 2 (SH2) domain (LckSH2) and, more recently, that Tyr319 of ZAP-70 is phosphorylated in vivo and plays a positive regulatory role. Here, we investigated the possibility that Tyr319 mediates the SH2-dependent interaction between Lck and ZAP-70. We show that a phosphopeptide encompassing the motif harboring Tyr319, YSDP, interacted with LckSH2, although with a lower affinity compared with a phosphopeptide containing the optimal binding motif, YEEI. Moreover, mutation of Tyr319 to phenylalanine prevented the interaction of ZAP-70 with LckSH2. Based on these results, a gain-of-function mutant of ZAP-70 was generated by changing the sequence Y319SDP into Y319EEI. As a result of its increased ability to bind LckSH2, this mutant induced a dramatic increase in NFAT activity in Jurkat T-cells, was hyperphosphorylated, and displayed a higher catalytic activity compared with wild-type ZAP-70. Collectively, our findings indicate that Tyr319-mediated binding of the SH2 domain of Lck is crucial for ZAP-70 activation and consequently for the propagation of the signaling cascade leading to T-cell activation. |
| first_indexed | 2024-03-06T20:56:42Z |
| format | Journal article |
| id | oxford-uuid:39816780-b7b0-491f-bfe0-a178dd1c0b6e |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:56:42Z |
| publishDate | 1999 |
| record_format | dspace |
| spelling | oxford-uuid:39816780-b7b0-491f-bfe0-a178dd1c0b6e2022-03-26T13:55:57ZTyrosine 319 in the interdomain B of ZAP-70 is a binding site for the Src homology 2 domain of Lck.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:39816780-b7b0-491f-bfe0-a178dd1c0b6eEnglishSymplectic Elements at Oxford1999Pelosi, MDi Bartolo, VMounier, VMège, DPascussi, JDufour, EBlondel, AAcuto, OT-cell antigen receptor-induced signaling requires both ZAP-70 and Lck protein-tyrosine kinases. One essential function of Lck in this process is to phosphorylate ZAP-70 and up-regulate its catalytic activity. We have previously shown that after T-cell antigen receptor stimulation, Lck binds to ZAP-70 via its Src homology 2 (SH2) domain (LckSH2) and, more recently, that Tyr319 of ZAP-70 is phosphorylated in vivo and plays a positive regulatory role. Here, we investigated the possibility that Tyr319 mediates the SH2-dependent interaction between Lck and ZAP-70. We show that a phosphopeptide encompassing the motif harboring Tyr319, YSDP, interacted with LckSH2, although with a lower affinity compared with a phosphopeptide containing the optimal binding motif, YEEI. Moreover, mutation of Tyr319 to phenylalanine prevented the interaction of ZAP-70 with LckSH2. Based on these results, a gain-of-function mutant of ZAP-70 was generated by changing the sequence Y319SDP into Y319EEI. As a result of its increased ability to bind LckSH2, this mutant induced a dramatic increase in NFAT activity in Jurkat T-cells, was hyperphosphorylated, and displayed a higher catalytic activity compared with wild-type ZAP-70. Collectively, our findings indicate that Tyr319-mediated binding of the SH2 domain of Lck is crucial for ZAP-70 activation and consequently for the propagation of the signaling cascade leading to T-cell activation. |
| spellingShingle | Pelosi, M Di Bartolo, V Mounier, V Mège, D Pascussi, J Dufour, E Blondel, A Acuto, O Tyrosine 319 in the interdomain B of ZAP-70 is a binding site for the Src homology 2 domain of Lck. |
| title | Tyrosine 319 in the interdomain B of ZAP-70 is a binding site for the Src homology 2 domain of Lck. |
| title_full | Tyrosine 319 in the interdomain B of ZAP-70 is a binding site for the Src homology 2 domain of Lck. |
| title_fullStr | Tyrosine 319 in the interdomain B of ZAP-70 is a binding site for the Src homology 2 domain of Lck. |
| title_full_unstemmed | Tyrosine 319 in the interdomain B of ZAP-70 is a binding site for the Src homology 2 domain of Lck. |
| title_short | Tyrosine 319 in the interdomain B of ZAP-70 is a binding site for the Src homology 2 domain of Lck. |
| title_sort | tyrosine 319 in the interdomain b of zap 70 is a binding site for the src homology 2 domain of lck |
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