Prevalence of tick-borne encephalitis virus antibodies in dogs from Denmark

Background  

Large regions of central and eastern Europe are recognized as areas where tick-borne encephalitis virus (TBEV) is endemic, including countries neighbouring Denmark. It is therefore timely and relevant to determine if TBEV infections occur in Denmark. This study investigates the presence of antibodies against TBEV in a cross-section of the Danish canine population to assess the level of exposure to TBEV and possibly identify TBEV microfoci in Denmark.     

1H, 15N and 13C assignments of yellow fluorescent protein (YFP) Venus

We present here the backbone and side-chain NMR assignments of YFP Venus, a 238-residue protein that emits yellow fluorescence in its native state. Venus is a variant of the green fluorescent protein (GFP), which has improved chromophore maturation and brightness, and the photochemistry and photophysics of which are insensitive to experimental conditions, such as the pH value and buffer content, making it a favourable biomarker.     

The E3 Ubiquitin-Ligase Bmi1/Ring1A Controls the Proteasomal Degradation of Top2α Cleavage Complex – A Potentially New Drug Target

Background

The topoisomerases Top1, Top2α and Top2β are important molecular targets for antitumor drugs, which specifically poison Top1 or Top2 isomers. While it was previously demonstrated that poisoned Top1 and Top2β are subject to proteasomal degradation, this phenomena was not demonstrated for Top2α.

Methodology/Principal Findings

We show here that Top2α is subject to drug induced proteasomal degradation as well, although at a lower rate than Top2β. Using an siRNA screen we identified Bmi1 and Ring1A as subunits of an E3 ubiquitin ligase involved in this process. We show that silencing of Bmi1 inhibits drug-induced Top2α degradation, increases the persistence of Top2α-DNA cleavage complex, and increases Top2 drug efficacy. The Bmi1/Ring1A ligase ubiquitinates Top2α in-vitro and cellular overexpression of Bmi1 increases drug induced Top2α ubiquitination. A small-molecular weight compound, identified in a screen for inhibitors of Bmi1/Ring1A ubiquitination activity, also prevents Top2α ubiquitination and drug-induced Top2α degradation. This ubiquitination inhibitor increases the efficacy of topoisomerase 2 poisons in a synergistic manner.

Conclusions/Significance

The discovery that poisoned Top2α is undergoing proteasomal degradation combined with the involvement of Bmi1/Ring1A, allowed us to identify a small molecule that inhibits the degradation process. The Bmi1/Ring1A inhibitor sensitizes cells to Top2 drugs, suggesting that this type of drug combination will have a beneficial therapeutic outcome. As Bmi1 is also a known oncogene, elevated in numerous types of cancer, the identified Bmi1/Ring1A ubiquitin ligase inhibitors can also be potentially used to directly target the oncogenic properties of Bmi1.     

Apolipoprotein E structure: insights into function

Human apolipoprotein E (apoE) is a member of the family of soluble apolipoproteins. Through its interaction with members of the low-density lipoprotein receptor family, apoE has a key role in lipid transport both in the plasma and in the central nervous system. Its three common structural isoforms differentially affect the risk of developing atherosclerosis and neurodegenerative disorders, including Alzheimer's disease. Because the function of apoE is dictated by its structure, understanding the structural properties of apoE and its isoforms is required both to determine its role in disease and for the development of therapeutic strategies.     

Preparation of fluorescent tocopherols for use in protein binding and localization with the alpha-tocopherol transfer protein

Sixteen fluorescent analogues of the lipid-soluble antioxidant vitamin alpha-tocopherol were prepared incorporating fluorophores at the terminus of omega-functionalized 2-n-alkyl-substituted chromanols (1a-d and 4a-d) that match the methylation pattern of alpha-tocopherol, the most biologically active form of vitamin E. The fluorophores used include 9-anthroyloxy (AO), 7-nitrobenz-2-oxa-1,3-diazole (NBD), N-methyl anthranilamide (NMA), and dansyl (DAN). The compounds were designed to function as fluorescent reporter ligands for protein-binding and lipid transfer assays. The fluorophores were chosen to maximize the fluorescence changes observed upon moving from an aqueous environment (low fluorescence intensity) to an hydrophobic environment such as a protein's binding site (high fluorescence intensity). Compounds 9d (anthroyloxy) and 10d (nitrobenzoxadiazole), having a C9-carbon chain between the chromanol and the fluorophore, were shown to bind specifically and reversibly to recombinant human tocopherol transfer protein (alpha-TTP) with dissociation constants of approximately 280 and 60 nM, respectively, as compared to 25 nM for the natural ligand 2R,4'R,8'R-alpha-tocopherol. Thus, compounds have been prepared that allow the investigation of the rate of alpha-TTP-mediated inter-membrane transfer of alpha-tocopherol and to investigate the mechanism of alpha-TTP function at membranes of different composition.     

Sarcomere lesion damage occurs mainly in slow fibers of reloaded rat adductor longus muscles

Sarcomerelesions were previously observed with reloading of rat adductor longusmuscles after spaceflight and hindlimb unloading (HU).Spaceflown rats displayed more lesioned fibers in the"slow-fiber" region, suggesting a damage-susceptible fiber type.Unloading induces fast myosin expression in some slow fibers,generating hybrid fibers. We examined whether lesion damage differedamong slow-, hybrid-, and fast-fiber types in HU-reloaded adductorlongus muscles. Temporal HU for 5, 8, 11, 14, and 17 days revealed that hybrid fiber percent, detected by antimyosin immunostaining, peaked at29 ± 12% by 14 days. A 14-day HU followed by 12-14 h ofvoluntary reloading was performed to induce lesions.² analysis showed that slowfibers were preferentially damaged, accounting for 92 ± 5% oflesioned fibers; hybrid and fast fibers accounted for 7 ± 4 and<0.5%, respectively. Atrophy did not explain differential lesiondamage across fiber types, as slow and hybrid fibers atrophied to asimilar extent. Because active myofiber contractions are requisite forlesion formation, selective recruitment of slow fibers most likelyexplains their damage susceptibility.

     

Effect of Endophytic Fusarium oxysporum on Host Preference of Radopholus similis to Tissue Culture Banana Plants

The burrowing nematode Radopholus similis is one of the major constraints to banana (Musa spp.) production worldwide. Resource-poor farmers can potentially manage R. similis by using naturally occurring banana endophytes, such as nonpathogenic Fusarium oxysporum, that are inoculated into tissue culture banana plantlets. At present, it is unclear at what stage in the R. similis infection process the endophytes are most effective. In this study, the effect of three endophytic F. oxysporum isolates (V5w2, Eny1.31i and Eny7.11o) on R. similis host preference of either endophyte-treated or untreated banana plants was investigated. No differences were observed between the proportion of nematodes attracted to either root segments excised from endophyte-treated or untreated plants, or in experiments using endophyte-treated and untreated tissue culture banana plantlets. These results imply that the early processes of banana plant host recognition by R. similis are not affected by endophyte infection.     

An Integrated Mass-Spectrometry Pipeline Identifies Novel Protein Coding-Regions in the Human Genome

Background

Most protein mass spectrometry (MS) experiments rely on searches against a database of known or predicted proteins, limiting their ability as a gene discovery tool.

Results

Using a search against an in silico translation of the entire human genome, combined with a series of annotation filters, we identified 346 putative novel peptides [False Discovery Rate (FDR)<5%] in a MS dataset derived from two human breast epithelial cell lines. A subset of these were then successfully validated by a different MS technique. Two of these correspond to novel isoforms of Heterogeneous Ribonuclear Proteins, while the rest correspond to novel loci.

Conclusions

MS technology can be used for ab initio gene discovery in human data, which, since it is based on different underlying assumptions, identifies protein-coding genes not found by other techniques. As MS technology continues to evolve, such approaches will become increasingly powerful.     

Environmental cues and extended estuarine residence in seaward migrating eels (Anguilla australis)

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