National Repository of Grey Literature 37 records found  beginprevious26 - 35next  jump to record: Search took 0.01 seconds. 
Promoter-terminator interactions in eukaryotic RNA polymerase II transcription
Petr, Martin ; Hozák, Pavel (advisor) ; Vaňková Hausnerová, Viola (referee)
Gene loops are chromatin structures formed by juxtaposition of distal genomic regions. Since these regions are often involved in transcription cycle control, gene loops therefore provide another mechanism of regulation of gene expression. This thesis summarizes recent findings about gene loops, focusing specifically on loops formed by interactions between promoter and terminator regions of genes transcribed by the eukaryotic RNA polymerase II. Different cases of gene loops discovered in several yeast genes, the mammalian BRCA1 tumor suppressor and the HIV-1 integrated provirus are described, including mechanisms that possibly lead to the formation of these structures. Since gene loops and interactions between promoter and terminator in yeast have been linked to the transcriptional memory, their involvement in this phenomenon is discussed. Finally, as BRCA1 and HIV-1 are directly linked to serious human diseases, the potential significance of alterations of gene loops in the development of various pathological conditions is presented. Keywords: gene loops, chromatin loops, chromatin conformation, transcriptional memory, transcription, gene expression, regulation
Promyelocytic leukemia protein function in normal, tumor and senescent human cells
Rossmeislová, Lenka ; Hozák, Pavel (advisor) ; Forstová, Jitka (referee) ; Anděra, Ladislav (referee)
Promyelocytic leukemia protein (PML) gene encodes a nuclear protein localizing into the nucleoplasm and distinct nuclear bodies, referred to as PML nuclear bodies (PML NBs). PML is now considered as a gene with tumor-suppressive properties since it is implicated in many nuclear functions affecting cellular proliferation, apoptosis and senescence. The presented work is a part of a larger project that aims to clarify the regulation of promyelocytic leukemia protein expression and investigates the role of PML protein in cellular senescence. The specific goals of my PhD project were to evaluate new in vitro models for the study of PML, to elucidate the effects of histone deacetylase inhibitors on PML gene expression, and to investigate the association of PML with the nucleolus.
Optical microscopy to study the role of cytoskeleton in cell locomotion and virus trafficking
Difato, Francesco ; Forstová, Jitka (advisor) ; Hozák, Pavel (referee) ; Plášek, Jaromír (referee)
3. General conclusions 150 The interest in optical microscopy is constanly growing, mainly because of its unique features in examining biological systems in four dimensions (x-y-z-t)1 . The work presented here was focused on biological applications of optical microscopy by exploring and improving the spatial and temporal resolution performances and by futher developing optical tools for manipulating biological samples. First, I studied the resolution performances of the system in the three dimensional space and I contributed in improving the experimental spatial resolution of microscope by applying deconvolution. In this respect, theoretical modelling can characterize the image formation process of the microscope, but only experimental measurement of the PSF can quantify the limitations of the real system. Indeed, experimental PSF presents shape assymetry due to spherical aberrations introduced by optical elements, while theoretical PSF is symmetric and account only for the resolution limits of an ideal imaging system. The disadvantage of experimental PSF is that could be corrupted by noise, otherwise deconvolution with the theoretical PSF offer only a qualitative improvement of the image, because the introduced artefacts cannot be quantified. Deconvolution of the acquired data with experimental PSF...
Possible role of spermatogenic protein glyceraldehyde-3-phosphate dehydrogenase (GAPDHS) in mammalian sperm
Margaryan, Hasmik ; Dorosh, Andriy ; Čapková, Jana ; Postlerová, Pavla ; Philimonenko, Anatoly ; Hozák, Pavel ; Pěknicová, Jana
Sperm proteins are important for the structure and function of these specific, highly differentiated cells. Certain of these proteins play a role in sperm-egg recognition during primary or secondary binding at zona pellucida glycoprotein matrix. The aim of this study was to characterize the acrosomal sperm protein recognized by a monoclonal antibody (MoAb) Hs-8, prepared in our laboratory by immunization of BALB/c mice with human ejaculated sperm, and to test the possible role of this protein in gamete interaction. MoAb Hs-8 specifically labelled a 45 kDa protein from the sperm extract in the immunoblotting test. Sequence analysis identified this Hs-8 protein as GAPDHS. In order to perform a control tests, a commercial mouse anti-GAPDHS MoAb was applied. Both antibodies showed similar staining patterns using immunofluorescence labelling, transmission electron microscopy and immunoblot analysis. Moreover, both Hs-8 and commercial anti-GAPDHS antibodies blocked the secondary sperm-zona pellucida binding. Generally, GAPDHS was considered mainly as sperm-specific glycolytic enzyme involved in energy production during spermatogenesis and sperm motility and its role in the sperm head was unknown. In this study, we confirmed the potential additional role of GAPDHS as a binding protein that is involved in the sperm-zona pellucida interaction.
Microscopy 2008
Hozák, Pavel
Two-day conference responding to novel trends in light and electron microscopy and their impact on researchers in the Czech Republic and Slovakia. Contributions were presented in biomedical as well as physics and material science fields. The Conference was held in a sports area in the heart of the Czech-Moravian Heights and was closed by an opulent rout with wine degustation.
Interactions between PML nuclear bodies and nuclear DNA helicase II
Fuchsová, Beáta ; Novák, P. ; Kafková, J. ; Hozák, Pavel
Our findings suggest that NDH II recruitment to PML NBs might be important for the role of this nuclear domain in transcriptional regulation and are consistent with the model that PML protein functions as a transcription factor.

National Repository of Grey Literature : 37 records found   beginprevious26 - 35next  jump to record:
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