Quantitative phosphoproteomics reveals SLP-76 dependent regulation of PAG and Src family kinases in T cells.
The SH2-domain-containing leukocyte protein of 76 kDa (SLP-76) plays a critical scaffolding role in T cell receptor (TCR) signaling. As an adaptor protein that contains multiple protein-binding domains, SLP-76 interacts with many signaling molecules and links proximal receptor stimulation to downstream effectors. The function of SLP-76 in TCR signaling has been widely studied using the Jurkat human leukaemic T cell line through protein disruption or site-directed mutagenesis. However, a wide-scale characterization of SLP-76-dependant phosphorylation events is still lacking. Quantitative profiling of over a hundred tyrosine phosphorylation sites revealed new modes of regulation of phosphorylation of PAG, PI3K, and WASP while reconfirming previously established regulation of Itk, PLCγ, and Erk phosphorylation by SLP-76. The absence of SLP-76 also perturbed the phosphorylation of Src family kinases (SFKs) Lck and Fyn, and subsequently a large number of SFK-regulated signaling molecules. Altogether our data suggests unique modes of regulation of positive and negative feedback pathways in T cells by SLP-76, reconfirming its central role in the pathway.
Department of Chemistry, Brown University, Providence, Rhode Island, United States of America.
Lulu
L
Cao
Yiyuan
Y
Ding
Norris
N
Hung
Kebing
K
Yu
Anna
A
Ritz
Benjamin J
BJ
Raphael
Arthur R
AR
Salomon
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D020816:Amino Acid Motifs; D002460:Cell Line; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D007700:Kinetics; D008565:Membrane Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D040901:Proteomics; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000378:metabolism*; D019061:src-Family Kinases / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C498710:PAG1 protein, human; D010750:Phosphoproteins; D011948:Receptors, Antigen, T-Cell; C092947:SLP-76 signal Transducing adaptor proteins; D019061:src-Family Kinases