Purification of an eight subunit RNA polymerase I complex in Trypanosoma brucei.


: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 promoters and sequestered to two distinct nuclear locations, namely the nucleolus and the expression site body. This versatility may require parasite-specific protein-protein interactions, subunits or subunit domains. Thus far, data mining of trypanosomatid genomes have revealed 13 potential RNA pol I subunits which include two paralogous sets of RPB5, RPB6, and RPB10. Here, we analyzed a cDNA library prepared from procyclic insect form T. brucei and found that all 13 candidate subunits are co-expressed. Moreover, we PTP-tagged the largest subunit TbRPA1, tandem affinity-purified the enzyme complex to homogeneity, and determined its subunit composition. In addition to the already known subunits RPA1, RPA2, RPC40, 1RPB5, and RPA12, the complex contained RPC19, RPB8, and 1RPB10. Finally, to evaluate the absence of RPB6 in our purifications, we used a combination of epitope-tagging and reciprocal coimmunoprecipitation to demonstrate that 1RPB6 but not 2RPB6 binds to RNA pol I albeit in an unstable manner. Collectively, our data strongly suggest that T. brucei RNA pol I binds a distinct set of the RPB5, RPB6, and RPB10 paralogs.


Mol Biochem Parasitol


Nguyen TN,Schimanski B,Zahn A,Klumpp B,Günzl A




Has Abstract


2006-09-01 00:00:00














  • An epitope recognised by inhibitory monoclonal antibodies that react with a 51 kilodalton merozoite surface antigen in Plasmodium falciparum.

    abstract::Monoclonal antibodies designated 8G10/48 and 9E3/48 raised against mature asexual blood stages of Plasmodium falciparum inhibit parasite growth in vitro. Both antibodies bind to an epitope which includes the linear sequence Ser Thr Asn Ser and which is present in a cDNA clone from a P. falciparum expression library. T...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Epping RJ,Goldstone SD,Ingram LT,Upcroft JA,Ramasamy R,Cooper JA,Bushell GR,Geysen HM

    更新日期:1988-02-01 00:00:00

  • Purification and properties of Plasmodium falciparum malate dehydrogenase.

    abstract::Asexual intraerythrocytic Plasmodium falciparum were shown to have a single isoenzyme of malate dehydrogenase. This malate dehydrogenase was purified to apparent homogeneity using a three-step purification protocol. The parasite malate dehydrogenase had an apparent subunit molecular weight of 32 kDa, a pH optimum of 7...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Lang-Unnasch N

    更新日期:1992-01-01 00:00:00

  • Expression of foreign proteins in Trypanosoma congolense.

    abstract::An expression vector was constructed to express foreign genes in Trypanosoma congolense. The foreign gene and a neomycin phosphotransferase (NPT) gene are flanked by glutamate and alanine rich protein (GARP) gene processing signals and their expression is driven by a ribosomal RNA gene promoter. The plasmid is not mai...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Downey N,Donelson JE

    更新日期:1999-10-25 00:00:00

  • TbARF1 influences lysosomal function but not endocytosis in procyclic stage Trypanosoma brucei.

    abstract::The ADP ribosylation factors (Arfs) are a highly conserved subfamily of the Ras small GTPases with crucial roles in vesicle budding and membrane trafficking. Unlike in other eukaryotes, the orthologue of Arf1 in the host bloodstream form of Trypanosoma brucei is essential for the maintenance of endocytosis. In contras...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Price HP,Stark M,Smith B,Smith DF

    更新日期:2007-10-01 00:00:00

  • A tubulin-related 55 kilodalton surface antigen recognized by different Trypanosoma cruzi stage-specific monoclonal antibodies from infected mice.

    abstract::Thirteen monoclonal antibodies (MAbs) specific for the membrane of live Trypanosoma cruzi have been obtained from BALB/c infected mice. Most of them had greater avidity for intact than for disrupted parasites. According to the staining by indirect immunofluorescence of the different live developmental stages of the pa...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Alcina A,Fresno M

    更新日期:1988-06-01 00:00:00

  • Actin sequestering protein, profilin, regulates intracellular vesicle transport in Leishmania.

    abstract::Profilins are the key regulators of actin dynamics in all eukaryotic cells. However, little information is available on their biochemical properties and functions in kinetoplastids, such as Trypanosoma and Leishmania. We show here that Leishmania parasites express only one homolog of profilin (LdPfn), which catalyzes ...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Ambaru B,Gopalsamy A,Tammana TVS,Subramanya HS,Gupta CM

    更新日期:2020-07-01 00:00:00

  • Arp1, an actin-related protein, in Plasmodium berghei.

    abstract::Actin-related proteins (Arps) constitute a family of eukaryotic cytoskeletal proteins involved in such diverse events as cell motility, cytokinesis, vesicle transport, and chromatin remodelling. Previously, in a study of Plasmodium berghei gene expression in ookinetes and oocysts, we detected stage-specific increased ...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Siden-Kiamos I,Schüler H,Liakopoulos D,Louis C

    更新日期:2010-10-01 00:00:00

  • Insights into blood feeding by schistosomes from a proteomic analysis of worm vomitus.

    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 anal...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Hall SL,Braschi S,Truscott M,Mathieson W,Cesari IM,Wilson RA

    更新日期:2011-09-01 00:00:00

  • The kinetic properties and sensitivities to inhibitors of lactate dehydrogenases (LDH1 and LDH2) from Toxoplasma gondii: comparisons with pLDH from Plasmodium falciparum.

    abstract::Toxoplasma gondii differentially expresses two forms of lactate dehydrogenase in tachyzoites and bradyzoites, respectively, designated LDH1 and LDH2. Previously it was demonstrated that LDH1 and LDH2 share a unique structural feature with LDH from the malarial parasite Plasmodium falciparum (pLDH), namely, the additio...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Dando C,Schroeder ER,Hunsaker LA,Deck LM,Royer RE,Zhou X,Parmley SF,Vander Jagt DL

    更新日期:2001-11-01 00:00:00

  • Identification and characterization of a Plasmodium falciparum RNA polymerase gene with similarity to mitochondrial RNA polymerases.

    abstract::Nearly all mitochondrial RNA polymerase genes identified to date are encoded in the nucleus and have similarities to T3 and T7 bacteriophage RNA polymerases. Some chloroplast genes are also transcribed by T3/T7 phage-like RNA polymerases, raising the possibility that the apicomplexan parasites, which have both a mitoc...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Li J,Maga JA,Cermakian N,Cedergren R,Feagin JE

    更新日期:2001-04-06 00:00:00

  • Antisense RNA and RNAi in protozoan parasites: working hard or hardly working?

    abstract::The complex life cycles of many protozoan parasites require the ability to respond to environmental and developmental cues through regulated gene expression. Traditionally, parasitologists have investigated these mechanisms by identifying and characterizing proteins that are necessary for the regulated expression of t...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章,评审


    authors: Militello KT,Refour P,Comeaux CA,Duraisingh MT

    更新日期:2008-02-01 00:00:00

  • Transcriptomic analysis of reduced sensitivity to praziquantel in Schistosoma mansoni.

    abstract::Schistosomiasis is an intravascular parasitic infection estimated to affect over 206 million people, the majority of whom live in Africa where the trematode worms Schistosoma mansoni and Schistosoma haematobium are the major causative agents. While a number of drugs have been used to treat schistosomiasis, praziquante...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Sanchez MC,Cupit PM,Bu L,Cunningham C

    更新日期:2019-03-01 00:00:00

  • Functional role of lysine 12 in Leishmania major AQP1.

    abstract::Leishmania major aquaglyceroporin (AQP1) is an adventitious metalloid channel that allows the bidirectional movement of arsenite and antimonite. Here we demonstrate that AQP1 is subjected to proteasome-dependent degradation. Treatment of Leishmania promastigotes with the proteasome inhibitor MG132 resulted in increase...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Sharma M,Mandal G,Mandal S,Bhattacharjee H,Mukhopadhyay R

    更新日期:2015-06-01 00:00:00

  • Isolation of a female-specific, highly repeated Schistosoma mansoni DNA probe and its use in an assay of cercarial sex.

    abstract::A 476 bp fragment of female-specific Schistosoma mansoni genomic DNA, clone W1, represents a degenerative repeat present in more than 500 copies per female genome, and may be part of the constitutive heterochromatin of the W chromosome. The cloning method described can be used as a general approach for isolating sex-s...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Webster P,Mansour TE,Bieber D

    更新日期:1989-10-01 00:00:00

  • The domain on the mouse Duffy protein for Plasmodium yoelii binding and invasion to mouse erythrocytes.

    abstract::Erythrocyte invasion by malaria parasites is a multi-step process requiring specific molecular interactions between merozoites and erythrocyte surface receptors. Human Duffy blood group protein is the receptor for Plasmodium vivax merozoite invasion to red blood cells. The cognate parasite ligand for Duffy protein is ...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Xu L,Niu J,Chaudhuri A

    更新日期:2006-04-01 00:00:00

  • Organization, sequence and stage-specific expression of the phosphoglycerate kinase genes of Leishmania mexicana mexicana.

    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


    authors: Adjé CA,Opperdoes FR,Michels PA

    更新日期:1997-12-01 00:00:00

  • Characterization of tubulin genes in Trypanosoma rangeli.

    abstract::Tubulin genes in Trypanosoma rangeli, the only trypanosome besides T. cruzi to infect humans in America, are organized in homogeneous, alternate alpha and beta gene tandem repeats of 3.8 kb. The basic repeat was cloned, mapped and partially sequenced. In contrast to most other eukaryotes, where tubulin genes are scatt...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Esquenazi D,Morel CM,Traub-Cseko YM

    更新日期:1989-05-15 00:00:00

  • A gene-family encoding small exported proteins is conserved across Plasmodium genus.

    abstract::A gene-family, named sep, encoding small exported proteins conserved across Plasmodium species has been identified. SEP proteins (13-16 kDa) contain a predicted signal peptide at the NH(2)-terminus, an internal hydrophobic region and a polymorphic, low-complexity region at the carboxy-terminus. One member of the Plasm...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Birago C,Albanesi V,Silvestrini F,Picci L,Pizzi E,Alano P,Pace T,Ponzi M

    更新日期:2003-02-01 00:00:00

  • Purification, characterization, and immunochemical studies of beta-N-acetyl-D-hexosaminidase from the parasitic nematode Trichinella spiralis.

    abstract::The exoglycosidase, beta-N-acetyl-D-hexosaminidase was purified 600-fold from the muscle-stage larvae (L1) of Trichinella spiralis. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the purified enzyme-active fraction contained 4 polypeptides with apparent molecular weights of 100,000, 68,000, 5...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Rhoads ML

    更新日期:1988-10-01 00:00:00

  • Genetic and antigenic characterization of Babesia bovis merozoite spherical body protein Bb-1.

    abstract::A Babesia bovis merozoite protein, Bb-1, was localized by immunoelectron microscopy to an apical organelle known as the spherical body. This unique structure appears to be analogous to dense granules of other apicomplexan protozoa. Similar to previously described dense granule proteins of Plasmodium spp., Bb-1 is secr...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Hines SA,Palmer GH,Brown WC,McElwain TF,Suarez CE,Vidotto O,Rice-Ficht AC

    更新日期:1995-02-01 00:00:00

  • Antibodies raised against receptor-binding domain of Plasmodium knowlesi Duffy binding protein inhibit erythrocyte invasion.

    abstract::Erythrocyte invasion by malaria parasites requires specific receptor-ligand interactions. Plasmodium vivax and Plasmodium knowlesi are completely dependent on binding the Duffy blood group antigen to invade human erythrocytes. P. knowlesi invades rhesus erythrocytes by multiple pathways using the Duffy antigen as well...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Singh AP,Puri SK,Chitnis CE

    更新日期:2002-04-30 00:00:00

  • Mimicry of elastin repetitive motifs by Theileria annulata sporozoite surface antigen.

    abstract::Theileria annulata is an important pathogen of cattle in the tropics. The gene sequence of a sporozoite surface antigen (SPAG-1) is reported. Data is also presented demonstrating that SPAG-1 is synthesised as a large precursor. This antigen, which is a candidate for inclusion in a subunit vaccine, shows a remarkable d...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Hall R,Hunt PD,Carrington M,Simmons D,Williamson S,Mecham RP,Tait A

    更新日期:1992-07-01 00:00:00

  • Microsatellite polymorphism in the sexually transmitted human pathogen Trichomonas vaginalis indicates a genetically diverse parasite.

    abstract::Given the growing appreciation of serious health sequelae from widespread Trichomonas vaginalis infection, new tools are needed to study the parasite's genetic diversity. To this end we have identified and characterized a panel of 21 microsatellites and six single-copy genes from the T. vaginalis genome, using seven l...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Conrad M,Zubacova Z,Dunn LA,Upcroft J,Sullivan SA,Tachezy J,Carlton JM

    更新日期:2011-01-01 00:00:00

  • Cloning and characterization of the ribosomal RNA gene repeat from Ostertagia ostertagi.

    abstract::Clones of the rRNA genes of Ostertagia ostertagi were selected from a library prepared from the genomic DNA of adult worms of strain LA-2. A 13.4-kb insert in a clone, lambda OOR78, is comprised of one complete 7.5-kb rDNA unit and portions of two adjacent units. The rDNA unit is directly repeated in a head-to-tail fa...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Dame JB,Yowell CA,Courtney CH,Lindgren WG

    更新日期:1991-04-01 00:00:00

  • Mitochondrial genomes of Meloidogyne chitwoodi and M. incognita (Nematoda: Tylenchina): comparative analysis, gene order and phylogenetic relationships with other nematodes.

    abstract::Root-knot nematodes (Meloidogyne spp.) are among the most important plant pathogens. In this study, the mitochondrial (mt) genomes of the root-knot nematodes, M. chitwoodi and M. incognita were sequenced. PCR analyses suggest that both mt genomes are circular, with an estimated size of 19.7 and 18.6-19.1kb, respective...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Humphreys-Pereira DA,Elling AA

    更新日期:2014-03-01 00:00:00

  • Translational repression controls temporal expression of the Plasmodium berghei LCCL protein complex.

    abstract::Plasmodium LCCL proteins comprise a family of six proteins that function as a protein complex and have essential roles in sporozoite transmission. In Plasmodium berghei, family members PbLAP1, PbLAP2 and PbLAP3 have been shown to be expressed in gametocytes and, following gametogenesis and fertilization, to be targete...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Saeed S,Carter V,Tremp AZ,Dessens JT

    更新日期:2013-05-01 00:00:00

  • Chaperoning a cellular upheaval in malaria: heat shock proteins in Plasmodium falciparum.

    abstract::In addition to their ability to help newly synthesized proteins to fold, molecular chaperones are also recognized for their participation in cellular processes ranging from protein trafficking, signal transduction, differentiation and development. Novel roles for this group of proteins have come to light through studi...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章,评审


    authors: Acharya P,Kumar R,Tatu U

    更新日期:2007-06-01 00:00:00

  • Uptake of the trypanocidal drug suramin by bloodstream forms of Trypanosoma brucei and its effect on respiration and growth rate in vivo.

    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


    authors: Fairlamb AH,Bowman IB

    更新日期:1980-10-01 00:00:00

  • Trypanosoma brucei: the effect of glycerol on the anaerobic metabolism of glucose.

    abstract::Studies measuring the glycolytic intermediate and adenine nucleotide concentrations in Trypanosoma brucei metabolising glucose either aerobically or under conditions where glycerol-3-phosphate oxidase is inactive have shown the following: 1. Inhibition with 0.5 mM salicylhydroxamic acid (SHAM) accurately simulates ana...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Hammond DJ,Bowman IB

    更新日期:1980-12-01 00:00:00

  • The T687G SNP in a P-glycoprotein gene of Fasciola hepatica is not associated with resistance to triclabendazole in two resistant Australian populations.

    abstract::Triclabendazole (TCBZ) is widely used for control of Fasciola hepatica (liver fluke) in animals and humans and resistance to this drug is now widespread. However, the mechanism of resistance to TCBZ is not known. A T687G single nucleotide polymorphism (SNP) in a P-glycoprotein gene was proposed as a molecular marker f...

    journal_title:Molecular and biochemical parasitology

    pub_type: 杂志文章


    authors: Elliott TP,Spithill TW

    更新日期:2014-11-01 00:00:00