The domain architecture of the protozoan protein J-DNA-binding protein 1 suggests synergy between base J DNA binding and thymidine hydroxylase activity DNA and Chromosomes

J-DNA–binding protein 1 (JBP1) contributes to the biosynthesis and maintenance of base J (β-d-glucosyl-hydroxymethyluracil), an epigenetic modification of thymidine (T) confined to pathogenic protozoa such as Trypanosoma and Leishmania. JBP1 has two known functional domains: an N-terminal T hydroxylase (TH) homologous to the 5-methylcytosine hydroxylase domain in TET proteins and a J-DNA–binding domain (JDBD) that resides in the middle of JBP1. Here, we show that removing JDBD from JBP1 results in a soluble protein (Δ-JDBD) with the N- and C-terminal regions tightly associated together in a well-ordered structure. We found that this Δ-JDBD domain retains TH activity in vitro but displays a 15-fold lower apparent rate of hydroxylation compared with JBP1. Small-angle X-ray scattering (SAXS) experiments on JBP1 and JDBD in the presence or absence of J-DNA and on Δ-JDBD enabled us to generate low-resolution three-dimensional models. We conclude that Δ-JDBD, and not the N-terminal region of JBP1 alone, is a distinct folding unit. Our SAXS-based model supports the notion that binding of JDBD specifically to J-DNA can facilitate T hydroxylation 12–14 bp downstream on the complementary strand of the J-recognition site. We postulate that insertion of the JDBD module into the Δ-JDBD scaffold during evolution provided a mechanism that synergized J recognition and T hydroxylation, ensuring inheritance of base J in specific sequence pat...
Source: Journal of Biological Chemistry - Category: Chemistry Authors: Tags: Protein Structure and Folding Source Type: research

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ConclusionThe MIL resistant L. infantum LEM3323 line is significantly hampered in its development and transmissibility potential in two sand fly vector species. Additional studies are warranted to evaluate whether this applies to other visceral Leishmania parasites with acquired MIL-resistance.Graphical abstract
Source: International Journal for Parasitology: Drugs and Drug Resistance - Category: Parasitology Source Type: research
In conclusion,L.infantum-derived LPG was recognized by antibodies elicited during CanL in different infection stages and was shown to be a suitable antigen for specific clinical settings of veterinary diagnosis and for public health usage.
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research
Abstract Parasitic protists belonging to the genus Leishmania synthesize the non-canonical carbohydrate reserve, mannogen, which is composed of β-1,2-mannan oligosaccharides. Here, we identify a class of dual-activity mannosyltransferase/phosphorylases (MTPs) that catalyze both the sugar nucleotide-dependent biosynthesis and phosphorolytic turnover of mannogen. Structural and phylogenic analysis shows that while the MTPs are structurally related to bacterial mannan phosphorylases, they constitute a distinct family of glycosyltransferases (GT108) that have likely been acquired by horizontal gene transfer ...
Source: Cell Host and Microbe - Category: Microbiology Authors: Tags: Cell Host Microbe Source Type: research
In conclusion, the results confirmed a positive association between CIC levels, their molecular size and disease progression that suggests a potential use of CIC as biomarkers of CanL.
Source: Veterinary Parasitology - Category: Veterinary Research Source Type: research
Leishmania (Viannia) braziliensis is responsible for the largest number of American tegumentary leishmaniasis in Brazil (ATL). ATL can present several clinical forms including typical (TL) and atypical (AL) cutaneous and mucocutaneous (ML) lesions. To identify parasite and host factors potentially associated with these diverse clinical manifestations, we first surveyed the expression of two virulence-associated glycoconjugates, lipophosphoglycan (LPG) and the metalloprotease GP63 by a panel of promastigotes of L. braziliensis strains isolated from patients with different clinical manifestations of ATL and from the sand fly...
Source: Frontiers in cellular and infection microbiology - Category: Microbiology Source Type: research
This study represents a definitive characterization of the role of IL-32γ in the trained phenotype induced by β-glucan or BCG, the results of which improve our understanding of the molecular mechanisms governing trained immunity and Leishmania infection control.Graphical Abstract
Source: Cell Reports - Category: Cytology Source Type: research
oacute;n Lilián Yépez-Mulia Rafael Castillo Leishmanicidal drugs have many side effects, and drug resistance to all of them has been documented. Therefore, the development of new drugs and the identification of novel therapeutic targets are urgently needed. Leishmania mexicana trypanothione reductase (LmTR), a NADPH-dependent flavoprotein oxidoreductase important to thiol metabolism, is essential for parasite viability. Its absence in the mammalian host makes this enzyme an attractive target for the development of new anti-Leishmania drugs. Herein, a tridimensional model of LmTR was constructed and th...
Source: Molecules - Category: Chemistry Authors: Tags: Article Source Type: research
In this study, the development of L. orientalis in two experimental vectors, Lutzomyia longipalpis sand flies and Culicoides sonorensis biting midges was investigated for the first time using light microscopy, scanning electron microscopy, and histological examination. The results showed that L. orientalis was unable to establish infection in Lu. longipalpis. No parasites were found in the sand fly gut 4 days post-infected blood meal (PIBM). In contrast, the parasite successfully established infection in C. sonorensis. The parasites differentiated from amastigotes to procyclic promastigotes in the abdominal midgut (AMG) on...
Source: Acta Tropica - Category: Infectious Diseases Authors: Tags: Acta Trop Source Type: research
Abstract Visceral leishmaniasis (VL) is a neglected tropical disease caused by protozoan Leishmania donovani parasite which may be fatal if left untreated. While drug-sensitive parasites are able to live and multiply within the host macrophages, they develop resistance to drugs used against them for survival and multiplication in the infected patients undergoing routine treatment. Development of new agents devoid of such drug resistance potential is achievable by identifying new drug targets in the parasite. One such target is the key regulator of intracellular vesicular trafficking protein, RabGTPase which belong...
Source: Acta Tropica - Category: Infectious Diseases Authors: Tags: Acta Trop Source Type: research
This study aimed to evaluate the antileishmanial efficacy of oxaliplatin against Leishmania major both in-vitro and in-vivo. The IC50, CC50, and SI of oxaliplatin against promastigotes, murine macrophages, Raw 264.7 cells, and intramacrophage amastigotes of L. major were investigated in-vitro. The effects of this drug on intracellular amastigotes were also assayed, and the percentage of infectivity and IIR were calculated. Flow cytometry was performed to assay apoptosis, using 50 and 100µg/mL of oxaliplatin in the promastigotes and macrophages. In-vivo, the BALB/c mice were classified into three groups, receivin...
Source: Iranian Journal of Pharmaceutical Research - Category: Drugs & Pharmacology Source Type: research
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