Impact of copper and zinc on the growth of saprotrophic fungi and the production of extracellular enzymes

Peer reviewe

Hantaviruses and TNF-alpha act synergistically to induce ERK1/2 inactivation in Vero E6 cells.

BACKGROUND: We have previously reported that the apathogenic Tula hantavirus induces apoptosis in Vero E6 epithelial cells. To assess the molecular mechanisms behind the induced apoptosis we studied the effects of hantavirus infection on cellular signaling pathways which promote cell survival. We previously also observed that the Tula virus-induced cell death process is augmented by external TNF-a ... [More

Analysis of Potato virus Y Coat Protein Epitopes Recognized by Three Commercial Monoclonal Antibodies

Peer reviewe

Interactions and Oligomerization of Hantavirus Glycoproteins▿

In this report the basis for the structural architecture of the envelope of hantaviruses, family Bunyaviridae, is systematically studied by the interactions of two glycoproteins N and C (Gn and Gc, respectively) and their respective disulfide bridge-mediated homo- and heteromeric oligomerizations. In virion extracts Gn and Gc associated in both homo- and hetero-oligomers which were, at least partially, thiol bridge mediated. Due to strong homo-oligomerization, the hetero-oligomers of Gn and Gc are likely to be mediated by homo-oligomeric subunits. A reversible pH-induced disappearance of a neutralizing epitope in Gc and dissociation of the Gn-Gc complex at pH values below 6.2 provide proteochemical evidence for the fusogenicity of Gc. Incomplete inactivation of virions at acidic pH indicates that additional factors are required for hantavirus fusion, as in the case of pestiviruses of the Flaviviridae. Based on similarities to class II fusion proteins, a structure model was created of hantavirus Gc using the Semliki Forest virus E1 protein as a template. In total, 10 binding regions for Gn were found by peptide scanning, of which five represent homotypic (GnI to GnV) and five represent heterotypic (GcI to GcV) interaction sites that we assign as intra- and interspike connections, respectively. In conclusion, the glycoprotein associations were compiled to a model wherein the surface of hantaviruses is formed of homotetrameric Gn complexes interconnected with Gc homodimers. This organization would create the grid-like surface pattern described earlier for hantaviruses in negatively stained electron microscopy specimens

Hantaviruses and TNF-alpha act synergistically to induce ERK1/2 inactivation in Vero E6 cells

Abstract Background We have previously reported that the apathogenic Tula hantavirus induces apoptosis in Vero E6 epithelial cells. To assess the molecular mechanisms behind the induced apoptosis we studied the effects of hantavirus infection on cellular signaling pathways which promote cell survival. We previously also observed that the Tula virus-induced cell death process is augmented by external TNF-α. Since TNF-α is involved in the pathogenesis of hantavirus-caused hemorrhagic fever with renal syndrome (HFRS) we investigated its effects on HFRS-causing hantavirus-infected cells. Results We studied both apathogenic (Tula and Topografov) and pathogenic (Puumala and Seoul) hantaviruses for their ability to regulate cellular signaling pathways and observed a direct virus-mediated down-regulation of external signal-regulated kinases 1 and 2 (ERK1/2) survival pathway activity, which was dramatically enhanced by TNF-α. The fold of ERK1/2 inhibition correlated with viral replication efficiencies, which varied drastically between the hantaviruses studied. Conclusion We demonstrate that in the presence of a cytokine TNF-α, which is increased in HFRS patients, hantaviruses are capable of inactivating proteins that promote cell survival (ERK1/2). These results imply that hantavirus-infected epithelial cell barrier functions might be compromised in diseased individuals and could at least partially explain the mechanisms of renal dysfunction and the resulting proteinuria seen in HFRS patients.</p

Hematological and antifungal properties of temporin A and a cecropin A-temporin A hybrid.

Temporin A (TA) and a cecropin A-temporin A hybrid peptide (CATA) were synthesized and assayed for their hemolytic, anticoagulant, and antifungal properties. CATA retains significant antifungal activity, is less hemolytic than TA, and inhibits blood coagulation. These results recommend further studies of the biological activities of CATA