Collagen-induced STAT family members activation in<i>Entamoeba histolytica</i>trophozoites

Cruz-Vera, Jorge; Clara, L.; Hernández-Kelly, R.; Méndez, José Alfredo Tirado; Pérez-Salazar, Eduardo; Ortega, Arturo

doi:10.1016/s0378-1097(03)00822-x

Cited by 12 publications

(17 citation statements)

References 23 publications

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“…To determine if another ligand also induces the enrichment of Gal/GalNAc lectin subunits in lipid rafts, we exposed trophozoites to collagen type I, which has been shown to initiate signaling in E. histolytica (7,10,35). Trophozoites were incubated on collagen-coated flasks or uncoated control flasks.…”

Section: Exposure To Hrbcs Correlates With Enrichment Of Hgl and Lgl mentioning

confidence: 99%

“…For example, in B cells, calcium signaling has been shown to activate transcriptional regulators, such as NF-B and NFAT (13). Likewise, attachment to collagen by trophozoites induces an increase in the binding of transcriptional regulators AP-1, STAT1, and STAT3 to DNA (7,36) and an increase in the expression of several important virulence factors, including amoebapore and cysteine proteases (10). In E. histolytica, actin remodeling occurs during attachment to collagen (32) and hRBCs (1), and calcium mobilization can affect actin organization (5).…”

Section: Figmentioning

confidence: 99%

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Exposure to Host Ligands Correlates with Colocalization of Gal/GalNAc Lectin Subunits in Lipid Rafts and Phosphatidylinositol (4,5)-Bisphosphate Signaling in Entamoeba histolytica

et al. 2012

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bEntamoeba histolytica is an intestinal parasite that causes dysentery and liver abscess. Parasite cell surface receptors, such as the Gal/GalNAc lectin, facilitate attachment to host cells and extracellular matrix. The Gal/GalNAc lectin binds to galactose or N-acetylgalactosamine residues on host components and is composed of heavy (Hgl), intermediate (Igl), and light (Lgl) subunits. Although Igl is constitutively localized to lipid rafts (cholesterol-rich membrane domains), Hgl and Lgl transiently associate with this compartment in a cholesterol-dependent fashion. In this study, trophozoites were exposed to biologically relevant ligands to determine if ligand binding influences the submembrane distribution of the subunits. Exposure to human red blood cells (hRBCs) or collagen, which are bona fide Gal/GalNAc lectin ligands, was correlated with enrichment of Hgl and Lgl in rafts. This enrichment was abrogated in the presence of galactose, suggesting that direct lectin-ligand interactions are necessary to influence subunit location. Using a cell line that is able to attach to, but not phagocytose, hRBCs, it was shown that physical attachment to ligands was not sufficient to induce the enrichment of lectin subunits in rafts. Additionally, the mutant had lower levels of phosphatidylinositol (4,5)-bisphosphate (PIP 2 ); PIP 2 loading restored the ability of this mutant to respond to ligands with enrichment of subunits in rafts. Finally, intracellular calcium levels increased upon attachment to collagen; this increase was essential for the enrichment of lectin subunits in rafts. Together, these data provide evidence that ligand-induced enrichment of lectin subunits in rafts may be the first step in a signaling pathway that involves both PIP 2 and calcium signaling.

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Section: Exposure To Hrbcs Correlates With Enrichment Of Hgl and Lgl mentioning

confidence: 99%

Section: Figmentioning

confidence: 99%

Exposure to Host Ligands Correlates with Colocalization of Gal/GalNAc Lectin Subunits in Lipid Rafts and Phosphatidylinositol (4,5)-Bisphosphate Signaling in Entamoeba histolytica

et al. 2012

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“…The presence of tyrosine kinases in amoebae was confirmed in immunoprecipitation reaction with a combined use of the specific substrate peptide RR-SRC, tyrosine kinase inhibitor genistein, and monoclonal anti-p-tyr antibodies Sengupta et al, 2000Sengupta et al, , 2001. Interestingly, an amoeba non-receptor tyrosine kinase (pp 125 ) is responsible for the amoeba STATs phosphorylation in response to collagen and calcium in E. histolytica trophozoites (Cruz-Vera et al, 2003). STAT amoeba homologues are involved in membrane-to-nuclei signaling and their tyrosine phosphorylation is essential for DNA binding and transcriptional enhancement.…”

Section: Phosphotyrosine-containing Proteins and Tyrosine Kinases In mentioning

confidence: 91%

“…The existence of the STAT pathways in the slime mold Dictyostelium discoideum (Kawata et al, 1997;Araki et al, 2003) and in the protozoan parasite Entamoeba histolytica (Cruz-Vera et al, 2003) has turned out to be unexpected. By the present time, the best studied are the STAT pathways of D. discoideum.…”

Section: Participation Of Stat-protein Of Dictyostelium In Intracellumentioning

confidence: 99%

The Role of Tyrosine Phosphorylation in Regulation of Signal Transduction Pathways in Unicellular Eukaryotes

Schemarova

2006

Current Issues in Molecular Biology

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“…Although signaling in E. histolytica through G-proteins and mitogen-activated protein kinases has been described [4,5], the genome project has delineated an entirely new repertoire of potential signal-transduction pathways [2,6]. All of the major families contained within the eukaryotic protein kinase superfamily are represented within the E. histolytica genome, including tyrosine kinases with Src homology (SH)2 domains, tyrosinekinase-like protein kinases and putative receptor serine/threonine kinases.…”

Section: Something Newmentioning

confidence: 99%

The Entamoeba histolytica genome: something old, something new, something borrowed and sex too?

Stanley¹

2005

Trends in Parasitology

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An ancient and potent pathogenEntamoeba histolytica is an intestinal protozoan parasite of humans that causes amebic colitis and amebic liver abscess: diseases associated with significant levels of morbidity and mortality worldwide [1]. The organism has a simple life cycle, existing as either the motile trophozoite or the infectious, hardy cyst form. Trophozoites of E. histolytica reside within the anaerobic confines of the human colon, lack mitochondria, derive energy from fermentation and reproduce by binary fission. E. histolytica trophozoites can be potent pathogens, possessing an armamentarium that includes a galactose-N-acetyl-galactosamine-binding lectin that mediates adherence to host cells, pore-forming proteins (amebapores) that can lyse bacteria or eukaryotic cells, cysteine proteinases that can cleave extracellular-matrix proteins and facilitate invasion into the colonic mucosa, and impressive phagocytic capabilities [1]. During the past three decades, the tools of molecular biology have greatly increased the understanding of E. histolytica pathogenesis. The recent publication of the E. histolytica genome by Loftus et al.[2] provides remarkable new insights into the biology of E. histolytica, helps understanding of the requirements for intestinal parasitism and sets the stage for a new, far more detailed understanding of this important pathogen.

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Collagen-induced STAT family members activation inEntamoeba histolyticatrophozoites

Cited by 12 publications

References 23 publications

Exposure to Host Ligands Correlates with Colocalization of Gal/GalNAc Lectin Subunits in Lipid Rafts and Phosphatidylinositol (4,5)-Bisphosphate Signaling in Entamoeba histolytica

Exposure to Host Ligands Correlates with Colocalization of Gal/GalNAc Lectin Subunits in Lipid Rafts and Phosphatidylinositol (4,5)-Bisphosphate Signaling in Entamoeba histolytica

The Role of Tyrosine Phosphorylation in Regulation of Signal Transduction Pathways in Unicellular Eukaryotes

The Entamoeba histolytica genome: something old, something new, something borrowed and sex too?

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