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Biochemical analysis of interleukin‐2 receptor β chain phosphorylation by p56 lck
Author(s) -
Delespine-Carmagnat Maryvonnick,
Bouvier Ghislaine,
Allée Guillaume,
Fagard Remi,
Bertoglio Jacques
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)00301-4
Subject(s) - tyrosine phosphorylation , phosphorylation , tyrosine , sh2 domain , chemistry , tyrosine kinase , proto oncogene tyrosine protein kinase src , receptor tyrosine kinase , biochemistry , receptor , microbiology and biotechnology , biology
Tyrosine phosphorylation of multiple proteins, including the receptor itself, is an initial event in IL‐2 signaling and leads to recruitment of SH2 or PTB domain‐containing proteins to the receptor. In this study, we have used subdomains of the IL‐2 receptor β chain (IL‐2Rβ) expressed in Escherichia coli as GST fusion proteins to identify the tyrosine residues that could be phosphorylated by p56 lck , one of the critical tyrosine kinases activated by IL‐2. We report that recombinant p56 lck phosphorylates in vitro tyrosine residues within the IL‐2Rβ chain but not those within the IL‐2Rγ chain. p56 lck phosphorylates tyrosine residues 355, 358 and 361 but not 338 of the IL‐2Rβ chain acidic subdomain. Interestingly, phosphorylation of Tyr‐358 appears to require the presence of either Tyr‐355 or Tyr‐361. p56 lck also phosphorylates very efficiently the two tyrosines present in the IL‐2Rβ chain C‐terminal region, Tyr‐392 and Tyr‐510. We also investigated the association of p56 lck with the IL‐2Rβ chain which was found to depend on a short stretch of the IL‐2Rβ chain acidic subdomain, and to be independent of the presence of its tyrosine residues.