Dataset Information

Proteins involved in the biosynthesis of lipophosphoglycan in Leishmania: a comparative genomic and evolutionary analysis.

ABSTRACT: BACKGROUND:Leishmania spp. are digenetic parasites capable of infecting humans and causing a range of diseases collectively known as leishmaniasis. The main mechanisms involved in the development and permanence of this pathology are linked to evasion of the immune response. Crosstalk between the immune system and particularities of each pathogenic species is associated with diverse disease manifestations. Lipophosphoglycan (LPG), one of the most important molecules present on the surface of Leishmania parasites, is divided into four regions with high molecular variability. Although LPG plays an important role in host-pathogen and vector-parasite interactions, the distribution and phylogenetic relatedness of the genes responsible for its synthesis remain poorly explored. The recent availability of full genomes and transcriptomes of Leishmania parasites offers an opportunity to leverage insight on how LPG-related genes are distributed and expressed by these pathogens. RESULTS:Using a phylogenomics-based framework, we identified a catalog of genes involved in LPG biosynthesis across 22 species of Leishmania from the subgenera Viannia and Leishmania, as well as 5 non-Leishmania trypanosomatids. The evolutionary relationships of these genes across species were also evaluated. Nine genes related to the production of the glycosylphosphatidylinositol (GPI)-anchor were highly conserved among compared species, whereas 22 genes related to the synthesis of the repeat unit presented variable conservation. Extensive gain/loss events were verified, particularly in genes SCG1-4 and SCA1-2. These genes act, respectively, on the synthesis of the side chain attached to phosphoglycans and in the transfer of arabinose residues. Phylogenetic analyses disclosed evolutionary patterns reflective of differences in host specialization, geographic origin and disease manifestation. CONCLUSIONS:The multiple gene gain/loss events identified by genomic data mining help to explain some of the observed intra- and interspecies variation in LPG structure. Collectively, our results provide a comprehensive catalog that details how LPG-related genes evolved in the Leishmania parasite specialization process.

SUBMITTER: Azevedo LG

PROVIDER: S-EPMC6993435 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Proteins involved in the biosynthesis of lipophosphoglycan in Leishmania: a comparative genomic and evolutionary analysis.

Azevedo Lucas Gentil LG de Queiroz Artur Trancoso Lopo ATL Barral Aldina A Santos Luciane Amorim LA Ramos Pablo Ivan Pereira PIP

Parasites & vectors 20200130 1

<h4>Background</h4>Leishmania spp. are digenetic parasites capable of infecting humans and causing a range of diseases collectively known as leishmaniasis. The main mechanisms involved in the development and permanence of this pathology are linked to evasion of the immune response. Crosstalk between the immune system and particularities of each pathogenic species is associated with diverse disease manifestations. Lipophosphoglycan (LPG), one of the most important molecules present on the surface ...[more]

PMID: 32000835

Similar Datasets

Project description:Lipophosphoglycan (LPG), is the major cell surface molecule of promastigotes of all Leishmania species. It is comprised of three domains: a conserved glycosylphosphatidylinositol anchor linked to a repeating phosphorylated disaccharide (P2; PO4-6Gal beta 1-4Man alpha 1-) backbone and capped with a neutral oligosaccharide. In Leishmania major the backbone is substituted at the C(O)3 of the Galp residue with side chains containing Galp, Glcp and Arap residues whereas in Leishmania donovani the backbone is unsubstituted. We report the solubilization of a (beta 1-3) galactosyltransferase [(beta 1-3)GalT] from a L. major microsomal preparation using Triton X-100. Solubilization occurs with a 10-fold stimulation of enzyme activity. This (beta 1-3)GalT specifically transfers Gal residues from UDP-Gal to exogenously added L. donovani LPG acceptor. Depolymerization of the [14C]Gal-labelled LPG product with mild acid and analysis by high-performance anion-exchange chromatography detected only the phosphotrisaccharide. (P3; PO4-6([14C]Gal beta 1-3-4Man alpha 1-) found in L. major LPG. This contrasts with the activity of the membrane-bound enzyme which also synthesizes the larger phosphosaccharide units[Ng, Handman and Bacic (1994) Glycobiology 4, 845-853]. This suggests that more than one (beta 1-3)GalT is involved in the addition of these Gal units and that the solubilized activity is the (beta 1-3)GalT that adds the first beta Gal residue to the acceptor. The (beta 1-3)GalT was partially purified by lectin-affinity chromatography and used to establish the K(m) values for UDP-Gal (445 microM) and L. donovani acceptor (280 microM as P2 molar equivalent) in kinetic assays. Inhibition studies with various glycosides and mono- and di-saccharides established the P2 repeating unit as the minimum acceptor structure recognized by (beta 1-3)GalT. The detergent-solubilized (beta 1-3)GalT was reversibly inactivated by millimolar concentrations of univalent anionic salts. The (beta 1-3)GalT had an absolute requirement for Mn2+ and also required Mg2+ for optimum activity; Mg2+ cannot substitute for Mn2+, which is loosely bound to beta (1-3)GalT and is probably involved in the correct folding of the enzyme. The (beta 1-3)GalT was unaffected by Ca2+ ions, but were irreversibly inactivated by micromolar levels of transition metal ions (Cu2+ > Zn2+ > Ni2 > Co2+). The (beta 1-3)GalT activity was also inhibited by diethyl pyrocarbonate, but not by N-ethylmaleimide or iodoacetamide, suggesting that active-site histidine residues, rather than cysteine residue(s), are important for enzyme activity.

Project description:BackgroundThe Leishmania (Viannia) braziliensis complex is responsible for most cases of New World tegumentary leishmaniasis. This complex includes two closely related species but with different geographic distribution and disease phenotypes, L. (V.) peruviana and L. (V.) braziliensis. However, the genetic basis of these differences is not well understood and the status of L. (V.) peruviana as distinct species has been questioned by some. Here we sequenced the genomes of two L. (V.) peruviana isolates (LEM1537 and PAB-4377) using Illumina high throughput sequencing and performed comparative analyses against the L. (V.) braziliensis M2904 reference genome. Comparisons were focused on the detection of Single Nucleotide Polymorphisms (SNPs), insertions and deletions (INDELs), aneuploidy and gene copy number variations.ResultsWe found 94,070 variants shared by both L. (V.) peruviana isolates (144,079 in PAB-4377 and 136,946 in LEM1537) against the L. (V.) braziliensis M2904 reference genome while only 26,853 variants separated both L. (V.) peruviana genomes. Analysis in coding sequences detected 26,750 SNPs and 1,513 indels shared by both L. (V.) peruviana isolates against L. (V.) braziliensis M2904 and revealed two L. (V.) braziliensis pseudogenes that are likely to have coding potential in L. (V.) peruviana. Chromosomal read density and allele frequency profiling showed a heterogeneous pattern of aneuploidy with an overall disomic tendency in both L. (V.) peruviana isolates, in contrast with a trisomic pattern in the L. (V.) braziliensis M2904 reference. Read depth analysis allowed us to detect more than 368 gene expansions and 14 expanded gene arrays in L. (V.) peruviana, and the likely absence of expanded amastin gene arrays.ConclusionsThe greater numbers of interspecific SNP/indel differences between L. (V.) peruviana and L. (V.) braziliensis and the presence of different gene and chromosome copy number variations support the classification of both organisms as closely related but distinct species. The extensive nucleotide polymorphisms and differences in gene and chromosome copy numbers in L. (V.) peruviana suggests the possibility that these may contribute to some of the unique features of its biology, including a lower pathology and lack of mucosal development.

Project description:The major macromolecule on the surface of the protozoan parasite Leishmania major is a lipophosphoglycan (LPG) which contains a glycosylphosphatidylinositol glycolipid anchor. This parasite also synthesizes a complex family of abundant low-molecular-mass glycoinositolphospholipids (GIPLs) which are structurally related to the LPG anchor. In this study, L. major promastigotes were metabolically labelled with [3H]GlcN, and the kinetics of incorporation into free glycolipids and the LPG anchor followed to elucidate the pathway of GIPL biosynthesis and possible precursor-product relationships between the GIPLs and LPG. Labelled GIPLs were identified by TLC and by liquid chromatography of the released headgroups, before and after enzymic and chemical cleavage. On the basis of the measured specific radioactivities of the GIPLs, and their kinetics of radiolabelling, we suggest the pathway GlcN-PI-->Man1GlcN-PI (M1)-->Man2GlcN-PI (iM2)-->GalfMan2GlcN-PI (GIPL-1)-->Gal1GalfMan2GlcN-PI (GIPL-2)-->Gal2GalfMan2GlcN-PI (GIPL-3). All of the GIPLs were shown to contain alkylacylglycerol or lyso-alkylglycerol lipid moieties with the exception of the earliest intermediate, glucosaminylphosphatidylinositol (GlcN-PI), which contained both alkylacylglycerol and diacylglycerol. A significant proportion (approx. 50%) of GIPL-3 appeared to be selectively modified by the addition of a Glc-1-PO4 residue to one of the mannose residues (P-GIPL-3). On the basis of the specific radioactivity and kinetics of labelling of GIPL-3 and P-GIPL-3 we suggest that both of these low-abundance species are rapidly utilized as LPG precursors. The turnover of LPG and the GIPLs was also studied by [3H]Gal pulse-chase labelling and cell-surface labelling experiments. Whereas LPG was rapidly shed from the cell surface, consistent with previous studies, the GIPLs (both the total cellular and cell-surface pools) had a much slower turnover. These results suggest that the majority of the GIPLs do not act as LPG precursors and indicate that the cellular levels of these molecules is determined, at least in part, by the rate at which they are shed from the cell surface.

Project description:The genomic DNAs of strains JPCM5 and 263 of L. infantum, strains LV39 and Friedlin of L. major and strains Parrot-TarII and S125 of L. tarentolae were used in comparative genomic hybridizations to reveal the intra-species and inter-species gene content, and to validate L. tarentolae Parrot-TarII genome sequencing results. Leishmania (Sauroleishmania) tarentolae was first isolated in the lizard Tarentola mauritanica. This species is not known to be pathogenic to humans but is often used as a model organism for molecular analyses or protein overproduction. The Leishmania tarentolae Parrot-TarII strain genome sequence was resolved by high-throughput sequencing technologies. The L. tarentolae genome was first assembled de novo and then aligned against the reference L. major Friedlin genome to facilitate contig positioning and annotation, providing a 23-fold coverage of the genome. This is the first non-pathogenic to humans kinetoplastid protozoan genome to be described, and it provides an opportunity for comparison with the completed genomes of the pathogenic Leishmania species. A high synteny was observed in de novo assembled contigs between all sequenced Leishmania species. A number of limited chromosomal regions diverged between L. tarentolae and L. infantum, while remaining syntenic with L. major. Globally, over 90% of the L. tarentolae gene content was shared with the other Leishmania species. There were 250 L. major genes absent from L. tarentolae, and interestingly these missing genes were primarily expressed in the intracellular amastigote stage of the pathogenic parasites. This implies that L. tarentolae may have impaired ability to survive as an intracellular parasite. In contrast to other Leishmania genomes, two gene families were expanded in L. tarentolae, namely the leishmanolysin (GP63) and a gene related to the promastigote surface antigen (PSA31C). Overall, L. tarentolae appears to have a gene content more adapted to the insect stage rather than the mammalian one. This may partly explain its inability to replicate within mammalian macrophages and its suspected preferred life style as promastigote in the lizards.

Dataset Information

Proteins involved in the biosynthesis of lipophosphoglycan in Leishmania: a comparative genomic and evolutionary analysis.

Publications

Proteins involved in the biosynthesis of lipophosphoglycan in Leishmania: a comparative genomic and evolutionary analysis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets