Project description:To determine the modulation of gene expression of Leishmania mexicana(M379)-inoculated BALB/c ears in the presence of promastigote secretory gel (PSG) A genome-wide transcriptional analysis was performed by comparing the gene expression profiles of Leishmania mexicana- inoculated BALB/c ears and Leishmania mexicana plus PSG BALB/c ears. Leishmania mexicana amastigotes were purified from mouse cutaneous lesions and transformed in vitro in metacycic promastigotes (MT). After 6, 24 and 48 hours, ears were collected and processed for RNA extraction. Three Biological replicates per condition were run.
Project description:To determine the modulation of gene expression of Leishmania mexicana(M379)-inoculated BALB/c ears in the presence of promastigote secretory gel (PSG)
Project description:We examined the Leishmania mexicana transcriptome to identify differentially regulated mRNAs using high-density whole-genome oligonucleotide microarrays designed from the genome data of a closely related species, Leishmania major. Statistical analysis on array hybridization data representing 8156 predicted coding regions revealed 288 genes (3.5% of all genes) whose steady-state mRNA levels meet criteria for differential regulation between promastigotes and lesion-derived amastigotes. Interestingly, sample comparison of promastigotes to axenic amastigotes resulted in only 17 genes (0.2%) that meet the same statistical criteria for differential regulation. The reduced number of regulated genes is a consequence of an increase in the magnitude of the transcript levels in cells under axenic conditions. The expression data for a subset of genes was validated by quantitative PCR. Our studies show that interspecies hybridization on microarrays can be used to analyze closely related protozoan parasites, that axenic culture conditions may alter amastigote transcript abundance, and that there is only a relatively modest change in abundance of a few mRNAs between morphologically distinct promastigote and amastigote cultured cells. Leishmania may represent an alternative paradigm for eukaryotic differentiation with minimal contributions from changes in mRNA abundance. Keywords: RNA expression profiling
Project description:We used Illumina sequencing of poly-A selected RNA of Leishmania mexicana (WHO strain MNYC/BZ/62/M379) culture-adapted promastigotes (PRO), axenic amastigotes (AXA) and intracellular amastigotes (AMA) in mouse bone marrow derived macrophages (BMDM), 24h after infection, to map 5' and 3' ends of Leishmania transcripts and determine transcript abundances. The AMA samples were prepared from total RNA of infected macrophages thus containing a mixture of leishmanial and murine RNA transcripts. We also sequenced poly-A selected RNA from uninfected BMDMs. Three biological replicates per sample.
Project description:Using a combination of phosphoproteome enrichment and tandem mass tag (TMT) labelling-based quantitative proteomic mass spectrometry (MS), we robustly identified and quantified 1,833 phosphorylated proteins across three life cycle stages of Leishmania mexicana (L. mexicana) parasite. Protein kinase domain was the most enriched protein domain in the L. mexicana phosphoproteome. Additionally, this study systematically characterised the perturbing effect of HSP90 inhibition on the global phosphoproteome of the L. mexicana across its life cycle stages and showed that the inhibition causes substantially distinct molecular effects in the promastigotes and the amastigotes. While tanespimycin treatment decreased the phosphorylation of HSP90 and its co-chaperon HSP70 in the amastigotes, the opposite effect was observed in the promastigotes. Additionally, our results show that while kinase activity and microtubule motor activity are highly represented in the negatively affected phosphoproteins of the promastigotes, ribosomal proteins, protein folding, and proton channel activity are preferentially enriched in the perturbed amastigote phosphoproteome. Our results also show that RNA helicase domain was distinctively enriched among the positively affected RNA-binding amastigote phosphoproteome. This study reveals the dramatically different ways the HSP90 inhibition stress modulates the phosphoproteome of the pathogenic amastigotes and provides in-depth insight into the scope of selective molecular targeting in the therapeutically relevant amastigotes.
Project description:We examined the Leishmania mexicana transcriptome to identify differentially regulated mRNAs using high-density whole-genome oligonucleotide microarrays designed from the genome data of a closely related species, Leishmania major. This experiment appears as Fig. 1 of the associated publication. Keywords: RNA expression profiling
Project description:Non-poly(A) RNA molecules including noncoding RNAs (ncRNAs) comprise the major portion of the total transcribed molecules in the cell. In addition to the mRNAs the ncRNAs also function as ribonucleoprotein particles (RNPs) and carry out biological functions including synthesis of new proteins, RNA processing, genome remodelling and regulation of transcription. We therefore envisaged a comprehensive transcriptome-wide identification of coding and non-coding RNA-binding proteins (RBPs) in the Leishmania spp. Towards this we applied the recently reported orthogonal organic phase separation (OOPS) method in combination with tandem mass tag (TMT) labelling-based quantitative proteomic mass spectrometry (MS) and report herein the most comprehensive identification of RBPs in Leishmania mexicana (L. mexicana) parasites. This study identified novel RNA binding property of thousands of L. mexicana proteins, significantly expanding the RBP landscape of the parasite. Furthermore, we showed that the classical Hsp90 inhibitor tanespimycin differentially regulates the RNA-binding property of hundreds of L. mexicana RBPs, shedding light into hitherto unknown large-scale downstream molecular effects of the small molecule inhibitor in the parasite.