Abstract：
:The mechanism controlling transcription at several telomeric expression sites for variable surface glycoprotein (VSG) genes in Trypanosoma brucei is unknown. Most VSG genes in expression sites have a region 5' of the gene lacking restriction enzyme sites. This 'barren region' is involved in recombination events which replace the VSG gene with a copy of a different, non-telomeric, VSG gene leading to a switch in VSG expression. Alterations in the barren region have been considered as possible modulators of expression of the adjacent VSG gene in other switching events where no gene replacement occurs. The expressed copy of the ILTat 1.3 VSG gene remains in its expression site, on a 160 kilobase (kb) chromosome, in trypanosomes not expressing the ILTat 1.3 VSG. Here we report the complete sequence of the barren region adjacent to this gene, determined both from trypanosomes expressing the gene and from those that are not. The sequence is identical whether or not the ILTat 1.3 VSG gene is expressed. This confirms that alterations in the barren region are not involved in modulation of expression of the gene, as suggested by restriction enzyme mapping. Sequence data from the 5' flanking region of a second telomeric gene copy on an 80 kb minichromosome, and from the ILTat 1.3 expression site after replacement of the ILTat 1.3 gene by another gene from a minichromosome, provide evidence that telomeric VSG genes on minichromosomes are also flanked by long repeat arrays, and that these arrays are involved in inter-telomeric gene replacements as well as replacements by non-telomeric genes.
journal_name
Mol Biochem Parasitoljournal_title
Molecular and biochemical parasitologyauthors
Shah JS,Young JR,Kimmel BE,Iams KP,Williams ROdoi
10.1016/0166-6851(87)90103-4subject
Has Abstractpub_date
1987-06-01 00:00:00pages
163-74issue
2eissn
0166-6851issn
1872-9428pii
0166-6851(87)90103-4journal_volume
24pub_type
杂志文章abstract：:The 5' and 3' regions adjacent to the initiation codon in 22 Plasmodium falciparum sequences were examined. A 5' consensus sequence (AAAA/ATG) was found. Although P. falciparum non-translated DNA is A-rich, A occurred significantly more frequently in the 4 positions preceding the initiation ATG than in adjacent non-tr...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(90)90112-y
更新日期：1990-08-01 00:00:00
abstract：:Two cloned chromosomal segments of the hemoprotozoan Babesa bovis bearing genes from the polymorphic locus designated BabR were inserted into plasmid vector YCp19, cloned in Escherichia coli and then introduced into Saccharomyces cerevisiae. Both genes were transcribed producing poly(A+) RNAs. In at least one case, th...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(84)90044-6
更新日期：1984-05-01 00:00:00
abstract：:The schizont stage of the protozoan parasite Theileria annulata reversibly transforms bovine monocytes into an immortalised and metastatic state. We have been studying T. annulata induction of host matrix metalloproteinases (MMP) which are involved in parasite dissemination and pathogenesis. We have observed that prol...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(99)00213-3
更新日期：2000-02-25 00:00:00
abstract：:Antigenic variation in African trypanosomes proceeds by switching between different variant surface glycoprotein (VSG) molecules, whose extensive epitope differences enable evasion of antibody responses. Each trypanosome has approximately 1000 basic copy VSG genes inside chromosomes and a subset located at telomeres. ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(96)02642-4
更新日期：1996-07-01 00:00:00
abstract：:Antibodies raised against a Leishmania major recombinant promastigote surface antigen 2 (PSA-2) fragment recognized three major polypeptides of approximate M(r) 96,000, 80,000 and 50,000 in promastigotes of three Israeli isolates of L. major including the cloned line LRC-L137-V121, but detected a different array of po...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(94)90100-7
更新日期：1994-09-01 00:00:00
abstract：:Superposition of two unrelated processes, namely terminal reticulocyte differentiation and synchronous plasmodial development, takes place in experimental infections of Plasmodium berghei. The first process is shown to be responsible for the appearance of some discrete restriction bands of host origin when DNA is extr...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(89)90107-2
更新日期：1989-11-01 00:00:00
abstract：:Trypanosoma brucei is a unicellular parasite that is transmitted from one mammalian host to the next by tsetse flies. The expression of many trypanosome genes is regulated during the life cycle but there is no evidence for developmental control of transcription by RNA polymerase II. T. brucei expresses at least two he...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(95)02503-0
更新日期：1995-12-01 00:00:00
abstract：:Replication of kinetoplast DNA minicircles in Crithidia fasciculata occurs by a unidirectional mechanism involving continuous synthesis of one strand (L strand) and discontinuous synthesis of the complementary strand (H strand). L-strands are initiated by RNA priming at alternate origins (A and B) resulting in daughte...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(01)00272-9
更新日期：2001-06-01 00:00:00
abstract：:The FMRFamide-related peptides (FaRPs), KHEYLRFamide (AF2) and KSAYMRFamide (PF3) were structurally characterised from the parasitic nematode of sheep, Haemonchus contortus (MH isolate). Both peptides were sequenced in a single gas-phase sequencing run and their structure confirmed by mass spectrometry which identifie...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(99)00057-2
更新日期：1999-05-25 00:00:00
abstract：:Beta 1,3-glucan recognition proteins (GRP) have specific affinity for beta 1,3-glucan, a component on the surface of fungi and bacteria. By interacting with beta 1,3-glucan, GRP initiates activation of prophenoloxidase, a key enzyme in the signaling pathway leading to melanotic encapsulation in invertebrates. In this ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2004.09.009
更新日期：2005-01-01 00:00:00
abstract：:Benznidazole is the main drug used to treat Trypanosoma cruzi infections. However, frequent instances of treatment failure have been reported. To better understand potential resistance mechanisms, we analysed three clones isolated from a single parasite population that had undergone benznidazole-selection. These clone...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2014.01.002
更新日期：2014-01-01 00:00:00
abstract：:Schistosoma mansoni is a major causative agent of schistosomiasis, an important parasitic disease that constitutes a severe health problem in developing countries. Even though an effective treatment exists, it does not prevent re-infection and the development of an effective vaccine still remains the most desirable me...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2009.02.006
更新日期：2009-07-01 00:00:00
abstract：:The ATP-binding cassette (ABC) transporters are one of the largest evolutionarily conserved families of proteins. They are characterized by the presence of nucleotide-binding domains (NBDs), which are highly conserved among organisms. In the present study, we used human and protozoan ABC sequences, and ATP-binding con...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2006.02.008
更新日期：2006-06-01 00:00:00
abstract：:Genomic structure has been determined for a gene encoding a host-protective antigen of the parasitic platyhelminth Taenia ovis. An incomplete cDNA, known as 45W, encodes the protective antigen. Southern hybridisation experiments using 45W cDNA as a probe, revealed that the 45W gene was a member of a multigene family. ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(94)00104-u
更新日期：1995-07-01 00:00:00
abstract：:The activities of carbamoylphosphate synthase, aspartate transcarbamoylase, dihydroorotase, orotate phosphoribosyl transferase and orotidine-5'-phosphate decarboxylase, five of the six enzymes of pyrimidine biosynthesis, have been measured in Crithidia fasciculata, Trypanosoma cruzi, Leishmania major, Trichomonas vagi...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(81)90094-3
更新日期：1981-02-01 00:00:00
abstract：:The smallest chromosome (230 kb) of the HU3 stock of Leishmania donovani was purified from an orthogonal field alternation (OFAGE) gel, digested with PstI and cloned into the plasmid pUC13. When used to probe Southern blots of OFAGE gels, the cloned sequences recognised one or more large chromosomes in all L. donovani...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(90)90198-u
更新日期：1990-01-01 00:00:00
abstract：:In Leishmania mexicana two genes were detected coding for different isoforms of the glycolytic enzyme phosphoglycerate kinase. This situation contrasts with that observed in other Trypanosomatidae (Trypanosoma brucei, Trypanosoma congolense, Crithidia fasciculata) analyzed previously, which all contain three different...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(97)00152-7
更新日期：1997-12-01 00:00:00
abstract：:Toxoplasma gondii is an obligate intracellular parasite that causes toxoplasmosis in humans and animals. To invade host cells, T. gondii deploys the contents of its apically oriented secretory organelles that include the micronemes. Contained within the micronemes are proteins that possess adhesive motifs resembling t...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2003.12.001
更新日期：2004-04-01 00:00:00
abstract：:Cryptosporidium parvum is a protozoan parasite which produces self-limited disease in immunocompetent hosts and devastating, persistent diarrhea in immunocompromised individuals. There is no effective treatment for cryptosporidiosis and little is known about the basic biology of the organism. Cloning and sequence anal...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(98)00119-4
更新日期：1998-10-30 00:00:00
abstract：:The Giardia lamblia genome consists of 12 Mb divided among 5 chromosomes ranging in size from approximately 1 to 4 Mb. The assembled contigs of the genotype A1 isolate, WB, were previously mapped along the 5 chromosomes on the basis of hybridization of plasmid clones representing the contigs to chromosomes separated b...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2011.07.008
更新日期：2011-12-01 00:00:00
abstract：:The monosaccharide composition of an affinity-purified family of antigenically-related Trichinella spiralis larval glycoproteins was determined by gas chromatography/mass spectrometry. This group of 6 major glycoproteins, designated TSL-1, originates in the muscle stage (L1) larval stichosome. They are present on the ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(93)90155-q
更新日期：1993-09-01 00:00:00
abstract：:Repetitive DNA sequences of the Leishmania donovani genome have been identified by screening a recombinant DNA library made by cloning sheared genomic DNA into the vector pAT153. Bacterial clones containing a highly repetitive DNA sequence have been isolated. DNA sequencing has shown that this sequence is composed of ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(88)90114-4
更新日期：1988-05-01 00:00:00
abstract：:Natural antisense transcripts (NATs) are non-protein coding RNAs that could play an important role in regulating the expression of their counterpart protein encoding sense transcript. Although NATs are widespread in most eukaryotic genomes, very little is known about their functions. This study focuses on gaining a be...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2020.111334
更新日期：2020-11-01 00:00:00
abstract：:Trypanosoma brucei harbors a unique multifunctional RNA polymerase (pol) I which transcribes, in addition to ribosomal RNA genes, the gene units encoding the major cell surface antigens variant surface glycoprotein and procyclin. In consequence, this RNA pol I is recruited to three structurally different types of prom...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2006.02.023
更新日期：2006-09-01 00:00:00
abstract：:Antibodies were affinity purified from crude antiserum by elution from the 24 kDa region of preparative one-dimensional Western blots containing immobilized adult Schistosoma mansoni inner bilayer membrane proteins. They were shown to be specific for a single acidic polypeptide complex, Smgp24, following immunoblottin...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(88)90167-3
更新日期：1988-11-01 00:00:00
abstract：:Leishmania parasites cycle between the alimentary tract of a sandfly vector as free-living promastigotes and the acidified phagolysosomes of the vertebrate host macrophage as aflagellated amastigotes. The differentiation process can be mimicked in host-free culture by switching promastigotes (e.g. 25 degrees C, neutra...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2008.12.012
更新日期：2009-05-01 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：:Amastigotes of Leishmania major were isolated from infected mice and radiolabeled for 2 h with [3H]galactose. An acidic [3H]glycoconjugate was extracted from a dilipidated residue fraction with the solvent water/ethanol/diethylether/pyridine/NH4OH (15:15:5:1:0.017). The radioactivity labeled glycoconjugate was found t...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(91)90030-a
更新日期：1991-03-01 00:00:00
abstract：:AF3 (AVPGVLRFamide) is an endogenous RFamide-like peptide isolated from the parasitic nematode Ascaris suum. It has a potent and long lasting excitatory effect in A. suum and Ascaridia galli. This is mediated by a mechanism independent of the nicotinic-like acetylcholine (ACh) receptor, which mediates excitatory trans...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(98)00039-5
更新日期：1998-06-01 00:00:00
abstract：:Antigenic diversity was observed in the circumsporozoite (CS) proteins of five of the six Plasmodium cynomolgi isolates (NIH, Mulligan, London, Gombak, Ceylon, RO) that we examined. Monoclonal antibodies were produced against salivary gland sporozoites of three of the isolates. Interaction of these monoclonal antibodi...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(85)90110-0
更新日期：1985-01-01 00:00:00
