Genome-wide mapping of RPA1 and RAD9 reveals the management of polycistronic transcription, replication initiation, and responses to replication stress in Leishmania
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PROVIDER: PRJEB83580 | ENA |
REPOSITORIES: ENA
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Project description:Faithful inheritance of the large eukaryotic genomes requires the orchestrated activation of multiple DNA replication origins. Although origin activation is mechanistically conserved among eukaryotes, how replication origins are specified and selected for activation in each S-phase seem to differ across the model systems studied. Here we provide a complete analysis of the nucleosomal landscape and replication programme of the human parasite Leishmania major, building on a better evolutionary understanding of replication organization in Eukarya. We found that active transcription is a driving force for the nucleosomal organization of L. major genome, and that both the spatial and the temporal programme of DNA replication can be explained as associated to RNA polymerase kinetics, without the need to invoke specific regulatory mechanisms. This simple scenario likely provides these organisms with the flexibility and robustness to deal with the continuous environmental changes that impose alterations in their genetic programmes during their parasitic life cycle stages. Our findings also suggest that coupling replication initiation to transcription elongation could be an ancient solution used by eukaryotic cells for origin maintenance
2016-06-10 | GSE81991 | GEO
Project description:Faithful inheritance of the large eukaryotic genomes requires the orchestrated activation of multiple DNA replication origins. Although origin activation is mechanistically conserved among eukaryotes, how replication origins are specified and selected for activation in each S-phase seem to differ across the model systems studied. Here we provide a complete analysis of the nucleosomal landscape and replication programme of the human parasite Leishmania major, building on a better evolutionary understanding of replication organization in Eukarya. We found that active transcription is a driving force for the nucleosomal organization of L. major genome, and that both the spatial and the temporal programme of DNA replication can be explained as associated to RNA polymerase kinetics, without the need to invoke specific regulatory mechanisms. This simple scenario likely provides these organisms with the flexibility and robustness to deal with the continuous environmental changes that impose alterations in their genetic programmes during their parasitic life cycle stages. Our findings also suggest that coupling replication initiation to transcription elongation could be an ancient solution used by eukaryotic cells for origin maintenance Replication intitiation sites were defined using two replicates of short nascent strands of increasing sizes (F4 and F5) purified through three rounds of Lambda-exonuclease digestion, and a genomic DNA control (Ctrl). Nucleosome landscape was determined using two replicates of mononucleosomal-DNA derived from MNase-digested chromatin
2016-06-10 | E-GEOD-81991 | biostudies-arrayexpress
Project description:Autophagy generally participates in innate immunity by elimination of intracellular pathogens. However, many of them developed successful strategies to counteract their autolysosomal digestion and lastly to exploit this catabolic cellular process. Protozoan parasites of the genus Leishmania are the causative agent of leishmaniasis, one of the 13 most important tropical diseases. Leishmania persists as endo-parasite in host macrophages, where it uses multiple strategies to manipulate the microbicidal host cell functions and to escape from the host immune system. Understanding how Leishmania interacts with host macrophages during uptake, differentiation, intracellular replication, and release might be the key to develop new drugs in target-directed approaches to treat patient with leishmaniasis.
2015-08-03 | GSE52624 | GEO
Project description:Genomic integrity requires faithful chromosome duplication. Origins of replication are the genomic sites where DNA replication initiates in every cell cycle. There are multiple origins scattered throughout the eukaryotic genome whose genome-wide identification has been a hard challenge, especially in multicellular organisms. Thus, very little is known on the distinctive features of origins in terms of DNA sequence and chromatin context at a genomic scale. As part of a project for profiling replication origins in Arabidopsis thaliana, we have performed ChIP-chip analysis of the binding of ORC1 and CDC6, two proteins involved in initiation of DNA replication. Here, we provide the data of the ORC1-bound and CDC6-bound genomic sites using as control genomic DNA.
2011-02-06 | GSE21928 | GEO
Project description:Nuclear DNA replication in Leishmania major relies on a single constitutive origin per chromosome supplemented by thousands of stochastic initiation events
| PRJEB82099 | ENA
Project description:Protozoan parasites of the genus Leishmania are the causative agent of leishmaniasis, one of the 13 most important tropical diseases. Leishmania persists as endo-parasite in host macrophages, where it uses multiple strategies to manipulate the microbicidal host cell functions and to escape from the host immune system. Understanding how Leishmania interacts with host macrophages during uptake, differentiation, intracellular replication, and release might be the key to develop new drugs in target-directed approaches to treat patient with leishmaniasis. Short non-coding RNAs are known to regulate the expression of protein-coding genes at post-transcriptional level. Characterization of these processes during Leishmania infection provides deeper insight in the interaction between host and parasites.
2015-08-03 | GSE58369 | GEO
Project description:Base J and H3.V promote RNA Polymerase (RNAP) II termination within polycistronic gene clusters in the kinetoplastid species Trypanosoma brucei. Although base J has been shown to promote RNAP II termination in the related kinetoplastid species Leishmania major and Leishmania tarentolae, the role of H3.V was unclear. The effect of acute J loss on mRNA transcript abundance was also unknown. We find here that H3.V does not promote transcription termination in Leishmania major, but loss of H3.V does reduce J levels. The J loss in H3.V knockout cells is not enough to result in a termination defect, which we show is due to a threshold level of J that is sufficient to promote termination. Loss of J beyond that threshold results in termination defects. Further, the decreased J in H3.V knockout cells allowed greater reduction of J by dimethyloxalylglycine (DMOG), which inhibits J synthesis, compared to wild type cells treated with DMOG, and resulted in stronger defects in RNAP II termination and cell growth. By mRNA-seq we see largely upregulation of genes near the ends of gene clusters following J loss, indicating that J represses genes near termination sites. These findings reveal a conserved role of J in promoting termination prior to the end of polycistronic gene clusters in kinetoplastid parasites and suggest that the essential nature of J is related to its role in repressing genes by promoting termination.
2016-07-20 | GSE77632 | GEO
Project description:Autophagy generally participates in innate immunity by elimination of intracellular pathogens. However, many of them developed successful strategies to counteract their autolysosomal digestion and lastly to exploit this catabolic cellular process. Protozoan parasites of the genus Leishmania are the causative agent of leishmaniasis, one of the 13 most important tropical diseases. Leishmania persists as endo-parasite in host macrophages, where it uses multiple strategies to manipulate the microbicidal host cell functions and to escape from the host immune system. Understanding how Leishmania interacts with host macrophages during uptake, differentiation, intracellular replication, and release might be the key to develop new drugs in target-directed approaches to treat patient with leishmaniasis. Here, we generated expression profiles from bone marrow-derived macrophages (BMDM) at 1h and 24h post infection (p.i.) with Leishmania major and respective controls.
2015-08-03 | E-GEOD-52624 | biostudies-arrayexpress
Project description:Base J and H3.V promote RNA Polymerase (RNAP) II termination within polycistronic gene clusters in the kinetoplastid species Trypanosoma brucei. Although base J has been shown to promote RNAP II termination in the related kinetoplastid species Leishmania major and Leishmania tarentolae, the role of H3.V was unclear. The effect of acute J loss on mRNA transcript abundance was also unknown. We find here that H3.V does not promote transcription termination in Leishmania major, but loss of H3.V does reduce J levels. The J loss in H3.V knockout cells is not enough to result in a termination defect, which we show is due to a threshold level of J that is sufficient to promote termination. Loss of J beyond that threshold results in termination defects. Further, the decreased J in H3.V knockout cells allowed greater reduction of J by dimethyloxalylglycine (DMOG), which inhibits J synthesis, compared to wild type cells treated with DMOG, and resulted in stronger defects in RNAP II termination and cell growth. By mRNA-seq we see largely upregulation of genes near the ends of gene clusters following J loss, indicating that J represses genes near termination sites. These findings reveal a conserved role of J in promoting termination prior to the end of polycistronic gene clusters in kinetoplastid parasites and suggest that the essential nature of J is related to its role in repressing genes by promoting termination.
2016-09-26 | GSE77713 | GEO
Project description:Base J and H3.V promote RNA Polymerase (RNAP) II termination within polycistronic gene clusters in the kinetoplastid species Trypanosoma brucei. Although base J has been shown to promote RNAP II termination in the related kinetoplastid species Leishmania major and Leishmania tarentolae, the role of H3.V was unclear. The effect of acute J loss on mRNA transcript abundance was also unknown. We find here that H3.V does not promote transcription termination in Leishmania major, but loss of H3.V does reduce J levels. The J loss in H3.V knockout cells is not enough to result in a termination defect, which we show is due to a threshold level of J that is sufficient to promote termination. Loss of J beyond that threshold results in termination defects. Further, the decreased J in H3.V knockout cells allowed greater reduction of J by dimethyloxalylglycine (DMOG), which inhibits J synthesis, compared to wild type cells treated with DMOG, and resulted in stronger defects in RNAP II termination and cell growth. By mRNA-seq we see largely upregulation of genes near the ends of gene clusters following J loss, indicating that J represses genes near termination sites. These findings reveal a conserved role of J in promoting termination prior to the end of polycistronic gene clusters in kinetoplastid parasites and suggest that the essential nature of J is related to its role in repressing genes by promoting termination. The role of base J and H3.V in promoting RNA Polymerase II transcription termination was assessed by small RNA-seq, mRNA-seq, and strand-specific RT-PCR. Wild type cells were compared to H3.V knockout cells and to WT and H3.V knockout cells treated with dimethyloxalylglycine (DMOG) to reduce base J.
2016-07-20 | E-GEOD-77632 | biostudies-arrayexpress