scholarly journals Comparative Analysis of Apicoplast-Targeted Protein Extension Lengths in Apicomplexan Parasites

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Alexandr V. Seliverstov ◽  
Oleg A. Zverkov ◽  
Svetlana N. Istomina ◽  
Sergey A. Pirogov ◽  
Philip S. Kitsis
Keyword(s):  
Plasmodium Falciparum ◽  
Comparative Analysis ◽  
Protein Translocation ◽  
Neospora Caninum ◽  
Signal Peptides ◽  
Model Species ◽  
Apicomplexan Parasites ◽  
Important Region ◽  
Focus On Results ◽  
Species Comparisons

In general, the mechanism of protein translocation through the apicoplast membrane requires a specific extension of a functionally important region of the apicoplast-targeted proteins. The corresponding signal peptides were detected in many apicomplexans but not in the majority of apicoplast-targeted proteins inToxoplasma gondii. InT. gondiisignal peptides are either much diverged or their extension region is processed, which in either case makes the situation different from other studied apicomplexans. We propose a statistic method to compare extensions of the functionally important regions of apicoplast-targeted proteins. More specifically, we provide a comparison of extension lengths of orthologous apicoplast-targeted proteins in apicomplexan parasites. We focus on results obtained for the model speciesT. gondii,Neospora caninum, andPlasmodium falciparum. With our method, cross species comparisons demonstrate that, in average, apicoplast-targeted protein extensions inT. gondiiare 1.5-fold longer than inN. caninumand 2-fold longer than inP. falciparum. Extensions inP. falciparumless than 87 residues in size are longer than the corresponding extensions inN. caninumand, reversely, are shorter if they exceed 88 residues.

scholarly journals Interaction of Plasmodium falciparum apicortin with α- and β-tubulin is critical for parasite growth and survival

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Malabika Chakrabarti ◽  
Nishant Joshi ◽  
Geeta Kumari ◽  
Preeti Singh ◽  
Rumaisha Shoaib ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Life Cycle ◽  
Specific Protein ◽  
Parasite Growth ◽  
Growth And Survival ◽  
Apicomplexan Parasites ◽  
Parasite Replication ◽  
Main Components ◽  
Β Tubulin

AbstractCytoskeletal structures of Apicomplexan parasites are important for parasite replication, motility, invasion to the host cell and survival. Apicortin, an Apicomplexan specific protein appears to be a crucial factor in maintaining stability of the parasite cytoskeletal assemblies. However, the function of apicortin, in terms of interaction with microtubules still remains elusive. Herein, we have attempted to elucidate the function of Plasmodium falciparum apicortin by monitoring its interaction with two main components of parasite microtubular structure, α-tubulin-I and β-tubulin through in silico and in vitro studies. Further, a p25 domain binding generic drug Tamoxifen (TMX), was used to disrupt PfApicortin-tubulin interactions which led to the inhibition in growth and progression of blood stage life cycle of P. falciparum.

Identification and characterization of a novel Neospora caninum immune mapped protein 1

Parasitology ◽  
2012 ◽  
Vol 139 (8) ◽  
pp. 998-1004 ◽  
Author(s):  
X. CUI ◽  
T. LEI ◽  
D. Y. YANG ◽  
P. HAO ◽  
Q. LIU
Keyword(s):  
Neospora Caninum ◽  
Polyclonal Antibodies ◽  
Functional Protein ◽  
Reading Frame ◽  
Protein Motifs ◽  
Apicomplexan Parasites ◽  
Potential Vaccine ◽  
Palmitoylation Site

SUMMARYImmune mapped protein 1 (IMP1) is a newly discovered protein in Eimeria maxima. It is recognized as a potential vaccine candidate against E. maxima and a highly conserved protein in apicomplexan parasites. Although the Neospora caninum IMP1 (NcIMP1) orthologue of E. maxima IMP1 was predicted in the N. caninum genome, it was still not identified and characterized. In this study, cDNA sequence encoding NcIMP1 was cloned by RT-PCR from RNA isolated from Nc1 tachyzoites. NcIMP1 was encoded by an open reading frame of 1182 bp, which encoded a protein of 393 amino acids with a predicted molecular weight of 42·9 kDa. Sequence analysis showed that there was neither a signal peptide nor a transmembrane region present in the NcIMP1 amino acid sequence. However, several kinds of functional protein motifs, including an N-myristoylation site and a palmitoylation site were predicted. Recombinant NcIMP1 (rNcIMP1) was expressed in Escherichia coli and then purified rNcIMP1 was used to prepare specific antisera in mice. Mouse polyclonal antibodies raised against the rNcIMP1 recognized an approximate 43 kDa native IMP1 protein. Immunofluorescence analysis showed that NcIMP1 was localized on the membrane of N. caninum tachyzoites. The N-myristoylation site and the palmitoylation site were found to contribute to the localization of NcIMP1. Furthermore, the rNcIMP1-specific antibodies could inhibit cell invasion by N. caninum tachyzoites in vitro. All the results indicate that NcIMP1 is likely to be a membrane protein of N. caninum and may be involved in parasite invasion.

scholarly journals Comparison of an ELISA assay for the detection of adhesive/invasive Neospora caninum tachyzoites

2014 ◽  
Vol 23 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Luiz Miguel Pereira ◽  
Ana Patrícia Yatsuda
Keyword(s):  
Cell Culture ◽  
Neospora Caninum ◽  
Culture Cell ◽  
Quantitative Detection ◽  
Lacz Gene ◽  
Galactosidase Activity ◽  
Apicomplexan Parasites ◽  
Effects Of Temperature ◽  
Colorimetric Reaction

Neospora caninum belongs to the phylum Apicomplexa, the causative agent of neosporosis, which leads to economic impacts on cattle production. A common feature among apicomplexan parasites is the invasive process driven mostly by the parasite. As a first evaluation of candidate molecules that play a possible role by interfering in this invasive process, the in vitro invasion assay is a fast and direct way to screen future agonists or antagonists. This work involved the development of a new cell culture ELISA and transient β-galactosidase activity applied to the semi-quantitative detection of N. caninum in Vero cell culture. Cell culture ELISA is based on histochemistry and immunology, resulting in a colorimetric reaction. The β-galactosidase activity was obtained by the transient transfection of the lacZ gene under control of RPS13 promoter of N. caninum. These methods were used to evaluate the effects of temperature (37°C and 85°C) on the invasion and adhesion of tachyzoites. The three tested methods (real time PCR, β-galactosidase activity and ELISA) showed a similar pattern, indicating that different methods may be complementary.

scholarly journals Exposure of free-living jaguars to Toxoplasma gondii, Neospora caninum and Sarcocystis neurona in the Brazilian Pantanal

2014 ◽  
Vol 23 (4) ◽  
pp. 547-553 ◽  
Author(s):  
Selma Samiko Miyazaki Onuma ◽  
Andréia Lima Tomé Melo ◽  
Daniel Luis Zanella Kantek ◽  
Peter Gransden Crawshaw-Junior ◽  
Ronaldo Gonçalves Morato ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Neospora Caninum ◽  
Antibody Test ◽  
Free Living ◽  
Sarcocystis Neurona ◽  
Mato Grosso ◽  
Apicomplexan Parasites ◽  
Wide Range ◽  
Coccidian Parasites ◽  
Brazilian Pantanal

Toxoplasma gondii, Neospora caninum and Sarcocystis neurona are related apicomplexan parasites that cause reproductive and neurological disorders in a wide range of domestic and wild animals. In the present study, the immunofluorescence antibody test (IFAT) was used to investigate the presence of antibodies against T. gondii, N. caninum and S. neurona in the sera of 11 free-living jaguars (Panthera onca) in two protected areas in the Pantanal region of Mato Grosso state, Brazil. Ten jaguars (90.9%) showed seropositivity for T. gondii, eight (72.7%) for S. neurona, and seven (63.6%) for N. caninum antigens. Our findings reveal exposure of jaguars to these related coccidian parasites and circulation of these pathogens in this wild ecosystem. To the best of our knowledge, this is the first serological detection of N. caninum and S. neurona in free-living jaguars.

Plasmodium falciparum: a comparative analysis of the genetic diversity in malaria-mesoendemic areas of Brazil and Madagascar

2000 ◽  
Vol 86 (8) ◽  
pp. 692-698 ◽  
Author(s):  
S. Sallenave-Sales ◽  
P. Daubersies ◽  
O. Mercereau-Puijalon ◽  
L. Rahimalala ◽  
H. Contamin ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Plasmodium Falciparum ◽  
Comparative Analysis

scholarly journals Characterization of Two Putative Protein Translocation Components in the Apicoplast of Plasmodium falciparum

2009 ◽  
Vol 8 (8) ◽  
pp. 1146-1154 ◽  
Author(s):  
Ming Kalanon ◽  
Christopher J. Tonkin ◽  
Geoffrey I. McFadden
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Trafficking ◽  
Protein Translocation ◽  
Protein A ◽  
Integral Membrane Protein ◽  
Diatom Algae ◽  
Trophozoite Stage ◽  
Replacement Strategy ◽  
Putative Protein

ABSTRACT Protein trafficking to the stroma of the apicoplast of Plasmodium falciparum requires translocation across several membranes. To further elucidate the mechanisms responsible, we investigated two proteins: P. falciparum Tic22 (PfTic22), a putative component of the translocon of the inner chloroplast membrane; and PfsDer1-1, one of two homologues of the P. falciparum symbiont-derived Der1 (sDer1) protein, a putative component of an endoplasmic reticulum-associated degradation (ERAD) complex in the periplastid membrane. We constructed parasites expressing hemagglutinin (HA)-tagged PfTic22 and PfsDer1-1 under the control of their endogenous promoters using the 3′ replacement strategy. We show that both PfTic22-HA and PfsDer1-1-HA are expressed predominantly during the trophozoite stage of the asexual replication cycle, which corresponds to the most dynamic stages of apicoplast activity. Although both proteins localize to the periphery of the apicoplast, PfTic22-HA is a membrane-associated protein while PfsDer1-1-HA is an integral membrane protein. Phylogenetic analysis indicates that PfsDer1-1 is one of two Der1 paralogues predicted to localize to the apicoplast in P. falciparum and that it has orthologues in diatom algae, supporting the chromalveolate hypothesis. These observations are consistent with putative roles for PfTic22 and PfsDer1-1 in protein translocation into the apicoplast of P. falciparum.

scholarly journals Whole Cell Phenotypic Screening Of MMV Pathogen Box identifies Specific Inhibitors of Plasmodium falciparum merozoite maturation and egress

2019 ◽  
Author(s):  
Alok Tanala Patra ◽  
Tejashri Bhimashankar Hingmire ◽  
Meenakshi Belekar ◽  
Aoli Xiong ◽  
Gowtham Subramanian ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Target Identification ◽  
Calcium Ionophore ◽  
Apicomplexan Parasite ◽  
Cellular Phenotype ◽  
Mechanistic Studies ◽  
Apicomplexan Parasites ◽  
Specific Effects ◽  
Falciparum Merozoite ◽  
Specific Inhibitors

AbstractWe report a systematic, cellular phenotype-based antimalarial screening of the MMV Pathogen Box collection, which facilitated the identification of specific blockers of late stage intraerythrocytic Plasmodium falciparum maturation. First, from standard growth inhibition asays, we discovered 62 additional antimalarials (EC50 ≤ 10μM) over previously known antimalarial candidates from Pathogen Box. A total of 90 potent molecules (EC50 ≤ 1μM) were selected for evaluating their stage-specific effects during the intra-erythrocytic development of P. falciparum. None of these molecules had significant effect on ring-trophozoite transition, 10 molecules inhibited trophozoite-schizont transition, and 21 molecules inhibited schizont-ring transition at 1μM. These compounds were further validated in secondary assays by flow cytometry and microscopic imaging of treated cells to prioritize 12 molecules as potent and selective blockers of schizont-ring transition. Seven of these were found to strongly inhibit calcium ionophore induced egress of Toxoplasma gondii, a related apicomplexan parasite, suggesting that the inhibitors may be acting via similar mechanism in the two parasites, which can be further exploited for target identification studies. Two of these molecules, with previously unknown mechanism of action, MMV020670 and MMV026356, were found to induce fragmentation of DNA in developing merozoites. Further mechanistic studies would facilitate therapeutic exploitation of these molecules as broadly active inhibitors targeting development and egress of apicomplexan parasites relevant to human health.

scholarly journals Structural role of essential light chains in the apicomplexan glideosome

2019 ◽  
Author(s):  
Samuel Pazicky ◽  
Karthikeyan Dhamotharan ◽  
Karol Kaszuba ◽  
Haydyn Mertens ◽  
Tim Gilberger ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Light Chain ◽  
Structural Information ◽  
Host Cells ◽  
Light Chains ◽  
Apicomplexan Parasites ◽  
Membrane Complex ◽  
C Terminus ◽  
Inner Membrane Complex

AbstractApicomplexan parasites, such as Plasmodium falciparum and Toxoplasma gondii, traverse the host tissues and invade the host cells exhibiting a specific type of motility called gliding. The molecular mechanism of gliding lies in the actin-myosin motor localized to the intermembrane space between the plasma membrane and inner membrane complex (IMC) of the parasites. Myosin A (MyoA) is a part of the glideosome, a large multi-protein complex, which is anchored in the outer membrane of the IMC. MyoA is bound to the proximal essential light chain (ELC) and distal myosin light chain (MLC1), which further interact with the glideosome associated proteins GAP40, GAP45 and GAP50. Whereas structures of several individual glideosome components and small dimeric complexes have been solved, structural information concerning the interaction of larger glideosome subunits and their role in glideosome function still remains to be elucidated. Here, we present structures of a T. gondii trimeric glideosome sub complex composed of a myosin A light chain domain with bound MLC1 and TgELC1 or TgELC2. Regardless of the differences between the secondary structure content observed for free P. falciparum PfELC and T. gondii TgELC1 or TgELC2, the proteins interact with a conserved region of TgMyoA to form structurally conserved complexes. Upon interaction, the essential light chains undergo contraction and induce α-helical structure in the myosin A C-terminus, stiffening the myosin lever arm. The complex formation is further stabilized through binding of a single calcium ion to T. gondii ELCs. Our work provides an important step towards the structural understanding of the entire glideosome and uncovering the role of its members in parasite motility and invasion.Author summaryApicomplexans, such as Toxoplasma gondii or the malaria agent Plasmodium falciparum, are small unicellular parasites that cause serious diseases in humans and other animals. These parasites move and infect the host cells by a unique type of motility called gliding. Gliding is empowered by an actin-myosin molecular motor located at the periphery of the parasites. Myosin interacts with additional proteins such as essential light chains to form the glideosome, a large protein assembly that anchors myosin in the inner membrane complex. Unfortunately, our understanding of the glideosome is insufficient because we lack the necessary structural information. Here we describe the first structures of trimeric glideosome sub complexes of T. gondii myosin A bound to two different light chain combinations, which show that T. gondii and P. falciparum form structurally conserved complexes. With an additional calcium-free complex structure, we demonstrate that calcium binding does not change the formation of the complexes, although it provides them with substantial stability. With additional data, we propose that the role of the essential light chains is to enhance myosin performance by inducing secondary structure in the C-terminus of myosin A. Our work represents an important step in unveiling the gliding mechanism of apicomplexan parasites.

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