National Repository of Grey Literature 41 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Nuclear lamina, its function in the cell and its role in interaction with non-enveloped DNA viruses
Pápež, Samuel ; Bruštíková, Kateřina (advisor) ; Kuthan, Martin (referee)
The nuclear lamina is a protein network found in all metazoa. It is composed of intermediate filaments V, namely type A and type B lamins. It is a multifunctional cellular structure adjacent to the inner nuclear membrane, giving the nucleus its shape, ensuring its mechanical stability and participating in the regulation of many nuclear processes. The nuclear lamina also has a protective function manifested in the infection of cells with DNA viruses, whose life cycle takes place in the nucleoplasm. These include small non-enveloped DNA viruses. The nuclear lamina is an obstacle that viruses have had to learn to overcome in order to multiply. To do this, they use their own, but also cellular mechanisms, which disrupt the nuclear membrane together with the nuclear lamina and thus allow the virus nuclear entry and exit. This work summarizes the knowledge about changes in the nuclear lamina induced by viruses of the families Polyomaviridae, Parvoviridae and Circoviridae, on the way through the nuclear envelope. Keywords: Nuclear lamina, disassembly of nuclear lamina, DNA viruses, Polyomaviruses, Parvoviruses, Circoviruses
Cryptococcus neoformans virulence factors
Bauer, Martin ; Kuthan, Martin (advisor) ; Abrhámová, Kateřina (referee)
Cryptococcus neoformans is an opportunistic pathogenic yeast causing around 600 000 deaths annually. Its ability to cause a chronic infection is given by multiple virulence factors, which include the ability to grow in high temperature, polysaccharide capsule, oxidative stress tolerance and the expression of surface proteins. Unusual and resistant titan cells, which develop through the process of titanization, and the process of phenotypic switching can also be included. Despite intensive research, these virulence factors are yet to be fully described. Inducing factors of titan cells and participating signalling pathways are known. However, a complete model of titanization does not yet exist. So far, the mechanism of phenotypic switching is also unknown. In this work the current knowledge of virulence factors of C. neoformans is presented and summarised.
Phenotypic switching and cell differentiation in yeast Cryptococcus neoformans
Bauer, Martin ; Kuthan, Martin (advisor) ; Abrhámová, Kateřina (referee)
Cryptococcus neoformans is an opportunistic pathogenic yeast causing around 600 000 deaths annually. Its ability to cause a chronic infection is given by the emergence of different morfotypes. These morphotypes differ in cell structures and mechanisms (virulence factors) which have an influence on the resistance to stress factors encountered in the host. This work first describes molecular mechanisms of formation of these virulence factors. Next, it presents morphotypes occurring during infection and the hypovirulent pseudohyphal morphotype. However, this morphotype is interesting because of a modification in the signalisation leading to its manifestation. Finally, described signalling pathways present possible ways of regulating the virulence factors, and so the manifestation of different morphotypes. Understanding these signalling pathways could ultimately lead to improving the development of new drugs, given that Cryptococcus neoformans is highly resistant to the existing ones. Keywords: Cryptococcus neoformans, phenotypic switching, titan cells, cell differentiation, virulence, Vad1, Rim101, Usv101, RAM
Role of autophagy in yeast cell adaptation
Brádlerová, Michaela ; Kuthan, Martin (advisor) ; Zikánová, Blanka (referee)
Autophagy is an evolutionarily conserved degradative pathway. Autophagy occurs constitutively at a basal level and it is involved in the recycling and turnover of damaged or superfluous organelles and proteins. It has a critical role in cellular homeostasis. Autophagy can be induced in response to starvation or other types of stress. Induction of autophagy during these conditions has a major role in protection and adaptation of the cell. Autophagy needs to be properly regulated. A wide range of diseases is associated with dysregulation of autophagy. Better understanding of autophagy mechanisms can help to develop strategies designed to modulate autophagic responses occuring in a number of diseases. This work is focused on current knowledge of main types of autophagy and how autophagy helps yeast cells to adapt. Key words: autophagy, yeast, degradative pathway, adaptation, TORC1
Bats - viral Pandora's box
Mejsnar, Martin ; Saláková, Martina (advisor) ; Kuthan, Martin (referee)
Bats, as a very old order of mammals, are significant reservoirs of viral pathogens and in many cases are also scientifically proven carriers of the viruses. These viruses are becoming more and more known, mainly due to the growing human population and thus the frequent contact of humans and bats. In this work I will follow up only some zoonoses that the Chiroptera family carries and I selected them according to their scientific knowledge and, of course, the impact on human society. However, this area is still full of information unclear or completely unknown, so further research is desirable. The basic methods of virus identification that are used to investigate new viruses are discussed in the second part. Key words: bats, virus, zoonosis, reservoir, epidemics
Morphogenesis of the bacterial colonies and their mutually influencing
Rieger, Tomáš ; Markoš, Anton (advisor) ; Rulík, Martin (referee) ; Kuthan, Martin (referee)
This thesis follows previous works of our group (Rieger T. et al., 2008; Cepl J. et al., 2010 and Patkova I. et al., 2012), where we focused on the morphology of the bacterial colonies Serratia marcescens and its variety caused by changing of the inoculation conditions on nutrient agar. When bacterial colonies S. marcescens are grown on nutrient agar enriched with glucose isolated enough from other colonies in its living space, it can form coloured structured colonies, which we named morphotype "fountain" (F). This morpotype becomes ideal for following studies of mutual influencing of the bacterial colonies, because of its ability of pigmentation change or structure loss caused by altering surrounding inoculation conditions. We noticed in normal sowed agar plates, that bacterial colonies, which grows in the close distance with other colonies develop their pigmentation sooner, than colonies, that grows more isolated. We studied how is this influencing happening and what are the necessary conditions for it. We proved, that different species of bacterial macrocolonies (S. marcescens - morphotype (M), S. rubidea and E. coli) emits into the nutrient agar informative signal, which makes the recipient colonies S. marcescens reacts on this signal with the same manner (X structure). It looks, that this is...
Yeast colonies as a model of multicellular behaviour of microorganisms
Kuthan, Martin ; Palková, Zdena (advisor) ; Hašek, Jiří (referee) ; Kolarov, Jordan (referee)
- 32 - Závěr Již v úvodu jsem se zmínil, že mnohé laboratorní kmeny kvasinek ztratili vlivem domestikace schopnost filamentálního růstu. Ukázkovým příkladem cílené domestikace je laboratorní kmen S288C. Historie vzniku tohoto kmene je zajímavá a dokumentuje výrazný vliv genetiků na jeho vlastnosti. Velké množství kmenů S. cerevisiae používaných v laboratořích má společného předka kterým je kmen EM93. Tento diploidní kmen izoloval v Kalifornii v roce 1938 Emil Mrak z hnijícího fíku (MORTIMER and JOHNSTON 1986). Není však jasné, zda se jednalo o přirozenou mikroflóru fíků, nebo o kontaminaci komerčními pekařskými či kvasnými kmeny. Kmen EM93 je heterothalický a je schopen filamentálního růstu (LIU et al. 1996). Pro laboratorní účely ale nebyl úplně ʺpohodlnýʺ. Protože tvorba shluků buněk brání izolaci klonů vzniklých z jediné buňky a ztěžuje přesné určení počtu buněk v tekutých kulturách, snažili se genetici získat prototrofní kmen s neadherujícími, dobře resuspendovatelnými buňkami. Mnohonásobným křížením haploidních segregantů kmene EM93 s dalšími laboratorními kmeny a komerčními pekařskými kmeny vytvořil Robert Mortimer kmen S288C, jehož 90 % genomu pochází...

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