A Stretch of Negatively Charged Amino Acids of Linker for Activation of T-Cell Adaptor Has a Dual Role in T-Cell Antigen Receptor Intracellular Signaling.

Arbulo-Echevarria, Mikel MNarbona-Sanchez, IsaacFernandez-Ponce, Cecilia MVico-Barranco, InmaculadaRueda-Ygueravide, Mª DoloresDustin, Michael LMiazek, ArkadiuszDuran-Ruiz, Mª CarmenGarcia-Cozar, FranciscoAguado, Enrique2023-01-252023-01-252018-01-15Arbulo-Echevarria MM, Narbona-Sánchez I, Fernandez-Ponce CM, Vico-Barranco I, Rueda-Ygueravide MD, Dustin ML, et al. A Stretch of Negatively Charged Amino Acids of Linker for Activation of T-Cell Adaptor Has a Dual Role in T-Cell Antigen Receptor Intracellular Signaling. Front Immunol. 2018 Feb 2;9:1151664-3224http://hdl.handle.net/10668/12152The adaptor protein linker for activation of T cells (LAT) has an essential role transducing activatory intracellular signals coming from the TCR/CD3 complex. Previous reports have shown that upon T-cell activation, LAT interacts with the tyrosine kinase Lck, leading to the inhibition of its kinase activity. LAT-Lck interaction seemed to depend on a stretch of negatively charged amino acids in LAT. Here, we have substituted this segment of LAT between amino acids 113 and 126 with a non-charged segment and expressed the mutant LAT (LAT-NIL) in J.CaM2 cells in order to analyze TCR signaling. Substitution of this segment in LAT prevented the activation-induced interaction with Lck. Moreover, cells expressing this mutant form of LAT showed a statistically significant increase of proximal intracellular signals such as phosphorylation of LAT in tyrosine residues 171 and 191, and also enhanced ZAP70 phosphorylation approaching borderline statistical significance (p = 0.051). Nevertheless, downstream signals such as Ca2+ influx or MAPK pathways were partially inhibited. Overall, our data reveal that LAT-Lck interaction constitutes a key element regulating proximal intracellular signals coming from the TCR/CD3 complex.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/CD3LATLckTCRSignalingAdaptor proteins, signal transducingAmino acidsCell lineHumansLymphocyte specific protein tyrosine kinase p56(lck)Membrane proteinsReceptors, antigen, T-cellZAP-70 protein-tyrosine kinaseA Stretch of Negatively Charged Amino Acids of Linker for Activation of T-Cell Adaptor Has a Dual Role in T-Cell Antigen Receptor Intracellular Signaling.research article29456532open accessAminoácidosLínea celularProteína tirosina quinasa ZAP-70Proteína tirosina quinasa p56(lck) específica de linfocitoProteínas adaptadoras transductoras de señalesProteínas de la membranaReceptores de antígenos de linfocitos T10.3389/fimmu.2018.00115PMC5801411https://www.frontiersin.org/articles/10.3389/fimmu.2018.00115/pdfhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC5801411/pdf