scholarly journals Modulation of RECK levels in Xenopus A6 cells: effects on MT1-MMP, MMP-2 and pERK levels

2019 ◽  
Vol 26 (1) ◽  
Author(s):  
Jessica A. Willson ◽  
Bradley S. Bork ◽  
Carlie A. Muir ◽  
Sashko Damjanovski
Keyword(s):  
Cell Migration ◽  
Cell Surface ◽  
Mammalian Cells ◽  
Mmp Inhibitors ◽  
Erk Activation ◽  
A6 Cells ◽  
A Cell ◽  
Plasmid Transfection

Abstract Background MT1-MMP is a cell-surface enzyme whose regulation of pro-MMP-2 and ERK activation position it as a key facilitator of ECM remodelling and cell migration. These processes are modulated by endogenous MMP inhibitors, such as RECK, a GPI-anchored protein which has been shown to inhibit both MT1-MMP and MMP-2 activity. Our previous studies have revealed a link between MT1-MMP levels, and pro-MMP-2 and ERK activation in mammalian cells, as well as MT1-MMP and RECK co-localization in Xenopus embryos. We here investigated how modulation of RECK would impact MT1-MMP and MMP-2 levels, as well as ERK signalling in Xenopus A6 cells. Results We used a Morpholino approach to knockdown RECK, plasmid transfection to overexpress RECK, and PI-PLC treatment to shed RECK from the cell surface of Xenopus A6 cells. RECK reduction did not alter pERK or MT1-MMP levels, nor MMP-2 activity as measured by zymography; thus RECK-knockdown cells maintained the ability to remodel the ECM. RECK overexpression and PI-PLC treatment both increased ECM remodelling potential through increased MT1-MMP protein and relative MMP-2 activation levels. Conclusions RECK changes that reduce the ability of the cell to remodel the ECM (overexpression and cell surface shedding) are compensated for by increases in MT1-MMP, and MMP-2 levels as seen by zymography.

scholarly journals Interaction of Chlamydia trachomatis with Mammalian Cells Is Independent of Host Cell Surface Heparan Sulfate Glycosaminoglycans

2006 ◽  
Vol 74 (3) ◽  
pp. 1795-1799 ◽  
Author(s):  
Richard S. Stephens ◽  
Jesse M. Poteralski ◽  
Lynn Olinger
Keyword(s):  
Chlamydia Trachomatis ◽  
Cell Surface ◽  
Heparan Sulfate ◽  
Host Cell ◽  
Cell Line ◽  
Mammalian Cells ◽  
Chlamydial Infection ◽  
Functional Role ◽  
A Cell ◽  
Host Cell Surface

ABSTRACT The hypothesis that host cell surface heparan sulfate is required to promote chlamydial infection was tested using a cell line (CHO-18.4) containing a single retroviral insertion and the concomitant loss of heparan sulfate biosynthesis. Tests of chlamydial infectivity of heparan sulfate-deficient CHO-18.4 cells and parental cells, CHO-22, demonstrated that both were equally sensitive to infection by Chlamydia trachomatis serovars L2 and D. These data do not support the hypothesis and demonstrate that host cell surface heparan sulfate does not serve an essential functional role in chlamydial infectivity.

scholarly journals Involvement of Domain 3 in Oligomerization by the Protective Antigen Moiety of Anthrax Toxin

2001 ◽  
Vol 183 (6) ◽  
pp. 2111-2116 ◽  
Author(s):  
Jeremy Mogridge ◽  
Michael Mourez ◽  
R. John Collier
Keyword(s):  
Cell Surface ◽  
Mammalian Cells ◽  
Protective Antigen ◽  
Anthrax Toxin ◽  
Membrane Insertion ◽  
A Cell ◽  
Domain 3 ◽  
Active Fragment ◽  
Cell Surface Protease ◽  
Pa Domain

ABSTRACT Protective antigen (PA), a component of anthrax toxin, binds receptors on mammalian cells and is activated by a cell surface protease. The resulting active fragment, PA63, forms ring-shaped heptamers, binds the enzymic moieties of the toxin, and translocates them to the cytosol. Of the four crystallographic domains of PA, domain 1 has been implicated in binding the enzymic moieties; domain 2 is involved in membrane insertion and oligomerization; and domain 4 binds receptor. To determine the function of domain 3, we developed a screen that allowed us to isolate random mutations that cause defects in the activity of PA. We identified several mutations in domain 3 that affect monomer-monomer interactions in the PA63 heptamer, indicating that this may be the primary function of this domain.

scholarly journals α4β1 integrin and 190-kDa CD44v constitute a cell surface docking complex for gelatinase B/MMP-9 in chronic leukemic but not in normal B cells

Blood ◽  
2008 ◽  
Vol 112 (1) ◽  
pp. 169-178 ◽  
Author(s):  
Javier Redondo-Muñoz ◽  
Estefanía Ugarte-Berzal ◽  
José A. García-Marco ◽  
Mercedes Hernández del Cerro ◽  
Philippe E. Van den Steen ◽  
...  
Keyword(s):  
Cell Migration ◽  
B Cells ◽  
Cell Surface ◽  
Lymphocytic Leukemia ◽  
Lymphoid Tissues ◽  
Gelatinase B ◽  
A Cell ◽  
Blocking Antibodies ◽  
Hemopexin Domain ◽  
Cell Chronic Lymphocytic Leukemia

Abstract As B-cell chronic lymphocytic leukemia (B-CLL) progresses, malignant cells extravasate and infiltrate lymphoid tissues. Several molecules, including gelatinase B/MMP-9, contribute to these processes. Although mainly a secreted protease, some MMP-9 is present at the B-CLL cell surface and the function, mode of anchoring, and interactions of this MMP-9 are unknown. Here we show that anti–MMP-9 antibodies immunoprecipitated a 190-kDa CD44v isoform and α4β1 integrin from B-CLL cells, but not from normal B cells. Function-blocking antibodies to α4β1 or CD44, or transfection with specific siRNAs, decreased cell-associated proMMP-9 and increased the secreted form. B-CLL cells attached to and bound proMMP-9 and active MMP-9, and this was inhibited by blocking the expression or function of α4β1 or CD44. The MMP-9 hemopexin domain was critical in these interactions. α4β1 and 190-kDa CD44v (but not CD44H) formed a complex at the cell surface, since they both coimmunoprecipitated with anti-α4, anti-β1, or anti-CD44 antibodies. Immunofluorescence analyses confirmed that α4β1 and CD44v colocalized with MMP-9. Binding of proMMP-9 inhibited B-CLL cell migration, and this required MMP-9 proteolytic activity. Thus, we have identified α4β1 and CD44v as a novel proMMP-9 cell surface docking complex and show that cell-associated MMP-9 may regulate B-CLL cell migration and arrest.

scholarly journals PSGL-1 Inhibits the Incorporation of SARS-CoV and SARS-CoV-2 Spike Glycoproteins into Pseudovirions and Impairs Pseudovirus Attachment and Infectivity

Viruses ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 46
Author(s):  
Sijia He ◽  
Abdul A. Waheed ◽  
Brian Hetrick ◽  
Deemah Dabbagh ◽  
Ivan V. Akhrymuk ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cell Surface ◽  
Immune Cells ◽  
Interferon Γ ◽  
Surface Glycoprotein ◽  
Target Cells ◽  
Cell Surface Glycoprotein ◽  
A Cell ◽  
Antiviral Activities ◽  
Hiv 1

P-selectin glycoprotein ligand-1 (PSGL-1) is a cell surface glycoprotein that binds to P-, E-, and L-selectins to mediate the tethering and rolling of immune cells on the surface of the endothelium for cell migration into inflamed tissues. PSGL-1 has been identified as an interferon-γ (INF-γ)-regulated factor that restricts HIV-1 infectivity, and has recently been found to possess broad-spectrum antiviral activities. Here we report that the expression of PSGL-1 in virus-producing cells impairs the incorporation of SARS-CoV and SARS-CoV-2 spike (S) glycoproteins into pseudovirions and blocks pseudovirus attachment and infection of target cells. These findings suggest that PSGL-1 may potentially inhibit coronavirus replication in PSGL-1+ cells

scholarly journals A knockout cell library of GPI biosynthetic genes for functional studies of GPI-anchored proteins

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Si-Si Liu ◽  
Yi-Shi Liu ◽  
Xin-Yu Guo ◽  
Yoshiko Murakami ◽  
Ganglong Yang ◽  
...  
Keyword(s):  
Cell Surface ◽  
Intracellular Trafficking ◽  
Mammalian Cells ◽  
Surface Expression ◽  
Human Embryonic Kidney ◽  
Functional Studies ◽  
Cell Library ◽  
Biological Phenomena ◽  
293 Cells ◽  
A Cell

AbstractOver 100 kinds of proteins are expressed as glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) on the cell surface in mammalian cells. GPI-APs possess unique properties in terms of their intracellular trafficking and association with lipid rafts. Although it is clear that GPI-APs play critical roles in various biological phenomena, it is poorly understood how the GPI moiety contributes to these mechanisms. More than 30 genes are involved in the correct biosynthesis of GPI-APs. We here constructed a cell library in which 32 genes involved in GPI biosynthesis were knocked out in human embryonic kidney 293 cells. Using the cell library, the surface expression and sensitivity to phosphatidylinositol-specific phospholipase C of GPI-APs were analyzed. Furthermore, we identified structural motifs of GPIs that are recognized by a GPI-binding toxin, aerolysin. The cell-based GPI-knockout library could be applied not only to basic researches, but also to applications and methodologies related to GPI-APs.

scholarly journals Identification of the atypical cadherin FAT1 as a novel glypican-3 interacting protein in liver cancer cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Panpan Meng ◽  
Yi-Fan Zhang ◽  
Wangli Zhang ◽  
Xin Chen ◽  
Tong Xu ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cell Surface ◽  
Transmembrane Protein ◽  
Tyrosine Phosphatase ◽  
Interacting Protein ◽  
Extracellular Signaling ◽  
Putative Receptor ◽  
Elevated Expression ◽  
A Cell ◽  
Receptor Tyrosine Phosphatase

AbstractGlypican-3 (GPC3) is a cell surface heparan sulfate proteoglycan that is being evaluated as an emerging therapeutic target in hepatocellular carcinoma (HCC). GPC3 has been shown to interact with several extracellular signaling molecules, including Wnt, HGF, and Hedgehog. Here, we reported a cell surface transmembrane protein (FAT1) as a new GPC3 interacting protein. The GPC3 binding region on FAT1 was initially mapped to the C-terminal region (Q14517, residues 3662-4181), which covered a putative receptor tyrosine phosphatase (RTP)-like domain, a Laminin G-like domain, and five EGF-like domains. Fine mapping by ELISA and flow cytometry showed that the last four EGF-like domains (residues 4013-4181) contained a specific GPC3 binding site, whereas the RTP domain (residues 3662-3788) and the downstream Laminin G-2nd EGF-like region (residues 3829-4050) had non-specific GPC3 binding. In support of their interaction, GPC3 and FAT1 behaved concomitantly or at a similar pattern, e.g. having elevated expression in HCC cells, being up-regulated under hypoxia conditions, and being able to regulate the expression of EMT-related genes Snail, Vimentin, and E-Cadherin and promoting HCC cell migration. Taken together, our study provides the initial evidence for the novel mechanism of GPC3 and FAT1 in promoting HCC cell migration.

scholarly journals EWI-2 regulates α3β1 integrin–dependent cell functions on laminin-5

2003 ◽  
Vol 163 (5) ◽  
pp. 1167-1177 ◽  
Author(s):  
Christopher S. Stipp ◽  
Tatiana V. Kolesnikova ◽  
Martin E. Hemler
Keyword(s):  
Cell Migration ◽  
Complex Formation ◽  
Cell Surface ◽  
Laminin 5 ◽  
Cell Functions ◽  
Α3β1 Integrin ◽  
Surface Localization ◽  
Dependent Cell ◽  
A Cell ◽  
Integrin Ligand

EWI-2, a cell surface immunoglobulin SF protein of unknown function, associates with tetraspanins CD9 and CD81 with high stoichiometry. Overexpression of EWI-2 in A431 epidermoid carcinoma cells did not alter cell adhesion or spreading on laminin-5, and had no effect on reaggregation of cells plated on collagen I (α2β1 integrin ligand). However, on laminin-5 (α3β1 integrin ligand), A431 cell reaggregation and motility functions were markedly impaired. Immunodepletion and reexpression experiments revealed that tetraspanins CD9 and CD81 physically link EWI-2 to α3β1 integrin, but not to other integrins. CD81 also controlled EWI-2 maturation and cell surface localization. EWI-2 overexpression not only suppressed cell migration, but also redirected CD81 to cell filopodia and enhanced α3β1–CD81 complex formation. In contrast, an EWI-2 chimeric mutant failed to suppress cell migration, redirect CD81 to filopodia, or enhance α3β1–CD81 complex formation. These results show how laterally associated EWI-2 might regulate α3β1 function in disease and development, and demonstrate how tetraspanin proteins can assemble multiple nontetraspanin proteins into functional complexes.

scholarly journals Mitogenesis, cell migration, and loss of focal adhesions induced by tenascin-C interacting with its cell surface receptor, annexin II.

1996 ◽  
Vol 7 (6) ◽  
pp. 883-892 ◽  
Author(s):  
C Y Chung ◽  
J E Murphy-Ullrich ◽  
H P Erickson
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Cell Surface ◽  
Focal Adhesions ◽  
Cell Surface Receptor ◽  
Annexin Ii ◽  
Tenascin C ◽  
Subsequent Response ◽  
Surface Receptor ◽  
A Cell

In a previous study we demonstrated that the alternatively spliced region of tenascin-C, TNfnA-D, bound with high affinity to a cell surface receptor, annexin II. In the present study we demonstrate three changes in cellular activity that are produced by adding intact tenascin-C or TNfnA-D to cells, and we show that all three activities are blocked by antibodies against annexin II. 1) TNfnA-D added to confluent endothelial cells induced loss of focal adhesions. 2) TNfnA-D produced a mitogenic response of confluent, growth-arrested endothelial cells in 1% serum. TNfnA-D stimulated mitogenesis only when it was added to cells before or during exposure to other mitogens, such as basic fibroblast growth factor or serum. Thus the effect of TNfnA-D seems to be to facilitate the subsequent response to growth factors. 3) TNfnA-D enhanced cell migration in a cell culture wound assay. Antibodies to annexin II blocked all three cellular responses to TNfnA-D. These data show that annexin II receptors on endothelial cells mediate several cell regulatory functions attributed to tenascin-C, potentially through modulation of intracellular signalling pathways.

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