Category Archive: Genomics of Apicomplexa

Sep 25

The apicoplast genome of Leucocytozoon caulleryi, a pathogenic apicomplexan parasite of the chicken.

Related Articles
The apicoplast genome of Leucocytozoon caulleryi, a pathogenic apicomplexan parasite of the chicken.
Parasitol Res. 2014 Mar;113(3):823-8
Authors: Imura T, Sato S, Sato Y, Sakamoto D, Isobe T, Mur…

Sep 25

The evolutionary dynamics of variant antigen genes in Babesia reveal a history of genomic innovation underlying host-parasite interaction.

Related Articles
The evolutionary dynamics of variant antigen genes in Babesia reveal a history of genomic innovation underlying host-parasite interaction.
Nucleic Acids Res. 2014;42(11):7113-31
Authors: Jackson A…

Sep 25

New insights into the evolutionary history of Plasmodium falciparum from mitochondrial genome sequence analyses of Indian isolates.

Related Articles

New insights into the evolutionary history of Plasmodium falciparum from mitochondrial genome sequence analyses of Indian isolates.

Mol Ecol. 2014 Jun;23(12):2975-87

Authors: Tyagi S, Pande V, Das A

Abstract
Estimating genetic diversity and inferring the evolutionary history of Plasmodium falciparum could be helpful in understanding origin and spread of virulent and drug-resistant forms of the malaria pathogen and therefore contribute to malaria control programme. Genetic diversity of the whole mitochondrial (mt) genome of P. falciparum sampled across the major distribution ranges had been reported, but no Indian P. falciparum isolate had been analysed so far, even though India is highly endemic to P. falciparum malaria. We have sequenced the whole mt genome of 44 Indian field isolates and utilized published data set of 96 genome sequences to present global genetic diversity and to revisit the evolutionary history of P. falciparum. Indian P. falciparum presents high genetic diversity with several characteristics of ancestral populations and shares many of the genetic features with African and to some extent Papua New Guinean (PNG) isolates. Similar to African isolates, Indian P. falciparum populations have maintained high effective population size and undergone rapid expansion in the past with oldest time to the most recent common ancestor (TMRCA). Interestingly, one of the four single nucleotide polymorphisms (SNPs) that differentiates P. falciparum from P. falciparum-like isolates (infecting non-human primates in Africa) was found to be segregating in five Indian P. falciparum isolates. This SNP was in tight linkage with other two novel SNPs that were found exclusively in these five Indian isolates. The results on the mt genome sequence analyses of Indian isolates on the whole add to the current understanding on the evolutionary history of P. falciparum.

PMID: 24845521 [PubMed – indexed for MEDLINE]

Jul 11

Description and molecular characterization of Plasmodium (Novyella) unalis sp. nov. from the Great Thrush (Turdus fuscater) in highland of Colombia.

Related Articles

Description and molecular characterization of Plasmodium (Novyella) unalis sp. nov. from the Great Thrush (Turdus fuscater) in highland of Colombia.

Parasitol Res. 2013 Dec;112(12):4193-204

Authors: Mantilla JS, González AD, Valkiūnas G, Moncada LI, Matta NE

Abstract
Plasmodium (Novyella) unalis sp. nov. was found in the Great Thrush, Turdus fuscater (Passeriformes, Turdidae) in Bogotá, Colombia, at 2,560 m above sea level where the active transmission occurs. This parasite is described based on the morphology of its blood stages and a fragment of the mitochondrial cytochrome b gene (lineage UN227). Illustrations of blood stages of new species are given, and the phylogenetic analysis identifies closely related species and lineages of avian malaria parasites. The new species is most similar to Plasmodium (Novyella) vaughani (lineage SYAT05), a cosmopolitan avian malaria parasite; these parasites are also closely related genetically, with a genetic difference of 3.2% between them. P. unalis can be readily distinguished from the latter species morphologically, primarily due to the (1) presence of a single large, circular shaped pigment granule in the erythrocytic trophozoites and meronts; (2) presence of prominent vacuoles in trophozoites and growing meronts; and (3) presence of predominantly fan-like shaped erythrocytic meronts. Cytochrome b lineages with high similarity to the new species have been reported in Costa Rica, Brazil, Chile, and USA. It is probable that the new species of malaria parasite is widely distributed in the New World. This parasite has been reported only in the Great Thrush at the study site and might have a narrow range of avian hosts. Records of P. unalis are of particular theoretical interest due to its active transmission at highlands in Andes. Possible influence of urbanization on transmission of this malaria parasite in Bogotá is discussed.

PMID: 24048707 [PubMed – indexed for MEDLINE]

Jul 11

Molecular characterization of Cryptosporidium spp. from foals in Italy.

Related Articles
Molecular characterization of Cryptosporidium spp. from foals in Italy.
Vet J. 2013 Nov;198(2):531-3
Authors: Caffara M, Piva S, Pallaver F, Iacono E, Galuppi R
Abstract
Fourteen Cr…

Jul 08

Identification and sequence characterization of novel Theileria genotypes from the waterbuck (Kobus defassa) in a Theileria parva-endemic area in Kenya.

Related Articles
Identification and sequence characterization of novel Theileria genotypes from the waterbuck (Kobus defassa) in a Theileria parva-endemic area in Kenya.
Vet Parasitol. 2014 May 28;202(3-4):180-93
Au…

Jun 04

Sequence and organization of the rhoptry-associated-protein-1 (rap-1) locus for the sheep hemoprotozoan Babesia sp. BQ1 Lintan (B. motasi phylogenetic group).

Related Articles
Sequence and organization of the rhoptry-associated-protein-1 (rap-1) locus for the sheep hemoprotozoan Babesia sp. BQ1 Lintan (B. motasi phylogenetic group).
Vet Parasitol. 2013 Nov 15;198(1-2):24-38

May 17

A secretory multifunctional serine protease, DegP of Plasmodium falciparum, plays an important role in thermo-oxidative stress, parasite growth and development.

Related Articles

A secretory multifunctional serine protease, DegP of Plasmodium falciparum, plays an important role in thermo-oxidative stress, parasite growth and development.

FEBS J. 2014 Mar;281(6):1679-99

Authors: Sharma S, Jadli M, Singh A, Arora K, Malhotra P

Abstract
UNLABELLED: Plasmodium falciparum heat shock proteins and proteases are known for their indispensable roles in parasite virulence and survival in the host cell. They neutralize various host-derived stress responses that are deleterious for parasite growth and invasion. We report identification and functional characterization of the first DegP from an apicomplexan (P. falciparum). To determine the molecular identity and functions of the parasite-encoded DegP, we complemented the Escherichia coli degP null mutant with a putative PfdegP gene, and the results showed that PfDegP complements the growth defect of the temperature sensitive DegP-deficient mutant and imparts resistance to non-permissive temperatures and oxidative stress. Molecular interaction studies showed that PfDegP exists as a complex with parasite-encoded heat shock protein 70, iron superoxide dismutase and enolase. DegP expression is significantly induced in parasite culture upon heat shock/oxidative stress. Our data suggest that the PfDegP protein may play a role in the growth and development of P. falciparum through its ability to confer protection against thermal/oxidative stress. Antibody against DegP showed anti-plasmodial activity against blood-stage parasites in vitro, suggesting that PfDegP and its associated complex may be a potential focus for new anti-malarial therapies.
STRUCTURED DIGITAL ABSTRACT: ●PfDegP physically interacts with PfHsp70 and PfEno by anti-bait co-immunoprecipitation (View interaction) ●PfDegP physically interacts with PfEno, PfSod, PfOat, PfHsp70, PfLDH and PfGpi by anti-bait co-immunoprecipitation (View interaction) ●PfHsp-70 and PfDegP co-localize by fluorescence microscopy (View interaction) ●PfDegP physically interacts with PfOat, PfHsp70, PfEno, PfSod, PfGpi and PfLDH by surface plasmon resonance (View interaction) ●PfEno and PfDegP co-localize by fluorescence microscopy (View interaction) ●PfDegP and PfHsp70 co-localize by co-sedimentation through density gradient (View interaction).

PMID: 24494818 [PubMed – indexed for MEDLINE]

May 06

Transcriptomic Analysis Reveals Evidence for a Cryptic Plastid in the Colpodellid Voromonas pontica, a Close Relative of Chromerids and Apicomplexan Parasites

Colpodellids are free-living, predatory flagellates, but their close relationship to photosynthetic chromerids and plastid-bearing apicomplexan parasites suggests they were ancestrally photosynthetic. Colpodellids may therefore retain a cryptic plastid, or they may have lost their plastids entirely, like the apicomplexan Cryptosporidium. To find out, we generated transcriptomic data from Voromonas pontica ATCC 50640 and searched for homologs of genes …

Continue reading »

Jan 23

Global analysis of apicomplexan protein S-acyl transferases reveals an enzyme essential for invasion.

Related Articles

Global analysis of apicomplexan protein S-acyl transferases reveals an enzyme essential for invasion.

Traffic. 2013 Aug;14(8):895-911

Authors: Frénal K, Tay CL, Mueller C, Bushell ES, Jia Y, Graindorge A, Billker O, Rayner JC, Soldati-Favre D

Abstract
The advent of techniques to study palmitoylation on a whole proteome scale has revealed that it is an important reversible modification that plays a role in regulating multiple biological processes. Palmitoylation can control the affinity of a protein for lipid membranes, which allows it to impact protein trafficking, stability, folding, signalling and interactions. The publication of the palmitome of the schizont stage of Plasmodium falciparum implicated a role for palmitoylation in host cell invasion, protein export and organelle biogenesis. However, nothing is known so far about the repertoire of protein S-acyl transferases (PATs) that catalyse this modification in Apicomplexa. We undertook a comprehensive analysis of the repertoire of Asp-His-His-Cys cysteine-rich domain (DHHC-CRD) PAT family in Toxoplasma gondii and Plasmodium berghei by assessing their localization and essentiality. Unlike functional redundancies reported in other eukaryotes, some apicomplexan-specific DHHCs are essential for parasite growth, and several are targeted to organelles unique to this phylum. Of particular interest is DHHC7, which localizes to rhoptry organelles in all parasites tested, including the major human pathogen P. falciparum. TgDHHC7 interferes with the localization of the rhoptry palmitoylated protein TgARO and affects the apical positioning of the rhoptry organelles. This PAT has a major impact on T. gondii host cell invasion, but not on the parasite’s ability to egress.

PMID: 23638681 [PubMed – indexed for MEDLINE]

Older posts «

» Newer posts