| 1. |
- El-Sayed, Najib M., et al.
(author)
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The genome sequence of Trypanosoma cruzi, etiologic agent of Chagas disease.
- 2005
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In: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 309:5733, s. 409-15
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Journal article (peer-reviewed)abstract
- Whole-genome sequencing of the protozoan pathogen Trypanosoma cruzi revealed that the diploid genome contains a predicted 22,570 proteins encoded by genes, of which 12,570 represent allelic pairs. Over 50% of the genome consists of repeated sequences, such as retrotransposons and genes for large families of surface molecules, which include trans-sialidases, mucins, gp63s, and a large novel family (>1300 copies) of mucin-associated surface protein (MASP) genes. Analyses of the T. cruzi, T. brucei, and Leishmania major (Tritryp) genomes imply differences from other eukaryotes in DNA repair and initiation of replication and reflect their unusual mitochondrial DNA. Although the Tritryp lack several classes of signaling molecules, their kinomes contain a large and diverse set of protein kinases and phosphatases; their size and diversity imply previously unknown interactions and regulatory processes, which may be targets for intervention.
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| 2. |
- Constantinidis, Ioannis, et al.
(author)
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Non-invasive evaluation of alginate/poly-L-lysine/alginate microcapsules by magnetic resonance microscopy
- 2007
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In: Biomaterials. - : Elsevier BV. - 0142-9612 .- 1878-5905. ; 28:15, s. 2438-2445
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Journal article (peer-reviewed)abstract
- In this report, we present data to demonstrate the utility of H-1 MR microscopy to non-invasively examine alginate/poly-L-lysine/ alginate (APA) microcapsules. Specifically, high-resolution images were used to visualize and quantify the poly-L-lysine (PLL) layer, and monitor temporal changes in the alginate gel microstructure during a month long in vitro culture. The thickness of the alginate/PLL layer was quantified to be 40.6 +/- 6.2 mu m regardless of the alginate composition used to generate the beads or the time of alginate/PLL interaction (2, 6, or 20 min). However, there was a notable difference in the contrast of the PLL layer that depended upon the guluronic content of the alginate and the alginate/PLL interaction time. The T-2 relaxation time and the apparent diffusion coefficient (ADC) of the alginate matrix were measured periodically throughout the month long culture period. Alginate beads generated with a high guluronic content alginate demonstrated a temporal decrease in T-2 over the duration of the experiment, while ADC was unaffected. This decrease in T-2 is attributed to a reorganization of the alginate microstructure due to periodic media exchanges that mimicked a regular feeding regiment for cultured cells. In beads coated with a PLL layer, this temporal decrease in T-2 was less pronounced suggesting that the PLL layer helped maintain the integrity of the initial alginate microstructure. Conversely, alginate beads generated with a high mannuronic content alginate (with or without a PLL layer) did not display temporal changes in either T-2 or ADC. This observation suggests that the microstructure of high mannuronic content alginate beads is less susceptible to culture conditions.
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| 3. |
- Simpson, Jeremy C, et al.
(author)
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Biogenesis of tubular ER-to-Golgi transport intermediates.
- 2006
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In: Molecular biology of the cell. - 1059-1524. ; 17:2, s. 723-37
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Journal article (peer-reviewed)abstract
- Tubular transport intermediates (TTIs) have been described as one class of transport carriers in endoplasmic reticulum (ER)-to-Golgi transport. In contrast to vesicle budding and fusion, little is known about the molecular regulation of TTI synthesis, transport and fusion with target membranes. Here we have used in vivo imaging of various kinds of GFP-tagged proteins to start to address these questions. We demonstrate that under steady-state conditions TTIs represent approximately 20% of all moving transport carriers. They increase in number and length when more transport cargo becomes available at the donor membrane, which we induced by either temperature-related transport blocks or increased expression of the respective GFP-tagged transport markers. The formation and motility of TTIs is strongly dependent on the presence of intact microtubules. Microinjection of GTPgammaS increases the frequency of TTI synthesis and the length of these carriers. When Rab proteins are removed from membranes by microinjection of recombinant Rab-GDI, the synthesis of TTIs is completely blocked. Microinjection of the cytoplasmic tails of the p23 and p24 membrane proteins also abolishes formation of p24-containing TTIs. Our data suggest that TTIs are ER-to-Golgi transport intermediates that form preferentially when transport-competent cargo exists in excess at the donor membrane. We propose a model where the interaction of the cytoplasmic tails of membrane proteins with microtubules are key determinants for TTI synthesis and may also serve as a so far unappreciated model for aspects of transport carrier formation.
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