Fakultät für Biologie - Digitale Hochschulschriften der LMU - Teil 03/06

Perceptual strategies in active and passive hearing of neotropical bats

Basic spectral and temporal sound properties, such as frequency content and timing, are evaluated by the auditory system to build an internal representation of the external world and to generate auditory guided behaviour. Using echolocating bats as model system, I investigated aspects of spectral and temporal processing during echolocation and in relation to passive listening, and the echo-acoustic object recognition for navigation. In the first project (chapter 2), the spectral processing du...

Identifikation, Klonierung und retroviraler Transfer allorestringierter FMNL1-peptidspezifischer T-Zellrezeptoren für die Entwicklung adoptiver Immuntherapien gegen B-Zell-Non-Hodgkin-Lymphome

Die adoptive T-Zelltherapie ist eine attraktive Alternative zu konventionellen Therapien zur Behandlung von malignen Erkrankungen. So konnten bereits Tumorremissionen bei Melanompatienten nach adoptivem T-Zelltransfer erreicht werden (Dudley et al, 2002b; Morgan et al, 2006). Während im autologen System jedoch oft nur unzureichende Antitumorantworten zu generieren sind, zeigt der Erfolg der allogenen Stammzelltransplantation, dass im allogenen System T-Zellen hoch effektiv Tumorzellen bekämpf...

Der LuxP/AI-2- und LuxQ-abhängige Signaltransduktionsweg des Quorum sensing-Systems von V. harveyi

Evolution of avian olfaction

The sense of smell enables animals to e.g. locate food, to navigate or to avoid predators. In vertebrates, odorants are detected by olfactory receptors (ORs) that are expressed in the olfactory epithelium on olfactory sensory neurons. In this study, I investigated OR gene repertoires in both closely and distantly related bird species. Using polymerase chain reaction (PCR) with degenerate primers designed to amplify OR genes, I showed that the majority of OR genes sequenced (~ 84%) were pote...

Alters-, Aktivitäts- und Krankheitsmerkmale in der menschlichen Knochenmikrostruktur

Mechanisms of Rejection of High Grade B cell Lymphoma in Mice

The incidence of high grade B cell lymphoma in western countries has increased over the last decades. Improvement of conventional chemotherapy regimens has significantly contributed to prolonged 5-year survival rates which currently reach around 60%. However, relapse after conventional chemotherapy is an important challenge, especially in high grade B cell lymphomas. The potential benefit of immunological approaches for the elimination of such lymphomas still remains unclear. In this study, w...

Factors for stability, assembly and function of photosynthetic complexes

Die Architektur des X-Chromosoms

Phycobiliprotein Lyases

Phycobilins are light harvesting pigments of cyanobacteria and red algae. In cyanobacteria, four phycobiliproteins are organized in phycobilisomes: phycocyanin (PC), allophycocyanin (APC), and often also phycoerythrocyanin (PEC) or phycoerythrin (PE). Their phycobilin chromophores, linear tetrapyrroles, are generally bound to the apoprotein at conserved positions by cysteinyl thioether linkages. A final step in phycobiliprotein biosynthesis is the post-translational phycobilin addition to the...

Identifizierung des Rezeptors und Charakterisierung der Aufnahme des vakuolisierenden Cytotoxins VacA von Helicobacter pylori in T-Zellen

Untersuchung von Kandidatengenen als mögliche Angriffspunkte einer gezielten Krebstherapie

Geographische Parthenogenese bei der Schabe Phyllodromica subaptera (Blattoptera, Blattellidae, Ectobiinae) und Revision des subaptera-Artenkomplexes

Mapping of genomes and plastomes of subsection Oenothera with molecular marker technologies

The transmembrane protein golden goal regulates retinal axon guidance in Drosophila

Biogenese mitochondrialer Proteine mit C-terminalem Anker

Einfluss des onkogenen RAS-Signalweges auf die Tumorerkennung durch zytotoxische T-Lymphozyten und NK-Zellen

Analyse von Regulatorproteinen des Yersinia Typ III Sekretionssystems

Bei Yersinia enterocolitica handelt es sich um einen humanpathogenen Keim, der ein Typ III Sekretionssystem (T3SS) zur Translokation von Effektorproteinen in Wirtszellen nutzt, um die Zellen zu paralysieren und der angeborenen Immunantwort zu entgehen. Die homologen Proteine YscM1 und YscM2, die bisher als funktionell äquivalent galten, wurden als Interaktionspartner der Phosphoenolpyruvatcarboxylase (PEPC) identifiziert. Die PEPC trägt durch die Bildung von Oxalacetat zur Auffüllung des Citr...

Funktionalität des Interferon TypI- und TypII-Signalwegs in Burkitt-Lymphom-Zellen

The Role of Bone Morphogenetic Protein Mediated Signalling in the Neurogenic Niche of Adult Mouse brain

Der Wnt/ß-Catenin-Signaltransduktionsweg in humanen und murinen mesenchymalen Stammzellen

Mesenchymale Stammzellen (MSC) stellen aufgrund ihres Differenzierungspotentials einen großen Hoffnungsträger in der regenerativen Medizin dar. Entsprechend zahlreicher zell- und tierexperi-menteller Untersuchungen scheint die klinische Anwendung dieser adulten Stammzellpopulation im Rahmen einer Zelltherapie in greifbare Nähe zu rücken, wobei MSC als Basis für einen Patien-ten-spezifischen Zell- und Gewebeersatz dienen könnten. In welcher Weise die regenerative Kapazität der MSC durch spezie...

The Golgin GMAP-210

The protein GMAP-210 (Golgi Microtubule Associated Protein of 210 kDa) is a long coiled-coil protein, which localises to the Golgi apparatus. It is part of the loosely defined protein group of the golgins, which are involved in establishing the Golgi morphology and in vesicular trafficking around the Golgi. By using biochemical, cell biological and molecular biological methods GMAP-210 was examined in regards to its Golgi targeting capability, its interaction partners and its function in esta...

Coordination of late stages of cytokinesis by the inhibitor of apoptosis protein BRUCE

Cytokinesis involves the formation of a cleavage furrow, followed by abscission, the cutting of the midbody channel, the final bridge between dividing cells. Recently, the midbody ring became known as central for abscission, but its regulation remains enigmatic. This study identifies BRUCE, a 528 kDa multi-functional protein, which processes ubiquitin-conjugating activity, as a major regulator of abscission. During cytokinesis, BRUCE moves from the vesicular system to the midbody ring and ser...

Entwicklung der Array-CGH zur hochauflösenden, genomweiten Untersuchung von DNA-Veränderungen einzelner Tumorzellen

Trotz erfolgreicher Resektion des Primärtumors sterben bis heute ca. 40% aller Brustkrebspatientinnen an den Folgen der Metastasierung. Inzwischen ist zunehmend anerkannt, dass wenige selektierte Tumorzellen für die Progression der Erkrankung und eine Therapie-Resistenz verantwortlich sind. Es ist deshalb fraglich, ob genomische Veränderungen, die zur Disseminierung führen, entdeckt werden können, wenn die Masse der Zellen eines heterogenen Primärtumors untersucht wird. Einzelne Tumorzellen d...

The influence of light, nutrients and mixing on pelagic communities and ecosystem dynamics

Die Bedeutung der GRAS-Proteine für die Entwicklung von Pflanzen untersucht am Modellorganismus Arabidopsis thaliana

Chup1 - a chloroplast movement protein and its interactions

The molecular mechanisms of light dependent chloroplast movement could for a long time not be unravelled. But the recent discovery of a mutant deficient in chloroplast movement sparked new impulses in the field. This study investigates the molecular mechanisms of chloroplast movement based on the protein Chup1 and the interactions of Chup1 and cytoskeletal effectors. It is demonstrated that Chup1 is exclusively and directly targeted to the chloroplast surface in an N-terminus dependent manner...

Expressionsregulation des Transkriptionsfaktors KLF2 durch bakterielle Toxine

The role of microtubules in initial neuronal polarization

Neurons are highly polarized cells with two structurally and functionally distinct compartments, axons and dendrites. This dichotomy is the basis for unidirectional signal propagation, the quintessential function of neurons. During neuronal development, the formation of the axon is the initial step in breaking cellular symmetry and the establishment of neuronal polarity. Although a number of polarity regulators involved in this process have been identified, our understanding of the intracellu...

Analyse der biologischen Funktionen der Gene hUBC13 und TRAF6 des Ubiquitinmetabolismus in Säugerzellen

Die hyperosmotische Stressantwort von Escherichia coli-von der Proteomanalyse zu einzelnen Komponenten

Ein Habitat von Escherichia coli ist der Gastrointestinaltrakt von Säugetieren, der sich durch anaerobe Bedingungen und eine hohe Osmolalität auszeichnet. E. coli ist aber auch freilebend in Gegenwart von Sauerstoff in der Umwelt bei variierenden Osmolalitäten nachzuweisen. Eine Adaptation an diese ständig wechselnden Umweltbedingungen ist entscheidend für Wachstum und Überleben. In dieser Arbeit wurde der Adaptationsprozess an erhöhte Osmolalitäten durch globale Proteomanalysen untersucht. Z...

Foxc1 regulates Pecam-1 Expression in embryonic Endothelial Progenitor Cells

Funktionelle Charakterisierung des Prion-Proteins

Protein import into the inner envelope membrane of chloroplasts

Most of the proteins localized in the chloroplast inner envelope membrane are synthesized on cytosolic ribosomes with a cleavable N-terminal chloroplast transit peptide. Most of them reach their final localization via the so called general import pathway consisting of the Toc complex at the chloroplast outer envelope membrane and the Tic complex at the chloroplast inner envelope membrane. Recent studies characterized precursor proteins which are targeted into the chloroplast inner envelope me...

3D Reconstruction of Neural Circuits from Serial EM Images

A basic requirement for reconstructing and understanding complete circuit diagrams of neuronal processing units is the availability of electron microscopic 3D data sets of large ensembles of neurons. A recently developed technique, "Serial Block Face Scanning Electron Microscopy" (SBFSEM, Denk and Horstmann 2004) allows automatic sectioning and imaging of biological tissue inside the vacuum chamber of a scanning electron microscope. Image stacks generated with this technology have a resolutio...

Oenothera, a unique model to study the role of plastids in speciation

The subject of this thesis was to develop molecular approaches appropriate to investigate speciation processes. The genus Oenothera was chosen for study, since it offers the unique possibility to exchange plastids, individual or more chromosomes and/or even entire haploid genomes (so-called Renner complexes) between species. In addition, a rich stock of information in taxonomy, cytogenetics and formal genetics is available, collected for more than a century of research. Interspecific exchange...

Initial Characterization of two novel spindle proteins, CHICA and HURP

During mitotic spindle assembly, the sister chromatids have to be captured by kinetochore (K) -fibers (bundles of kinetochore microtubules; KMTs) to ensure stable attachment of the chromosomes. This is a prerequisite for chromosome congression at the metaphase plate, and the subsequent segregation of separated sister chromatids to the spindle poles. Although, this is a critical step during mitosis, the identity and regulation of the proteins that mediate the formation and stabilization of K-f...

Oogenese in Hydra vulgaris

Regulation of endocytosis and secretion by Rab GTPase activating proteins

Vesicle traffic in eukaryotic cells is a tightly organized process involving a multitude of regulatory proteins. Key regulators of this traffic are small GTPases called Rabs. With about 60 members in the human genome, they constitute the largest subgroup in the superfamily of Ras like monomeric GTPases. They recruit effector proteins to specific membranes and thus define the identity of organelles. Rabs switch between an active, GTP bound state and an inactive GDP bound state. Key regulators ...

Identifikation und Validierung EpCAM-assoziierter Interaktionspartner

Investigation into the cellular radiosensitivity of the LEC rat and analysis of candidate genes

Recent work has underlined the importance of animal models in discovery and characterisation of molecular mechanisms determining radiosensitivity and radioresistance. Enhanced sensitivity of LEC rats to ionizing radiation in terms of the acute radiation syndrome was investigated in the present work on the cellular level and compared to that of LE rats. To understand the molecular basis for the increased radiation sensitivity a series of studies were performed, which included the classical clo...

The Role of NBS1 in the Insulin-Like Growth Factor-1 Signaling

The Nbs1 protein (nibrin, p95) is a member of the DNA repair/checkpoint complex Mre11/Rad50/Nbs1 (MRN), which plays a critical role in the cellular responses to DNA damage, cell cycle checkpoints, and telomere and genome stability. Many transgenic models in mice and clinical symptoms of NBS patients have clearly shown that Nbs1 exerts pleiotropic actions in growth and development of mammals. However, the molecular role of Nbs1 in mitogenic signaling pathways which could explain the growth ret...

Koordination von Synthese und Membraninsertion mitochondrialer Translationsprodukte

Biogenese photosynthetischer Elektronentransport-Komplexe in Plastiden der Gerste(Hordeum vulgare L.)

Die Synthese von Chlorophyll ist in Angiospermen ein streng lichtabhängiger Prozess. Keimlinge, welche im Dunkeln angezogen werden, bilden anstelle der (grünen) Chloroplasten (gelb-orange) Etioplasten. In diesen ist die Thylakoidmembran durch den parakristallinen Prolamellarkörper und einige Prothylakoidmembranen ersetzt. Auf Ebene der Proteine kann zwar bereits im Dunkeln die Translation aller plastidencodierten Chlorophyll-bindenden Proteine nachgewiesen werden, allerdings werden diese mit ...

Nachweis von Genveränderungen bei der Strahlenkarzinogenese von Brustzellen mittels Array-Painting

Behavioral phenotyping, gene expression profiles, and cognitive aspects in a mouse model of trait anxiety

Anxiety reflects a fundamental emotion, essential for survival. However, if it occurs unpredictably and exaggerated for a long period of time, it becomes pathological, confining a normal course of life. Anxiety disorders are among the most disabling psychiatric diseases, with increasing incidence. They are complex and occur as a combination of both, inherited and stress-related phenomena, whose origin and underlying mechanisms are still poorly understood. Besides clinical studies, extensive p...

Analyse des neuen Proteins TMEM59 und seiner Funktion in dem Transport und der Prozessierung des Amyloid-Vorläufer-Proteins

Das Golgi-lokalisierte Protein TMEM59 stellt zusammen mit seinem Homolog BSMAP eine neue Proteingruppe von Modulatoren dar, welche die Golgi-Glykosylierungs-Prozesse beeinflussen können. Vorliegende Arbeit identifiziert das Protein TMEM59 als einen starken Inhibitor der APP-Glykosylierung und der APP-Prozessierung.

Epigenetik von Epstein-Barr Virus

Molecular characterisation of three novel photosynthetic proteins in arabidopsis thaliana

Untersuchung der systemischen Tumorprogression des Mammakarzinoms anhand Her2/neu-transgener Mäuse

Imaging activity-dependent structural and functional plasticity of hippocampal CA3-CA1 synapses