Abstract:
:CK2 is a ubiquitous but enigmatic kinase. The difficulty in assigning a role to CK2 centers on the fact that, to date, no biologically relevant modulator of its function has been identified. One common theme revolves around a constellation of known substrates involved in growth control, compatible with its concentration in the nucleus and nucleolus. We had previously described the identification of two catalytic subunits of CK2 in Trypanosoma brucei and characterized one of them. Here we report the characterization of the second catalytic subunit, CK2alpha', and the identification and characterization of the regulatory subunit CK2beta. All three subunits are primarily localized to the nucleolus in T. brucei. We also show that CK2beta interacts with the nucleolar protein NOG1, adding to the interaction map which previously linked CK2alpha to the nucleolar protein NOPP44/46, which in turn associates with the rRNA binding protein p37. CK2 activity has four distinctive features: near equal affinity for GTP and ATP, heparin sensitivity, and stimulation by polyamines and polybasic peptides. Sequence comparison shows that the parasite orthologues have mutations in residues previously mapped as important in specifying affinity for GTP and stimulation by both polyamines and polybasic peptides. Studies of the enzymatic activity of the T. brucei CK2s show that both the affinity for GTP and stimulation by polyamines have been lost and only the features of heparin inhibition and stimulation by polybasic peptides are conserved.
journal_name
Mol Biochem Parasitoljournal_title
Molecular and biochemical parasitologyauthors
Jensen BC,Kifer CT,Brekken DL,Randall AC,Wang Q,Drees BL,Parsons Mdoi
10.1016/j.molbiopara.2006.10.002subject
Has Abstractpub_date
2007-01-01 00:00:00pages
28-40issue
1eissn
0166-6851issn
1872-9428pii
S0166-6851(06)00287-8journal_volume
151pub_type
杂志文章abstract::Entamoeba histolytica is a eukaryotic intestinal parasite of humans, and is endemic in developing countries. We have characterized the E. histolytica putative low molecular weight protein tyrosine phosphatase (LMW-PTP). The structure for this amebic tyrosine phosphatase was solved, showing the ligand-induced conformat...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2014.01.003
更新日期:2014-01-01 00:00:00
abstract::Distinct 3'- and 5'-nucleotidase activities were localized to the surface membrane of Leishmania donovani promastigotes using enzymatic reactions with live intact cells and fine structure enzyme-mediated cytochemical reactions with intact cells, cell homogenates, and isolated surface membranes. The results indicated t...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(84)90002-1
更新日期:1984-02-01 00:00:00
abstract::Trypanosome alternative oxidase (TAO) is the cyanide-resistant but SHAM-sensitive terminal oxidase of the mitochondrial electron transport chain in African trypanosomes. The bloodstream forms of Trypanosoma brucei lack cytochromes and respire exclusively via TAO. On the other hand, the insect, or procyclic form posses...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2004.11.003
更新日期:2005-02-01 00:00:00
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
doi:10.1016/0166-6851(88)90173-9
更新日期:1988-02-01 00:00:00
abstract::To investigate whether the lysosomes of Trypanosoma brucei are capable of uptake of macromolecules after internalization by the cell, we used Triton WR-1339, a non-digestible macromolecular compound, which is known to cause a marked decrease in the density of hepatic lysosomes due to massive intralysosomal storage. In...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(82)90077-9
更新日期:1982-09-01 00:00:00
abstract::A Plasmodium falciparum gene closely linked to the chloroquine resistance locus encodes PfCG2, a predicted 320-330kDa protein. In the parasitized erythrocyte, PfCG2 expression rises sharply in the trophozoite stage and is detected in electron-dense patches along the parasitophorous vacuolar membrane (PVM), in the cyto...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2005.07.009
更新日期:2005-12-01 00:00:00
abstract::We have cloned and expressed the full-length gene encoding the hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRTase) from the anaerobic protozoan parasite Tritrichomonas foetus. This enzyme is essential in nucleic acid metabolism of T. foetus because the parasite is unable to synthesize purine nucleotide...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(94)90058-2
更新日期:1994-02-01 00:00:00
abstract::The cyst wall of Entamoeba invadens (Ei), a model for the human pathogen Entamoeba histolytica, contains chitin, which is a homopolymer of beta-1, 4-linked N-acetyl-glucosamine (GlcNAc). In fungi and in bacteria that make nodulation factors, chitin deacetylases make chitosan, which is a mixture of GlcNAc and glucosami...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2006.03.002
更新日期:2006-07-01 00:00:00
abstract::The precursor of the glycosylphosphatidylinositol membrane anchor of the variant surface glycoprotein of Trypanosoma brucei is known as glycolipid A and it has the structure: EtN-PO4-6Man alpha 1-2Man alpha 1-6Man alpha 1-4GlcN alpha 1-6myo-inositol-PO4-(sn-1,2-dimyristoylglycerol). This precursor exists in equilibriu...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(96)02585-6
更新日期:1996-05-01 00:00:00
abstract::We previously customized a Nipkow spinning disk confocal microscope (SDCM) to acquire 4D data for live, intraerythrocytic malarial parasites [Gligorijevic B, McAllister R, Urbach JS, Roepe, PD. Spinning disk confocal microscopy of live, intraerythrocytic malarial parasites. 1. Quantification of hemozoin development fo...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2007.12.014
更新日期:2008-05-01 00:00:00
abstract::The cysteine proteinase B of Leishmania parasites is an important virulence factor. In this study we have expressed, isolated and characterized for the first time a recombinant CPB from Leishmania braziliensis, the causative agent of mucocutaneous leishmaniosis. The mature region of the recombinant CPB shares a high p...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2008.06.005
更新日期:2008-10-01 00:00:00
abstract::The surface of the erythrocyte undergoes a number of modifications during infection by Plasmodium falciparum. These modifications are critical for pathogenesis of severe disease and the acquisition of host immunity through their role in interactions between the host and the parasite and in antigenic variation. Our kno...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章,评审
doi:10.1016/s0166-6851(01)00275-4
更新日期:2001-07-01 00:00:00
abstract::Cyclic AMP-dependent protein kinase (protein kinase A, PKA) is a key element in many cell signaling pathways. An essential role of Plasmodium falciparum PKA (PfPKA) activity was reported in the intraerythrocytic growth of the malaria parasite. However, molecular characterization of PfPKA using purified recombinant pro...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2008.03.011
更新日期:2008-08-01 00:00:00
abstract::We have demonstrated previously that Nopp44/46, an abundant nucleolar phosphoprotein of Trypanosoma brucei, is associated with a protein kinase. In many organisms multiple nucleolar proteins are phosphorylated by the protein kinase CK2, formerly known as casein kinase II. Here we report the identification of two T. br...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/s0166-6851(01)00407-8
更新日期:2002-01-01 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::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
doi:10.1016/s0166-6851(01)00360-7
更新日期:2001-11-01 00:00:00
abstract::The use of transfection in the study of the biology of malaria parasites has been limited due to poor transfection efficiencies (frequency of 10(-6) to 10(-9)) and a paucity of selection markers. Here, a new method of transfection, using non-viral Nucleofector technology, is described for the rodent parasite Plasmodiu...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2005.09.007
更新日期:2006-01-01 00:00:00
abstract::Plasma membrane vesicles of Trypanosoma cruzi (PMVs) formed saturation binding isotherms with naive murine T lymphocytes. Parasite membrane attachment to the muscarinic cholinergic receptors of Lyt 2.2+T cells (suppressor cells) resulted in the synthesis of cGMP, attenuation of cAMP levels and in the secretion of pros...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(91)90151-u
更新日期:1991-07-01 00:00:00
abstract::The scarcity of molecular tools for genetic manipulation is a critical obstacle for functional genomics studies on Trypanosoma cruzi. The current study adapted an inducible site-specific recombination system based on Dimerizable CRE recombinase (DiCRE). Two vectors for stable transfection were created, a first one to ...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2015.01.001
更新日期:2014-12-01 00:00:00
abstract::Adenylosuccinate synthetase (AdSS) catalyses the Mg(2+) dependent formation of adenylosuccinate from IMP and aspartate, the reaction being driven by the hydrolysis of GTP to GDP. All characterized AdSS thus far exhibit a random kinetic mechanism. We present here kinetic evidence that unlike all other AdSS, Plasmodium ...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2004.06.013
更新日期:2004-11-01 00:00:00
abstract::The complete sequence for a major Schistosome mansoni eggshell protein gene has been determined from a genomic DNA fragment. The use of an open reading frame encoding a glycine-rich polypeptide was confirmed by in vitro translation of schistosome mRNA in the presence of [3H]glycine and comparison with the amino acid c...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(89)90124-2
更新日期:1989-01-01 00:00:00
abstract::Amoebiasis is spread by the ingestion of dormant Entamoeba histolytica cysts. Intervention of encystation could break the transmission cycle, thereby reducing disease burden. The model system used to study trophozoite to cyst differentiation is Entamoeba invadens. Here we describe an electroporation-based method for s...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2012.02.012
更新日期:2012-07-01 00:00:00
abstract::Human and porcine cysticercosis is a parasitic disease caused by the larval stage (cysts) of the tapeworm Taenia solium. Cysts may live in several host tissues such as skeletal muscle or brain. We have previously described the presence of host haptoglobin (Hp) and hemoglobin (Hb) in different protein extracts of the T...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2016.05.010
更新日期:2016-06-01 00:00:00
abstract::The minichromosomes M210 and M230 of Leishmania major are linear amplicons which have an inverted repeat structure. We report here the molecular cloning of the megabasic chromosome region where M210 and M230 recombination points are located. The analysis of this chromosomal region revealed a 374 bp fragment directly r...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(96)02724-7
更新日期:1996-11-25 00:00:00
abstract::A 25-kb CpFAS1 gene from Cryptosporidium parvum has been engineered and expressed as five individual maltose-binding protein (MBP)-fusion proteins: an N-terminal loading unit, three fatty acyl elongation modules, and a C-terminal reductase. Enzymatic activities of all domains (except the reductase) were individually a...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2003.11.011
更新日期:2004-03-01 00:00:00
abstract::Plasmepsins (PM), aspartic proteases of Plasmodium, comprises a family of ten proteins that perform critical functions in Plasmodium life cycle. Except VII and VIII, functions of the remaining plasmepsin members have been well characterized. Here, we have generated a mutant parasite lacking PM VII in Plasmodium berghe...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/j.molbiopara.2014.05.004
更新日期:2014-06-01 00:00:00
abstract::The glycosome, a microbody organelle found only in kinetoplastid protozoa, compartmentalizes the first six enzymes of glycolysis. In order to better understand the regulation and targeting of glycolytic enzymes in trypanosomes, we have cloned and analyzed the three genes of the phosphoglycerate kinase (PGK) complex of...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(94)00208-5
更新日期:1995-02-01 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::Cloning by limit dilution of an isolate of Leishmania tropica (LRC-L137) that is infective for mice resulted in 7 stable clones, only one of which was infective in BALB/c mice. Three of the non-infective clones that were examined for survival in BALB/c macrophages in vitro seemed to be killed more readily, suggesting ...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(83)90039-7
更新日期:1983-02-01 00:00:00
abstract::A polyprotein composed of multiple units arranged in direct tandem arrays has been identified in parasitic and free living nematodes. Analysis of previously cloned units from the Dirofilaria immitis polyprotein antigen (DiPA) indicated the units were nearly identical but here we demonstrate that they segregate into tw...
journal_title:Molecular and biochemical parasitology
pub_type: 杂志文章
doi:10.1016/0166-6851(96)02721-1
更新日期:1996-11-12 00:00:00