Project description:In this study we report the complete repertoire of 2'-O-methylation sites present in the rRNA of Leishmania amazonensis rRNAs and a subset of small RNAs using RibOxi-seq.
Project description:In this study we profiled the complete repertoire of 2'-O-methylation sites present in the rRNA and a subset of small RNAs of Leishmania major rRNA using RibOxi-seq.
Project description:Background: Drug resistance is a major problem in leishmaniasis chemotherapy. RNA expression profiling using DNA microarrays is a suitable approach to study simultaneous events leading to a drug-resistance phenotype. Genomic analysis has been performed primarily with Old World Leishmania species and here we investigate molecular alterations in antimony resistance in the New World species L. amazonensis. Methods/Principal Findings: We selected populations of L. amazonensis for resistance to antimony by step-wise drug pressure. Gene expression of highly resistant mutants was studied using DNA microarrays. RNA expression profiling of antimony-resistant L. amazonensis revealed the overexpression of genes involved in drug resistance including the ABC transporter MRPA and several genes related to thiol metabolism. The MRPA overexpression was validated by quantitative real-time PCR and further analysis revealed that this increased expression was correlated to gene amplification as part of extrachromosomal linear amplicons in some mutants and as part of supernumerary chromosomes in other mutants. The expression of several other genes encoding hypothetical proteins but also nucleobase and glucose transporter encoding genes were found to be modulated. Conclusions/Significance: Mechanisms classically found in Old World antimony resistant Leishmania were also highlighted in New World antimony-resistant L. amazonensis. These studies were useful to the identification of resistance molecular markers.
Project description:To determine the modulation of gene expression of C57BL/6 and DBA/2 BMDLs in the presence of living intracellular Leishmania amazonensis amastigotes
Project description:Protozoan parasites of the genus Leishmania are causative agents of leishmaniasis, a wide range of diseases affecting 12 million people worldwide. The species L. (L.) infantum and L. (L.) amazonensis are causative agents of visceral and cutaneous leishmaniasis, respectively. Most proteome analyses of Leishmania have been carried out on whole-cell extracts. However, this approach tends to underrepresent membrane-associated proteins because of their high hydrophobicity and low solubility. Due to the great importance of membrane-associated proteins in biological processes, including host–parasite interactions, virulence and invasiveness, this study applied label-free shotgun proteomics to characterize and evaluate abundance levels of plasma membrane sub-proteome of promastigotes life-stage. The total number of proteins identified in L. (L.) infantum and L. (L.) amazonensis was 2033 and 2243, respectively. Both species shared 1908 of these quantified proteins. After cell localization prediction of all identified proteins, 394 proteins were described as plasma membrane-associated proteins and their majority (320 proteins) was presented in both species. Considering only exclusive proteins, 18 proteins were detected only in L. (L.) infantum and 56 proteins in L. (L.) amazonensis. We used two criteria to define “regulated” proteins; i) proteins with p-value < 0.05 after One-Way ANOVA analysis (quantitative analysis) and proteins detected only in L. (L.) infantum or L. (L.) amazonensis (qualitative analysis).