|
|
Tick-borne encephalitis virus inhibits rRNA synthesis and host protein production in human cells of neural origin
SELINGER, Martin
Tick-borne encephalitis virus (TBEV), a member of the genus Flavivirus (Flaviviridae), is a causative agent of a severe neuroinfection. Recently, several flaviviruses have been shown to interact with host protein synthesis. In order to determine whether TBEV interacts with this host process in its natural target cells, we analysed de novo protein synthesis in a human cell line derived from cerebellar medulloblastoma (DAOY HTB-186). We observed a significant decrease in the rate of host protein synthesis, including the housekeeping genes HPRT1 and GAPDH and the known interferon-stimulated gene viperin. In addition, TBEV infection resulted in a specific decrease of RNA polymerase I transcripts, 18S and 28S rRNAs and their precursor, 45-47S pre-rRNA, but had no effect on the RNA polymerase III-transcribed 5S rRNA levels.
|
|
|
Replication and transcription of nucleolar DNA
Flusser, Michal ; Smirnov, Evgeny (advisor) ; Staněk, David (referee)
The nucleolus is the most prominent compartment of the cell nucleus and is the place where ribosomal RNAs (rRNAs) are synthesized, processed and assembled with ribosomal proteins. Although the nucleolus has been studied for decades its structural and functional organization is still unclear. In particular, the role of various types of DNA participating in the formation of nucleoli along with ribosomal genes is not understood. The present thesis summarizes the current knowledge and views on the nucleolus, focusing on the two synthetic processes, replication and transcription, in mammalian cells. Specific features of these processes in the context of nucleolar ultrastructure remains an unsolved problem of the modern molecular biology.
|
|
|
Impact of the rRNA modifications on protein synthesis
Kročová, Eliška ; Pospíšek, Martin (advisor) ; Holá, Dana (referee)
A ribosome is a supramolecular structure, which mediates synthesis of all cellular proteins, and therefore is essential for cell life. The fact, that some nucleotides of ribosomal RNA are modified, is known for forty years. However only recently, successful deeper studies on how the individual modifications are synthesized and what is their effect on ribosome synthesis and function appear. Some particular nucleotide modifications are important for the ribosome formation (like m1 acp3 Ψ1191 SSU), some others influence proper function of the ribosome (e.g. Um2921, Gm2922, Ψ2923 LSU, m1 acp3 Ψ1191 SSU). Majority of modified nucleotides in eukaryotic rRNA is being recognized by small nucleolar RNA (snoRNA). Few nucleotides is, however, recognized and subsequently modified by specific proteins. These proteins also play crucial role in ribosome maturation. In thesis presented, current knowledge on the role of ribosomal RNA nucleotide modifications during their formation and maturation, and on their function is summarized and overviewed.
|
|
|
The use of environmental sequencing in the studies on eukaryotic diversity
Lukešová, Soňa ; Hampl, Vladimír (advisor) ; Škaloud, Pavel (referee)
The bachelor's thesis focuses on environmental sequencing method and its usage in examining the diversity of microbial eukaryotic organisms. It describes the method, its mechanism, application and the problems associated with it. The work describes the current view of the phylogeny of the major eukaryotic lineages with their closer characteristics. Particular attention is paid to newly discovered groups. The work addresses the relationships inside these groups, summarizes findings of their ecology, food resources, and morphology. A separate chapter is devoted to the occurrence of the protist groups in extreme environmental conditions. Key words: Diversity of eukaryotes, environmental DNA, sequencing, rRNA, phylogenetics.
|
|
|
Influence of rRNA modifications on translation initiation in eukaryots
Kročová, Eliška ; Pospíšek, Martin (advisor) ; Kouba, Tomáš (referee)
Modifications of ribosomal RNA are present in every livivng organism. The function of rRNA modifications could be studied only when the process of modifications was described. Currently, scientists study not only individual modifications but also the importance of global level of modifications for maturation and function of ribosome. This thesis deals with the influence of 2'-O-methylation of citidine 1639 and adenosine 100 in 18S rRNA and uridine 2729 in 25S rRNA on initiation in yeast Saccharomyces cerevisiae with special attention of translation controlled by internal ribosome entry site (IRES). Strains with deletion in genes snR51, snR70 and duoble deletion in both genes were successfully created during my master study. Pilot experiments showed the importance of products of both genes in translation initiation.
|
|
|
Replication and transcription of nucleolar DNA
Flusser, Michal ; Smirnov, Evgeny (advisor) ; Staněk, David (referee)
The nucleolus is the most prominent compartment of the cell nucleus and is the place where ribosomal RNAs (rRNAs) are synthesized, processed and assembled with ribosomal proteins. Although the nucleolus has been studied for decades its structural and functional organization is still unclear. In particular, the role of various types of DNA participating in the formation of nucleoli along with ribosomal genes is not understood. The present thesis summarizes the current knowledge and views on the nucleolus, focusing on the two synthetic processes, replication and transcription, in mammalian cells. Specific features of these processes in the context of nucleolar ultrastructure remains an unsolved problem of the modern molecular biology.
|
|
|
Impact of the rRNA modifications on protein synthesis
Kročová, Eliška ; Pospíšek, Martin (advisor) ; Holá, Dana (referee)
A ribosome is a supramolecular structure, which mediates synthesis of all cellular proteins, and therefore is essential for cell life. The fact, that some nucleotides of ribosomal RNA are modified, is known for forty years. However only recently, successful deeper studies on how the individual modifications are synthesized and what is their effect on ribosome synthesis and function appear. Some particular nucleotide modifications are important for the ribosome formation (like m1 acp3 Ψ1191 SSU), some others influence proper function of the ribosome (e.g. Um2921, Gm2922, Ψ2923 LSU, m1 acp3 Ψ1191 SSU). Majority of modified nucleotides in eukaryotic rRNA is being recognized by small nucleolar RNA (snoRNA). Few nucleotides is, however, recognized and subsequently modified by specific proteins. These proteins also play crucial role in ribosome maturation. In thesis presented, current knowledge on the role of ribosomal RNA nucleotide modifications during their formation and maturation, and on their function is summarized and overviewed.
|
|
|
RNA biology of symbiotic bacteria in insects
MACHOVÁ, Kamila
Non-coding RNAs (ncRNAs) represent an important part of bacterial genomes. However, only few studies RNAs with limited sampling were done concerning ncRNAs of insect endosymbiontic bacteria. This study provides a broad in silico genome sampling of insect endosymbionts (63 lineages of 27 genera) for ncRNAs and their modifications. Most strikingly it was found out that i) genes encoding modification enzymes conserved in particular genomes differ to high extent, ii) most of tRNA and rRNA modifications sites are conserved regardless whether the gene encoding the corresponding modification enzyme is conserved, iii) multiple endosymbiont lineages do not encode a full set of tRNAs. Our data imply that translation of endosymbionts is much less efficient compared to phylogenetically related free-living bacteria and that some of symbionts possibly need to cooperate with their cosymbionts or maybe even with their host to maintain translation.
|
|
|
Molecular analysis of the mitochondrial genom of \kur{Diuraphis noxia} (Aphididae)
CHUNDELOVÁ, Daniela
The complete sequence of mitochondrial DNA from Diuraphis noxia was obtained and characterized. The mitogenome contains a standard set of 13 protein-coding genes, 19 tRNA genes, 2 ribosomal RNA genes. A+T-rich and ?repets? regions in the same order as those of the other analyzed aphids. Comparison to mtDNAs from other Sternorrhyncha species obtained from GenBank revealed possible markers for studies on population differentiation. Phylogenetic analysis using parsimony and maximum likelihood confirmed the classification of Diuraphis noxia into the Aphididae.
|
|
|
Analysis of low-copy sequences and its utilization for evaluation of genetic polymorphism in selected \kur{Beauveria bassiana} strains/isolates
JOZOVÁ, Eva
Beauveria bassiana is used in biological control against the economically significant pests. Detection of morphological and genetic polymorphism between different species and strains isolated in the natural environment is important to study the distribution and effects in the ecosystem. The aim of this study was to determine in which links are "local tribes" with ecological aspects of biological control in protected zone and assess the polymorphism of the sections by using molecular markers. Were analyzed 36 strains collected in the National Park Šumava in the Czech Republic. Polymorphism of these strains was determined according to a sequence of LSU (28S Large Subunit Ribosomal DNA). It is observed that the populations from National Park is closed, "the local tribes" because these methods can be very well characterized and compared with other strains from different parts of the Czech Republic and other countries. Populations from National Park showed no differences in polymorphism. Through this analysis, the sample Bba I101 was aligned. This preparation is re-used for bark beetle occurring in the National Park Šumava in the Czech Republic. This study was supported by grants GACR 521/08/H042, MSM 60076658-06, MGA SP/2d1/41/08.
|
guest ::
