Thursday, May 28, 2009

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, 2009 May 28
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 -4 of 4

1: Tunis Med. 2008 May;86(5):512-3.

[Cutaneous leishmaniasis in Tunisia: discovery of leishmania infantum in south of the country]

[Article in French]

Masmoudi A, Ben Salah H, Meziou TJ, Bouzid L, Maalej S, Akrout F, Bouassida S, Baba H, Turki H, Zahaf A.

PMID: 19472498 [PubMed - in process]

2: J Mol Model. 2009 May 27. [Epub ahead of print]

Kinetoplastid RNA editing ligases 1 and 2 exhibit different electrostatic properties.

Shaneh A, Salavati R.

Institute of Parasitology, McGill Centre for Bioinformatics, 21-111 Lakeshore Road, Ste. Anne de Bellevue, Quebec, H9X 3V9, Canada.

Kinetoplastid RNA editing ligases 1 and 2 (KREL1 and KREL2) share a significant degree of sequence homology. However, biochemical experiments have reported that KREL1 and KREL2 differ in their functional roles during the RNA editing process. In this study, we hypothesize that dissimilar roles for KREL1 and KREL2 proteins arise from their different physicochemical characteristics. To test our hypothesis at sequence level, we plotted theoretical titration curves for KREL1, KREL2 and their binding partner proteins. The plots showed a lower isoelectric point for KREL1 compared to that for KREL2 as well as more relative alkalinity and acidity for binding partner proteins of KREL1 and KREL2 at net charge zero, respectively. At structure level, based on the available high resolution structure of KREL1 N-terminal domain and strong sequence similarity between KRELs and other ligases, we built the homology model of KREL2 N-terminal domain. Using Poisson-Boltzmann continuum approach, we calculated the electrostatic potential isosurfaces of KREL1 structure and KREL2 model. KREL1 and KREL2 coordinates differed in their electrostatic isopotential patterns. A wider negative patch on the surface of KREL1 suggests differential affinity for another protein compared to KREL2. In contrast, a larger positive patch on the KREL2 surface predicts its differential affinity and/or specificity for its RNA substrate. Subsequently, we employed in silico mutational scanning and identified the surface-exposed residues contributing to the long-range electrostatic energy of KRELs. We predict that two structurally conserved loops of KRELs, not previously reported in the literature, also recognize their RNA substrates. Our results provide important information about the physicochemical properties of RNA editing ligases that could contribute to the ligation step of RNA editing.

PMID: 19471975 [PubMed - as supplied by publisher]

3: Cell Tissue Res. 2009 May 27. [Epub ahead of print]

Peritrophic matrix of Phlebotomus duboscqi and its kinetics during Leishmania major development.

Sádlová J, Volf P.

Department of Parasitology, Charles University, Vinicna 7, Prague 2, Czech Republic.

Light microscopy of native preparations, histology, and electron microscopy have revealed that Phlebotomus duboscqi belongs to a class of sand fly species with prompt development of the peritrophic matrix (PM). Secretion of electron-lucent fibrils, presumably chitin, starts immediately after the ingestion of a blood meal and, about 6 h later, is followed by secretion of amorphous electron-dense components, presumably proteins and glycoproteins. The PM matures in less than 12 h and consists of a thin laminar outer layer and a thick amorphous inner layer. No differences have been found in the timing of the disintegration of the PM in females infected with Leishmania major. In both groups of females (infected and uninfected), the disintegration of the PM is initiated at the posterior end. Although parasites are present at high densities in the anterior part of the blood meal bolus, they escape from the PM at the posterior end only. These results suggest that L. major chitinase does not have an important role in parasite escape from the PM. Promastigotes remain in the intraperitrophic space until the PM is broken down by sand-fly-derived chitinases and only then migrate anteriorly. Disintegration of the PM occurs simultaneously with the morphological transformation of parasites from procyclic forms to long nectomonads. A novel role is ascribed to the anterior plug, a component of the PM secreted by the thoracic midgut; this plug functions as a temporary barrier to stop the forward migration of nectomonads to the thoracic midgut.

PMID: 19471970 [PubMed - as supplied by publisher]

4: Mol Cell Probes. 2009 Feb;23(1):44-51. Epub 2008 Nov 24.Click here to read Nucleotide, Taxonomy via GenBank, Protein, LinkOut

Cathepsin L-like genes of Trypanosoma vivax from Africa and South America--characterization, relationships and diagnostic implications.

Cortez AP, Rodrigues AC, Garcia HA, Neves L, Batista JS, Bengaly Z, Paiva F, Teixeira MM.

Department of Parasitology, University of São Paulo, Av. Prof. Lineu Prestes 1374, 05508-900 São Paulo, SP, Brazil.

We characterized sequences from genes encoding cathepsin L-like (CatL-like) cysteine proteases from African and South American isolates of Trypanosoma vivax and T. vivax-like organisms, and evaluated their suitability as genetic markers for population structure analysis and diagnosis. Phylogenetic analysis of sequences corresponding to CatL-like catalytic domains revealed substantial polymorphism, and clades of sequences (TviCatL1-9) were separated by large genetic distances. TviCatL1-4 sequences were from cattle isolates from West Africa (Nigeria and Burkina Faso) and South America (Brazil and Venezuela), which belonged to the same T. vivax genotype. T. vivax-like genotypes from East Africa showed divergent sequences, including TviCatL5-7 for isolates from Mozambique and TviCatL8-9 for an isolate from Kenya. Phylogenetic analysis of CatL-like gene data supported the relationships among trypanosome species reflected in the phylogenies based on the analysis of small subunit (SSU) of ribosomal RNA gene sequence data. The discovery of different CatL-like sequences for each genotype, defined previously by ribosomal DNA data, indicate that these sequences provide useful targets for epidemiological and population genetic studies. Regions in CatL-like sequences shared by all T. vivax genotypes but not by other trypanosomes allowed the establishment of a specific and sensitive diagnostic PCR for epidemiological studies in South America and Africa.

PMID: 19063960 [PubMed - indexed for MEDLINE]

Posted by at

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)