The Entamoeba histolytica methylated LINE-binding protein EhMLBP provides protection against heat shock.

Adaptation to environmental stress is a key process that allows the unicellular parasite Entamoeba histolytica to survive in its human host. We previously characterized EhMLBP as an essential protein for the growth and the virulence of the parasite. EhMLBP binds to methylated repetitive DNA, and is one of the core proteins of the parasite's epigenetic machinery.

Glucose starvation boosts Entamoeba histolytica virulence.

The unicellular parasite, Entamoeba histolytica, is exposed to numerous adverse conditions, such as nutrient deprivation, during its life cycle stages in the human host. In the present study, we examined whether the parasite virulence could be influenced by glucose starvation (GS). The migratory behaviour of the parasite and its capability to kill mammalian cells and to lyse erythrocytes is strongly enhanced following GS.

A new nuclear function of the Entamoeba histolytica glycolytic enzyme enolase: the metabolic regulation of cytosine-5 methyltransferase 2 (Dnmt2) activity.

Cytosine-5 methyltransferases of the Dnmt2 family function as DNA and tRNA methyltransferases. Insight into the role and biological significance of Dnmt2 is greatly hampered by a lack of knowledge about its protein interactions. In this report, we address the subject of protein interaction by identifying enolase through a yeast two-hybrid screen as a Dnmt2-binding protein.

Insights into the mechanism of DNA recognition by the methylated LINE binding protein EhMLBP of Entamoeba histolytica.

EhMLBP is an essential Entamoeba histolytica protein that binds preferentially to methylated long interspersed nuclear elements and rDNA. In an effort to identify more EhMLBP DNA substrates, we developed an affinity-based technique in which the C-terminal DNA binding domain of EhMLBP (GST-CterEhMLBP) was used as the ligand. Bioinformatic analysis of the DNA sequences that were isolated by this affinity method revealed the presence of a 29-nucleotide consensus motif that includes a stretch of ten adenines.

EhMLBP is an essential constituent of the Entamoeba histolytica epigenetic machinery and a potential drug target.

EhMLBP has been identified as a protein that specifically binds to methylated long interspersed element (LINE) retrotransposons and rDNA in Entamoeba histolytica. EhMLBP is unique to Entamoeba parasites, which makes this protein a possible drug target for treating amebiasis. In the work described here, we evaluated this potential.

Trichostatin A regulates peroxiredoxin expression and virulence of the parasite Entamoeba histolytica.

Histone deacetylation is associated with a repressed chromatin state, and histone acetylase and deacetylase activities have been previously described in Entamoeba histolytica. To investigate their roles in the control of Entamoeba gene expression, the parasite was grown in 50 nM trichostatin A (TSA), an inhibitor of histone deacetylase. TSA enhanced the cytopathic and hemolytic activity of the parasite and its resistance to oxidative stress.

Sensing DNA methylation in the protozoan parasite Entamoeba histolytica.

In the protozoan parasite Entamoeba histolytica, 5-methylcytosine (m5C) was found predominantly in repetitive elements. Its formation is catalysed by Ehmeth, a DNA methyltransferase that belongs to the Dnmt2 subfamily. Here we describe a 32 kDa nuclear protein that binds in vitro with higher affinity to the methylated form of a DNA encoding a reverse transcriptase of an autonomous non-long-terminal repeat retrotransposon (RT LINE) compared with the non-methylated RT LINE.

DNA methylation and targeting of LINE retrotransposons in Entamoeba histolytica and Entamoeba invadens.

In this study, we have isolated by affinity chromatography, using anti-m5C antibody as a ligand, a DNA encoding reverse transcriptase of LINE retrotransposon (RT LINE) in both Entamoeba invadens and Entamoeba histolytica. RT LINE transcripts were detected in E. histolytica but were absent from E.

Pleiotropic phenotype in Entamoeba histolytica overexpressing DNA methyltransferase (Ehmeth).

The protozoan parasite Entamoeba histolytica expresses a cytosine-5 DNA methyltransferase (Ehmeth) that belongs to the Dnmt2 proteins family. The biological function of members of the Dnmt2 family is unknown. Constitutive overexpression of Ehmeth resulted in a pleiotropic phenotype that includes accumulation of multinucleated cells, upregulation of Heat shock protein 70 (HSP70) expression and resistance to oxidative stress.

Epigenetic and classical activation of Entamoeba histolytica heat shock protein 100 (EHsp100) expression.

The protozoan parasite Entamoeba histolytica expresses a cytosine-5 DNA methyltransferase (Ehmeth) that belongs to the DNMT2 protein family. The biological function of members of this DNMT2 family is unknown. In the present study, the 5' region of E.

Identification of methylated sequences in genomic DNA of adult Drosophila melanogaster.

The genome of Drosophila melanogaster contains methylated cytosines. Recent studies indicate that DNA methylation in the fruit fly depends on one DNA methyltransferase, dDNMT2. No obvious phenotype is associated with the downregulation of this DNA methyltransferase.

Consumption of L-arginine mediated by Entamoeba histolytica L-arginase (EhArg) inhibits amoebicidal activity and nitric oxide production by activated macrophages.

In this study we discuss the cloning and expression of Entamoeba histolytica arginase (EhArg), an enzyme that catalyses the hydrolysis of L-arginine to L-ornithine and urea. L-norvaline, a competitive inhibitor of E. histolytica L-arginase, inhibits the growth of the parasite, which suggests that the catabolism of L-arginine mediated by EhArg is essential.

Characterization of cytosine methylated regions and 5-cytosine DNA methyltransferase (Ehmeth) in the protozoan parasite Entamoeba histolytica.

The DNA methylation status of the protozoan parasite Entamoeba histolytica was heretofore unknown. In the present study, we developed a new technique, based on the affinity of methylated DNA to 5-methylcytosine antibodies, to identify methylated DNA in this parasite. Ribosomal DNA and ribosomal DNA circles were isolated by this method and we confirmed the validity of our approach by sodium bisulfite sequencing.

Nitric oxide inhibits cysteine proteinases and alcohol dehydrogenase 2 of Entamoeba histolytica.

Nitric oxide is involved in the neutrophil and macrophage killing of the protozoan parasite Entamoeba histolytica. In the present study, we found that cysteine proteinases, significant contributors to amebic virulence and alcohol dehydrogenase 2, an enzyme absolutely required for the survival of the parasite, are both significantly inhibited by S-nitroso-glutathione, a physiological nitric oxide donor, within the concentration range 0.5-2.