Journal: The Journal of Biological Chemistry
Article Title: The stress-activated kinase p38 mediates non-canonical activation of Src and tyrosine phosphorylation of the adapter protein TAB1
doi: 10.1016/j.jbc.2026.111200
Figure Lengend Snippet: Src directly phosphorylates TAB1-Y481. A , the domain structure of TAB1 and the amino acid sequence around Y481. Conserved phosphorylation serine/threonine and tyrosine sites in the C-terminal regions are highlighted in green / blue and red . B , COS-7 cells were transfected with EGFP-tagged full-length (FL), N-terminal (N), or C-terminal (C) TAB1 and Src. C , COS-7 cells were transfected with EGFP-TAB1 and Src. Dasatinib (0.1 μM) was added 1 h before cells were harvested. D , COS-7 cells were transfected with TAB1-C or its Y481F mutant (YF) and Src. Cell lysates and immunoprecipitates with an anti-GFP antibody were immunoblotted with anti-phosphotyrosine and anti-GFP antibodies. The expression of active Src was detected by an anti-phospho-Src family kinase (Y419) antibody ( B – D ). E , an in vitro kinase assay was performed using recombinant GST-TAB1-C and active GST-Src proteins. F , COS-7 cells were transfected with EGFP-TAB1 with SFKs, including Src, Fyn, Lyn, and Lck. G , HCT-116-Src cells were treated with 10 ng/ml doxycycline (Dox) for 24 h. TAB1-Y481 phosphorylation and other proteins were detected by an anti-phospho-Y481-TAB1 antibody and the antibodies described above, respectively ( E – G ). H , the relative quantification of pY481-TAB1, normalized to total TAB1, is presented as the mean ± SD from three independent experiments. p values were calculated using Welch’s two-tailed t test. ∗ p < 0.05.
Article Snippet: The recombinant human GST-TAB1-C protein (WT and Y481F) derived from Escherichia coli ( ) was reacted with the recombinant human active GST-Src kinase derived from insect cells (Carna Bioscience) at 30 °C for 30 min in 30 μl of reaction buffer containing 20 mM HEPES (pH 7.6), 20 mM MgCl 2 , 0.2 mM ATP, 2 mM DTT, 20 mM β-glycerophosphate, and 0.1 mM sodium orthovanadate.
Techniques: Sequencing, Phospho-proteomics, Transfection, Mutagenesis, Expressing, In Vitro, Kinase Assay, Recombinant, Quantitative Proteomics, Two Tailed Test