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Biogenesis and function of nuclear iron-sulfur proteins
Panova, Ekaterina ; Benda, Martin (advisor) ; Smutná, Tamara (referee)
Iron-sulfur clusters are important inorganic cofactors of many cellular reactions, including those that occur in the nucleus. Nuclear iron-sulfur proteins play an important role in DNA replication, genome repair, and maintenance of genome stability. The biosynthesis of these iron-sulfur clusters is initiated in the mitochondria by the iron-sulfur cluster assembly pathway (ISC), continues in the cytosol by the cytosolic iron-sulfur cluster assembly pathway (CIA), and ends with the incorporation of the clusters into target apoproteins such as polymerases, primases, helicases, endonucleases, or glycosylases. This bachelor thesis summarizes current knowledge about the pathways of iron-sulfur cluster biosynthesis, the functions of nuclear iron-sulfur proteins, and the role of the clusters in these proteins, including the phenotypes and clinical manifestations caused by the absence of iron-sulfur clusters. Keywords: iron-sulfur clusters, metalloproteins, nucleus, DNA replication, DNA repair
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Nuclear Transport Signals in the proteins of the ARP2/3 complex
Němcová, Barbora ; Bellinvia, Erica (advisor) ; Cvrčková, Fatima (referee)
The intracellular movement of macromolecules such as proteins and RNA is essential for maintaining cellular homeostasis and coordinating various cellular processes. In eukaryotic cells, the transport of these molecules between the cytoplasm and the nucleus is carefully regulated. Nuclear transport signals (NTS) play a key role in facilitating the import and export of proteins across the nuclear envelope. The ARP2/3 complex, which is an important regulator of activity dynamics, has been studied mainly for its functions in the cytoplasm, such as cell movement and cell division. However, new findings suggest that the ARP2/3 complex might also have nuclear functions in plants. Plants are unique multicellular organisms that rely on precisely coordinated cellular activities for growth, development, and response to stimuli. Understanding the molecular mechanisms behind nuclear processes in plants has recently become a focus of research. The ARP2/3 complex, which consists of seven subunits, is known for its ability to branch actin filaments and thereby control cellular processes requiring actin remodeling. However, recent studies have revealed a potential link between the ARP2/3 complex and nuclear functions in plants. Proteins associated with the ARP2/3 complex have been found to localize within the plant...
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Design and Synthesis of cell nucleus-targeted compounds for use in bioorthogonal reactions
Hrušák, Jáchym ; Vrábel, Milan (advisor) ; Míšek, Jiří (referee)
This bachelor thesis focuses on the design and synthesis of 1,2,4,5-tetrazine and trans- cyclooctene derivatives containing functional moieties which are able to target cellular nucleus and participate in bioorthogonal reactions. Based on literature research, the targeting moieties and the structure of the tetrazine and trans-cyclooctene derivatives were designed with the aim to achieve selective nuclear targeting and to ensure sufficient reactivity of the resulting conjugates under biological conditions. Selected candidates were then synthesized and their properties together with cellular reactivity were investigated in model experiments.
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Photon strength functions in 162Dy from two-step gamma cascade measurement
Chudoba, Petr ; Krtička, Milan (advisor) ; Knapp, František (referee)
Photon strength functions quantities, which describe deexcitation of nucleus by emiting gamma rays within statistical model of the nucleus. Information about these quantities can be gained from study of two-step gamma cascades. The thesis is focused on processing of experimental data from measurement of these cascades in 162Dy nucleus. Data were acquired using experimental set-up istalled on the research reactor in Řež near Prague. In the experiment the 161Dy targed was bombarded by thermal neutrons. Following gamma deexcitation of 162Dy nucleus was measured by coincident spectrometer composed of two semi-conductor detectors. The aim of the thesis is to perform energy and efficiency calibration and to process experimental data into the form of two-step gamma cascades spectra. In adition, a comparsion of the two-step cascades spectra with the outcome of simulations of a few basic models of photon strength functions is made.
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Giardia intestinalis karyotypes
Hudosová, Lenka ; Nohýnková, Eva (advisor) ; Král, Jiří (referee)
Giardia intestinalis is a parasitic protist that causes one of the most common diarrheal disease of parasite origin. The cell of Giardia contains two nuclei with unknown number of chromosomes until recently. Karyotype was determined five years ago using conventional cytogenetic method by Tůmová and collaborators. In my work, I assessed karyotype of four isolates, six lines and three clonal lines by the same method. It was confirmed, that two nuclei within one cell could differ in chromosome number, the differences found were 1, 2 or 6 chromosomes. Aneuploid number of chromosomes was found too. In case that both nuclei within single cell contained the same number of chromosomes, there were 10 chromosomes indentified in each nucleus. It was also revealed, that karyotype is not specific feature for different genetic groups (in this work assemblages A and E). Karyotype can be different even among lines and clonal populations derived from the same isolate. Changes in karyotype in the course of in vitro cultivation were detected within three populations. Results are discussed in relation to known facts.
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The role of tubulin transport between the nucleus and the cytoplasm
Bokvaj, Pavel ; Schwarzerová, Kateřina (advisor) ; Zažímalová, Eva (referee)
Tubulin is the basic building block of microtubules which ensure intracellular transport, morphological changes, the connection of proteins of metabolic pathways, the segregation of chromosomes during mitosis and many other essential processes in plant cells. The localization of tubulin regarding nucleus is strictly controlled and during the interphase, tubulin is usually not present in the nucleus. As we previously showed, one of the exceptions of the presence of tubulin in the nucleus is the cold stress condition. Also, we discovered several plant-specific nuclear export sequences (NES) in tubulin molecules: one in α-tubulin and two in β-tubulin. In this work I found that double mutation of both functional β-tubulin NESes cause slight accumulation of the protein in the nuclei. However, the phenotype of the transgenic plants expressing β-tubulin with mutations is probably not affected by the presence of the mutated protein. The effect of the expression of the mutated β-tubulins was observed in Nicotiana tabacum BY-2 cells as well. The expression of β-tubulin carrying a single NES3 mutation or double mutation of both NESes bring changes of the division activity of the cells, while the NES2 mutation does not have any effect. Furthermore, it was discovered that the 0řC cold tr eatment does not cause...
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Formy a funkce přímé řeči v žánrové struktuře novinových zpráv
Urbanová, Zuzana ; Dušková, Libuše (advisor) ; Hornová, Libuše (referee) ; Malá, Markéta (referee)
Zuzana Urbanová The Function of Direct Forms of Presentation in the Generic Structure of Newspaper Reports Abstract The thesis deals with the employment of direct forms of presentation in the genre of hard news. The texts for the analysis were excerpted from the main British broadsheet newspapers. The classification of forms of presentation is based on Semino and Short (2004) and focuses on their deictic and syntactic properties, interpreted in terms of the pragmatic concepts of perspective, faithfulness claims and the role of the reported and reporting speaker. Attention is paid to various direct forms, including direct speech, free direct speech and combined forms, i.e. non-direct forms appearing with a partial direct quote. The thesis draws heavily on the work by White (1998), whose approach to genre is informed by the ideas proposed by the Sydney School and Systemic Functional Linguistics. Hard news is characterised by the orbital generic structure, consisting of the nucleus and a number of specifying satellites (White 1998). The occurrence of direct and combined forms of presentation is explained by their deictic, syntactic and pragmatic properties, the generic role and characteristic features of the nucleus and individual satellites, and the overall function of hard news. The function of hard news and...
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