Porcine Arterivirus Entry in Macrophages: Heparan Sulfate – Mediated Attachment, Sialoadhesin-Mediated Internalization, and a Cell-Specific Factor Mediating Virus Disassembly and Genome Release

We show that expression in fibroblasts of a single cDNA, encoding the erythroid DNA-binding protein Eryf1 (GF-1, NF-E1), very efficiently activates transcription of a chicken alpha-globin promoter, trans-Activation in these cells occurred when Eryf1 bound to a single site within a minimal globin promoter. In contrast, efficient activation in erythroid cells required multiple Eryf1 binding sites. Our results indicate that mechanisms exist that are capable of modulating the trans-acting capabilities of Eryf1 in a cell-specific manner, without affecting DNA binding. The response of the minimal globin promoter to Eryf1 in fibroblasts was at least as great as for optimal constructions in erythroid cells. Therefore, the assay provides a very simple and sensitive system with which to study gene activation by a tissue-specific factor.

Download Full-text

A cell-specific factor represses stimulation of transcription in vitro by transcriptional enhancer factor 1

Molecular and Cellular Biology ◽

10.1128/mcb.14.8.5290-5299.1994 ◽

1994 ◽

Vol 14 (8) ◽

pp. 5290-5299

Author(s):

S Chaudhary ◽

C Brou ◽

M E Valentin ◽

N Burton ◽

L Tora ◽

...

Keyword(s):

Hela Cell ◽

Binding Protein ◽

Activation Function ◽

Tata Binding Protein ◽

Lymphoid Cells ◽

Specific Factor ◽

Transcriptional Enhancer ◽

Cell Extracts ◽

A Cell

Transcription in HeLa cell extracts in vitro was stimulated 8- to 10-fold by a recombinant chimera, GAL-TEF-1, consisting of the DNA-binding domain of GAL4 and the activation function of the HeLa cell activator TEF-1. In contrast, only a 2- to 3-fold stimulation was obtained with GAL-TEF-1 in extracts from BJA-B lymphoid cells. Stimulation by GAL-TEF-1 in BJA-B extracts was dramatically increased by the addition of immunopurified HeLa cell TFIID, suggesting that BJA-B TFIID lacks or contains lower quantities of a TATA-binding-protein-associated factor(s) required for the activity of the TEF-1 activation function. However, chromatography, immunopurification, and transcriptional reconstitution experiments indicated that BJA-B extracts did not lack the previously identified TATA-binding-protein-associated factors required for TEF-1 activity but rather contained a negatively acting factor(s) which inhibited transactivation by GAL-TEF-1. These results indicate that the relative lack of activity of the TEF-1 activation function in vitro in BJA-B cell extracts does not result from the absence of positively acting factors from the presence of a cell-specific negatively acting factor(s).

Download Full-text

A cell-surface heparan sulfate proteoglycan mediates neural cell adhesion and spreading on a defined sequence from the C-terminal cell and heparin binding domain of fibronectin, FN-C/H II

Journal of Neuroscience ◽

10.1523/jneurosci.12-07-02597.1992 ◽

1992 ◽

Vol 12 (7) ◽

pp. 2597-2608 ◽

Cited By ~ 29

Author(s):

PK Haugen ◽

PC Letourneau ◽

SL Drake ◽

LT Furcht ◽

JB McCarthy

Keyword(s):

Cell Adhesion ◽

Cell Surface ◽

Heparan Sulfate ◽

Heparan Sulfate Proteoglycan ◽

Neural Cell ◽

Sulfate Proteoglycan ◽

Heparin Binding ◽

Neural Cell Adhesion ◽

Heparin Binding Domain ◽

A Cell

Download Full-text

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

Infection and Immunity ◽

10.1128/iai.74.3.1795-1799.2006 ◽

2006 ◽

Vol 74 (3) ◽

pp. 1795-1799 ◽

Cited By ~ 16

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.

Download Full-text

A cell type specific factor recognizes the rat thyroglobulin promoter

Nucleic Acids Research ◽

10.1093/nar/15.20.8149 ◽

1987 ◽

Vol 15 (20) ◽

pp. 8149-8166 ◽

Cited By ~ 55

Author(s):

Anna Maria Musti ◽

Valeria Matilde Ursini ◽

Enrico Vittorio Avvedimento ◽

Vincenzo Zimarino ◽

Roberto Di Lauro

Keyword(s):

Specific Factor ◽

Cell Type ◽

A Cell ◽

Cell Type Specific

Download Full-text

Heparan sulfate of AH-130 ascites hepatoma cells: a cell-surface glycosaminoglycan not displaced by heparin.

Journal of Histochemistry & Cytochemistry ◽

10.1177/29.6.6166666 ◽

1981 ◽

Vol 29 (6) ◽

pp. 731-737 ◽

Cited By ~ 11

Author(s):

R E Hurst ◽

R T Parmley ◽

N Nakamura ◽

S S West ◽

F R Denys

Keyword(s):

Cell Surface ◽

Heparan Sulfate ◽

Hepatoma Cell ◽

Ascites Hepatoma ◽

Binding Studies ◽

A Cell ◽

Intracellular Organelles ◽

Light Staining ◽

A Site ◽

Quantitative Fluorescence

This study reports on the ultrastructural location and biophysical properties of cell-associated glycosaminoglycans of AH-130 cells, an azo dye-induced ascites hepatoma. Earlier studies have shown that a low-sulfated heparan sulfate, which comprises 93% of their total glycosaminoglycan (GAG) content, is associated with these cells. High-iron diamine, an ultrastructural stain for sulfated glycoconjugates, stained the hepatoma cell surfaces heavily. With the exception of occasional light staining in a few cytoplasmic granules, intracellular organelles did not stain with this method. The lack of an extensive pool of intracellular GAG was confirmed by quantitative fluorescence microscopy of cells vitally stained with acridine orange. The nature of the binding of the cell-surface heparan sulfate was explored by competitive binding studies with exogenous heparin. When cells were incubated with exogenous heparin, release of heparan sulfate into the medium was not detected, although heparin was bound. We conclude that low-sulfated heparan sulfate is an integral component of the AH-130 hepatoma cell surface and is bound at a site different than heparin.

Download Full-text

Epac increases melanoma cell migration by a heparan sulfate-related mechanism

AJP Cell Physiology ◽

10.1152/ajpcell.00129.2009 ◽

2009 ◽

Vol 297 (4) ◽

pp. C802-C813 ◽

Cited By ~ 33

Author(s):

Erdene Baljinnyam ◽

Kousaku Iwatsubo ◽

Reiko Kurotani ◽

Xu Wang ◽

Coskun Ulucan ◽

...

Keyword(s):

Cell Migration ◽

Heparan Sulfate ◽

Melanoma Cell ◽

Translation Rate ◽

Sulfate Production ◽

Lung Colonization ◽

A Cell ◽

Interfering Rna ◽

Kinase Pathway

Melanoma, the most malignant form of human skin cancer, has a poor prognosis due to its strong metastatic ability. It was recently demonstrated that Epac, an effector molecule of cAMP, is involved in regulating cell migration; however, the role of Epac in melanoma cell migration remains unclear. We thus examined whether Epac regulates cell migration and metastasis of melanoma. Epac activation, by either specific agonist or overexpression of Epac, increased melanoma cell migration. Deletion of endogenous Epac with small interfering RNA decreased basal melanoma cell migration. These data suggested a major role of Epac in melanoma cell migration. Epac-induced cell migration was mediated by translocation of syndecan-2, a cell-surface heparan sulfate proteoglycan, to lipid rafts. This syndecan-2 translocation was regulated by tubulin polymerization via the Epac/phosphoinositol-3 kinase pathway. Epac-induced cell migration was also regulated by the production of heparan sulfate, a major extracellular matrix. Epac-induced heparan sulfate production was attributable to the increased expression of N-deacetylase/ N-sulfotransferase-1 (NDST-1) accompanied by an increased NDST-1 translation rate. Finally, Epac overexpression enhanced lung colonization of melanoma cells in mice. Taken together, these data indicate that Epac regulates melanoma cell migration/metastasis mostly via syndecan-2 translocation and heparan sulfate production.

Download Full-text