Lck is required for stromal cell–derived factor 1α (CXCL12)–induced lymphoid cell chemotaxis

Blood ◽  
2002 ◽  
Vol 99 (12) ◽  
pp. 4318-4325 ◽  
Author(s):  
Marit Inngjerdingen ◽  
Knut Martin Torgersen ◽  
Azzam A. Maghazachi
Keyword(s):  
Nk Cells ◽  
Cell Line ◽  
Tyrosine Kinases ◽  
Stromal Cell ◽  
Wild Type ◽  
Src Homology 2 ◽  
Jurkat T Cell ◽  
Src Homology ◽  
Syk Inhibitor ◽  
Stromal Cell Derived Factor

Stromal cell–derived factor 1α (CXCL12) induces chemotaxis of lymphocytes through its receptor CXCR4. We examined the role of nonreceptor tyrosine kinases in CXCL12-induced chemotaxis of T cells and natural killer (NK) cells. Damnacanthal, a specific Lck inhibitor, but not the Syk inhibitor piceatannol, inhibited CXCL12-induced chemotaxis of both lymphocyte subsets. Similarly, damnacanthal was shown to inhibit CXCL12-induced chemotaxis of the Jurkat T-cell line. Stimulating T and NK cells with CXCL12 increased both the tyrosine phosphorylation and the kinase activity of Lck. A direct involvement of Lck in CXCL12-induced chemotaxis was demonstrated in the Lck-deficient Jurkat-derived cell line JCaM1.6. Although JCaM1.6 cells express CXCR4, no significant migration was detected after CXCL12 stimulation. Reconstitution with wild-type Lck restored both CXCL12-induced chemotaxis and Lck activation. Furthermore, cotransfection of wild-type Lck with C-terminal Src kinase (Csk) into JCaM1.6 failed to restore the chemotactic response induced by CXCL12. Finally, by targeting critical residues in the Src homology–2 (SH2) or SH3 domains of Lck, we observed that the SH3 domain is important for the function of Lck in CXCL12-mediated chemotaxis. Together, these results suggest a role for Lck in CXCL12-induced signaling pathways leading to lymphocyte chemotaxis.

scholarly journals T-Cell-Line-Tropic Human Immunodeficiency Virus Type 1 That Is Made Resistant to Stromal Cell-Derived Factor 1α Contains Mutations in the Envelope gp120 but Does Not Show a Switch in Coreceptor Use

1998 ◽  
Vol 72 (5) ◽  
pp. 4032-4037 ◽  
Author(s):  
Dominique Schols ◽  
José A. Esté ◽  
Cecilia Cabrera ◽  
Erik De Clercq
Keyword(s):  
T Cell ◽  
Cell Line ◽  
Stromal Cell ◽  
Wild Type Virus ◽  
Type Virus ◽  
Resistant Virus ◽  
Wild Type ◽  
Immunodeficiency Virus ◽  
Stromal Cell Derived Factor

ABSTRACT The NL4.3 T-cell-line-tropic human immunodeficiency virus type 1 strain is sensitive to the CXC chemokine stromal cell-derived factor 1α (SDF-1α), the natural ligand for CXC chemokine receptor 4 (CXCR4); the 50% inhibitory concentration (IC50) in MT-4 cells is 130 ng/ml. We generated resistant virus through passaging of the virus in the presence of increasing concentrations of SDF-1α. After 24 passages, the virus was no longer sensitive to SDF-1α (SDF-1αres virus) (IC50, >2 μg/ml) and became resistant to SDF-1β (IC50, >2 μg/ml) and to a specific CXCR4 monoclonal antibody (IC50, >20 μg/ml). The SDF-1αres virus was about 10-fold less sensitive than the wild-type virus to the bicyclam AMD3100, a specific CXCR4 antagonist. The SDF-1αres virus contained the following mutations in the gp120 molecule: N106K in the V1 loop; S134N and F145L in the V2 loop; F245I in the C2 loop; K269E, Q278H, I288V, and N293D in the V3 loop; a deletion of 5 amino acids (FNSTW) at positions 364 to 368 in the V4 loop; and R378T in the CD4 binding domain. Replication of the NL4.3 wild-type virus and the SDF-1αres virus was demonstrated in U87 cells that coexpressed CD4 and CXCR4 (U87.CD4.CXCR4) but not in U87.CD4.CCR5 cells. Thus, the resistant virus was not able to switch to the CC chemokine receptor 5 (CCR5) coreceptor (the main coreceptor for macrophage-tropic viruses). The SDF-1αres virus replicated in HOS.CD4 cells expressing CCR1, CCR2b, CCR3, CCR4, CCR5, and CXCR4 but also in HOS.CD4.pBABE cells. However, all HOS transfectant cells expressed a low level of CXCR4. Neither of the two virus strains was able to infect HOS.CXCR4 or HOS.CCR5 transfectants, demonstrating the necessity of the CD4 receptor. The T-cell-line-tropic SDF-1αres virus was thus able to overcome the inhibitory effect of SDF-1α through mutations in gp120 but still needed CXCR4 to enter the cells.

scholarly journals The inositol 5-phosphatase SHIP2 is an effector of RhoA and is involved in cell polarity and migration

2012 ◽  
Vol 23 (13) ◽  
pp. 2593-2604 ◽  
Author(s):  
Katsuhiro Kato ◽  
Tsubasa Yazawa ◽  
Kentaro Taki ◽  
Kazutaka Mori ◽  
Shujie Wang ◽  
...  
Keyword(s):  
Small Gtpases ◽  
Cell Polarization ◽  
Dependent Manner ◽  
Wild Type ◽  
Functional Interaction ◽  
Src Homology 2 ◽  
Motile Cells ◽  
Lipid Turnover ◽  
Src Homology ◽  
And Migration

Cell migration is essential for various physiological and pathological processes. Polarization in motile cells requires the coordination of several key signaling molecules, including RhoA small GTPases and phosphoinositides. Although RhoA participates in a front–rear polarization in migrating cells, little is known about the functional interaction between RhoA and lipid turnover. We find here that src-homology 2–containing inositol-5-phosphatase 2 (SHIP2) interacts with RhoA in a GTP-dependent manner. The association between SHIP2 and RhoA is observed in spreading and migrating U251 glioma cells. The depletion of SHIP2 attenuates cell polarization and migration, which is rescued by wild-type SHIP2 but not by a mutant defective in RhoA binding. In addition, the depletion of SHIP2 impairs the proper localization of phosphatidylinositol 3,4,5-trisphosphate, which is not restored by a mutant defective in RhoA binding. These results suggest that RhoA associates with SHIP2 to regulate cell polarization and migration.

SRC-homology 2 domain-containing phosphatase 2 (SHP2) in epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma (LUAD).

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 9540-9540
Author(s):  
Rafael Rosell ◽  
Masaoki Ito ◽  
Jordi Codony-Servat ◽  
Ana Giménez-Capitán ◽  
Mireia Serra-Mitjans ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Mrna Expression ◽  
Mrna Levels ◽  
Wild Type ◽  
Src Homology 2 ◽  
Src Homology ◽  
Epidermal Growth ◽  
Src Homology 2 Domain ◽  
Egfr Mutant

9540 Background: Epidermal growth factor (EGFR)-mutant lung adenocarcinomas (LUADs) display impaired phosphorylation of extracellular signal-regulated kinase (ERK) and SRC-homology 2 domain-containing phosphatase 2 (SHP2) in comparison with EGFR wild-type LUADs. However, the function of SHP2 in early EGFR-mutant LUADs and EGFR wild-type LUADs has not been reported. We posit that SHP2 mRNA expression could be a predictive marker in resected EGFR-mutant LUADs versus EGFR wild-type patients (pts). Methods: We examined 267 resected LUADs from Japan and Spain. mRNA expression levels of AXL, MET, CDCP1, STAT3, YAP1 and SHP2 were analyzed by quantitative reverse transcriptase polymerase chain reaction (PCR). EGFR mutant cell lines were investigated for their activity of SHP2. Results: Among the 267 enrolled pts, 100 (37.3%) were EGFR-mutant LUADs. Five-year recurrence-free survival (RFS) and overall survival (OS) were lower for EGFR-mutant LUADs with high SHP2 mRNA levels (hazard ratio = 1.83 and 2.28, respectively. p = 0.03 and p = 0.04). However, SHP2 was not associated with RFS nor OS in the 167 wild-type EGFR LUADs. In EGFR-mutant cells, RMC-4550 (SHP2 inhibitor) plus erlotinib showed synergism via inhibition of AKT (S473) and ERK1/2 (T202/Y204). While erlotinib translocates SHP2 (Y542) into the nucleus, either RMC-4550 alone, or in combination with erlotinib, relocalizes SHP2 into the cytoplasm membrane, limiting AKT and ERK activation. Conclusions: High SHP2 mRNA is related to shorter RFS and OS in EGFR-mutant LUADs, but not in EGFR wild-type LUADs. The findings indicate that the addition of SHP2 inhibitors could improve adjuvant therapy in EGFR-mutant LUADs.

scholarly journals Structural Basis and Functional Consequence of Helicobacter pylori CagA Multimerization in Cells

2006 ◽  
Vol 281 (43) ◽  
pp. 32344-32352 ◽  
Author(s):  
Shumei Ren ◽  
Hideaki Higashi ◽  
Huaisheng Lu ◽  
Takeshi Azuma ◽  
Masanori Hatakeyama
Keyword(s):  
Helicobacter Pylori ◽  
Tyrosine Phosphorylation ◽  
Cell Shape ◽  
Host Cells ◽  
Structural Basis ◽  
Sequence Motif ◽  
Wild Type ◽  
Src Homology 2 ◽  
Src Homology ◽  
In Cells

Helicobacter pylori cagA-positive strains are associated with gastric adenocarcinoma. The cagA gene product CagA is delivered into gastric epithelial cells where it localizes to the plasma membrane and undergoes tyrosine phosphorylation at the EPIYA-repeat region, which contains the EPIYA-A segment, EPIYA-B segment, and Western CagA-specific EPIYA-C or East Asian CagA-specific EPIYA-D segment. In host cells, CagA specifically binds to and deregulates SHP-2 phosphatase via the tyrosine-phosphorylated EPIYA-C or EPIYA-D segment, thereby inducing an elongated cell shape known as the hummingbird phenotype. In this study, we found that CagA multimerizes in cells in a manner independent of its tyrosine phosphorylation. Using a series of CagA mutants, we identified a conserved amino acid sequence motif (FPLXRXXXVXDLSKVG), which mediates CagA multimerization, within the EPIYA-C segment as well as in a sequence that located immediately downstream of the EPIYA-C or EPIYA-D segment. We also found that a phosphorylation-resistant CagA, which multimerizes but cannot bind SHP-2, inhibits the wild-type CagA-SHP-2 complex formation and abolishes induction of the hummingbird phenotype. Thus, SHP-2 binds to a preformed and tyrosinephosphorylated CagA multimer via its two Src homology 2 domains. These results, in turn, indicate that CagA multimerization is a prerequisite for CagA-SHP-2 interaction and subsequent deregulation of SHP-2. The present work raises the possibility that inhibition of CagA multimerization abolishes pathophysiological activities of CagA that promote gastric carcinogenesis.

Regulation of class IA PI3Ks

2007 ◽  
Vol 35 (2) ◽  
pp. 242-244 ◽  
Author(s):  
H. Wu ◽  
Y. Yan ◽  
J.M. Backer
Keyword(s):  
Tyrosine Kinases ◽  
Regulatory Subunit ◽  
Sh2 Domains ◽  
Src Homology 2 ◽  
Pi3k Activity ◽  
Wide Range ◽  
Rho Family Gtpases ◽  
Src Homology ◽  
Rho Family

Class IA PI3Ks (phosphoinositide 3-kinases) regulate a wide range of cellular responses through the production of PI(3,4,5)P3 (phosphatidylinositol 3,4,5-trisphosphate) in cellular membranes. They are activated by receptor tyrosine kinases, by Ras and Rho family GTPases, and in some cases by Gβγ subunits from trimeric G-proteins. Crystallographic studies on the related class IB PI3Kγ, and biochemical and structural studies on the class IA PI3Ks, have led to new insights into how these critical enzymes are regulated in normal cells and how mutations can lead to their constitutive activation in transformed cells. The present paper will discuss recent studies on the regulation of class I (p85/p110) PI3Ks, with a focus on the role of SH2 domains (Src homology 2 domains) in the p85 regulatory subunit in modulating PI3K activity.

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