What's new for 'Trypanosomatids' in PubMed

This message contains My NCBI what's new results from the National Center for Biotechnology Information (NCBI) at the U.S. National Library of Medicine (NLM).
Do not reply directly to this message.

Sender's message:

Sent on Thursday, 2012 May 24
Search: kinetoplastids OR kinetoplastid OR Kinetoplastida OR "trypanosoma brucei" OR leishmania OR brucei OR leishmaniasis OR "African trypanosomiasis"

Click here to view complete results in PubMed (Results may change over time.)
To unsubscribe from these e-mail updates click here.

PubMed Results

Items 1 - 5 of 5

1.	Int J Parasitol. 2012 Apr;42(4):401-9. Extra-glycosomal localisation of Trypanosoma brucei hexokinase 2. Joice AC, Lyda TL, Sayce AC, Verplaetse E, Morris MT, Michels PA, Robinson DR, Morris JC. Source Department of Genetics and Biochemistry, Clemson University, Clemson, SC 39634, USA. Abstract The majority of the glycolytic enzymes in the African trypanosome are compartmentalised within peroxisome-like organelles, the glycosomes. Polypeptides harbouring peroxisomal targeting sequences (PTS type 1 or 2) are targeted to these organelles. This targeting is essential to parasite viability, as compartmentalisation of glycolytic enzymes prevents unregulated ATP-dependent phosphorylation of intermediate metabolites. Here, we report the surprising extra-glycosomal localisation of a PTS-2 bearing trypanosomal hexokinase, TbHK2. In bloodstream form parasites, the protein localises to both glycosomes and to the flagellum. Evidence for this includes fractionation and immunofluorescence studies using antisera generated against the authentic protein as well as detection of epitope-tagged recombinant versions of the protein. In the insect stage parasite, distribution is different, with the polypeptide localised to glycosomes and proximal to the basal bodies. The function of the extra-glycosomal protein remains unclear. While its association with the basal body suggests that it may have a role in locomotion in the insect stage parasite, no detectable defect in directional motility or velocity of cell movement were observed for TbHK2-deficient cells, suggesting that the protein may have a different function in the cell.
	PMID: 22619756 [PubMed - in process]

2.	Int J Parasitol. 2012 Apr;42(4):323-7. Leishmania infantum nicotinamidase is required for late-stage development in its natural sand fly vector, Phlebotomus perniciosus. Gazanion E, Seblova V, Votypka J, Vergnes B, Garcia D, Volf P, Sereno D. Source MIVEGEC (UM1-CNRS 5290-IRD 224), Institut de Recherche pour le Développement (IRD), 911 Avenue Agropolis BP 64501, 34394 Montpellier Cedex 5, France. elogazanion@yahoo.fr Abstract Leishmania infantum nicotinamidase, encoded by the Lipnc1 gene, converts nicotinamide into nicotinicacid to ensure Nicotinamide–Adenine–Dinucleotide (NAD+) biosynthesis. We were curious to explore the role of this enzyme during L. infantum development in its natural sand fly vector, Phlebotomus perniciosus (Diptera, Phlebotominae), using null mutants with a deleted Lipnc1 gene. The null mutants developed as well as the wild type L. infantum at the early time points post their ingestion within the bloodmeal. In contrast, once the blood meal digestion was completed, the null mutants were unable to develop further and establish late-stage infections. Data highlight the importance of the nicotinamide degradation pathway for Leishmania development in sand flies. They indicate that the endogenous nicotinamidase is essential for Leishmania development in the sand fly after the blood meal has been digested and the remnants defecated.
	PMID: 22619752 [PubMed - in process]

3.	Int J Nanomedicine. 2012;7:2115-27. Epub 2012 Apr 24. Towards development of novel immunization strategies against leishmaniasis using PLGA nanoparticles loaded with kinetoplastid membrane protein-11. Santos DM, Carneiro MW, de Moura TR, Fukutani K, Clarencio J, Soto M, Espuelas S, Brodskyn C, Barral A, Barral-Netto M, de Oliveira CI. Source Centro de Pesquisas Gonçalo Moniz, FIOCRUZ, Salvador, BA, Brazil. Abstract BACKGROUND: Vaccine development has been a priority in the fight against leishmaniases, which are vector-borne diseases caused by Leishmania protozoa. Among the different immunization strategies employed to date is inoculation of plasmid DNA coding for parasite antigens, which has a demonstrated ability to induce humoral and cellular immune responses. In this sense, inoculation of plasmid DNA encoding Leishmania kinetoplasmid membrane protein-11 (KMP-11) was able to confer protection against visceral leishmaniasis. However, recently the use of antigen delivery systems such as poly(lactic-co-glycolic acid) (PLGA) nanoparticles has also proven effective for eliciting protective immune responses. METHODS: In the present work, we tested two immunization strategies with the goal of obtaining protection, in terms of lesion development and parasite load, against cutaneous leishmaniasis caused by L. braziliensis. One strategy involved immunization with plasmid DNA encoding L. infantum chagasi KMP-11. Alternatively, mice were primed with PLGA nanoparticles loaded with the recombinant plasmid DNA and boosted using PLGA nanoparticles loaded with recombinant KMP-11. RESULTS: Both immunization strategies elicited detectable cellular immune responses with the presence of both proinflammatory and anti-inflammatory cytokines; mice receiving the recombinant PLGA nanoparticle formulations also demonstrated anti-KMP-11 IgG1 and IgG2a. Mice were then challenged with L. braziliensis, in the presence of sand fly saliva. Lesion development was not inhibited following either immunization strategy. However, immunization with PLGA nanoparticles resulted in a more prominent reduction in parasite load at the infection site when compared with immunization using plasmid DNA alone. This effect was associated with a local increase in interferon-gamma and in tumor necrosis factor-alpha. Both immunization strategies also resulted in a lower parasite load in the draining lymph nodes, albeit not significantly. CONCLUSION: Our results encourage the pursuit of immunization strategies employing nanobased delivery systems for vaccine development against cutaneous leishmaniasis caused by L. braziliensis infection.
	PMID: 22619548 [PubMed - in process]

4.	Biochim Biophys Acta. 2012 May 19. [Epub ahead of print] Role of K(+) binding residues in stabilization of heme spin state of Leishmania major peroxidase. Pal S, Yadav RK, Adak S. Abstract The endogenous cation in peroxidases may contribute to the type of heme coordination. Here a series of ferric and ferrous derivatives of wild-type Leishmania major peroxidase (LmP) and of engineered K(+) site mutants of LmP, lacking potassium cation binding site, have been examined by electronic absorption spectroscopy at 25°C. Using UV-visible spectrophotometry, we show that the removal of K(+) binding site causes substantial changes in spin states of both the ferric and ferrous forms. The spectral changes are interpreted to be, most likely, due to the formation of a bis-histidine coordination structure in both the ferric and ferrous oxidation states at neutral pH 7.0. Stopped flow spectrophotometric techniques revealed that characteristics of compound I was not observed in the K(+) site double mutants in presence of H(2)O(2). Similarly electron donor oxidation rate was two orders less for the K(+) site double mutants compared to the wild type. These data show that K(+) functions in preserving the protein structure in the heme surroundings as well as the spin state of the heme iron, in favor of the enzymatically active form of LmP. Copyright © 2012. Published by Elsevier B.V.
	PMID: 22617686 [PubMed - as supplied by publisher]

5.	BMC Plant Biol. 2011 Dec 30;11:185. Conservation of ciliary proteins in plants with no cilia. Hodges ME, Wickstead B, Gull K, Langdale JA. Source Department of Plant Sciences, University of Oxford, South Parks Rd, Oxford OX1 3RB, UK. Abstract BACKGROUND: Eukaryotic cilia are complex, highly conserved microtubule-based organelles with a broad phylogenetic distribution. Cilia were present in the last eukaryotic common ancestor and many proteins involved in cilia function have been conserved through eukaryotic diversification. However, cilia have also been lost multiple times in different lineages, with at least two losses occurring within the land plants. Whereas all non-seed plants produce cilia for motility of male gametes, some gymnosperms and all angiosperms lack cilia. During these evolutionary losses, proteins with ancestral ciliary functions may be lost or co-opted into different functions. RESULTS: Here we identify a core set of proteins with an inferred ciliary function that are conserved in ciliated eukaryotic species. We interrogate this genomic dataset to identify proteins with a predicted ancestral ciliary role that have been maintained in non-ciliated land plants. In support of our prediction, we demonstrate that several of these proteins have a flagellar localisation in protozoan trypanosomes. The phylogenetic distribution of these genes within the land plants indicates evolutionary scenarios of either sub- or neo-functionalisation and expression data analysis shows that these genes are highly expressed in Arabidopsis thaliana pollen cells. CONCLUSIONS: A large number of proteins possess a phylogenetic ciliary profile indicative of ciliary function. Remarkably, many genes with an ancestral ciliary role are maintained in non-ciliated land plants. These proteins have been co-opted to perform novel functions, most likely before the loss of cilia, some of which appear related to the formation of the male gametes. © 2011 Hodges et al; licensee BioMed Central Ltd. PMCID: PMC3268115 Free PMC Article
	PMID: 22208660 [PubMed - indexed for MEDLINE]
	Related citations