scholarly journals An unexpected 2-histidine phosphoesterase activity of suppressor of T-cell receptor signaling protein 1 contributes to the suppression of cell signaling

2020 ◽  
Vol 295 (25) ◽  
pp. 8514-8523
Author(s):  
Yue Yin ◽  
David Frank ◽  
Weijie Zhou ◽  
Neena Kaur ◽  
Jarrod B. French ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
T Cell ◽  
Cell Signaling ◽  
Signaling Pathways ◽  
T Cell Receptor ◽  
Critical Role ◽  
Cell Receptor ◽  
Specific Cell ◽  
Phosphatase Domain ◽  
Cyclic Phosphate

The suppressor of T-cell receptor (TCR) signaling (Sts) proteins Sts-1 and Sts-2 suppress receptor-mediated signaling pathways in various immune cells, including the TCR pathway in T cells and the Dectin-1 signaling pathway in phagocytes. As multidomain enzymes, they contain an N-terminal ubiquitin-association domain, a central Src homology 3 domain, and a C-terminal histidine phosphatase domain. Recently, a 2-histidine (2H) phosphoesterase motif was identified within the N-terminal portion of Sts. The 2H phosphoesterase motif defines an evolutionarily ancient protein domain present in several enzymes that hydrolyze cyclic phosphate bonds on different substrates, including cyclic nucleotides. It is characterized by two invariant histidine residues that play a critical role in catalytic activity. Consistent with its assignment as a phosphoesterase, we demonstrate here that the Sts-1 2H phosphoesterase domain displays catalytic, saturable phosphodiesterase activity toward the dinucleotide 2′,3′-cyclic NADP. The enzyme exhibited a high degree of substrate specificity and selectively generated the 3′-nucleotide as the sole product. Sts-1 also had phosphodiesterase catalytic activity toward a 5-mer RNA oligonucleotide containing a 2′,3′-cyclic phosphate group at its 3′ terminus. To investigate the functional significance of Sts-1 2H phosphoesterase activity, we generated His-to-Ala variants and examined their ability to negatively regulate cellular signaling pathways. Substitution of either conserved histidine compromised the ability of Sts-1 to suppress signaling pathways downstream of both the TCR and the Dectin-1 receptor. Our results identify a heretofore unknown cellular enzyme activity associated with Sts-1 and indicate that this catalytic activity is linked to specific cell-signaling outcomes.

scholarly journals Large-scale proteomic analysis of tyrosine-phosphorylation induced by T-cell receptor or B-cell receptor activation reveals new signaling pathways

PROTEOMICS ◽  
2009 ◽  
Vol 9 (13) ◽  
pp. 3549-3563 ◽  
Author(s):  
Masaki Matsumoto ◽  
Koji Oyamada ◽  
Hidehisa Takahashi ◽  
Takamichi Sato ◽  
Shigetsugu Hatakeyama ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Signaling Pathways ◽  
Tyrosine Phosphorylation ◽  
T Cell Receptor ◽  
Proteomic Analysis ◽  
Large Scale ◽  
Cell Receptor ◽  
Receptor Activation ◽  
B Cell Receptor

scholarly journals T cell receptor for antigen induces linker for activation of T cell–dependent activation of a negative signaling complex involving Dok-2, SHIP-1, and Grb-2

2006 ◽  
Vol 203 (11) ◽  
pp. 2509-2518 ◽  
Author(s):  
Shen Dong ◽  
Béatrice Corre ◽  
Eliane Foulon ◽  
Evelyne Dufour ◽  
André Veillette ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Critical Role ◽  
Adaptor Proteins ◽  
Cell Receptor ◽  
Negative Control ◽  
Inositol Polyphosphate ◽  
Tcr Signaling ◽  
Signaling Complex ◽  
Src Homology 2 Domain

Adaptor proteins positively or negatively regulate the T cell receptor for antigen (TCR) signaling cascade. We report that after TCR stimulation, the inhibitory adaptor downstream of kinase (Dok)-2 and its homologue Dok-1 are involved in a multimolecular complex including the lipid phosphatase Src homology 2 domain–containing inositol polyphosphate 5′-phosphatase (SHIP)-1 and Grb-2 which interacts with the membrane signaling scaffold linker for activation of T cells (LAT). Knockdown of LAT and SHIP-1 expression indicated that SHIP-1 favored recruitment of Dok-2 to LAT. Knockdown of Dok-2 and Dok-1 revealed their negative control on Akt and, unexpectedly, on Zap-70 activation. Our findings support the view that Dok-1 and -2 are critical elements of a LAT-dependent negative feedback loop that attenuates early TCR signal. Dok-1 and -2 may therefore exert a critical role in shaping the immune response and as gatekeepers for T cell tolerance.

Canonical T cell receptor docking on peptide–MHC is essential for T cell signaling

Science ◽  
2021 ◽  
Vol 372 (6546) ◽  
pp. eabe9124
Author(s):  
Pirooz Zareie ◽  
Christopher Szeto ◽  
Carine Farenc ◽  
Sachith D. Gunasinghe ◽  
Elizabeth M. Kolawole ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Signaling ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Cell Activation ◽  
Direct Consequence ◽  
Cell Receptor ◽  
T Cell Signaling ◽  
Cell Repertoire

T cell receptor (TCR) recognition of peptide–major histocompatibility complexes (pMHCs) is characterized by a highly conserved docking polarity. Whether this polarity is driven by recognition or signaling constraints remains unclear. Using “reversed-docking” TCRβ-variable (TRBV) 17+ TCRs from the naïve mouse CD8+ T cell repertoire that recognizes the H-2Db–NP366 epitope, we demonstrate that their inability to support T cell activation and in vivo recruitment is a direct consequence of reversed docking polarity and not TCR–pMHCI binding or clustering characteristics. Canonical TCR–pMHCI docking optimally localizes CD8/Lck to the CD3 complex, which is prevented by reversed TCR–pMHCI polarity. The requirement for canonical docking was circumvented by dissociating Lck from CD8. Thus, the consensus TCR–pMHC docking topology is mandated by T cell signaling constraints.

scholarly journals Leukocyte-associated immunoglobulin-like receptor 1 inhibits T-cell signaling by decreasing protein phosphorylation in the T-cell signaling pathway

2020 ◽  
Vol 295 (8) ◽  
pp. 2239-2247 ◽  
Author(s):  
Jeoung-Eun Park ◽  
David D. Brand ◽  
Edward F. Rosloniec ◽  
Ae-Kyung Yi ◽  
John M. Stuart ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tyrosine Kinase ◽  
Cell Signaling ◽  
Signaling Pathway ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
T Cell Signaling ◽  
Tcr Signaling ◽  
Cell Signaling Pathway

Multiple observations implicate T-cell dysregulation as a central event in the pathogenesis of rheumatoid arthritis. Here, we investigated mechanisms for suppressing T-cell activation via the inhibitory receptor leukocyte-associated immunoglobulin-like receptor 1 (LAIR-1). To determine how LAIR-1 affects T-cell receptor (TCR) signaling, we compared 1) T cells from LAIR-1–sufficient and –deficient mice, 2) Jurkat cells expressing either LAIR-1 mutants or C-terminal Src kinase (CSK) mutants, and 3) T cells from mice that contain a CSK transgene susceptible to chemical inhibition. Our results indicated that LAIR-1 engagement by collagen or by complement C1q (C1Q, which contains a collagen-like domain) inhibits TCR signaling by decreasing the phosphorylation of key components in the canonical T-cell signaling pathway, including LCK proto-oncogene SRC family tyrosine kinase (LCK), LYN proto-oncogene SRC family tyrosine kinase (LYN), ζ chain of T-cell receptor–associated protein kinase 70 (ZAP-70), and three mitogen-activated protein kinases (extracellular signal–regulated kinase, c-Jun N-terminal kinase 1/2, and p38). The intracellular region of LAIR-1 contains two immunoreceptor tyrosine-based inhibition motifs that are both phosphorylated by LAIR-1 activation, and immunoprecipitation experiments revealed that Tyr-251 in LAIR-1 binds CSK. Using CRISPR/Cas9-mediated genome editing, we demonstrate that CSK is essential for the LAIR-1–induced inhibition of the human TCR signal transduction. T cells from mice that expressed a PP1 analog–sensitive form of CSK (CskAS) corroborated these findings, and we also found that Tyr-251 is critical for LAIR-1's inhibitory function. We propose that LAIR-1 activation may be a strategy for controlling inflammation and may offer a potential therapeutic approach for managing autoimmune diseases.

scholarly journals Effect of Redox Balance Alterations on Cellular Localization of LAT and Downstream T-Cell Receptor Signaling Pathways

2002 ◽  
Vol 22 (2) ◽  
pp. 400-411 ◽  
Author(s):  
Sonja I. Gringhuis ◽  
Ellen A. M. Papendrecht-van der Voort ◽  
Angela Leow ◽  
E. W. Nivine Levarht ◽  
Ferdinand C. Breedveld ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
T Cell ◽  
T Lymphocytes ◽  
Signaling Pathways ◽  
T Cell Receptor ◽  
Cellular Localization ◽  
Redox Balance ◽  
Cell Receptor ◽  
Chronic Oxidative Stress ◽  
Membrane Displacement

ABSTRACT The integral membrane protein linker for activation of T cells (LAT) is a central adapter protein in the T-cell receptor (TCR)-mediated signaling pathways. The cellular localization of LAT is extremely sensitive to intracellular redox balance alterations. Reduced intracellular levels of the antioxidant glutathione (GSH), a hallmark of chronic oxidative stress, resulted in the membrane displacement of LAT, abrogated TCR-mediated signaling and consequently hyporesponsiveness of T lymphocytes. The membrane displacement of LAT is accompanied by a considerable difference in the mobility of LAT upon native and nonreducing denaturing polyacrylamide gel electrophoresis analysis, a finding indicative of a conformational change. Targeted mutation of redox-sensitive cysteine residues within LAT created LAT mutants which remain membrane anchored under conditions of chronic oxidative stress. The expression of redox-insensitive LAT mutants allows for restoration of TCR-mediated signal transduction, whereas CD28-mediated signaling pathways remained impaired. These results are indicative that the membrane displacement of LAT as a result of redox balance alterations is a consequence of a conformational change interfering with the insertion of LAT into the plasma membrane. Conclusively, the data suggest a role for LAT as a crucial intermediate in the sensitivity of TCR signaling and hence T lymphocytes toward chronic oxidative stress.

scholarly journals A role for interleukin 4 in the differentiation of mature T cell receptor gamma/delta + cells from human intrathymic T cell precursors.

1990 ◽  
Vol 172 (2) ◽  
pp. 439-446 ◽  
Author(s):  
A Bárcena ◽  
M L Toribio ◽  
L Pezzi ◽  
C Martínez
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Critical Role ◽  
Cell Receptor ◽  
Interleukin 4 ◽  
Gamma Delta ◽  
Consistent Finding ◽  
Delta Cells ◽  
Gamma Delta Cells

We have analyzed the effect of human recombinant interleukin 4 (rIL-4) on the growth and differentiation of human intrathymic pre-T cells (CD7+2+1-3-4-8-). We describe that this population of T cell precursors proliferates in response to rIL-4 (in the absence of mitogens or other stimulatory signals) in a dose-dependent way. The IL-4-induced proliferation is independent of the IL-2 pathway, as it cannot be inhibited with an anti-IL-2 receptor alpha chain antibody. In our culture conditions, rIL-4 also promotes the differentiation of pre-T cells into phenotypically mature T cells. Although both CD3/T cell receptor (TCR)-alpha/beta + and CD3-gamma/delta + T cells were obtained, the preferential differentiation into TCR-gamma/delta + cells was a consistent finding. These results suggest that, in addition to IL-2, IL-4 plays a critical role in promoting growth and differentiation of intrathymic T cell precursors at early stages of T cell development.

Sign in / Sign up

Export Citation Format

Share Document