scholarly journals Identification of a Novel Prostaglandin F2α Synthase in Trypanosoma brucei

2000 ◽  
Vol 192 (9) ◽  
pp. 1327-1338 ◽  
Author(s):  
Bruno Kilunga Kubata ◽  
Michael Duszenko ◽  
Zakayi Kabututu ◽  
Marc Rawer ◽  
Alexander Szallies ◽  
...  

Members of the genus Trypanosoma cause African trypanosomiasis in humans and animals in Africa. Infection of mammals by African trypanosomes is characterized by an upregulation of prostaglandin (PG) production in the plasma and cerebrospinal fluid. These metabolites of arachidonic acid (AA) may, in part, be responsible for symptoms such as fever, headache, immunosuppression, deep muscle hyperaesthesia, miscarriage, ovarian dysfunction, sleepiness, and other symptoms observed in patients with chronic African trypanosomiasis. Here, we show that the protozoan parasite T. brucei is involved in PG production and that it produces PGs enzymatically from AA and its metabolite, PGH2. Among all PGs synthesized, PGF2α was the major prostanoid produced by trypanosome lysates. We have purified a novel T. brucei PGF2α synthase (TbPGFS) and cloned its cDNA. Phylogenetic analysis and molecular properties revealed that TbPGFS is completely distinct from mammalian PGF synthases. We also found that TbPGFS mRNA expression and TbPGFS activity were high in the early logarithmic growth phase and low during the stationary phase. The characterization of TbPGFS and its gene in T. brucei provides a basis for the molecular analysis of the role of parasite-derived PGF2α in the physiology of the parasite and the pathogenesis of African trypanosomiasis.

Author(s):  
B. L. Soloff ◽  
T. A. Rado

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.


Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 347 ◽  
Author(s):  
Miguel Fontecha-Barriuso ◽  
Diego Martin-Sanchez ◽  
Julio Manuel Martinez-Moreno ◽  
Maria Monsalve ◽  
Adrian Mario Ramos ◽  
...  

Chronic kidney disease (CKD) is one of the fastest growing causes of death worldwide, emphasizing the need to develop novel therapeutic approaches. CKD predisposes to acute kidney injury (AKI) and AKI favors CKD progression. Mitochondrial derangements are common features of both AKI and CKD and mitochondria-targeting therapies are under study as nephroprotective agents. PGC-1α is a master regulator of mitochondrial biogenesis and an attractive therapeutic target. Low PGC-1α levels and decreased transcription of its gene targets have been observed in both preclinical AKI (nephrotoxic, endotoxemia, and ischemia-reperfusion) and in experimental and human CKD, most notably diabetic nephropathy. In mice, PGC-1α deficiency was associated with subclinical CKD and predisposition to AKI while PGC-1α overexpression in tubular cells protected from AKI of diverse causes. Several therapeutic strategies may increase kidney PGC-1α activity and have been successfully tested in animal models. These include AMP-activated protein kinase (AMPK) activators, phosphodiesterase (PDE) inhibitors, and anti-TWEAK antibodies. In conclusion, low PGC-1α activity appears to be a common feature of AKI and CKD and recent characterization of nephroprotective approaches that increase PGC-1α activity may pave the way for nephroprotective strategies potentially effective in both AKI and CKD.


Reproduction ◽  
2004 ◽  
Vol 128 (5) ◽  
pp. 537-543 ◽  
Author(s):  
Takashi Shimizu ◽  
Yasunori Miyahayashi ◽  
Masaki Yokoo ◽  
Yumi Hoshino ◽  
Hiroshi Sasada ◽  
...  

Growth differentiation factor-9 (GDF-9) is a growth factor secreted by oocytes in growing ovarian follicles. To investigate the ovarian function of GDF-9 in pigs, we first cloned porcine GDF-9 complementary DNA (cDNA), and then injected its gene fragments into the ovary in gilts. Porcine GDF-9 has open reading frame (ORF) homologies of 81.4%, 84.6%, 84.2%, 72.7% and 72.6% with its human, bovine, ovine, rat and mouse counterparts respectively. Regarding the deduced amino-acid sequence of the mature protein, the corresponding homologies reach 92.1%, 97.8%, 97.0%, 89.6% and 88.1% respectively. To investigate the role of GDF-9 in early folliculogenesis, the ovaries of 2-month-old prepubertal gilts were injected with GDF-9 gene fragments. The injection of porcine GDF-9 gene fragments resulted in an increase in the number of primary, secondary and tertiary follicles, concomitant with a decrease in the number of primordial follicles. These results indicated that exogenous GDF-9 can promote early folliculogenesis in the porcine ovary, and that a technique for direct ovarian injection of GFD-9 gene fragments may contribute to a novel therapy for prevention and treatment of infertility associated with ovarian dysfunction.


2019 ◽  
Vol 7 (10) ◽  
pp. 452 ◽  
Author(s):  
Xu ◽  
Guo ◽  
Li ◽  
Zhang ◽  
Wu ◽  
...  

Cryptosporidium parvum is a protozoan parasite that can cause moderate-to-severe diarrhea. Insulinase-like proteases (INS) are one of the largest protein families within the small proteome of the pathogen. However, their roles in C. parvum biology remain un-elucidated. In this study, a member of the protein family, INS-15 of C. parvum encoded by cgd3_4260, was cloned, expressed and characterized to understand its function. INS-15 and its domain I were expressed in Escherichia coli and polyclonal antibodies against the domain I and one specific polypeptide were prepared in rabbits. The role of INS-15 protein in the C. parvum invasion was preliminarily studied. Recombinant INS-15 protein and its domain I were successfully expressed in E. coli, together with various degraded products. The cgd3_4260 gene had a peak expression at 2 h of in vitro C. parvum culture, while the INS-15 protein was expressed in the mid-anterior region of sporozoites and the area of merozoites opposite to the nucleus. Anti-INS-15 domain I antibodies reduced the invasion of C. parvum sporozoites by over 40%. The anterior location of INS-15 in invasion stages and partial reduction of in vitro growth indicate that INS-15 plays some roles in the invasion or early development of C. parvum.


mSystems ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Arijit Bhattacharya ◽  
Mansi Sharma ◽  
Charles Packianathan ◽  
Barry P. Rosen ◽  
Philippe Leprohon ◽  
...  

The two main cellular metabolic one-carbon donors are reduced folates and S-adenosylmethionine, whose biosynthetic pathways have proven highly effective in chemotherapeutic interventions in various cell types. Sinefungin, a nucleoside analogue of S-adenosylmethionine, was shown to have potent activity against the protozoan parasite Leishmania. Here, we studied resistance to sinefungin using whole-genome approaches as a way to further our understanding of the role of S-adenosylmethionine in this parasite and to reveal novel potential drug targets. These approaches allowed the characterization of novel features related to S-adenosylmethionine function in Leishmania which could further help in the development of sinefungin-like compounds against this pathogenic parasite.


2007 ◽  
Vol 76 (1) ◽  
pp. 278-288 ◽  
Author(s):  
Karina Picazarri ◽  
Kumiko Nakada-Tsukui ◽  
Tomoyoshi Nozaki

ABSTRACT Autophagy is one of the three systems responsible for the degradation of cytosolic proteins and organelles. Autophagy has been implicated in the stress response to starvation, antigen cross-presentation, the defense against invading bacteria and viruses, differentiation, and development. Saccharomyces cerevisiae Atg8 and its mammalian ortholog, LC3, play an essential role in autophagy. The intestinal protozoan parasite Entamoeba histolytica and a related reptilian species, Entamoeba invadens, possess the Atg8 conjugation system, consisting of Atg8, Atg4, Atg3, and Atg7, but lack the Atg5-to-Atg12 conjugation system. Immunofluorescence imaging revealed that polymorphic Atg8-associated structures emerged in the logarithmic growth phase and decreased in the stationary phase and also increased in the early phase of encystation in E. invadens. Immunoblot analysis showed that the increase in phosphatidylethanolamine-conjugated membrane-associated Atg8 was also accompanied by the emergence of Atg8-associated structures during the proliferation and differentiation mentioned above. Specific inhibitors of class I and III phosphatidylinositol 3-kinases simultaneously inhibited both the growth of trophozoites and autophagy and also both encystation and autophagy in E. invadens. These results suggest that the core machinery for autophagy is conserved and plays an important role during proliferation and differentiation in Entamoeba.


2020 ◽  
Vol 82 (4) ◽  
pp. 261-275
Author(s):  
Ibrahem Wasti ◽  
Foo She Fui ◽  
Tan Qin Zhi ◽  
Cheh Wai Mun ◽  
Mohammad Hafiz Syukri Kassim ◽  
...  

Borneo is a biodiversity and ecotourism hotspot, yet one of its least-studied ecosystems is their limestone caves. Not many studies have been conducted on the role fungi play in tropical cave ecosystems, and no fungal surveys have been conducted in the caves of Sabah, Malaysia. Here, we assess the mycofloral diversity on bat and arthropod cadavers in one of the most popular ecotourism destinations of northern Borneo, Gomantong caves. Opportunistic sampling of cadavers within the Semud Hitam chamber of Gomantong cave yielded nine dead arthropods and four dead bats. Twenty-four culturable fungi were isolated, of which 14 morphological taxonomic units (MTU) were observed. Twelve of the 14 MTUs underwent molecular characterization of the ITS gene region to confirm identification. All fungi were Ascomycetes except for one Basidiomycete isolate. Aspergillus spp. had the highest occurrence (45.8%), followed by Penicillium spp. (25.0%), and Fusarium sp. (12.5%). Ceratobasidium sp., Diaporthe sp., Pestalotiopsis sp., and Xylaria feejeensis were isolated once each. No more than one fungal taxon was isolated from each arthropod cadaver, and not all arthropods yielded culturable fungi. Bat cadavers yielded 14 out of 24 isolates (58.3%), with the highest occurrence of the fungi sampled from their skin. Our results corroborate that bats and arthropods play a role in fungal dispersion and introduction in the cave because their exteriors are likely to harbor fungi they are exposed to in the environment. We also conclude that cadavers are important substrates for fungal growth and proliferation, perpetuating the role of fungi as important decomposers in caves. This study provides a baseline of information of the mycobiome of Bornean caves for future bioprospecting and potential biotechnological applications.


2007 ◽  
Vol 50 (2) ◽  
pp. 249-258 ◽  
Author(s):  
Alessandra Einsfeld Ferreira ◽  
Natália Canal ◽  
Daiana Morales ◽  
Daiane Bopp Fuentefria ◽  
Gertrudes Corção

The aim of this study was to characterize bacteriocins produced by 70 strains of Enterococcus mundtii.Four strains exhibited antibiotic activity towards Listeria innocua, L. monocytogenes, Lactobacillus plantarum, and Salmonella Enteritidis. They remained active under temperatures of up to 121ºC for 20 min, and under pH treatments that varied from 2.0 to 10.0. Antimicrobial activity was maintained during the storage test for 60 days under freezing. The kinetics of production revealed the peak activity of 1600 AU /mL during the logarithmic growth phase and the molecular weight found was approximately 3.0 kDa. The characterization of the products with antimicrobial activity indicated their proteic nature, presenting a typical kinetics of primary metabolite and a molecular weight similar to many purified enterocins.


2004 ◽  
Vol 379 (1) ◽  
pp. 183-190 ◽  
Author(s):  
G. AGRIMI ◽  
M. A. Di NOIA ◽  
C. M. T. MAROBBIO ◽  
G. FIERMONTE ◽  
F. M. LASORSA ◽  
...  

The mitochondrial carriers are a family of transport proteins that, with a few exceptions, are found in the inner membranes of mitochondria. They shuttle metabolites and cofactors through this membrane, and connect cytoplasmic functions with others in the matrix. SAM (S-adenosylmethionine) has to be transported into the mitochondria where it is converted into S-adenosylhomocysteine in methylation reactions of DNA, RNA and proteins. The transport of SAM has been investigated in rat liver mitochondria, but no protein has ever been associated with this activity. By using information derived from the phylogenetically distant yeast mitochondrial carrier for SAM and from related human expressed sequence tags, a human cDNA sequence was completed. This sequence was overexpressed in bacteria, and its product was purified, reconstituted into phospholipid vesicles and identified from its transport properties as the human mitochondrial SAM carrier (SAMC). Unlike the yeast orthologue, SAMC catalysed virtually only countertransport, exhibited a higher transport affinity for SAM and was strongly inhibited by tannic acid and Bromocresol Purple. SAMC was found to be expressed in all human tissues examined and was localized to the mitochondria. The physiological role of SAMC is probably to exchange cytosolic SAM for mitochondrial S-adenosylhomocysteine. This is the first report describing the identification and characterization of the human SAMC and its gene.


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