Abstract:
:Whilst the schistosome tegument has been intensively studied there is little information about processes in the gut, the other major interface with the bloodstream, apart from the well characterised cascade of proteases involved in haemoglobin digestion. To gain insights into gut function we undertook a proteomic analysis of worm vomitus and performed in vitro erythrocyte feeding experiments. Additional to known gut constituents we identified two proline carboxypeptidases as well as enzymes capable of hydrolysing carbohydrate and ester linkages. Schistosome serpin and a2 macroglobulin protease inhibitors were also present. A series of "carrier proteins", principally lipid-binding saposins and cholesterol-binding NPC-2 were also detected, together with ferritins and calumenin that bind ferric iron and calcium, respectively. The presence of these lysosomal proteins and other lysosomal markers in the vomitus, plus observations on the cytology of the gut epithelium suggest that lysosomes directly secrete their contents into the gut lumen to digest incoming plasma constituents as well as haemoglobin. It is also likely that the carrier proteins function to sequester essential organic and inorganic nutrients for uptake into the epithelium. The feeding experiments indicate that erythrocytes are uncoated as they pass through the oesophagus, intersecting with its secretions, whilst the endocytosis of space-filling dextran into the gut epithelium provides a potential mechanism for carrier uptake by macropinocytosis.
journal_name
Mol Biochem Parasitoljournal_title
Molecular and biochemical parasitologyauthors
Hall SL,Braschi S,Truscott M,Mathieson W,Cesari IM,Wilson RAdoi
10.1016/j.molbiopara.2011.05.002subject
Has Abstractpub_date
2011-09-01 00:00:00pages
18-29issue
1eissn
0166-6851issn
1872-9428pii
S0166-6851(11)00119-8journal_volume
179pub_type
杂志文章abstract::Schistosoma mansoni eggs, consisting of an ovum surrounded by nutritive vitelline cells packaged in a tanned protein shell, are produced by paired worms residing in the mesenteric veins of the human host. The vitelline cells are degraded as the larval miracidium matures, the fully developed egg either crossing the gut...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2010.10.005
更新日期:2011-02-01 00:00:00
abstract::The merozoite surface protein-1 of the human malaria parasite Plasmodium falciparum undergoes an extracellular proteolytic cleavage (secondary processing) intrinsic to successful erythrocyte invasion. In the T9/96 clone of P. falciparum the protease responsible has been characterised as a membrane-associated, calcium-...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(93)90182-w
更新日期:1993-11-01 00:00:00
abstract::A genomic clone, pTt21, containing DNA apparently transcribed specifically in Trypanosoma cruzi trypomastigotes, was obtained by differentially screening a genomic library with trypomastigote and epimastigote cDNA. This 3444-bp clone contained open reading frames at each end, separated by a 1.8-kb non-coding region. T...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(92)90159-h
更新日期:1992-11-01 00:00:00
abstract::A gene which overexpresses a 36-kDa protein (p36) in tunicamycin-resistant Leishmania was mapped by transfection and overexpression to the upstream region of the drug maker in the extrachromosomal amplicon. Complete sequencing of this region revealed a single open reading frame of about 1 kb. Authenticity of the clone...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(94)90147-3
更新日期:1994-08-01 00:00:00
abstract::Some restriction fragments of kinetoplast minicircles from several trypanosomatid species (Leishmania tarentolae, Trypanosoma brucei, T. equiperdum, Herpetomonas muscarum, Crithidia fasciculata, but not T. cruzi) migrate anomalously on polyacrylamide gels. This behavior is probably due to a natural curvature of the he...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(84)90084-7
更新日期:1984-07-01 00:00:00
abstract::We have compared a total of 44 recognition sites for 12 restriction endonucleases on the 20 kilobase pair maxi-circle of kinetoplast DNA from nine Trypanosoma brucei stocks, four which are known to be infective to man (tow 'gambiense' and two 'rhodesiense' variants). In addition to five polymorphic sites, these DNAs d...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(81)90011-6
更新日期:1981-06-01 00:00:00
abstract::A family of Schistosoma mansoni proteins (18-22 kDa, pI 5.3-5.8) are biosynthesized in juvenile worms and immunoprecipitated by antibodies uniquely present in protective Fischer rat antiserum. A cDNA clone, lambda gt11-40, expressing epitopes common to this protein family was used to obtain a genomic DNA clone, by hyb...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(91)90132-p
更新日期:1991-11-01 00:00:00
abstract::Recombinant proteins and synthetic peptides representing various sequences of gp82, a surface glycoprotein of Trypanosoma cruzi metacyclic trypomastigotes implicated in mammalian cell invasion, were used in this study aiming at the identification of the domain(s) of this molecule required for interaction with target c...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/s0166-6851(96)02626-6
更新日期:1996-06-01 00:00:00
abstract::The steady-state level of the hsp70 mRNAs of Trypanosoma cruzi cultured at different temperatures and growth conditions has been analyzed by Northern blotting. We show that only one size class of hsp70 mRNA, of about 2.2 kb, is transcribed from the hsp70 cluster and that its transcription is constitutive at 28 degrees...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(92)90022-c
更新日期:1992-07-01 00:00:00
abstract::Sequestration of Plasmodium falciparum infected erythrocytes in the cerebral circulation is strongly implicated in the pathogenesis of cerebral malaria. From previous studies it was postulated that genes essential for cytoadherence were located on the right arm of chromosome 9 as P. falciparum isolates with a deletion...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(94)90092-2
更新日期:1994-09-01 00:00:00
abstract::Both the alpha- and beta-tubulin genes of Leishmania enriettii are encoded by mRNA of 2.0-2.2 kb in length. We have shown previously that the alpha- and beta-tubulin genes are arranged in separate, tandem repeats of 2 and 4 kb, respectively, and now report the mapping of mature mRNA onto these cloned genes. Here we sh...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(85)90029-5
更新日期:1985-04-01 00:00:00
abstract::Cryptosporidiosis is an obligate intracellular pathogen causing diarrhea. Merozoite egress is essential for infection to spread between host cells. However, the mechanisms of egress have yet to be defined. We hypothesized that Cyclic GMP-Dependent Protein Kinase G (PKG) may be involved in Cryptosporidium egress. In th...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2020.111277
更新日期:2020-05-01 00:00:00
abstract::Glutamate-cysteine ligase (GCL) is a heterodimer enzyme composed of a catalytic subunit (GCLC) and a modifier subunit (GCLM). This enzyme catalyses the synthesis of γ-glutamylcysteine, a precursor of glutathione. cDNAs of the putative glutamate-cysteine ligase catalytic (Ace-GCLC) and modifier subunits (Ace-GCLM) of A...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2014.07.003
更新日期:2014-08-01 00:00:00
abstract::Plasmodium falciparum extensively modifies the infected red blood cell (RBC), resulting in changes in deformability, shape and surface properties. These alterations suggest that the RBC cytoskeleton is a major target for modification during infection. However, the molecular mechanisms leading to these changes are larg...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2017.06.002
更新日期:2017-09-01 00:00:00
abstract::The extent of structural conservation of the Plasmodium falciparum sporozoite surface protein gene, STARP, recently characterized in the T9/96 clone, has been analyzed using the polymerase chain reaction. Results from Ivory Coast and Thai clones, field isolates originating from Brazil and Kenya and laboratory-maintain...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(94)00138-3
更新日期:1994-10-01 00:00:00
abstract::Cryptosporidium spp. are waterborne apicomplexan parasites responsible for outbreaks of diarrheal disease worldwide. Antigens involved in zoite invasion into host cells have been the focus of many investigations as these may prove to be good vaccine candidates. gp40/15 is a zoite antigen synthesized as a precursor pro...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2007.07.010
更新日期:2007-11-01 00:00:00
abstract::We have examined changes in the relative synthesis of individual proteins in promastigotes of Leishmania major subjected to decreasing serum levels in vitro. We observed increases in the relative synthesis of the putative heat-shock proteins of 82 and 70 kDa and of proteins of 79 and 41 kDa but decreases in the synthe...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(89)90136-9
更新日期:1989-06-01 00:00:00
abstract::Trypanosoma cruzi presents high genetic diversity and parasite isolates show remarkable differences in biological parameters. In this study, we evaluated whether DNA microarrays containing CL Brener cDNAs can be used for comparative genomics and for the analysis of gene expression in T. cruzi. We constructed a prototy...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2004.06.017
更新日期:2004-12-01 00:00:00
abstract::TgPrx2 represents a recently discovered cytosolic 1-Cys peroxiredoxin (Prx) from the intracellular parasite Toxoplasma gondii. Over-expression of the respective gene confers protection against H(2)O(2), suggesting that the protein possesses peroxidase activity. According to the current nomenclature eukaryotic typical ...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2004.12.008
更新日期:2005-03-01 00:00:00
abstract::Peptidomimetic inhibitors of mammalian zinc metalloproteases have been tested as potential agents for intervention in disease caused by kinetoplastid protozoa. Certain metalloprotease inhibitors were able to inhibit the release of variant surface glycoprotein from cultured transgenic procyclic Trypanosoma brucei, conf...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/s0166-6851(01)00244-4
更新日期:2001-04-25 00:00:00
abstract::Plasmodium falciparum invades human erythrocytes by redundant pathways. Unlike Plasmodium vivax that has one Duffy Binding-Like (DBL) receptor, P. falciparum has four members of the DBL receptor family. Furthermore, one of these DBL genes, BAEBL, has polymorphisms at four amino acids in region II; each polymorphism bi...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2009.06.006
更新日期:2009-11-01 00:00:00
abstract::The complete sequences of the genomic small subunit ribosomal RNA gene from two Phytomonas isolates: one associated with palm pathologies (P. cocos FGuiana) and one found in lactiferous plants with no apparent pathology (P. Euphorbe Senegal), were analyzed. Partial sequences from a number of other Phytomonas isolates ...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(95)00029-z
更新日期:1995-04-01 00:00:00
abstract::Seven beta-naphthylamine-linked peptides were tested as substrates for a previously described thiol proteinase of adult Schistosoma mansoni. The enzyme was not active on carbobenoxy-arginyl-arginyl-4-methoxy-2-naphthylamide and carbobenzoxy-alanyl-arginyl-arginyl-4-methoxy-2-naphthylamide. Enzyme activity was maximal ...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(81)90029-3
更新日期:1981-11-01 00:00:00
abstract::Most of the signaling pathways are regulated by reversible phosphorylation-dephosphorylation which involves enzymes- kinases and phosphatases. Current knowledge about the protein phosphatases in parasites like Trypanosoma and Leishmania is very minimal despite their enormousity. In present study, full length ORF of Le...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2018.06.005
更新日期:2018-07-01 00:00:00
abstract::Sj23, the 23-kDa target antigen in Schistosoma japonicum adult worms of the hybridoma monoclonal antibody (mAb) I-134, has been identified and cloned from cDNA libraries, mAb I-134 has been successfully used in immunodiagnostic assays to detect S. japonicum infection in Philippine patients. Sequence analysis has shown...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(91)90165-3
更新日期:1991-09-01 00:00:00
abstract::In order to clarify the interpretation of molecular karyotype polymorphisms in Leishmania, the three smallest chromosomes from five cloned strains of Leishmania infantum were identified by chromosome-specific anonymous DNA probes. The presence in the same clone of homologous chromosomes of a different size was demonst...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(91)90053-9
更新日期:1991-06-01 00:00:00
abstract::The usefulness of random amplified polymorphic DNA markers (RAPD) was assayed in an attempt to discriminate among species, strains and individuals within the genus Schistosoma. Depending on the species, 40-50 arbitrary decamer oligonucleotides were used as primers to amplify total DNA by the polymerase chain reaction ...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(93)90219-n
更新日期:1993-06-01 00:00:00
abstract::After a single intravenous injection of suramin the rate of removal of the drug from the plasma into other tissue compartments of the rat is independent of initial concentration. The data can be fitted to the sum of two exponential functions, consistent with a two-compartment, open model system. Trypanosomes take up o...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(80)90050-x
更新日期:1980-10-01 00:00:00
abstract::Cytoadherence of infected erythrocytes is a hallmark of Plasmodium falciparum infection and a key determinant in the particular virulence of this species. Infected erythrocytes bind a variety of host receptors but certain adhesion traits are associated with more severe disease. A large, diverse protein family named P....
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/s0166-6851(03)00099-9
更新日期:2003-06-01 00:00:00
abstract::Four Trypanosoma cruzi genomic DNA fragments carrying different TcP2 beta genes have been isolated and sequenced. Three of them had a single TcP2 beta gene, while the 3.8-kb-long DNA segment encoding the TcP2 beta-H1.8 locus showed two TcP2 beta genes arranged in tandem. These genes were physically connected by a 428-...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(94)00026-3
更新日期:1994-04-01 00:00:00