@article{BazihizinaBoehmMessereretal.2022, author = {Bazihizina, Nadia and B{\"o}hm, Jennifer and Messerer, Maxim and Stigloher, Christian and M{\"u}ller, Heike M. and Cuin, Tracey Ann and Maierhofer, Tobias and Cabot, Joan and Mayer, Klaus F. X. and Fella, Christian and Huang, Shouguang and Al-Rasheid, Khaled A. S. and Alquraishi, Saleh and Breadmore, Michael and Mancuso, Stefano and Shabala, Sergey and Ache, Peter and Zhang, Heng and Zhu, Jian-Kang and Hedrich, Rainer and Scherzer, S{\"o}nke}, title = {Stalk cell polar ion transport provide for bladder-based salinity tolerance in Chenopodium quinoa}, series = {New Phytologist}, volume = {235}, journal = {New Phytologist}, number = {5}, doi = {10.1111/nph.18205}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-287222}, pages = {1822 -- 1835}, year = {2022}, abstract = {Chenopodium quinoa uses epidermal bladder cells (EBCs) to sequester excess salt. Each EBC complex consists of a leaf epidermal cell, a stalk cell, and the bladder. Under salt stress, sodium (Na\(^{+}\)), chloride (Cl\(^{-}\)), potassium (K\(^{+}\)) and various metabolites are shuttled from the leaf lamina to the bladders. Stalk cells operate as both a selectivity filter and a flux controller. In line with the nature of a transfer cell, advanced transmission electron tomography, electrophysiology, and fluorescent tracer flux studies revealed the stalk cell's polar organization and bladder-directed solute flow. RNA sequencing and cluster analysis revealed the gene expression profiles of the stalk cells. Among the stalk cell enriched genes, ion channels and carriers as well as sugar transporters were most pronounced. Based on their electrophysiological fingerprint and thermodynamic considerations, a model for stalk cell transcellular transport was derived.}, language = {en} } @phdthesis{Bausenwein2000, author = {Bausenwein, Burkhard}, title = {Funktionelle Charakterisierung von Daughter of Sevenless}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-814}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2000}, abstract = {Ein Weg, der von Rezeptor-Tyrosin-Kinasen benutzt wird um Signale auf "downstream" gelegene Effektormolek{\"u}le zu {\"u}bertragen, erfolgt {\"u}ber Adaptorproteine, die Bindungsstellen f{\"u}r verschiedene Proteine zur Verf{\"u}gung stellen. Das daughter of sevenless (dos) Gen wurde in einem Screen nach Downstream-Komponenten der Sevenless (Sev) Rezeptor-Tyrosin-Kinase gefunden. Dos besitzt eine N-terminale PH-Dom{\"a}ne und mehrere Tyrosinreste in Konsensussequenzen f{\"u}r SH2-Dom{\"a}nen Bindungsstellen von verschiedenen Proteinen. Die strukturellen Merkmale von Dos und Experimente, die zeigten, daß Tyrosine im Dos Protein nach der Aktivierung von Sev phosphoryliert werden, legen den Schluß nahe, daß Dos zur Familie der Multi-Adaptor-Proteine geh{\"o}rt. Zu dieser Familie werden die Insulin-Rezeptor-Substrat (IRS) Proteine, Gab1 und Gab2 gerechnet. In dieser Arbeit wurde ein monoklonaler Maus anti-Dos Antik{\"o}rper etabliert. Das Epitop dieses Antik{\"o}rpers liegt im Bereich der C-terminalen 416 Aminos{\"a}uren des Dos Proteins. Mittels Westernblot Analysen wurde f{\"u}r Dos ein Molekulargewicht von 115 kD ermittelt. Antik{\"o}rperf{\"a}rbungen von wildtypischen Augenimaginalscheiben dritter Larven zeigten, daß das Dos Protein in Zellen in und posterior der morphogenetischen Furche exprimiert wird und in diesen Zellen apikal lokalisiert ist. Zur Charakterisierung des homozygot letalen dosR31 Allels, wurde der genomische Bereich sequenziert und die erhaltenen Daten mit der cDNA Sequenz verglichen. Die so etablierte Aminos{\"a}uresequenz f{\"u}r das DosR31 Protein hat sechs Aminos{\"a}uresubstitutionen, die m{\"o}glicherweise die Terti{\"a}rstruktur beeinflussen. Zus{\"a}tzlich wurde ein Stopcodon in Position 463 der Aminos{\"a}uresequenz gefunden. Bei dosR31 handelt es sich um ein "loss of function" Allel, das nicht in der Lage ist, die normale Dos Funktion zu erf{\"u}llen. Um die funktionelle Rolle der potentiellen SH2-Dom{\"a}nen Bindungsstellen f{\"u}r die Dos Funktion in der Rezeptor-Tyrosin-Kinasen vermittelten Signaltransduktion zu untersuchen, wurden mutierte dos Transgene in Fliegen exprimiert. Die potentiellen Bindungsstellen f{\"u}r die SH2-Dom{\"a}nen des SH2/SH3 Adaptorproteins Shc, der PhospholipaseC-g (PLCg), der regulatorische Untereinheit der Phosphatidylinositol-3-Kinase (PI3Kinase) und der Corkscrew (Csw) Tyrosin Phosphatase wurden durch den Austausch des f{\"u}r die Bindung wichtigen Tyrosins gegen ein Phenylalanin mutiert. Die ektopische Expression der mutierten Konstrukte ohne Bindungsstellen f{\"u}r die Shc, PLCg und PI3Kinasen SH2-Dom{\"a}nen konnte in Abwesenheit von endogenem Dos die fehlende Dos Funktion w{\"a}hrend der Entwicklung vollst{\"a}ndig ersetzen. Im Gegensatz dazu ist das Tyrosin 801 als nachgewiesene Bindungsstelle f{\"u}r Csw SH2-Dom{\"a}nen essentiell f{\"u}r die Funktion von Dos. Ektopische Expression von Transgene durch Hitzeschock kann zu ph{\"a}notypischen Effekten f{\"u}hren, die nicht auf das Transgen zur{\"u}ckzuf{\"u}hren sind. Um dieses Problem zu umgehen wurde das endogene dos Enhancer/Promotor Element kloniert, damit die Funktion von mutierten Transgenen auch im endogenen Expressionsmuster untersucht werden konnte. Das klonierte genE-dos Minigen war in der Lage, den Verlust von endogenem Dos in dosR31 und dosP115 Tieren vollst{\"a}ndig zu ersetzen und zeigte eine v{\"o}llig wildtypische Expression in Augenimaginalscheiben. Zur Untersuchung, welche Rolle die mutierten SH2-Dom{\"a}nen Bindungsstellen bei der Dos Funktion in der Augenentwicklung spielen, wurde ein neues in vivo Testsystem basierend auf der Flp/FRT Flipase Rekombinase Technik etabliert. Dieses klonale Testsystem erlaubt die Expression mutierter Transgene unter der Kontrolle der dos Enhancer/Promotor Sequenzen in Klonen von Zellen, denen die endogene Dos Funktion fehlt. Die klonale Analyse der mutierten Konstrukte konnte zeigen, daß das Tyrosin 801, als Bindungsstelle f{\"u}r eine Csw SH2-Dom{\"a}ne, eine essentielle Rolle f{\"u}r die Dos Funktion spielt. Die Tyrosinreste in den potentiellen SH2-Dom{\"a}nen Bindungsstellen f{\"u}r Shc, PLCg und PI3Kinase spielen hingegen keine essentielle Rolle f{\"u}r die Dos Funktion bei der Augenentwicklung. Das etablierte klonale Testsystem kann allgemein zur Untersuchung der in vivo Funktion von potentiellen Protein-Protein Interaktionsregionen im Dos Protein bei der Augenentwicklung eingesetzt werden unabh{\"a}ngig von deren Erfordernis f{\"u}r andere Entwicklungsprozesse.}, subject = {Taufliege}, language = {de} } @article{BaurRautenbergFaulstichetal.2014, author = {Baur, Stefanie and Rautenberg, Maren and Faulstich, Manuela and Grau, Timo and Severin, Yannik and Unger, Clemens and Hoffmann, Wolfgang H. and Rudel, Thomas and Autenrieth, Ingo B. and Weidenmaier, Christopher}, title = {A Nasal Epithelial Receptor for Staphylococcus aureus WTA Governs Adhesion to Epithelial Cells and Modulates Nasal Colonization}, series = {PLOS PATHOGENS}, volume = {10}, journal = {PLOS PATHOGENS}, number = {5}, issn = {1553-7374}, doi = {10.1371/journal.ppat.1004089}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-116280}, pages = {e1004089}, year = {2014}, abstract = {Nasal colonization is a major risk factor for S. aureus infections. The mechanisms responsible for colonization are still not well understood and involve several factors on the host and the bacterial side. One key factor is the cell wall teichoic acid (WTA) of S. aureus, which governs direct interactions with nasal epithelial surfaces. We report here the first receptor for the cell wall glycopolymer WTA on nasal epithelial cells. In several assay systems this type F-scavenger receptor, termed SREC-I, bound WTA in a charge dependent manner and mediated adhesion to nasal epithelial cells in vitro. The impact of WTA and SREC-I interaction on epithelial adhesion was especially pronounced under shear stress, which resembles the conditions found in the nasal cavity. Most importantly, we demonstrate here a key role of the WTA-receptor interaction in a cotton rat model of nasal colonization. When we inhibited WTA mediated adhesion with a SREC-I antibody, nasal colonization in the animal model was strongly reduced at the early onset of colonization. More importantly, colonization stayed low over an extended period of 6 days. Therefore we propose targeting of this glycopolymer-receptor interaction as a novel strategy to prevent or control S. aureus nasal colonization.}, language = {en} } @article{BaurNietzerKunzetal.2020, author = {Baur, Florentin and Nietzer, Sarah L. and Kunz, Meik and Saal, Fabian and Jeromin, Julian and Matschos, Stephanie and Linnebacher, Michael and Walles, Heike and Dandekar, Thomas and Dandekar, Gudrun}, title = {Connecting cancer pathways to tumor engines: a stratification tool for colorectal cancer combining human in vitro tissue models with boolean in silico models}, series = {Cancers}, volume = {12}, journal = {Cancers}, number = {1}, issn = {2072-6694}, doi = {10.3390/cancers12010028}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193798}, pages = {28}, year = {2020}, abstract = {To improve and focus preclinical testing, we combine tumor models based on a decellularized tissue matrix with bioinformatics to stratify tumors according to stage-specific mutations that are linked to central cancer pathways. We generated tissue models with BRAF-mutant colorectal cancer (CRC) cells (HROC24 and HROC87) and compared treatment responses to two-dimensional (2D) cultures and xenografts. As the BRAF inhibitor vemurafenib is—in contrast to melanoma—not effective in CRC, we combined it with the EGFR inhibitor gefitinib. In general, our 3D models showed higher chemoresistance and in contrast to 2D a more active HGFR after gefitinib and combination-therapy. In xenograft models murine HGF could not activate the human HGFR, stressing the importance of the human microenvironment. In order to stratify patient groups for targeted treatment options in CRC, an in silico topology with different stages including mutations and changes in common signaling pathways was developed. We applied the established topology for in silico simulations to predict new therapeutic options for BRAF-mutated CRC patients in advanced stages. Our in silico tool connects genome information with a deeper understanding of tumor engines in clinically relevant signaling networks which goes beyond the consideration of single drivers to improve CRC patient stratification.}, language = {en} } @article{BatzkeBuechelHansenetal.2018, author = {Batzke, Katharina and B{\"u}chel, Gabriele and Hansen, Wiebke and Schramm, Alexander}, title = {TrkB-target Galectin-1 impairs immune activation and radiation responses in neuroblastoma: implications for tumour therapy}, series = {International Journal of Molecular Sciences}, volume = {19}, journal = {International Journal of Molecular Sciences}, number = {3}, issn = {1422-0067}, doi = {10.3390/ijms19030718}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285097}, year = {2018}, abstract = {Galectin-1 (Gal-1) has been described to promote tumour growth by inducing angiogenesis and to contribute to the tumour immune escape. We had previously identified up-regulation of Gal-1 in preclinical models of aggressive neuroblastoma (NB), the most common extracranial tumour of childhood. While Gal-1 did not confer a survival advantage in the absence of exogenous stressors, Gal-1 contributed to enhanced cell migratory and invasive properties. Here, we review these findings and extend them by analyzing Gal-1 mediated effects on immune cell regulation and radiation resistance. In line with previous results, cell autonomous effects as well as paracrine functions contribute to Gal-1 mediated pro-tumourigenic functions. Interfering with Gal-1 functions in vivo will add to a better understanding of the role of the Gal-1 axis in the complex tumour-host interaction during immune-, chemo- and radiotherapy of neuroblastoma.}, language = {en} } @phdthesis{Batzilla2011, author = {Batzilla, Julia}, title = {Complete genome sequence of Yersinia enterocolitica subspecies palearctica serotype O:3: Identification of novel virulence-associated genes and evolutionary aspects}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-69668}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2011}, abstract = {Yersinia enterocolitica subsp. palearctica Serobiotyp O:3/4 ist verantwortlich f{\"u}r 80-90 \% aller Yersiniosen beim Menschen in Deutschland und Europa. Y. enterocolitica Infektionen zeigen vielf{\"a}ltige Krankheitsbilder wie Gastroenteritis, Lymphadenitis und verschiedene Sp{\"a}tkomplikationen wie reaktive Arthritis. Das wichtigste Tierreservoir stellt das Hausschwein dar. Rohes Schweinefleisch in Metzgereien in Deutschland und anderen Regionen in Nord-Ost Europa ist h{\"a}ufig mit Yersinien kontaminiert (Bayern: 25 \%). Da sich Serobiotyp O:3/4-St{\"a}mme geografisch und phylogenetisch deutlich von dem bisher sequenzierten Serobiotyp O:8/1B Stamm 8081 unterscheiden, wurde eine komplette Genomsequenzierung des europ{\"a}ischen Serobiotyp O:3/4 DSMZ Referenzstammes Y11 (aus Patientenstuhl isoliert) durchgef{\"u}hrt. Um einen genaueren Einblick in die Y. enterocolitica subsp. palearctica Gruppe zu erhalten, wurden zus{\"a}tzlich zwei weitere Serobiotyp O:3/4 Isolate (Stamm Y8265, Patientenisolat, und Stamm Y5307, mit reaktiver Arthritis assoziiertes Patientenisolat), sowie ein eng verwandtes Y. enterocolitica subsp. palearctica Serobiotyp O:5,27/3 Isolat, Stamm Y527P, und zwei Biotyp 1A Isolate (ein Isolat nosokomialer Herkunft (Serogruppe O:5) und ein Umwelt-Isolat (O:36)) unvollst{\"a}ndig sequenziert. Die nicht mausvirulenten St{\"a}mme wurden mit dem mausvirulenten Y. enterocolitica subsp. enterocolitica Serobiotyp O:8/1B Stamm 8081 verglichen, um genetische Besonderheiten von Stamm Y11 und der Y. enterocolitica subsp. palearctica Gruppe zu identifizieren. Besonderer Fokus lag hierbei auf dem pathogenen Potential von Stamm Y11, um neue potentielle Virulenz Faktoren und Fitnessfaktoren zu identifizieren, darunter vor allem solche, die eine Rolle bei der Wirtsspezifit{\"a}t von Serobiotyp O:3/4 spielen k{\"o}nnten. Y. enterocolitica subsp. palearctica Serobiotyp O:3/4 St{\"a}mmen fehlen einige der Charakteristika der mausvirulenten Gruppe Y. enterocolitica subsp. enterocolitica, beispielsweise die Yersiniabactin kodierende‚ High-Pathogenicity Island (HPI), das Yts1 Typ 2 Sekretionssystem und das Ysa Typ 3 Sekretionssystem. Die Serobiotyp O:3/4-St{\"a}mme haben ein anderes Repertoir von Virulenz Faktoren erworben, darunter Gene bzw. genomische Inseln f{\"u}r das Ysp Typ 3 Sekretionssystem, Rtx-{\"a}hnliches putatives Toxin, Insektizid-Toxine und ein funktionelles PTS System f{\"u}r die Aufnahme von N-acetyl-galactosamin, dem aga-Operon. Nach dem Transfer des aga-Operons in Y. enterocolitica subsp. enterocolitica O:8/1B konnte Wachstum auf N-acetyl-galactosamin festgestellt werden. Neben diesen Genen k{\"o}nnen m{\"o}glicherweise auch zwei Prophagen (PhiYep-2 und PhiYep-3) und eine asn tRNA assoziierte genomische Insel (GIYep-01) zur Pathoadaptation von Y. enterocolitica subsp. palearctica Serobiotyp O:3/4 beitragen. Der PhiYep-3 Prophage und die GIYep-01 Insel weisen Rekombinationsaktivit{\"a}t auf, und PhiYep-3 wurde nicht in allen untersuchten Serobiotyp O:3/4 St{\"a}mmen gefunden. Y. enterocolitica subsp. palearctica Serobiotyp O:5,27/3 Stamm Y527P ist genetisch eng verwandt zu allen Serobiotyp O:3/4 Isolaten, wohingegen die Biotyp 1A Isolate ein mehr Mosaik-artiges Genom aufweisen und potentielle Virulenzgene sowohl mit Serobiotyp O:8/1B als auch O:3/4 gemeinsam haben, was einen gemeinsamen Vorfahren impliziert. Neben dem pYV Virulenz-Plasmid fehlen den Biotyp 1A Isolaten klassische Virulenzmarker wie das Ail Adhesin, das YstA Enterotoxin und das Virulenz-assoziierte Protein C (VapC). Interessanterweise gibt es keine betr{\"a}chtlichen Unterschiede zwischen den bekannten Virulenzfaktoren des nosokomialen Isolats und dem Umweltisolat der Biotyp 1A-Gruppe, abgesehen von einem verk{\"u}rzten Rtx Toxin-{\"a}hnlichem Genkluster und {\"U}berresten eines P2-{\"a}hnlichen Phagen im Krankenhausisolat der Serogruppe O:5.}, subject = {Genanalyse}, language = {en} } @article{BatramJonesJanzenetal.2014, author = {Batram, Christopher and Jones, Nivola G. and Janzen, Christian J. and Markert, Sebastian M. and Engstler, Markus}, title = {Expression site attenuation mechanistically links antigenic variation and development in Trypanosoma brucei}, series = {eLife}, volume = {3}, journal = {eLife}, number = {e02324}, issn = {2050-084X}, doi = {10.7554/eLife.02324}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119727}, year = {2014}, abstract = {We have discovered a new mechanism of monoallelic gene expression that links antigenic variation, cell cycle, and development in the model parasite Trypanosoma brucei. African trypanosomes possess hundreds of variant surface glycoprotein (VSG) genes, but only one is expressed from a telomeric expression site (ES) at any given time. We found that the expression of a second VSG alone is sufficient to silence the active VSG gene and directionally attenuate the ES by disruptor of telomeric silencing-1B (DOT1B)-mediated histone methylation. Three conserved expression-site-associated genes (ESAGs) appear to serve as signal for ES attenuation. Their depletion causes G1-phase dormancy and reversible initiation of the slender-to-stumpy differentiation pathway. ES-attenuated slender bloodstream trypanosomes gain full developmental competence for transformation to the tsetse fly stage. This surprising connection between antigenic variation and developmental progression provides an unexpected point of attack against the deadly sleeping sickness.}, language = {en} } @article{BassetCizekCuenoudetal.2015, author = {Basset, Yves and Cizek, Lukas and Cu{\´e}noud, Philippe and Didham, Raphael K. and Novotny, Vojtech and {\O}degaard, Frode and Roslin, Tomas and Tishechkin, Alexey K. and Schmidl, J{\"u}rgen and Winchester, Neville N. and Roubik, David W. and Aberlenc, Henri-Pierre and Bail, Johannes and Barrios, Hector and Bridle, Jonathan R. and Casta{\~n}o-Meneses, Gabriela and Corbara, Bruno and Curletti, Gianfranco and da Rocha, Wesley Duarte and De Bakker, Domir and Delabie, Jacques H. C. and Dejean, Alain and Fagan, Laura L. and Floren, Andreas and Kitching, Roger L. and Medianero, Enrique and de Oliveira, Evandro Gama and Orivel, Jerome and Pollet, Marc and Rapp, Mathieu and Ribeiro, Servio P. and Roisin, Yves and Schmidt, Jesper B. and S{\o}rensen, Line and Lewinsohn, Thomas M. and Leponce, Maurice}, title = {Arthropod Distribution in a Tropical Rainforest: Tackling a Four Dimensional Puzzle}, series = {PLoS ONE}, volume = {10}, journal = {PLoS ONE}, number = {12}, doi = {10.1371/journal.pone.0144110}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-136393}, pages = {e0144110}, year = {2015}, abstract = {Quantifying the spatio-temporal distribution of arthropods in tropical rainforests represents a first step towards scrutinizing the global distribution of biodiversity on Earth. To date most studies have focused on narrow taxonomic groups or lack a design that allows partitioning of the components of diversity. Here, we consider an exceptionally large dataset (113,952 individuals representing 5,858 species), obtained from the San Lorenzo forest in Panama, where the phylogenetic breadth of arthropod taxa was surveyed using 14 protocols targeting the soil, litter, understory, lower and upper canopy habitats, replicated across seasons in 2003 and 2004. This dataset is used to explore the relative influence of horizontal, vertical and seasonal drivers of arthropod distribution in this forest. We considered arthropod abundance, observed and estimated species richness, additive decomposition of species richness, multiplicative partitioning of species diversity, variation in species composition, species turnover and guild structure as components of diversity. At the scale of our study (2km of distance, 40m in height and 400 days), the effects related to the vertical and seasonal dimensions were most important. Most adult arthropods were collected from the soil/litter or the upper canopy and species richness was highest in the canopy. We compared the distribution of arthropods and trees within our study system. Effects related to the seasonal dimension were stronger for arthropods than for trees. We conclude that: (1) models of beta diversity developed for tropical trees are unlikely to be applicable to tropical arthropods; (2) it is imperative that estimates of global biodiversity derived from mass collecting of arthropods in tropical rainforests embrace the strong vertical and seasonal partitioning observed here; and (3) given the high species turnover observed between seasons, global climate change may have severe consequences for rainforest arthropods.}, language = {en} } @phdthesis{Basile2009, author = {Basile, Rebecca}, title = {Thermoregulation and Resource Management in the Honeybee (Apis mellifera)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-39793}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2009}, abstract = {Ein grundlegender Faktor, der f{\"u}r das {\"U}berleben einer Kolonie sozialer Insekten ausschlaggebend ist, liegt in der F{\"a}higkeit Nahrung durch sogenannte „Trophallaxis" auszutauschen. Diese F{\"u}tterungskontakte sorgen f{\"u}r die gleichm{\"a}ßige Verteilung der Nahrung innerhalb der Kolonie und werden als einer der Grundpfeiler der Sozialit{\"a}t der Staatenbildenden Insekten erachtet. Im Fall der Honigbienen finden diese Kontakte in vollkommener Dunkelheit statt. Damit es in dieser Situation {\"u}berhaupt zum Nahrungsaustausch kommen kann, sind die Antennen von großer Wichtigkeit. Ein erster Schritt in den Verhaltensweisen, die der Rezipient eines trophallaktischen Kontaktes zeigt, ist der Kontakt einer Antennenspitze mit den Mundwerkzeugen des Donoren, da sich dort die regurgitierte Nahrung befindet. Diese Ber{\"u}hrung hat aufgrund der gustatorischen Sensibilit{\"a}t der Antenne den Zweck, das angebotene Futter zu „erschmecken". Die rechte Antenne wird vom Rezipienten eines trophallaktischen Kontakts signifikant h{\"a}ufiger eingesetzt als die linke Antenne. Die Pr{\"a}ferenz f{\"u}r die rechte Antenne bleibt dabei auch erhalten, wenn ein Teil der Antennengeisel abgetrennt wurde, also die sensorischen F{\"a}higkeiten der rechten Antenne stark beeintr{\"a}chtigt wurden. Der Grund f{\"u}r die Pr{\"a}ferenz der rechten Antenne k{\"o}nnte ihrer erh{\"o}hten Sensibilit{\"a}t gegen{\"u}ber Zuckerwasser zugrunde liegen, da die rechte Antenne im Laborversuch signifikant st{\"a}rker auf Stimulationen mit Zuckerwasser verschiedener Konzentrationen reagierte als die linke. Trophallaktische Kontakte sichern Individuen innerhalb einer Kolonie den Zugang zur lebenswichtigen Nahrung. Im Beispiel der Honigbienen ist st{\"a}ndige Zugriff auf Nahrung besonders wichtig, da es sich um ein heterothermes Tier handelt, das die F{\"a}higkeit besitzt, aktiv seine K{\"o}rpertemperatur zu regulieren. Obgleich jedes Individuum in der Lage ist, seine K{\"o}rpertemperatur den eigenen Bed{\"u}rfnissen anzupassen, ist diese F{\"a}higkeit streng durch den in der Nahrung aufgenommenen Zucker reguliert. Im Gegensatz zu den S{\"a}ugetieren oder V{\"o}geln, die f{\"u}r eine Erh{\"o}hung des Blutzuckerspiegels auch auf Fett- oder Eiweißressourcen zur{\"u}ckgreifen k{\"o}nnen, ist die Honigbiene auf die Glucose aus der aufgenommenen Nahrung angewiesen. Die Ergebnisse dieser Untersuchung zeigen, dass der Zuckergehalt der aufgenommenen Nahrung positiv mit der Thoraxtemperatur der Bienen korreliert. Dieser Zusammenhang tritt auf, selbst wenn keine W{\"a}rmeerzeugung f{\"u}r die Brutpflege oder f{\"u}r das Erw{\"a}rmen der Wintertraube notwendig ist und die Tiere außerhalb des Stockes ohne eigentliche Notwendigkeit f{\"u}r die W{\"a}rmeerzeugung in einem K{\"a}fig gehalten werden. Die Ergebnisse der Untersuchung zeigen, dass die Rezipienten beim Nahrungsaustausch eine signifikant h{\"o}here Thoraxtemperatur haben als die Donoren. Außerdem zeigen die Rezipienten nach der F{\"u}tterung signifikant h{\"a}ufiger Brutw{\"a}rmeverhalten als die Donoren. Letztere haben eine signifikant niedrigere Thoraxtemperatur als die Rezipienten und zeigen eine Verhaltenstendenz, h{\"a}ufig zwischen Brutbereich und Honiglager hin- und her zu pendeln. Dabei nehmen sie im Honiglager Honig in ihren Kropf auf und f{\"u}ttern mit dieser Nahrung danach Bienen im Brutbereich. Außerdem zeigen die Ergebnisse, dass es einen w{\"a}rmegesteuerten Ausl{\"o}semechanismus gibt, der den Donoren und Rezipienten des trophallaktischen Kontakts dazu verhilft, trotz der Dunkelheit des Stocks praktisch verz{\"o}gerungsfreie Nahrungs{\"u}bertragung am Ort des h{\"o}chsten Energieverbrauchs zu gew{\"a}hrleisten. Das Hervorw{\"u}rgen von Nahrung angesichts einer W{\"a}rmequelle k{\"o}nnte seinen Ursprung in einer Beschwichtigungsgeste haben. Aggressive Tiere zeigen neben sichtbaren aggressiven Verhalten auch durch ihre erh{\"o}hte K{\"o}rpertemperatur, dass sie bereit sind sich auf einen Kampf einzulassen. Die Temperaturerh{\"o}hung eines aggressiven Tieres beruht dabei auf der erh{\"o}hten Muskelaktivit{\"a}t, die vor allem bei Insekten dazu n{\"o}tig ist, einen entsprechende Reaktion im Falle eines Kampfes oder der Flucht zeigen zu k{\"o}nnen. Wird ein Individuum mit Aggression konfrontiert, so bleibt ihm die Wahl sich auf einen Kampf einzulassen, zu fl{\"u}chten oder durch eine Beschwichtigungsgeste eine Deeskalation der Situation einzuleiten. Besonders h{\"a}ufig wird f{\"u}r diesen Zweck Nahrung regurgitiert und dem dominanteren Tier angeboten, um einem Konflikt aus dem Weg zu gehen. Die F{\"a}higkeit, Arbeiterinnen mit kleinen Portionen konzentrierter Nahrung zu versorgen tr{\"a}gt zu einer {\"o}konomischen Verteilung der Ressourcen bei, die mit den physiologischen Bed{\"u}rfnissen der Honigbienen konform geht und die {\"o}kologischen Erfordernisse des Stockes erf{\"u}llt. Das daraus resultierende Managementsystem, welches sparsam mit den Ressourcen haushaltet und auf die individuellen Bed{\"u}rfnisse jeder einzelnen Biene einzugehen vermag, k{\"o}nnte ein Grund f{\"u}r die F{\"a}higkeit der Honigbienen zur Entwicklung mehrj{\"a}hriger Kolonien sein, die, anders als Hummeln oder Wespen, auch den Winter in gem{\"a}ßigten Zonen als Gemeinschaft zu {\"u}berstehen verm{\"o}gen.}, subject = {Biene}, language = {en} } @phdthesis{Bartossek2018, author = {Bartossek, Thomas}, title = {Structural and functional analysis of the trypanosomal variant surface glycoprotein using x-ray scattering techniques and fluorescence microscopy}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-144775}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2018}, abstract = {Trypanosoma brucei is an obligate parasite and causative agent of severe diseases affecting humans and livestock. The protist lives extracellularly in the bloodstream of the mammalian host, where it is prone to attacks by the host immune system. As a sophisticated means of defence against the immune response, the parasite's surface is coated in a dense layer of the variant surface glycoprotein (VSG), that reduces identification of invariant epitopes on the cell surface by the immune system to levels that prevent host immunity. The VSG has to form a coat that is both dense and mobile, to shield invariant surface proteins from detection and to allow quick recycling of the protective coat during immune evasion. This coat effectively protects the parasite from the harsh environment that is the mammalian bloodstream and leads to a persistent parasitemia if the infection remains untreated. The available treatment against African Trypanosomiasis involves the use of drugs that are themselves severely toxic and that can lead to the death of the patient. Most of the drugs used as treatment were developed in the early-to-mid 20th century, and while developments continue, they still represent the best medical means to fight the parasite. The discovery of a fluorescent VSG gave rise to speculations about a potential interaction between the VSG coat and components of the surrounding medium, that could also lead to a new approach in the treatment of African Trypanosomiasis that involves the VSG coat. The initially observed fluorescence signal was specific for a combination of a VSG called VSG'Y' and the triphenylmethane (TPM) dye phenol red. Exchanging this TPM to a bromo-derivative led to the observation of another fluorescence effect termed trypanicidal effect which killed the parasite independent of the expressed VSG and suggests a structurally conserved feature between VSGs that could function as a specific drug target against T. b. brucei. The work of this thesis aims to identify the mechanisms that govern the unique VSG'Y' fluorescence and the trypanocidal effect. Fluorescence experiments and protein mutagenesis of VSG'Y' as well as crystallographic trials with a range of different VSGs were utilized in the endeavour to identify the binding mechanisms between TPM compounds and VSGs, to find potentially conserved structural features between VSGs and to identify the working mechanisms of VSG fluorescence and the trypanocidal effect. These trials have the potential to lead to the formulation of highly specific drugs that target the parasites VSG coat. During the crystallographic trials of this thesis, the complete structure of a VSG was solved experimentally for the first time. This complete structure is a key component in furthering the understanding of the mechanisms governing VSG coat formation. X-ray scattering techniques, involving x-ray crystallography and small angle x-ray scattering were applied to elucidate the first complete VSG structures, which reveal high flexibility of the protein and supplies insight into the importance of this flexibility in the formation of a densely packed but highly mobile surface coat.}, subject = {Trypanosoma brucei brucei}, language = {en} } @article{BartomeusPottsSteffanDewenteretal.2014, author = {Bartomeus, Ignasi and Potts, Simon G. and Steffan-Dewenter, Ingolf and Vaissiere, Bernard E. and Woyciechowski, Michal and Krewenka, Kristin M. and Tscheulin, Thomas and Roberts, Stuart P. M. and Szentgyoergyi, Hajnalka and Westphal, Catrin and Bommarco, Riccardo}, title = {Contribution of insect pollinators to crop yield and quality varies with agricultural intensification}, series = {PEERJ}, volume = {2}, journal = {PEERJ}, number = {e328}, issn = {2167-9843}, doi = {10.7717/peerj.328}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-116928}, year = {2014}, abstract = {Background. Up to 75\% of crop species benefit at least to some degree from animal pollination for fruit or seed set and yield. However, basic information on the level of pollinator dependence and pollinator contribution to yield is lacking for many crops. Even less is known about how insect pollination affects crop quality. Given that habitat loss and agricultural intensification are known to decrease pollinator richness and abundance, there is a need to assess the consequences for different components of crop production. Methods. We used pollination exclusion on flowers or inflorescences on a whole plant basis to assess the contribution of insect pollination to crop yield and quality in four flowering crops (spring oilseed rape, field bean, strawberry, and buckwheat) located in four regions of Europe. For each crop, we recorded abundance and species richness of flower visiting insects in ten fields located along a gradient from simple to heterogeneous landscapes. Results. Insect pollination enhanced average crop yield between 18 and 71\% depending on the crop. Yield quality was also enhanced in most crops. For instance, oilseed rape had higher oil and lower chlorophyll contents when adequately pollinated, the proportion of empty seeds decreased in buckwheat, and strawberries' commercial grade improved; however, we did not find higher nitrogen content in open pollinated field beans. Complex landscapes had a higher overall species richness of wild pollinators across crops, but visitation rates were only higher in complex landscapes for some crops. On the contrary, the overall yield was consistently enhanced by higher visitation rates, but not by higher pollinator richness. Discussion. For the four crops in this study, there is clear benefit delivered by pollinators on yield quantity and/or quality, but it is not maximized under current agricultural intensification. Honeybees, the most abundant pollinator, might partially compensate the loss of wild pollinators in some areas, but our results suggest the need of landscape-scale actions to enhance wild pollinator populations.}, language = {en} } @article{BartmannJanakiRamanFloeteretal.2018, author = {Bartmann, Catharina and Janaki Raman, Sudha R. and Fl{\"o}ter, Jessica and Schulze, Almut and Bahlke, Katrin and Willingstorfer, Jana and Strunz, Maria and W{\"o}ckel, Achim and Klement, Rainer J. and Kapp, Michaela and Djuzenova, Cholpon S. and Otto, Christoph and K{\"a}mmerer, Ulrike}, title = {Beta-hydroxybutyrate (3-OHB) can influence the energetic phenotype of breast cancer cells, but does not impact their proliferation and the response to chemotherapy or radiation}, series = {Cancer \& Metabolism}, volume = {6}, journal = {Cancer \& Metabolism}, number = {8}, doi = {10.1186/s40170-018-0180-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-175607}, year = {2018}, abstract = {Background: Ketogenic diets (KDs) or short-term fasting are popular trends amongst supportive approaches for cancer patients. Beta-hydroxybutyrate (3-OHB) is the main physiological ketone body, whose concentration can reach plasma levels of 2-6 mM during KDs or fasting. The impact of 3-OHB on the biology of tumor cells described so far is contradictory. Therefore, we investigated the effect of a physiological concentration of 3 mM 3-OHB on metabolism, proliferation, and viability of breast cancer (BC) cells in vitro. Methods: Seven different human BC cell lines (BT20, BT474, HBL100, MCF-7, MDA-MB 231, MDA-MB 468, and T47D) were cultured in medium with 5 mM glucose in the presence of 3 mM 3-OHB at mild hypoxia (5\% oxygen) or normoxia (21\% oxygen). Metabolic profiling was performed by quantification of the turnover of glucose, lactate, and 3-OHB and by Seahorse metabolic flux analysis. Expression of key enzymes of ketolysis as well as the main monocarboxylic acid transporter MCT2 and the glucose-transporter GLUT1 was analyzed by RT-qPCR and Western blotting. The effect of 3-OHB on short- and long-term cell proliferation as well as chemo- and radiosensitivity were also analyzed. Results: 3-OHB significantly changed the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in BT20 cells resulting in a more oxidative energetic phenotype. MCF-7 and MDA-MB 468 cells had increased ECAR only in response to 3-OHB, while the other three cell types remained uninfluenced. All cells expressed MCT2 and GLUT1, thus being able to uptake the metabolites. The consumption of 3-OHB was not strongly linked to mRNA overexpression of key enzymes of ketolysis and did not correlate with lactate production and glucose consumption. Neither 3-OHB nor acetoacetate did interfere with proliferation. Further, 3-OHB incubation did not modify the response of the tested BC cell lines to chemotherapy or radiation. Conclusions: We found that a physiological level of 3-OHB can change the energetic profile of some BC cell lines. However, 3-OHB failed to influence different biologic processes in these cells, e.g., cell proliferation and the response to common breast cancer chemotherapy and radiotherapy. Thus, we have no evidence that 3-OHB generally influences the biology of breast cancer cells in vitro.}, language = {en} } @phdthesis{Bartl2012, author = {Bartl, Jasmin}, title = {Impairment of insulin signaling pathway in Alzheimer's disease}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-74197}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {The neurodegenerative disorder Alzheimer's disease (AD) is the cause of approximately 60\% of the world's 35 million patients suffering from dementia. Current research focuses here are on association with other diseases such as diabetes type 2 (T2DM), possible genetic markers, specific signal transduction pathways within the brain and potential protein modification, because the pathogenesis and etiology of AD are still not fully understood. Specifically association of T2DM with AD came to the focus with the so-called "Rotterdam study" in 1999, indicating that T2DM doubles the risk of developing AD. In the meantime, it is known that the prevalence rate in patients with T2DM is 30\%. Drugs commonly used in the treatment of T2DM such as peroxisome proliferator-activated receptors gamma (PPARγ) agonists show improvement of the cognitive abilities in patients with early stage of dementia, with potential therapeutically relevance. Therefore it is important not only to investigate a link between these diseases, but also to investigate the insulin signaling pathway in the brain of AD patients. In order to investigate this complex issue in more details and demonstrate additional links between T2DM and AD, the present study used several basic biological methods to clarify the question: "Is impaired insulin signaling pathway within the brain crucial for the development of AD?" from several points of view. The methods used in this work have been i) an analysis of single nucleotide (SNP) polymorphism of the insulin-degrading enzyme gene (IDE) in relation to risk of AD and / or of T2DM, ii) post-mortem histochemical studies of brain tissue of patients with only AD, with AD combined with T2DM and with only T2DM compared with an age-matched control group, and iii.) investigations of neurochemical pathways and gene/protein expression changes of a human cell culture as a consequences of amyloid β (Aβ) treatment. After analysis of the IDE SNP polymorphism in the selected VITA (Vienna Trans Danube Aging) cohort disease-specific effects were discovered. The upstream polymorphism (IDE2) was found to influence AD risk in a protective manner, while the downstream polymorphism (IDE7) modified the T2DM risk. Based on the SNP results, the presented study delineate the model that IDE promoter and 3‟ untranslated region/downstream variation can have different effects on IDE expression, maybe a relevant endophenotype with disorder-specific effects on AD and T2DM susceptibility. Furthermore, the human post-mortem studies could show that both AD as well as T2DM patients had a significantly lower density of the insulin receptor (IR) in the hippocampus, whereas a significantly increased density of inactive phosphorylated PPARγ has been found and this persisted even in patients with both diseases. Summarizing the histological study, it was possible to reveal common histological features of AD and T2DM, but no direct connection between the two diseases. Although AD is nowadays not only characterized by amyloid-containing plaque deposits and by the hyperphosphorylation of tau protein, the excessive Aβ42 presence in the brains of AD patients is still playing a key role. Up to date it is still not entirely clear which physical form of Aβ42 is responsible for the development of AD. The present work investigated, what impact has the state of aggregation of Aβ42 on genes and proteins of the insulin signaling pathway and the amyloid cascade. It could be shown that the oligomeric variant enhanced specifically the gene and protein expression of glycogen synthase kinase (GSK) 3β and also the enzyme activity was significantly increased, but has in turn strongly inhibited the IR gene and protein expression. Additionally, the effect of Aβ42 on monoamine oxidase B (MAO-B) was examined. An effect of both aggregated forms of Aβ42 had on enzyme activity was discovered. However, the fibrillar variants led to significantly increased activity of MAO-B while the oligomeric variants inhibited the enzyme activity. Several previous studies have demonstrated the involvement of increased MAO-B activity in AD, but the present work provides for the first time a direct link between the states of aggregation of Aβ42 to enzyme activity. Finally the results of the presented thesis can be summarized to following conclusion: Although AD and T2DM sharing some degrees of common features, still there is a lack of direct association, and therefore the diseases must be considered more independent rather than linked. But the impaired cerebral insulin signaling pathway seems to be another manifested hallmark of AD.}, subject = {Alzheimer-Krankheit}, language = {en} } @phdthesis{Barth2008, author = {Barth, Enrico}, title = {Study of the properties of channel-forming proteins of the cell walls of different Corynebacteriae}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-36325}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2008}, abstract = {Die Gattung Corynebacterium geh{\"o}rt, neben Mycobacterium, Nocardia, Rhodococcus und weiteren nahverwandten Gattungen, dem unverwechselbaren, gattungs{\"u}bergreifenden Taxon Mycolata an. Viele Spezies aus dieser heterogenen Gruppe Mycols{\"a}ure-haltiger Actinomyceten sind entweder aufgrund ihrer medizinischen oder ihrer biotechnologischen Bedeutung bekannt. Beispielsweise z{\"a}hlen Mycobacterium tuberculosis, Mycobacterium leprae, Corynebacterium diphtheriae und Nocardia farcinica, welche weltweit Verursacher besonders gef{\"a}hrlicher bakterieller Infektionskrankheiten sind, zu dieser ungew{\"o}hnlichen Gruppe Gram-positiver Bakterien. Ebenso bedeutsam sind einige apathogene Mycolata-Arten, die industrielle Anwendung finden. Corynebacterium glutamicum und Corynebacterium efficiens sind leistungsf{\"a}hige Bakterien, die zum Beispiel in der Produktion des Geschmacksverst{\"a}rkers Glutamat und des Tierfuttermittelzusatzes Lysin eingesetzt werden, w{\"a}hrend verschiedene Rhodococcus Spezies Anwendung bei der Herstellung von Acryls{\"a}uren finden. Die Zellwand der Mycolata zeigt, verglichen mit der klassischer Gram-positiver Bakterien, eine außergew{\"o}hnliche Zusammensetzung und Struktur auf. Abgesehen von einem Arabinogalactan-Peptidoglycan-Komplex enth{\"a}lt die Zellwand der meisten Actinomyceten einen hohen Anteil an Mycols{\"a}uren. Diese langkettigen, verzweigten Fetts{\"a}uren formen eine, mit der {\"a}ußeren Membran Gram-negativer Bakterien vergleichbare, stark undurchl{\"a}ssige, hydrophobe {\"a}ußere H{\"u}lle, welche die Grundlage der außergew{\"o}hnlichen Medikamentenresistenz bei den Mycolata bildet. Wie die {\"a}ußere Membran Gram-negativer Bakterien enth{\"a}lt die Zellwand der Mycolata porenformende Proteine, die den Durchlass hydrophiler Substanzen gestatten. Indem sie eine Verbindung zwischen dem Zellinneren und der Umwelt, in der das Bakterium lebt, schaffen und einen kontrollierten Austausch zwischen beiden erm{\"o}glichen, tragen die Kanalproteine entscheidend zur Funktion der bakteriellen Zellh{\"u}lle bei. Das Ziel dieser Arbeit war das Wissen {\"u}ber Zellwandkan{\"a}le in Corynebakterien zu erweitern. Deshalb untersuchten wir PorA und PorH Proteine, die basierend auf fr{\"u}heren Studien Zellwandkan{\"a}len in C. glutamicum, C. efficiens und Corynebacterium callunae zugeordnet werden, um ungekl{\"a}rten Fragen nachzugehen und um Wissen {\"u}ber deren Struktur zu erlangen. Ferner inspizierten wir Zellw{\"a}nde pathogener Corynebakterien, genauer gesagt von Corynebacterium diphtheriae und Corynebacterium jeikeium, um herauszufinden, ob diese Spezies wie ihre harmlosen Verwandten Kanalproteine besitzen. In dieser Arbeit wiesen wir mit C. diphtheriae und C. jeikeium in zwei weiteren Corynebacterium-Arten offene, mit Wasser gef{\"u}llte Zellwandkan{\"a}le nach. Des Weiteren stellten wir fest, dass sich die Zellwandkan{\"a}le von C. glutamicum, C. efficiens und C. diphtheriae aus zwei Proteinen zusammensetzen, einem zugeh{\"o}rig zu der Gruppe der PorH Proteine und einem weiteren aus der Gruppe der PorA Proteine. Diese heteromere Struktur von Zellwandkan{\"a}len bei Corynebakterien stellt ein Novum f{\"u}r Zellwandkan{\"a}le bei den Mycolata dar. Indessen besteht der Zellwandkanal von C. jeikeium aus nur einem Protein, CjPorA, angeordnet zu einem Oligomer. Obgleich das Molekulargewicht dieses Proteins (4 kDa) mit dem von PorH und PorA Proteinen vergleichbar ist (5-7 kDa), weißt seine Prim{\"a}rsequenz keine eindeutige Homologie zu diesen auf. Dennoch deutet vieles auf eine Verwandtschaft zwischen CjPorA und PorH/PorA Proteinen hin, da das Gen jk0268, welches f{\"u}r CjPorA kodiert, sich in einer Region des C. jeikeium Chromosoms befindet, die der Genomregion entspricht in welcher die porH/porA Gene der anderen Corynebakterien lokalisiert sind. Dies l{\"a}sst vermuten, dass jk0268 (welches f{\"u}r den homomeren Zellwandkanal in C. jeikeium kodiert) und die porH/porA Gene von C. glutamicum, C. efficiens und C. diphtheriae (die einen heteromeren Zellwandkanal kodieren) wahrscheinlich Nachkommen eines gemeinsamen Vorl{\"a}ufergens sind. Phylogenetische Analysen der Gattung Corynebacterium unterst{\"u}tzen diese Annahme. Desweitern legen sie nahe, dass die hier untersuchten Zellwandkan{\"a}le innerhalb dieser Gattung wahrscheinlich weit verbreitet sind. Ein umfassendes Wissen {\"u}ber Zellwandkan{\"a}le, denen beim Transport gel{\"o}ster Stoffe {\"u}ber die {\"a}ußere Membran in Corynebakterien und anderen Mitgliedern der Mycolata eine entscheidende Rolle zukommt, k{\"o}nnte von großem wirtschaftlichem und medizinischem Nutzen sein.}, subject = {Zellwand}, language = {en} } @article{BartelPeinPopperetal.2019, author = {Bartel, Karin and Pein, Helmut and Popper, Bastian and Schmitt, Sabine and Janaki-Raman, Sudha and Schulze, Almut and Lengauer, Florian and Koeberle, Andreas and Werz, Oliver and Zischka, Hans and M{\"u}ller, Rolf and Vollmar, Angelika M. and Schwarzenberg, Karin von}, title = {Connecting lysosomes and mitochondria - a novel role for lipid metabolism in cancer cell death}, series = {Cell Communication and Signaling}, volume = {17}, journal = {Cell Communication and Signaling}, doi = {10.1186/s12964-019-0399-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221524}, year = {2019}, abstract = {Background The understanding of lysosomes has been expanded in recent research way beyond their view as cellular trash can. Lysosomes are pivotal in regulating metabolism, endocytosis and autophagy and are implicated in cancer. Recently it was discovered that the lysosomal V-ATPase, which is known to induce apoptosis, interferes with lipid metabolism in cancer, yet the interplay between these organelles is poorly understood. Methods LC-MS/MS analysis was performed to investigate lipid distribution in cells. Cell survival and signaling pathways were analyzed by means of cell biological methods (qPCR, Western Blot, flow cytometry, CellTiter-Blue). Mitochondrial structure was analyzed by confocal imaging and electron microscopy, their function was determined by flow cytometry and seahorse measurements. Results Our data reveal that interfering with lysosomal function changes composition and subcellular localization of triacylglycerids accompanied by an upregulation of PGC1α and PPARα expression, master regulators of energy and lipid metabolism. Furthermore, cardiolipin content is reduced driving mitochondria into fission, accompanied by a loss of membrane potential and reduction in oxidative capacity, which leads to a deregulation in cellular ROS and induction of mitochondria-driven apoptosis. Additionally, cells undergo a metabolic shift to glutamine dependency, correlated with the fission phenotype and sensitivity to lysosomal inhibition, most prominent in Ras mutated cells. Conclusion This study sheds mechanistic light on a largely uninvestigated triangle between lysosomes, lipid metabolism and mitochondrial function. Insight into this organelle crosstalk increases our understanding of mitochondria-driven cell death. Our findings furthermore provide a first hint on a connection of Ras pathway mutations and sensitivity towards lysosomal inhibitors.}, language = {en} } @article{BarnekowJahnSchartl1990, author = {Barnekow, Angelika and Jahn, Reinhard and Schartl, Manfred}, title = {Synaptophysin: a substrate for the protein tyrosine kinase pp60c-src in intact synaptic vesicles}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86168}, year = {1990}, abstract = {Expression of pp60 c-src, the first well defined proto-oncogene product, is developmentally regulated and tissue-specific, with neuronal tissues displaying high amounts of the c-src encoded pp60 c-src kinase activity. In the central nervous system pp60 s-src is preferentially expressed in regions characterized by a high content of grey matter and elevated density of nerve terminals. In this study we show for the first time a direct interaction between pp60 c-src and synaptophysin as a physiological target protein in neurons by demonstrating that endogenous pp60 c-src is able to phosphorylate synaptophysin (p38). p38 is a major constituent of the synaptic vesicle membrane protein and is thought to play a key role in the exocytosis of small synaptic vesicles and possibly small clear vesicles in neuroendocrine cells.}, subject = {Synaptophysin}, language = {en} } @article{BarnekowGessler1986, author = {Barnekow, Angelika and Gessler, Manfred}, title = {Activation of the pp60\(^{c-src}\) kinase during differentiation of monomyelocytic cells in vitro}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-59278}, year = {1986}, abstract = {Tbe proto-oncogene c-src, the cellular homolog of the Rous sarcoma virus (RSV) transforming gene v-src, is expressed in a tissue-specific and age-dependent manner. Its physiological function, although still unknown, appears to be more closely related to differentiation processes than to proliferation processes. To obtain more information about the physiological role of the c-src gene in cells, we have studied differentiation-dependent alterations using the human HL-60 leukaemia cell line as a model system. Induction of monocytic and granulocytic differentiation of HL-60 cells by 12-0-tetradecanoylphorbol-13-acetate (TPA) and dimethylsulfoxide (DMSO) is associated with an activation of the pp60c-src tyrosine kinase, but not with increased c-src gene expression. Control experiments exclude an interaction of TPA and DMSO themselves with the pp60c-src kinase.}, subject = {Biochemie}, language = {en} } @article{BarnekowSchartlAndersetal.1982, author = {Barnekow, A. and Schartl, Manfred and Anders, F. and Bauer, H.}, title = {Identification of a fish protein associated with a kinase activity and related to the Rous sarcoma virus transforming protein}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61946}, year = {1982}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{BarnekowSchartl1987, author = {Barnekow, A. and Schartl, Manfred}, title = {Comparative studies on the src proto-oncogene and its gene product pp60\(^{c-src}\) in normal and neoplastic tissues of lower vertebrates}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61869}, year = {1987}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{BarnekowPaulSchartl1987, author = {Barnekow, A. and Paul, E. and Schartl, Manfred}, title = {Expression of the c-src protooncogene in human skin tumors}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61870}, year = {1987}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} }