title: Quantitative phosphoproteome analysis unveils LAT as a modulator of CD3ζ and ZAP-70 tyrosine phosphorylation.
abstract: Signaling through the T cell receptor (TCR) initiates adaptive immunity and its perturbation may results in autoimmunity. The plasma membrane scaffolding protein LAT acts as a central organizer of the TCR signaling machinery to activate many functional pathways. LAT-deficient mice develop an autoimmune syndrome but the mechanism of this pathology is unknown. In this work we have compared global dynamics of TCR signaling by MS-based quantitative phosphoproteomics in LAT-sufficient and LAT-defective Jurkat T cells. Surprisingly, we found that many TCR-induced phosphorylation events persist in the absence of LAT, despite ERK and PLCγ1 phosphorylation being repressed. Most importantly, the absence of LAT resulted in augmented and persistent tyrosine phosphorylation of CD3ζ and ZAP70. This indicates that LAT signaling hub is also implicated in negative feedback signals to modulate upstream phosphorylation events. Phosphorylation kinetics data resulting from this investigation is documented in a database (phosphoTCR) accessible online. The MS data have been deposited to the ProteomeXchange with identifier PXD000341.
authors.affiliation: T cell Signaling Laboratory, Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom.
authors.forename: Mogjiborahman
authors.initials: M
authors.lastname: Salek
authors.forename: Simon
authors.initials: S
authors.lastname: McGowan
authors.forename: David C
authors.initials: DC
authors.lastname: Trudgian
authors.forename: Omer
authors.initials: O
authors.lastname: Dushek
authors.forename: Ben
authors.initials: B
authors.lastname: de Wet
authors.forename: Georgios
authors.initials: G
authors.lastname: Efstathiou
authors.forename: Oreste
authors.initials: O
authors.lastname: Acuto
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000172:deficiency / Q000235:genetics*; D017252:CD3 Complex / Q000235:genetics* / Q000378:metabolism; D002853:Chromatography, Liquid; D030562:Databases, Protein; D025461:Feedback, Physiological; D005786:Gene Expression Regulation; D006801:Humans; D019169:Jurkat Cells; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000172:deficiency / Q000235:genetics*; D051966:Phospholipase C gamma / Q000235:genetics / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D010766:Phosphorylation; D025941:Protein Interaction Mapping; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics*; D014443:Tyrosine / Q000378:metabolism; D051746:ZAP-70 Protein-Tyrosine Kinase / Q000235:genetics* / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D017252:CD3 Complex; C121704:CD3 antigen, zeta chain; C110810:LAT protein, human; D008565:Membrane Proteins; D010750:Phosphoproteins; D011948:Receptors, Antigen, T-Cell; D014443:Tyrosine; D051746:ZAP-70 Protein-Tyrosine Kinase; C497261:ZAP70 protein, human; D051966:Phospholipase C gamma