@phdthesis{Degenhardt2000, author = {Degenhardt, Birgit}, title = {Wachstum und physiologisches Verhalten von Zea mays bei multiplem Streß unter besonderer Ber{\"u}cksichtigung des Wurzelsystems}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-16964}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2000}, abstract = {In der vorgestellten Arbeit wurden das Wachstum und das physiologische Verhalten von Zea mays auf M{\"u}llheizkraftwerk (MHKW) -Schlacke im Vergleich zu Gartenerde als Kulturmedium untersucht. Dabei stand das Wurzelsystem der Maispflanzen im Mittelpunkt des Interesses. Da feste Bodensubstrate verwendet wurden, mußten diese zu Beginn der Experimente chemisch, physikalisch und bodenbiologisch charakterisiert werden. Die Analyse der Schlacke zeigte, daß Schlacke ein multifaktorielles Streßsystem darstellt: Sie enth{\"a}lt einen hohen Gehalt an leicht l{\"o}slichen Salzen, v.a. NaCl (bis zu 220 mM in der Bodenl{\"o}sung). MHKW-Schlacke ist dagegen arm an Stickstoff und pflanzenverf{\"u}gbarem Phosphat. Der pH-Wert der Bodenl{\"o}sung von Schlacke ist stark alkalisch (pH 8.4 - 9.0). Dar{\"u}ber hinaus besitzt Schlacke einen hohen Gehalt an potentiell toxischen Schwermetallen und weist im Vergleich zum Kontrollsubstrat Gartenerde eine verdichtete Bodenstruktur mit erh{\"o}htem mechanischen Widerstand auf. Im Vergleich zu der Kontroll-Anzucht auf Gartenerde reagierten die auf Schlacke kultivierten Mais-Pflanzen mit vermindertem Wachstum: Sproß und Wurzel erreichten nur die H{\"a}lfte der L{\"a}nge der Kontrollpflanzen. Ein Vergleich der Biomassen von Sproß und Wurzel zeigte, daß das Sproßwachstum der Schlacke-Pflanzen st{\"a}rker eingeschr{\"a}nkt ist als das Wurzelwachstum, woraus ein vergr{\"o}ßertes Wurzel / Sproß-Verh{\"a}ltnis resultiert. Das Wachstum von jungen Mais-Pflanzen auf Schlacke ist jedoch nicht in dem Maß eingeschr{\"a}nkt, wie es aufgrund der hohen Salzbelastung zu erwarten w{\"a}re. In einem Vergleichsexperiment mit Mais-Pflanzen, die in einer N{\"a}hrl{\"o}sung mit Zusatz von 100 mM NaCl kultiviert wurden, war das Wachstum erheblich schlechter und in den Bl{\"a}ttern akkumulierte weitaus mehr Natrium als in Schlacke-Pflanzen. Hier wird der positive Einfluß des hohen Calciumgehaltes der Schlacke deutlich. Die Beeintr{\"a}chtigung des Wachstums von Mais bei Kultur auf Schlacke wird haupts{\"a}chlich auf Phosphatmangel zur{\"u}ckgef{\"u}hrt, da durch D{\"u}ngung eine betr{\"a}chtliche Wachstumsverbesserung erzielt werden kann. Zudem wurden keine toxischen Konzentrationen an Schwermetallen im Blattgewebe von auf Schlacke kultivierten Pflanzen gefunden. Der Photosynthese-Apparat der Schlacke-kultivierten Pflanzen war sehr leistungsf{\"a}hig: Es bestand keine Beeintr{\"a}chtigung in der Energieverf{\"u}gbarkeit (Quantenausbeute des Photosystems II) und die Lichts{\"a}ttigung der photo-synthetischen Elektronentransportrate lag sogar h{\"o}her als bei den Kontrollpflanzen. Die Bestimmung des „adenylate energy charge" best{\"a}tigte diesen Sachverhalt. Das Wurzelsystem von Zea mays auf Schlacke wies strukturelle Ver{\"a}nderungen auf. Neben der verk{\"u}rzten Wurzell{\"a}nge und dem vergr{\"o}ßerten Wurzeldurchmesser der Schlacke-Pflanzen ergaben mikroskopische Untersuchungen, daß die Wurzeln durch Kultur auf Schlacke mit einer mechanischen Verst{\"a}rkung reagieren: St{\"a}rker ausgepr{\"a}gte tangentiale Zellwandverdickungen der Endodermis im terti{\"a}ren Zustand und Zellwandmodifikationen in den radialen Zellw{\"a}nden der Rhizodermis (Phi-Verdickungen). F{\"u}r monokotyle Arten, insbesondere f{\"u}r Mais, gibt es bisher keine Beschreibung von Phi-Verdickungen in der Literatur. Gaschromatographische und massenspektrometrische Untersuchungen belegen, daß sich die Zellw{\"a}nde von auf Erde und Schlacke kultivierten Maiswurzeln im Hinblick auf den Gesamtgehalt an Lignin (endodermale Zellwandisolate) und in der Ligninzusammensetzung (hypodermale Zellwandisolate) unterscheiden: In Schlacke-kultivierten Maiswurzeln wurde ein h{\"o}herer Anteil an dem Lignin-Monomer p Hydroxyphenyl gefunden, was zu einem h{\"o}her verdichteten Lignin f{\"u}hrt (Streßlignin). Die endodermalen Zellw{\"a}nde von auf Schlacke-kulivierten Pflanzen hatten dagegen einen h{\"o}heren Gesamtlignin-Gehalt als die entsprechenden Kontrollen, was ebenfalls eine mechanische Verst{\"a}rkung der Wurzel bewirkt. In Bezug auf Suberin konnten keine Unterschiede zwischen den verschiedenen Anzuchten gefunden werden, weder in den hypodermalen noch in den endodermalen Zellwandisolaten. Die verschiedenen Streßfaktoren f{\"u}hren demnach nicht zu einer verst{\"a}rkten Impr{\"a}gnierung der Zellw{\"a}nde mit lipophilem Material. Die Zellw{\"a}nde von Mais spielen eine wichtige Rolle bei der Immobilisierung von Schwermetallen. Die Zellwandisolate von auf Erde und Schlacke kultivierten Mais-Pflanzen wiesen je nach Schwermetall-Element 43 - 100 \% des Gesamtgehaltes auf. Die absoluten Gehalte in den Zellwandisolaten von auf Schlacke angezogenen Pflanzen waren dabei h{\"o}her als die entsprechenden Werte der Kontrolle. Eine Anreicherung in den Zellw{\"a}nden wurde haupts{\"a}chlich f{\"u}r die Schwermetalle Zink, Blei, Nickel und Chrom beobachtet. Als unspezifische Streßantwort reagierten Maispflanzen auf die Kultur in Schlacke mit einer erh{\"o}hten Peroxidaseaktivit{\"a}t in der interzellul{\"a}ren Waschfl{\"u}ssigkeit. Die Peroxidaseaktivit{\"a}t des Symplastens der Wurzel unterscheidet sich zwischen den beiden Anzuchten dagegen nicht. Die Konzentration des Phytohormons Abscisins{\"a}ure (ABA) war in Bl{\"a}ttern von auf Schlacke kultivierten Pflanzen von Zea mays und Vicia faba im Vergleich zu den Kontrollpflanzen erh{\"o}ht. Dieser Anstieg ist eine Folge der erh{\"o}hten Salzbelastung der Schlacke, da die ABA-Gehalte entsprechender Bl{\"a}tter von auf gewaschener Schlacke kultivierten Pflanzen ann{\"a}hernd den Kontrollwerten entsprachen. Bei der Verteilung von ABA zwischen der Wurzel und der Bodenl{\"o}sung der umliegenden Rhizosph{\"a}re konnte das als Anionenfalle bekannte Prinzip best{\"a}tigt werden. Nach diesem Modell reichert sich ABA im alkalischten Kompartiment an (hier: Schlacke-Bodenl{\"o}sung). In den Wurzeln konnte nur in der Maiskultur auf Schlacke ein erh{\"o}hter Gehalt gefunden werden, nicht dagegen in der Vicia faba-Kultur. Dieser Unterschied liegt daran, daß Mais im Gegensatz zu Vicia faba eine exodermale Spezies ist und die Exodermis f{\"u}r ABA eine Barriere darstellt, was den ABA-Efflux in die Rhizosph{\"a}re verhindert. Im Wurzelgewebe von auf Schlacke kultivierten Maispflanzen wurde ein im Vergleich zur Kontrolle 15-facher Gehalt an wasserl{\"o}slichen, nicht proteingebundenen Sulfhydrylgruppen nachgewiesen. Diese auf Schwermetallstreß zur{\"u}ckzuf{\"u}hrende Reaktion impliziert, daß die in der Schlacke-Bodenl{\"o}sung vorhandenen Schwermetalle nicht ausreichend im Apoplasten zur{\"u}ckgehalten werden und bis in den Symplasten vordringen k{\"o}nnen.}, subject = {Mais}, language = {de} } @phdthesis{Mueller2012, author = {M{\"u}ller, Andreas}, title = {Towards functional oxide heterostructures}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72478}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {Oxide heterostructures attract a lot of attention as they display a vast range of physical phenomena like conductivity, magnetism, or even superconductivity. In most cases, these effects are caused by electron correlations and are therefore interesting for studying fundamental physics, but also in view of future applications. This thesis deals with the growth and characterization of several prototypical oxide heterostructures. Fe3O4 is highly ranked as a possible spin electrode in the field of spintronics. A suitable semiconductor for spin injection in combination with Fe3O4 is ZnO due to its oxide character and a sufficiently long spin coherence length. Fe3O4 has been grown successfully on ZnO using pulsed laser deposition and molecular beam epitaxy by choosing the oxygen partial pressure adequately. Here, a pressure variation during growth reduces an FeO-like interface layer. Fe3O4 films grow in an island-like growth mode and are structurally nearly fully relaxed, exhibiting the same lattice constants as the bulk materials. Despite the presence of a slight oxygen off-stoichiometry, indications of the Verwey transition hint at high-quality film properties. The overall magnetization of the films is reduced compared to bulk Fe3O4 and a slow magnetization behavior is observed, most probably due to defects like anti-phase boundaries originating from the initial island growth. LaAlO3/SrTiO3 heterostructures exhibit a conducting interface above a critical film thickness, which is most likely explained by an electronic reconstruction. In the corresponding model, the potential built-up owing to the polar LaAlO3 overlayer is compensated by a charge transfer from the film surface to the interface. The properties of these heterostructures strongly depend on the growth parameters. It is shown for the first time, that it is mainly the total pressure which determines the macroscopic sample properties, while it is the oxygen partial pressure which controls the amount of charge carriers near the interface. Oxygen-vacancy-mediated conductivity is found for too low oxygen pressures. A too high total pressure, however, destroys interface conductivity, most probably due to a change of the growth kinetics. Post-oxidation leads to a metastable state removing the arbitrariness in controlling the electronic interface properties by the oxygen pressure during growth. LaVO3/SrTiO3 heterostructures exhibit similar behavior compared to LaAlO3/SrTiO3 when it comes to a thickness-dependent metal-insulator transition. But in contrast to LaAlO3, LaVO3 is a Mott insulator exhibiting strong electron correlations. Films have been grown by pulsed laser deposition. Layer-by-layer growth and a phase-pure pervoskite lattice structure is observed, indicating good structural quality of the film and the interface. An electron-rich layer is found near the interface on the LaVO3 side for conducting LaVO3/SrTiO3. This could be explained by an electronic reconstruction within the film. The electrostatic doping results in a band-filling-controlled metal-insulator transition without suffering from chemical impurities, which is unavoidable in conventional doping experiments.}, subject = {Oxide}, language = {en} } @article{GarciaMartinezBrunkAvalosetal.2015, author = {Garc{\´i}a-Mart{\´i}nez, Jorge and Brunk, Michael and Avalos, Javier and Terpitz, Ulrich}, title = {The CarO rhodopsin of the fungus Fusarium fujikuroi is a light-driven proton pump that retards spore germination}, series = {Scientific Reports}, volume = {5}, journal = {Scientific Reports}, number = {7798}, doi = {10.1038/srep07798}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149049}, year = {2015}, abstract = {Rhodopsins are membrane-embedded photoreceptors found in all major taxonomic kingdoms using retinal as their chromophore. They play well-known functions in different biological systems, but their roles in fungi remain unknown. The filamentous fungus Fusarium fujikuroi contains two putative rhodopsins, CarO and OpsA. The gene carO is light-regulated, and the predicted polypeptide contains all conserved residues required for proton pumping. We aimed to elucidate the expression and cellular location of the fungal rhodopsin CarO, its presumed proton-pumping activity and the possible effect of such function on F. fujikuroi growth. In electrophysiology experiments we confirmed that CarO is a green-light driven proton pump. Visualization of fluorescent CarO-YFP expressed in F. fujikuroi under control of its native promoter revealed higher accumulation in spores (conidia) produced by light-exposed mycelia. Germination analyses of conidia from carO\(^{-}\) mutant and carO\(^{+}\) control strains showed a faster development of light-exposed carO-germlings. In conclusion, CarO is an active proton pump, abundant in light-formed conidia, whose activity slows down early hyphal development under light. Interestingly, CarO-related rhodopsins are typically found in plant-associated fungi, where green light dominates the phyllosphere. Our data provide the first reliable clue on a possible biological role of a fungal rhodopsin.}, language = {en} } @article{HerterStauchGallantetal.2015, author = {Herter, Eva K. and Stauch, Maria and Gallant, Maria and Wolf, Elmar and Raabe, Thomas and Gallant, Peter}, title = {snoRNAs are a novel class of biologically relevant Myc targets}, series = {BMC Biology}, volume = {13}, journal = {BMC Biology}, number = {25}, doi = {10.1186/s12915-015-0132-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-124956}, year = {2015}, abstract = {Background Myc proteins are essential regulators of animal growth during normal development, and their deregulation is one of the main driving factors of human malignancies. They function as transcription factors that (in vertebrates) control many growth- and proliferation-associated genes, and in some contexts contribute to global gene regulation. Results We combine chromatin immunoprecipitation-sequencing (ChIPseq) and RNAseq approaches in Drosophila tissue culture cells to identify a core set of less than 500 Myc target genes, whose salient function resides in the control of ribosome biogenesis. Among these genes we find the non-coding snoRNA genes as a large novel class of Myc targets. All assayed snoRNAs are affected by Myc, and many of them are subject to direct transcriptional activation by Myc, both in Drosophila and in vertebrates. The loss of snoRNAs impairs growth during normal development, whereas their overexpression increases tumor mass in a model for neuronal tumors. Conclusions This work shows that Myc acts as a master regulator of snoRNP biogenesis. In addition, in combination with recent observations of snoRNA involvement in human cancer, it raises the possibility that Myc's transforming effects are partially mediated by this class of non-coding transcripts.}, language = {en} } @article{NorrmenFigliaLebrunJulienetal.2014, author = {Norrmen, Camilla and Figlia, Gianluca and Lebrun-Julien, Frederic and Pereira, Jorge A. and Tr{\"o}tzm{\"u}ller, Martin and K{\"o}feler, Harald C. and Rantanen, Ville and Wessig, Carsten and van Deijk, Anne-Lieke F. and Smit, August B. and Verheijen, Mark H. G. and R{\"u}egg, Markus A. and Hall, Michael N. and Suter, Ueli}, title = {mTORC1 Controls PNS Myelination along the mTORC1-RXR gamma-SREBP-Lipid Biosynthesis Axis in Schwann Cells}, series = {Cell Reports}, volume = {9}, journal = {Cell Reports}, number = {2}, issn = {2211-1247}, doi = {10.1016/j.celrep.2014.09.001}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-114847}, pages = {646-660}, year = {2014}, abstract = {Myelin formation during peripheral nervous system (PNS) development, and reformation after injury and in disease, requires multiple intrinsic and extrinsic signals. Akt/mTOR signaling has emerged as a major player involved, but the molecular mechanisms and downstream effectors are virtually unknown. Here, we have used Schwann-cell-specific conditional gene ablation of raptor and rictor, which encode essential components of the mTOR complexes 1 (mTORC1) and 2 (mTORC2), respectively, to demonstrate that mTORC1 controls PNS myelination during development. In this process, mTORC1 regulates lipid biosynthesis via sterol regulatory element-binding proteins (SREBPs). This course of action is mediated by the nuclear receptor RXRg, which transcriptionally regulates SREBP1c downstream of mTORC1. Absence of mTORC1 causes delayed myelination initiation as well as hypomyelination, together with abnormal lipid composition and decreased nerve conduction velocity. Thus, we have identified the mTORC1-RXR gamma-SREBP axis controlling lipid biosynthesis as a major contributor to proper peripheral nerve function.}, language = {en} } @article{SanzMorenoFuhrmannWolfetal.2014, author = {Sanz-Moreno, Adrian and Fuhrmann, David and Wolf, Elmar and von Eyss, Bj{\"o}rn and Eilers, Martin and Els{\"a}sser, Hans-Peter}, title = {Miz1 Deficiency in the Mammary Gland Causes a Lactation Defect by Attenuated Stat5 Expression and Phosphorylation}, series = {PLOS ONE}, volume = {9}, journal = {PLOS ONE}, number = {2}, doi = {10.1371/journal.pone.0089187}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117286}, pages = {e89187}, year = {2014}, abstract = {Miz1 is a zinc finger transcription factor with an N-terminal POZ domain. Complexes with Myc, Bcl-6 or Gfi-1 repress expression of genes like Cdkn2b (p15(Ink4)) or Cd-kn1a (p21(Cip1)). The role of Miz1 in normal mammary gland development has not been addressed so far. Conditional knockout of the Miz1 POZ domain in luminal cells during pregnancy caused a lactation defect with a transient reduction of glandular tissue, reduced proliferation and attenuated differentiation. This was recapitulated in vitro using mouse mammary gland derived HC11 cells. Further analysis revealed decreased Stat5 activity in Miz1 Delta POZ mammary glands and an attenuated expression of Stat5 targets. Gene expression of the Prolactin receptor (PrlR) and ErbB4, both critical for Stat5 phosphorylation (pStat5) or pStat5 nuclear translocation, was decreased in Miz1 Delta POZ females. Microarray, ChIP-Seq and gene set enrichment analysis revealed a down-regulation of Miz1 target genes being involved in vesicular transport processes. Our data suggest that deranged intracellular transport and localization of PrlR and ErbB4 disrupt the Stat5 signalling pathway in mutant glands and cause the observed lactation phenotype.}, language = {en} } @article{OttoRubenwolfBurgeretal.2012, author = {Otto, Wolfgang and Rubenwolf, Peter C. and Burger, Maximilian and Fritsche, Hans-Martin and R{\"o}ßler, Wolfgang and May, Matthias and Hartmann, Arndt and Hofst{\"a}dter, Ferdinand and Wieland, Wolf F. and Denzinger, Stefan}, title = {Loss of aquaporin 3 protein expression constitutes an independent prognostic factor for progression-free survival: an immunohistochemical study on stage pT1 urothelial bladder cancer}, series = {BMC Cancer}, volume = {12}, journal = {BMC Cancer}, number = {459}, doi = {10.1186/1471-2407-12-459}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-135679}, year = {2012}, abstract = {Background: Treatment of patients with stage pT1 urothelial bladder cancer (UBC) continues to be a challenge due to its unpredictable clinical course. Reliable molecular markers that help to determine appropriate individual treatment are still lacking. Loss of aquaporin (AQP) 3 protein expression has previously been shown in muscle-invasive UBC. The aim of the present study was to investigate the prognostic value of AQP3 protein expression with regard to the prognosis of stage pT1 UBC. Method: AQP 3 protein expression was investigated by immunohistochemistry in specimens of 87 stage T1 UBC patients, who were diagnosed by transurethral resection of the bladder (TURB) and subsequent second resection at a high-volume urological centre between 2002 and 2009. Patients underwent adjuvant instillation therapy with Bacillus Calmette-Guerin (BCG). Loss of AQP3 protein expression was defined as complete absence of the protein within the whole tumour. Expression status was correlated retrospectively with clinicopathological and follow-up data (median: 31 months). Multivariate Cox regression analysis was used to assess the value of AQP3 tumour expression with regard to recurrence-free (RFS), progression-free (PFS) and cancer-specific survival (CSS). RFS, PFS and CSS were calculated by Kaplan-Meier analysis and Log rank test. Results: 59\% of patients were shown to exhibit AQP3-positive tumours, whereas 41\% of tumours did not express the marker. Loss of AQP3 protein expression was associated with a statistically significantly worse PFS (20\% vs. 72\%, p=0.020). This finding was confirmed by multivariate Cox regression analysis (HR 7.58, CI 1.29 - 44.68; p=0.025). Conclusions: Loss of AQP3 protein expression in pT1 UBC appears to play a key role in disease progression and is associated with worse PFS. Considering its potential prognostic value, assessment of AQP3 protein expression could be used to help stratify the behavior of patients with pT1 UBC.}, language = {en} } @article{FrankeVilnedaCostaetal.2015, author = {Franke, Katharina and Vilne, Baiba and da Costa, Olivia Prazeres and Rudelius, Martina and Peschel, Christian and Oostendorp, Robert A. J. and Keller, Ulrich}, title = {In vivo hematopoietic Myc activation directs a transcriptional signature in endothelial cells within the bone marrow microenvironment}, series = {Oncotarget}, volume = {6}, journal = {Oncotarget}, number = {26}, doi = {10.18632/oncotarget.5217}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-145844}, pages = {21827 -- 21839}, year = {2015}, abstract = {Cancer pathogenesis involves tumor-intrinsic genomic aberrations and tumor-cell extrinsic mechanisms such as failure of immunosurveillance and structural and functional changes in the microenvironment. Using Myc as a model oncogene we established a conditional mouse bone marrow transduction/transplantation model where the conditional activation of the oncoprotein Myc expressed in the hematopoietic system could be assessed for influencing the host microenvironment. Constitutive ectopic expression of Myc resulted in rapid onset of a lethal myeloproliferative disorder with a median survival of 21 days. In contrast, brief 4-day Myc activation by means of the estrogen receptor (ER) agonist tamoxifen did not result in gross changes in the percentage/frequency of hematopoietic lineages or hematopoietic stem/progenitor cell (HSPC) subsets, nor did Myc activation significantly change the composition of the non-hematopoietic microenvironment defined by phenotyping for CD31, ALCAM, and Sca-1 expression. Transcriptome analysis of endothelial CD45-Ter119-cells from tamoxifen-treated MycER bone marrow graft recipients revealed a gene expression signature characterized by specific changes in the Rho subfamily pathway members, in the transcription-translation-machinery and in angiogenesis. In conclusion, intra-hematopoietic Myc activation results in significant transcriptome alterations that can be attributed to oncogene-induced signals from hematopoietic cells towards the microenvironment, e. g. endothelial cells, supporting the idea that even pre-leukemic HSPC highjack components of the niche which then could protect and support the cancer-initiating population.}, language = {en} } @article{PaligeLindeMartinetal.2013, author = {Palige, Katja and Linde, J{\"o}rg and Martin, Ronny and B{\"o}ttcher, Bettina and Citiulo, Francesco and Sullivan, Derek J. and Weber, Johann and Staib, Claudia and Rupp, Steffen and Hube, Bernhard and Morschh{\"a}user, Joachim and Staib, Peter}, title = {Global Transcriptome Sequencing Identifies Chlamydospore Specific Markers in Candida albicans and Candida dubliniensis}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {4}, doi = {10.1371/journal.pone.0061940}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131007}, pages = {e61940}, year = {2013}, abstract = {Candida albicans and Candida dubliniensis are pathogenic fungi that are highly related but differ in virulence and in some phenotypic traits. During in vitro growth on certain nutrient-poor media, C. albicans and C. dubliniensis are the only yeast species which are able to produce chlamydospores, large thick-walled cells of unknown function. Interestingly, only C. dubliniensis forms pseudohyphae with abundant chlamydospores when grown on Staib medium, while C. albicans grows exclusively as a budding yeast. In order to further our understanding of chlamydospore development and assembly, we compared the global transcriptional profile of both species during growth in liquid Staib medium by RNA sequencing. We also included a C. albicans mutant in our study which lacks the morphogenetic transcriptional repressor Nrg1. This strain, which is characterized by its constitutive pseudohyphal growth, specifically produces masses of chlamydospores in Staib medium, similar to C. dubliniensis. This comparative approach identified a set of putatively chlamydospore-related genes. Two of the homologous C. albicans and C. dubliniensis genes (CSP1 and CSP2) which were most strongly upregulated during chlamydospore development were analysed in more detail. By use of the green fluorescent protein as a reporter, the encoded putative cell wall related proteins were found to exclusively localize to C. albicans and C. dubliniensis chlamydospores. Our findings uncover the first chlamydospore specific markers in Candida species and provide novel insights in the complex morphogenetic development of these important fungal pathogens.}, language = {en} } @phdthesis{Rother2001, author = {Rother, Tobias}, title = {Die Plasmamembran-Kalzium-ATPase im Myokard}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-916}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2001}, abstract = {Die Plasmamembran Kalzium-ATPase (PMCA) ist ein in den meisten eukaryontischen Zellen exprimiertes Enzym. Sie katalysiert den Transport von Kalziumionen aus der Zelle und besitzt gegen{\"u}ber Kalzium eine hohe Affinit{\"a}t jedoch geringe Transportkapazit{\"a}t. Trotz der guten biochemischen Charakterisierung der Pumpe ist ihre Funktion in Zellen wie Kardiomyozyten, die zus{\"a}tzlich {\"u}ber andere Kalzium-Transportsysteme wie den Natrium/Kalzium-Austauscher verf{\"u}gen, weiterhin unklar. Erste Ergebnisse aus dem eigenen Labor an PMCA-{\"u}berexprimierenden L6-Myoblasten zeigten einen Einfluss des Enzyms auf deren Wachstum und Differenzierung. Um diese Erkenntnisse auf den Herzmuskel zu {\"u}bertragen war im Vorfeld ein transgenes Rattenmodel generiert worden, welches die hPMCA4CI unter einem myokardspezifischen Promotor {\"u}berexprimierte. Dieses Modell stand f{\"u}r die vorliegende Arbeit zur weiteren Charakterisierung zur Verf{\"u}gung. Untersucht wurde zun{\"a}chst das Wachstumsverhalten von Prim{\"a}rkulturen neonataler Kardiomyozyten unter Stimulation mit fetalem K{\"a}lberserum, Noradrenalin und dem Platelet Derived Growth Factor BB, jeweils im Vergleich zwischen transgenen und Wildtyp-Kardiomyozyten. Dabei zeigte sich ein beschleunigtes Wachstum der PMCA-{\"u}berexprimierenden Zellen. In einem zweiten Ansatz wurden Untersuchungen angestellt, um die subzellul{\"a}re Lokalisation der PMCA innerhalb der Herzmuskelzelle aufzudecken. Dabei wurden im Speziellen die Caveolae als Ort der m{\"o}glichen Lokalisation untersucht, kleine, ca. 50-100 nm große Einst{\"u}lpungen der Plasmamembran, mit charakteristischer Lipid- und Proteinzusammensetzung, darunter auch viele Rezeptoren und Signaltransduktionsmolek{\"u}le. Insgesamt konnte mit den Methoden der Detergenzextraktion, Doppelimmunfluoreszenz, Pr{\"a}paration Caveolae-reicher Membranen und Immunpr{\"a}zipitation gezeigt werden, dass die PMCA zu einem großen Teil in Caveolae lokalisiert ist. Zus{\"a}tzlich konnte in der Immunpr{\"a}zipitation eine Interaktion der PMCA mit dem Caveolae-assoziierten Zytoskelettprotein Dystrophin dargestellt werden. Zusammenfassend deuten die Ergebnisse darauf hin, dass die PMCA {\"u}ber eine Steuerung der lokalen Kalziumkonzentration im Bereich der Caveolae modulierend in wachstumsregulierende Signaltransduktionswege von Kardiomyozyten eingreifen kann.}, language = {de} }