the laticifer system of chamaesyce thymifolia: a closed host environment for plant trypanosomatids.specimens of chamaesyce thymifolia (euphorbiaceae) infected and uninfected by phytomonas sp., a parasite of the trypanosomatidae family, were anatomically and ultrastructurally analyzed with special emphasis on the laticifer system. c. thymifolia presents branched non-articulated laticifers and was heavily infected by phytomonas sp. in all collection sites. infection was often observed in the initial stages inside the vacuole, when the latex particles could be seen. in intermediary stages of lat ...200010979610
trypanosomatidae produce acetate via a mitochondrial acetate:succinate coa transferase.hydrogenosome-containing anaerobic protists, such as the trichomonads, produce large amounts of acetate by an acetate:succinate coa transferase (asct)/succinyl coa synthetase cycle. the notion that mitochondria and hydrogenosomes may have originated from the same alpha-proteobacterial endosymbiont has led us to look for the presence of a similar metabolic pathway in trypanosomatids because these are the earliest-branching mitochondriate eukaryotes and because they also are known to produce aceta ...19989501211
rotenone-sensitive mitochondrial potential in phytomonas serpens: electrophoretic ca(2+) accumulation.phytomonas sp. are flagellated trypanosomatid plant parasites that cause diseases of economic importance in plantations of coffee, oil palm, cassava and coconuts. here we investigated ca(2+) uptake by the vanadate-insensitive compartments using permeabilized phytomonas serpens promastigotes. this uptake occurs at a rate of 1.13+/-0.23 nmol ca(2+) mg x protein(-1) min(-1). it is completely abolished by the h(+) ionophore fccp and by valinomycin and nigericin. it is also inhibited by 2 microm ruth ...200415178471
impairment of growth of leishmania donovani by trypanosoma brucei during co-culture.cells of leishmania donovani in co-culture with trypanosoma brucei, were severely affected in their growth, resulting in swelling and subsequent lysis. similar effects were also observed when crithidia luciliae or phytomonas sp. were co-cultured with t. brucei. direct contact between the cells under investigation and t. brucei was necessary because t. brucei did not hamper the growth of the other trypanosomatids, when separated by a filter with 0.2 microns pore size. examination of this phenomen ...19921461680
a family of highly conserved glycosomal 2-hydroxyacid dehydrogenases from phytomonas sp.phytomonas sp. contains two malate dehydrogenase isoforms, a mitochondrial isoenzyme with a high specificity for oxaloacetate and a glycosomal isozyme that acts on a broad range of substrates (uttaro, a. d., and opperdoes, f.r. (1997) mol. biochem. parasitol. 89, 51-59). here, we show that the low specificity of the latter isoenzyme is the result of a number of recent gene duplications that gave rise to a family of glycosomal 2-hydroxyacid dehydrogenase genes. two of these genes were cloned, seq ...200010900211
identification of a surface metalloproteinase on 13 species of leishmania isolated from humans, crithidia fasciculata, and herpetomonas samuelpessoai.promastigotes of thirteen species of leishmania isolated from human patients, as well as l. enriettii, crithidia fasciculata and herpetomonas samuelpessoai, were examined for the expression of an amphiphilic, surface-oriented metalloproteinase by surface radioiodination of living cells, fractionation by triton x-114 extraction and phase separation, and zymogram analysis by fibrinogen-sds-page. in all species of leishmania, and the two monoxenous trypanosomatid parasites of insects, an ectoprotei ...19921348597
unexpected diversity in u6 snrna sequences from trypanosomatids.we have isolated and sequenced the genes for the trans-spliceosomal u6 small nuclear rnas (snrnas) from the trypanosomatid species leishmania mexicana (lm) and phytomonas sp. (ps). compared with the trypanosoma brucei (tb) u6 snrna, the lm u6 snrna contains only a single additional g-c bp in the 5' terminal stem-loop. in contrast, the ps u6 snrna sequence contains a g-->c change at the last nucleotide of the highly conserved and functionally important acagag hexanucleotide and three additional c ...19957642127
characterization of carbohydrate metabolism and demonstration of glycosomes in a phytomonas sp. isolated from euphorbia characias.phytomonas sp. isolated from euphorbia characias was adapted to sdm-79 medium. cells isolated in the early stationary phase of growth were analyzed for their capacity to utilize plant carbohydrates for their energy requirements. the cellulose-degrading enzymes amylase, amylomaltase, invertase, carboxymethylcellulase, and the pectin-degrading enzymes polygalacturonase and oligo-d-galactosiduronate lyase were present in phytomonas sp. and were all, except for amylomaltase, excreted into the extern ...19921435859
purification and characterization of two iron superoxide dismutases of phytomonas sp. isolated from euphorbia characias (plant trypanosomatids).two superoxide dismutases (sodi and sodii) have been purified by differential centrifugation, fractionation with ammonium sulphate followed by chromatographic separation (ionic exchange and affinity), from a plant trypanosomatid isolated from euphorbia characias, and then characterized for several biochemical properties. both enzymes were insensitive to cyanide but sensitive to hydrogen peroxide, properties characteristic of iron-containing superoxide dismutase. sodi had a molecular mass of appr ...200415267114
cytotoxicity of three new triazolo-pyrimidine derivatives against the plant trypanosomatid: phytomonas sp. isolated from euphorbia characias.there is no effective chemotherapy against diseases caused by phytomonas sp., a plant trypanosomatid responsible for economic losses in major crops. we tested three triazolo-pyrimidine complexes [two with pt(ii), and another with ru(iii)] against promastigotes of phytomonas sp. isolated from euphorbia characias. the incorporation of radiolabelled precursors, ultrastructural alterations and changes in the pattern of metabolite excretion were examined. different degrees of toxicity were found for ...200415558180
three-dimensional reconstruction of glycosomes in trypanosomatids of the genus aided three dimensional (3-d) reconstruction of cells from two isolates of protozoa of the genus phytomonas, trypanosomatids found in plants, were made from 0.3 microm thick sections, imaged on a zeiss 902 electron microscope with a energy filter for in ellastically scattered electrons, in order to obtain information about glycosomal shape diversity. direct counts of peroxisomes (glycosomes) from phytomonas sp. from chamaesyce thymifolia indicated that there were fewer glycosomes per ce ...199518621296
comparison and evolutionary analysis of the glycosomal glyceraldehyde-3-phosphate dehydrogenase from different this work, we present the sequences and a comparison of the glycosomal gapdhs from a number of kinetoplastida. the complete gene sequences have been determined for some species (crithidia fasciculata, herpetomonas samuelpessoai, leptomonas seymouri, and phytomonas sp), whereas for other species (trypanosoma brucei gambiense, trypanosoma congolense, trypanosoma vivax, and leishmania major), only partial sequences have been obtained by pcr amplification. the structure of all available glycosoma ...19989847415
characterisation of the two malate dehydrogenases from phytomonas sp. purification of the glycosomal isoenzyme.two nad(h)-dependent malate dehydrogenase (mdh) isoenzymes were detected in phytomonas isolated from the lactiferous tubes of euphorbia characias. the total specific activity in crude extracts using oxaloacetate as substrate was 3.3 u mg-1 of protein. the two isoenzymes had isoelectric points of 6.0 and 7.2, respectively. the acidic isoform represented 80% of the total activity in the cell and was present in the glycosome. it was purified to homogeneity by a method involving hydrophobic interact ...19979297700
the glycoinositol-phospholipids of phytomonas.the phytomonas spp. are trypanosomatid parasites of plants. a polar glycolipid fraction of a phytomonas sp., isolated from the plant euphorbia characias and grown in culture, was fractionated into four major glycolipid species (phy 1-4). the glycolipids were analysed by chemical and enzymic modifications, composition and methylation analyses, electrospray mass spectrometry and microsequencing after hno2 deamination and nab3h4 reduction. the water-soluble headgroup of the phy2 glycolipid was also ...19957487886
an m(r) 145,000 low-density lipoprotein (ldl)-binding protein is conserved throughout the kinetoplastida view of the importance of the low-density lipoprotein (ldl)-receptor in trypanosoma brucei, we have examined whether other bloodstream trypanosomes of medical and veterinary importance (t.b. rhodesiense, t. equiperdum, t. vivax, t. congolense), but also related parasites developing in mammalian (leishmania donovani) and non-mammalian hosts (crithidia luciliae and phytomonas sp. isolated from euphorbia), would possess an ldl-receptor of their own. (1) all these parasites specifically accumulat ...19968919994
the multifunctional isopropyl alcohol dehydrogenase of phytomonas sp. could be the result of a horizontal gene transfer from a bacterium to the trypanosomatid lineage.isopropyl alcohol dehydrogenase (ipdh) is a dimeric mitochondrial alcohol dehydrogenase (adh), so far detected within the trypanosomatidae only in the genus phytomonas. the cloning, sequencing, and heterologous expression of the two gene alleles of the enzyme revealed that it is a zinc-dependent medium-chain adh. both polypeptides have 361 amino acids. a mitochondrial targeting sequence was identified. the mature proteins each have 348 amino acids and a calculated molecular mass of 37 kda. they ...200312853449
characterization of proteinases in trypanosomatids.proteinases are important factors in the pathogenicity of many parasitic diseases. in this study, the proteolytic activities of 10 trypanosomatids from five different genera (crithidia, phytomonas, endotrypanum, trypanosoma and leishmania) were determined by sds-page containing copolymerized gelatin as substrate. in almost all species we could detect two proteolytic classes, cysteine- and metalloproteinases, based on the inhibition of their activities by e-64 and 1,10-phenanthroline, respectivel ...19948081271
glycerol kinase of trypanosoma brucei. cloning, molecular characterization and mutagenesis.trypanosoma brucei contains two tandemly arranged genes for glycerol kinase. the downstream gene was analysed in detail. it contains an orf for a polypeptide of 512 amino acids. the polypeptide has a calculated molecular mass of 56 363 da and a pi of 8.6. comparison of the t. brucei glycerol kinase amino-acid sequence with the glycerol kinase sequences available in databases revealed positional identities of 39.0-50.4%. the t. brucei glycerol kinase gene was overexpressed in escherichia coli cel ...200010759857
aerobic and anaerobic glucose metabolism of phytomonas sp. isolated from euphorbia characias.metabolic studies on phytomonas sp. isolated from the lactiferous tubes of the latex-bearing spurge euphorbia characias indicate that glucose is the preferred energy and carbon substrate during logarithmic growth. in stationary phase cells glucose consumption was dramatically reduced. glucose consumption and end-product formation were measured on logarithmically growing cells, both under aerobic (air and 95% o2/5% co2) and anaerobic (95% n2/5% co2 and 100% n2) conditions. the rate of glucose con ...19947870136
adenylyl cyclase and g-proteins in phytomonas.phytomonas sp. membranes have an adenylyl cyclase activity which is greater in the presence of mn2+ than with mg2+. the mg2+ and mn2+ activity ratio varies from one membrane preparation to another, suggesting that the adenylyl cyclase has a variable activation state. a[35s]gtp-gamma-s-binding activity with a kd of 171 nm was detected in phytomonas membranes. incubation of these membranes with activated cholera or pertussis toxin and [adenylate 23p]nad+ led to incorporation of radioactivity into ...199512075624
ultrastructural analysis of phytomonas species from euphorbia pinea reveals trans-cytoplasmic filaments 10 nm in diameter.phytomonas sp. derived from euphorbia pinea are digenetic plant trypanosomes that are transmitted by the squashbug stenocephalus agilis and exist exclusively as promastigotes. the stable sub-pellicular microtubular array, the flagellar axoneme and the paraflagellar rod represent the major cytoskeletal components common to all trypanosomes. the work described in this paper examines in detail the ultrastructural morphology of the organism and highlights a number of novel structural features, and i ...200011068818
fatty acid and sterol composition of three phytomonas species.fatty acid and sterol analysis were performed on phytomonas serpens and phytomonas sp. grown in chemically defined and complex medium, and p. françai cultivated in complex medium. the three species of the genus phytomonas had qualitatively identical fatty acid patterns. oleic, linoleic, and linolenic were the major unsaturated fatty acids. miristic and stearic were the major saturated fatty acids. ergosterol was the only sterol isolated from phytmonas sp. and p. serpens grown in a sterol-free me ...199910446013
kinetoplast dna minicircles of phloem-restricted phytomonas associated with wilt diseases of coconut and oil palms have a two-domain structure.we report the cloning and sequencing of the first minicircle from a phloem-restricted, pathogenic phytomonas sp. (hart 1) isolated from a coconut palm with hartrot disease. the minicircle possessed a two-domain structure of two conserved regions, each containing three conserved sequence blocks (csb). based on the sequence around csb 3 from hart 1, pcr primers were designed to allow specific amplification of phytomonas minicircles. this primer pair demonstrated specificity for at least six groups ...200111728717
purification and characterisation of a novel iso-propanol dehydrogenase from phytomonas alcohol dehydrogenase with two identical subunits and a subunit molecular mass of 40,000 was purified from phytomonas sp. isolated from the lactiferous tubes of euphorbia characias. digitonin titration and subcellular fractionation suggest that the enzyme is present in the mitochondrion. it utilises as substrates, primary and secondary alcohols, is specific for nad+ as coenzyme and is inhibited by hgcl(2). the ph optimum for the oxidation of ethanol is 9.5, and for the reverse reaction 8.5. t ...19979106194
axenic cultivation of a pathogenic phytomonas species isolated from tomato fruit, and from its phytophagic insect vector, phthia picta (hemiptera: coreidae).axenic cultures of phytomonas sp. were obtained from naturally infected tomatoes and from phthia picta, a predator of tomato plants, by using a biphasic medium with roitman's complex medium overlaying rabbit blood-agar slants. light and electron microscopy of both isolates showed a similarity of morphological characteristics among the flagellates in fresh material or after cultivation. other properties, including their agglutinability with the haemolymph of phthia picta, suggest that these isola ...19938243106
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