Zur Zikadenfauna des Naturparkes Drömling (Sachsen-Anhalt): (Hemiptera, Auchenorrhyncha)

Im Feuchtgebiet des Drömling im Nordwesten Sachsen- Anhalts wurden bei einer Ersterfassung 1994 sowie zwei Wiederholungsuntersuchungen 1999 und 2006 auf 18 Standard-Testflächen insgesamt 171 Zikadenarten nachgewiesen. Darunter sind 2 nach der Roten Liste Sachsen-Anhalts vom Aussterben bedrohte, 9 stark gefährdete und 12 gefährdete Arten. Die als verschollen geltende Ruchgras-Spornzikade Ribautodelphax angulosa (RL 0) wurde wiedergefunden. Feuchte Brachflächen wiesen den größten Reichtum charakteristischer Feuchtgebietsarten auf, gefolgt von Flächen mit Moordammgräben oder zu Naturschutzzwecken angelegte Vernässungsbereiche. Als relativ artenarm erwiesen sich hingegen strukturärmere und intensiver genutzte Grünlandflächen (mehrfache Mahd, intensivere Beweidung).Contribution to the Auchenorrhyncha fauna of the Drömling reserve in Northwestern Saxony-Anhalt. In 1994, 1999 and 2006 we conducted a study of the Auchenorrhyncha fauna in the Drömling wetland in Northwestern Saxony- Anhalt. Altogether 171 species were found on 18 standardised plots. According to the Red List of Saxony-Anhalt, two species were critically endangered, nine endangered and 12 vulnerable. Ribautodelphax angulosa, a planthopper believed to be locally extinct, was rediscovered. Richness of hygrophilous species was greatest on wet fallows, followed by plots with moor ditches or patches rewetted for conservation purpose. In contrast, more intensively utilised grasslands (mown more than once a year or subject to more intensive grazing) which were therefore structurally less diverse, were relatively poor in species

Identification of cis-acting determinants mediating the unconventional secretion of tau.

The deposition of tau aggregates throughout the brain is a pathological characteristic within a group of neurodegenerative diseases collectively termed tauopathies, which includes Alzheimer's disease. While recent findings suggest the involvement of unconventional secretory pathways driving tau into the extracellular space and mediating the propagation of the disease-associated pathology, many of the mechanistic details governing this process remain elusive. In the current study, we provide an in-depth characterization of the unconventional secretory pathway of tau and identify novel molecular determinants that are required for this process. Here, using Drosophila models of tauopathy, we correlate the hyperphosphorylation and aggregation state of tau with the disease-related neurotoxicity. These newly established systems recapitulate all the previously identified hallmarks of tau secretion, including the contribution of tau hyperphosphorylation as well as the requirement for PI(4,5)P2 triggering the direct translocation of tau. Using a series of cellular assays, we demonstrate that both the sulfated proteoglycans on the cell surface and the correct orientation of the protein at the inner plasma membrane leaflet are critical determinants of this process. Finally, we identify two cysteine residues within the microtubule binding repeat domain as novel cis-elements that are important for both unconventional secretion and trans-cellular propagation of tau

Rerouting of fibroblast growth factor 2 to the classical secretory pathway results in post-translational modifications that block binding to heparan sulfate proteoglycans

AbstractFGF-2 is a proangiogenic growth factor secreted by unconventional means. It is unknown why FGF-2 takes an ER/Golgi-independent secretory route. We find that secretion of FGF-2 via the ER/Golgi system causes post-translational modifications that prevent binding to heparan sulfate proteoglycans (HSPGs), an interaction that is critically important for both FGF-2 storage and signal transduction. This loss of function is due to artificial O-glycosylation mainly resulting in the addition of glycosaminoglycan chains of the chrondroitin sulfate type. Our findings suggest that the unconventional mechanism of FGF-2 export is an ancient pathway of protein secretion that, in the course of evolution, has been kept due to the inability of the classical secretory pathway to export FGF-2 in a functional form

A modular interface of IL-4 allows for scalable affinity without affecting specificity for the IL-4 receptor

BACKGROUND: Interleukin 4 (IL-4) is a key regulator of the immune system and an important factor in the development of allergic hypersensitivity. Together with interleukin 13 (IL-13), IL-4 plays an important role in exacerbating allergic and asthmatic symptoms. For signal transduction, both cytokines can utilise the same receptor, consisting of the IL-4Rα and the IL-13Rα1 chain, offering an explanation for their overlapping biological functions. Since both cytokine ligands share only moderate similarity on the amino acid sequence level, molecular recognition of the ligands by both receptor subunits is of great interest. IL-4 and IL-13 are interesting targets for allergy and asthma therapies. Knowledge of the binding mechanism will be important for the generation of either IL-4 or IL-13 specific drugs. RESULTS: We present a structure/function analysis of the IL-4 ligand-receptor interaction. Structural determination of a number of IL-4 variants together with in vitro binding studies show that IL-4 and its high-affinity receptor subunit IL-4Rα interact via a modular protein-protein interface consisting of three independently-acting interaction clusters. For high-affinity binding of wild-type IL-4 to its receptor IL-4Rα, only two of these clusters (i.e. cluster 1 centered around Glu9 and cluster 2 around Arg88) contribute significantly to the free binding energy. Mutating residues Thr13 or Phe82 located in cluster 3 to aspartate results in super-agonistic IL-4 variants. All three clusters are fully engaged in these variants, generating a three-fold higher binding affinity for IL-4Rα. Mutagenesis studies reveal that IL-13 utilizes the same main binding determinants, i.e. Glu11 (cluster 1) and Arg64 (cluster 2), suggesting that IL-13 also uses this modular protein interface architecture. CONCLUSION: The modular architecture of the IL-4-IL-4Rα interface suggests a possible mechanism by which proteins might be able to generate binding affinity and specificity independently. So far, affinity and specificity are often considered to co-vary, i.e. high specificity requires high affinity and vice versa. Although the binding affinities of IL-4 and IL-13 to IL-4Rα differ by a factor of more than 1000, the specificity remains high because the receptor subunit IL-4Rα binds exclusively to IL-4 and IL-13. An interface formed by several interaction clusters/binding hot-spots allows for a broad range of affinities by selecting how many of these interaction clusters will contribute to the overall binding free energy. Understanding how proteins generate affinity and specificity is essential as more and more growth factor receptor families show promiscuous binding to their respective ligands. This limited specificity is, however, not accompanied by low binding affinities

Biological activity of a genetically modified BMP-2 variant with inhibitory activity

<p>Abstract</p> <p>Background</p> <p>Alterations of the binding epitopes of bone morphogenetic protein-2 (BMP-2) lead to a modified interaction with the ectodomains of BMP receptors. In the present study the biological effect of a BMP-2 double mutant with antagonistic activity was evaluated in vivo.</p> <p>Methods</p> <p>Equine-derived collagenous carriers were loaded with recombinant human BMP-2 (rhBMP-2) in a well-known dose to provide an osteoinductive stimulus. The study was performed in a split animal design: carriers only coupled with rhBMP-2 (control) were implanted into prepared cavities of lower limb muscle of rats, specimens coupled with rhBMP-2 as well as BMP-2 double mutant were placed into the opposite limb in the same way. After 28 days the carriers were explanted, measured radiographically and characterized histologically.</p> <p>Results</p> <p>As expected, the BMP-2 loaded implants showed a typical heterotopic bone formation. The specimens coupled with both proteins showed a significant decreased bone formation in a dose dependent manner.</p> <p>Conclusion</p> <p>The antagonistic effect of a specific BMP-2 double mutant could be demonstrated in vivo. The dose dependent influence on heterotopic bone formation by preventing rhBMP-2 induced osteoinduction suggests a competitive receptor antagonism.</p

Penestragania apicalis (Osborn & Ball, 1898), another invasive Nearctic leafhopper found in Europe: (Hemiptera: Cicadellidae, Iassinae)

Penestragania apicalis (Osborn &amp; Ball, 1898), eine weitere invasive nearktische Zikade in Europa gefunden (Hemiptera: Cicadellidae, Iassinae). – Im Jahr 2010 wurde die nearktische Zikadenart Penestragania apicalis (Osb. &amp; Ball) erstmalig in Europa gefunden. Insgesamt sind derzeit 16 Fundorte in Frankreich, der Schweiz, Deutschland und Österreich bekannt; daher ist davon auszugehen, dass die Art bereits seit längerer Zeit fest etabliert und in Europa und vielleicht weltweit weiter verbreitet ist. Wie in Nordamerika lebt sie an Gleditschie (Gleditsia triacanthos L.), überwintert im Eistadium und hat eine oder zwei Generation pro Jahr, mit adulten Tieren von mindestens Ende Juni bis Anfang Oktober. Ob in Europa wirtschaftlich relevante Schäden verursacht werden, ist noch unklar.In 2010 the Nearctic leafhopper Penestragania apicalis (Osb. &amp; Ball) was found for the first time in Europe. Altogether there are now 16 known localities in France, Switzerland, Germany and Austria indicating that the species is well es‐ tablished for a rather long period and more widespread in Europe and perhaps worldwide. As in North America it lives on honeylocust (Gleditsia triacanthos L.), overwinters in the egg stage and probably has one or two generations a year, with adults at least from late June until early October. It is yet unclear if it causes relevant damage to the host plant in Europe