TY  - JOUR
A1  - Ranger, Christopher M.
A1  - Biedermann, Peter HW
A1  - Phuntumart, Vipaporn
A1  - Beligala, Gayathri U.
A1  - Ghosh, Satyaki
A1  - Palmquist, Debra E.
A1  - Mueller, Robert
A1  - Barnett, Jenny
A1  - Schultz, Peter B.
A1  - Reding, Michael E.
A1  - Benz, J. Philipp
T1  - Symbiont selection via alcohol benefits fungus farming by ambrosia beetles
JF  - Proceedings of the National Academy of Sciences
N2  - Animal-microbe mutualisms are typically maintained by vertical symbiont transmission or partner choice. A third mechanism, screening of high-quality symbionts, has been predicted in theory, but empirical examples are rare. Here we demonstrate that ambrosia beetles rely on ethanol within host trees for promoting gardens of their fungal symbiont and producing offspring. Ethanol has long been known as the main attractant for many of these fungus-farming beetles as they select host trees in which they excavate tunnels and cultivate fungal gardens. More than 300 attacks by Xylosandrus germanus and other species were triggered by baiting trees with ethanol lures, but none of the foundresses established fungal gardens or produced broods unless tree tissues contained in vivo ethanol resulting from irrigation with ethanol solutions. More X. germanus brood were also produced in a rearing substrate containing ethanol. These benefits are a result of increased food supply via the positive effects of ethanol on food-fungus biomass. Selected Ambrosiella and Raffaelea fungal isolates from ethanol-responsive ambrosia beetles profited directly and indirectly by (i) a higher biomass on medium containing ethanol, (ii) strong alcohol dehydrogenase enzymatic activity, and (iii) a competitive advantage over weedy fungal garden competitors (Aspergillus, Penicillium) that are inhibited by ethanol. As ambrosia fungi both detoxify and produce ethanol, they may maintain the selectivity of their alcohol-rich habitat for their own purpose and that of other ethanol-resistant/producing microbes. This resembles biological screening of beneficial symbionts and a potentially widespread, unstudied benefit of alcohol-producing symbionts (e.g., yeasts) in other microbial symbioses.
KW  - fungus-farming insects
KW  - plant-insect-microbe interactions
KW  - symbiosis
KW  - insect-fungus mutualism
KW  - host screening
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224953
VL  - 115
IS  - 17
ER  - 
TY  - JOUR
A1  - Benz, Peter M.
A1  - Merkel, Carla J.
A1  - Offner, Kristin
A1  - Abeßer, Marco
A1  - Ullrich, Melanie
A1  - Fischer, Tobias
A1  - Bayer, Barbara
A1  - Wagner, Helga
A1  - Gambaryan, Stepan
A1  - Ursitti, Jeanine A.
A1  - Adham, Ibrahim M.
A1  - Linke, Wolfgang A.
A1  - Feller, Stephan M.
A1  - Fleming, Ingrid
A1  - Renné, Thomas
A1  - Frantz, Stefan
A1  - Unger, Andreas
A1  - Schuh, Kai
T1  - Mena/VASP and alphaII-Spectrin complexes regulate cytoplasmic actin networks in cardiomyocytes and protect from conduction abnormalities and dilated cardiomyopathy
JF  - Cell Communication and Signaling
N2  - Background: In the heart, cytoplasmic actin networks are thought to have important roles in mechanical support, myofibrillogenesis, and ion channel function. However, subcellular localization of cytoplasmic actin isoforms and proteins involved in the modulation of the cytoplasmic actin networks are elusive. Mena and VASP are important regulators of actin dynamics. Due to the lethal phenotype of mice with combined deficiency in Mena and VASP, however, distinct cardiac roles of the proteins remain speculative. In the present study, we analyzed the physiological functions of Mena and VASP in the heart and also investigated the role of the proteins in the organization of cytoplasmic actin networks.
Results: We generated a mouse model, which simultaneously lacks Mena and VASP in the heart. Mena/VASP double-deficiency induced dilated cardiomyopathy and conduction abnormalities. In wild-type mice, Mena and VASP specifically interacted with a distinct αII-Spectrin splice variant (SH3i), which is in cardiomyocytes exclusively localized at Z- and intercalated discs. At Z- and intercalated discs, Mena and β-actin localized to the edges of the sarcomeres, where the thin filaments are anchored. In Mena/VASP double-deficient mice, β-actin networks were disrupted and the integrity of Z- and intercalated discs was markedly impaired.
Conclusions: Together, our data suggest that Mena, VASP, and αII-Spectrin assemble cardiac multi-protein complexes, which regulate cytoplasmic actin networks. Conversely, Mena/VASP deficiency results in disrupted β-actin assembly, Z- and intercalated disc malformation, and induces dilated cardiomyopathy and conduction abnormalities.
KW  - Mena/VASP
KW  - dilated cardiomyopathy
KW  - actin
KW  - heart
KW  - spectrin
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128760
VL  - 11
IS  - 56
ER  - 
TY  - JOUR
A1  - Korb, Doreen
A1  - Tng, Priscilla Y.
A1  - Milenkovic, Vladimir M.
A1  - Reichhart, Nadine
A1  - Strauss, Olaf
A1  - Ritter, Oliver
A1  - Fischer, Tobias
A1  - Benz, Peter M.
A1  - Schuh, Kai
T1  - Identification of PDZ domain containing proteins interacting with \(Ca_v1.2\) and PMCA4b
JF  - ISRN Cell Biology
N2  - PDZ (PSD-95/Disc large/Zonula occludens-1) protein interaction domains bind to cytoplasmic protein C-termini of transmembrane proteins. In order to identify new interaction partners of the voltage-gated L-type \(Ca^{2+}\) channel Cav1.2 and the plasma membrane \(Ca^{2+}\) ATPase 4b (PMCA4b), we used PDZ domain arrays probing for 124 PDZ domains. We confirmed this byGST pulldowns and immunoprecipitations. In PDZ arrays, strongest interactionswith \(Ca_v1.2\) and PMCA4b were found for the PDZ domains of SAP-102, MAST-205, MAGI-1, MAGI-2, MAGI-3, and ZO-1. We observed binding of the \(Ca_v1.2\) C-terminus to PDZ domains of NHERF1/2, Mint-2, and CASK. PMCA4b was observed to interact with Mint-2 and its known interactions with Chapsyn-110 and CASK were confirmed. Furthermore, we validated interaction of \(Ca_v1.2\) and PMCA4b with NHERF1/2, CASK,MAST-205 and MAGI-3 viaimmunoprecipitation. We also verified the interaction of \(Ca_v1.2\) and nNOS and hypothesized that nNOS overexpression might reduce \(Ca^{2+}\) influx through \(Ca_v1.2\). To address this, we measured \(Ca^{2+}\) currents in HEK 293 cells co-expressing \(Ca_v1.2\) and nNOS and observed reduced voltage-dependent \(Ca_v1.2\) activation. Taken together, we conclude that \(Ca_v1.2\) and PMCA4b bind promiscuously to various PDZ domains, and that our data provides the basis for further investigation of the physiological consequences of these interactions.
KW  - Cell
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130585
IS  - Article ID 265182
ER  -