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Studying of Gene Expression Involved in Hyaluronic Acid Synthesis in Streptococcus Equi Subsp. Zooepidemicus Using DNA Microarrays and Real-Time PCR
Hrudíková, Radka ; Šeda,, Ondřej (referee) ; Bobek,, Jan (referee) ; Velebný, Vladimír (advisor)
Hyaluronic acid (HA) is an important substance, which is mostly used in pharmaceutical and cosmetic industry. This substance is commonly found in the human body. HA is one of the factors contributing to virulence of microorganisms. Some bacterial strains produce hyaluronic acid in the form of a mucoid capsule that encapsulates the cell to protect bacteria against the immune system of the host organism. One of the main producers is the bacterial strain Streptococcus equi subsp. zooepidemicus. Contipro a.s. uses the strain CO4A to produce hyaluronic acid in large scale. The production strain was obtained by random mutagenesis by UV light. The aim of the work was to study changes in the genome, which led to a significant increase in hyaluronic acid production, using DNA microarray and real-time PCR (qPCR). The genome of the strain CO4A was sequenced and compared to reference ATCC35246 [1]. The size of the genome is 2,167,251 bp and 83 relevant variants (59 SNV and 34 indels) have been identified. Variants in coding regions were annotated and amino acid sequence changes were determined. In SNV mutations there was a change in the amino acid sequence in 45 cases. The change was identified in every case of indel mutations. The expression level of selected groups of genes was monitored in both strains by the method of DNA microarrays. A cascade of increased expression level of amino sugar metabolism genes leading to the synthesis of UDP-N-acetyl glucosamine was observed in strain CO4A (the increase in expression level of these genes compared to ATCC35246 was on average 28 %). Subsequently, the expression of selected genes was verified by qPCR. There was no significant difference in the expression level of the has operon genes of both strains. The effect of supplementation of the culture medium with N-acetylglucosamine (GlcNAc), which is one of the precursors of HA synthesis, was also studied by qPCR. A positive effect of the supplementation of the culture medium with external GlcNAc in the CO4A strain has been recorded. Also, the supplementation has positive effect on the yield of HA from the medium (increase in yield was on average by 17 %). GlcNAc has been shown to have a positive effect on the yield of HA in ATCC35246 strain as well (increase in yield was 9 % on average), but no significant changes in the expression levels were found in selected groups of genes in ATCC35246.
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The relationship between splicing and posttranslational modifications of chromatin in Saccharomyces cerevisiae
Kovaľová, Libuša ; Folk, Petr (advisor) ; Čáp, Michal (referee)
Protein Prp45, the yeast ortholog of the human transcription coregulator SNW1/SKIP, has been previously associated only with the regulation of pre-mRNA splicing. However, our laboratory found that protein Prp45 genetically interacts not only with the proteins involved in pre-mRNA splicing, but also with factors important for transcription elongation and with chromatin modifying enzymes. Our data and the information about the human ortholog SNW1/SKIP suggest that Prp45 could serve as a regulator coupling splicing, transcription and chromatin state in S. cerevisiae. The main aim of this diploma thesis was to find out whether the protein Prp45, which is essential for cotranscriptional assembly of the spliceosome, affects posttranslational modifications of chromatin on transcribed genes. Using chromatin immunoprecipitation, the influence of prp45(1-169) mutation on trimethylation of histone H3 at lysine 4 and acetylation of histone H3 at lysines 9, 14 and 18 on transcriptionally active genes was not confirmed. The other aim was to analyse the behavior of cells synchronized by α-factor by using flow cytometry. According to our results, prp45(1-169) mutation leads to the prolongation of the cell cycle. For the purpose of monitoring the dynamics of nucleosomes in S. cerevisiae strains, the system of...
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Mechanism of inducible gene expression of resistance protein Vga(A)LC from Staphylococcus haemolyticus.
Novotná, Michaela ; Balíková Novotná, Gabriela (advisor) ; Lišková, Petra (referee)
The staphylococcal protein VgaA belongs to ARE ABCF family, which confers resistance to ribosome binding antibiotics by the target protection mechanism. VgaA confers resistance to lincosamides, streptogramins A and pleuromutilins and thus provides the so-called LSAP resistance phenotype. The expression of resistance genes often reduces fitness in the absence of an antibiotic, therefore the expression of resistance genes is often tightly controlled and triggered only in response to the presence of an antibiotic to which the protein confers resistance. The inducible expression has also been observed for the vgaA gene, nevertheless, its mechanism has not been elucidated. In the diploma thesis, it was shown that the vgaALC gene from Staphylococcus haemolyticus is regulated by ribosome-mediated attenuation. The mechanism is based on the detection of translation inhibitors via a ribosome translating a special regulatory open reading frame (uORF), which is part of an attenuator located in the 5' untranslated region of the mRNA. The vgaALC gene is regulated at the transcriptional level in response to LSAP antibiotics. Antibiotic specificity of induction is affected not only by the nature of the peptide encoded by uORF but also by the antibiotic specificity of the resistance protein. Fluorescence microscopy...
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Preparation and validation of a system for the study of regulation of gene expression of yeast linear cytoplasmic plasmids
Horáčková, Kamila ; Vopálenský, Václav (advisor) ; Čáp, Michal (referee)
There is currently very few information about the transaltion of linear cytoplasmatic plasmids occured in yeast cells Kluyveromyces lactis. However, there is a relatively well developer information about their transcription apparatus. A study of transkript linear plasmids revealed an atypical organization at the 5ʼ end. Those ends contain nontemplate polyadenylation and they are missing the N7 methylguanosine hat. Because of the presence of this structure, which is localized at 5ʼend of plasmids specific mRNA, raised a question regarding the iniciation of the translation. The present thesis is focused on the preparation of reporter systém suitable for studying the influence of a number of the nontemplate adenosins, which were added at the 5ʼ ends of mRNA linear plasmids. The frist step was making a construction of dual yeast cell plasmids carring two reporters genes, which are under the controle of two different promoters. After a successfull construction, the aktivity of promoters TEF1 and PGK1 was measured, whereby the promoter TEF1 proved twice stronger. The transcription start site of both promotor was determined. The second step was the construction of a reporter system directly in yeast cell plasmid pGKL. Reporter genes were under the controle of two promoters originating from the pGKL...
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Studying of Gene Expression Involved in Hyaluronic Acid Synthesis in Streptococcus Equi Subsp. Zooepidemicus Using DNA Microarrays and Real-Time PCR
Hrudíková, Radka ; Šeda,, Ondřej (referee) ; Bobek,, Jan (referee) ; Velebný, Vladimír (advisor)
Hyaluronic acid (HA) is an important substance, which is mostly used in pharmaceutical and cosmetic industry. This substance is commonly found in the human body. HA is one of the factors contributing to virulence of microorganisms. Some bacterial strains produce hyaluronic acid in the form of a mucoid capsule that encapsulates the cell to protect bacteria against the immune system of the host organism. One of the main producers is the bacterial strain Streptococcus equi subsp. zooepidemicus. Contipro a.s. uses the strain CO4A to produce hyaluronic acid in large scale. The production strain was obtained by random mutagenesis by UV light. The aim of the work was to study changes in the genome, which led to a significant increase in hyaluronic acid production, using DNA microarray and real-time PCR (qPCR). The genome of the strain CO4A was sequenced and compared to reference ATCC35246 [1]. The size of the genome is 2,167,251 bp and 83 relevant variants (59 SNV and 34 indels) have been identified. Variants in coding regions were annotated and amino acid sequence changes were determined. In SNV mutations there was a change in the amino acid sequence in 45 cases. The change was identified in every case of indel mutations. The expression level of selected groups of genes was monitored in both strains by the method of DNA microarrays. A cascade of increased expression level of amino sugar metabolism genes leading to the synthesis of UDP-N-acetyl glucosamine was observed in strain CO4A (the increase in expression level of these genes compared to ATCC35246 was on average 28 %). Subsequently, the expression of selected genes was verified by qPCR. There was no significant difference in the expression level of the has operon genes of both strains. The effect of supplementation of the culture medium with N-acetylglucosamine (GlcNAc), which is one of the precursors of HA synthesis, was also studied by qPCR. A positive effect of the supplementation of the culture medium with external GlcNAc in the CO4A strain has been recorded. Also, the supplementation has positive effect on the yield of HA from the medium (increase in yield was on average by 17 %). GlcNAc has been shown to have a positive effect on the yield of HA in ATCC35246 strain as well (increase in yield was 9 % on average), but no significant changes in the expression levels were found in selected groups of genes in ATCC35246.
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Polyomavirus minichromosome structure
Satratzemis, Christos ; Forstová, Jitka (advisor) ; Mělková, Zora (referee)
The polyomavirus genome is present in the host cell as circular double-stranded DNA associated with nucleosomes. Consequently, the expression of polyomavirus genes is affected by the location of nucleosomes on DNA and histone modifications. This thesis reviews the current state of knowledge regarding the polyomavirus minichromosome structure and the effects of nucleosome phasing and histone modifications on polyomaviral replication cycle. In addition, factors conditioning these phenomena are discussed. Drawing on available literature, neither nucleosome phasing nor histone modifications appear to be random. However, not all viral DNA molecules are identical in these respects. Processes such as early and late transcription, replication and encapsidation thus occur only within certain fractions of the set of DNA molecules
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Study of gene regulation of nucleoside transporters in BeWo cell line
Strachoňová, Šárka ; Červený, Lukáš (advisor) ; Pávek, Petr (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Šárka Strachoňová Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Studium of gene regulation of nucleoside transporters in BeWo cell line Nucleoside transporters (NTs) localized in syncytiotrophoblast control placental uptake of nucleosides. Dysregulation of NTs can disrupt nucleoside homeostasis with a negative consequences on placental and fetal development and can lead to a change in placental pharmacokinetics of nucleoside-derived drugs. Therefore, understanding the expression and function of NTs is necessary for effective and safe pharmacotherapy during pregnancy. The aim of this diploma thesis was to study the adenylate cyclase (AC) activated regulatory pathways of gene expression of concentrative nukleoside transporter 2 (CNT2). For this purpose, qRT-PCR and in vitro accumulation assays using the model substrate [3 H]-adenosine were employed. The human placental choriocarcinoma-derived BeWo cell line has been exposed to an AC activator, forskolin (50 µM), and/or inhibitors of AC/cAMP/PKA, AC/cAMP/MAPK (MEK1/2, p38 MAPK) signaling pathways, PKA inhibitor, KT 5720 (5 μM), an inhibitor of MEK1/2, U0126 (10 μM) and an inhibitor of p38 MAPK, SB202190 (10 μM). The...
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Study of gene regulation of nucleoside transporters in BeWo cell line
Strachoňová, Šárka ; Červený, Lukáš (advisor) ; Pávek, Petr (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Šárka Strachoňová Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Studium of gene regulation of nucleoside transporters in BeWo cell line Nucleoside transporters (NTs) localized in syncytiotrophoblast control placental uptake of nucleosides. Dysregulation of NTs can disrupt nucleoside homeostasis with a negative consequences on placental and fetal development and can lead to a change in placental pharmacokinetics of nucleoside-derived drugs. Therefore, understanding the expression and function of NTs is necessary for effective and safe pharmacotherapy during pregnancy. The aim of this diploma thesis was to study the adenylate cyclase (AC) activated regulatory pathways of gene expression of concentrative nukleoside transporter 2 (CNT2). For this purpose, qRT-PCR and in vitro accumulation assays using the model substrate [3 H]-adenosine were employed. The human placental choriocarcinoma-derived BeWo cell line has been exposed to an AC activator, forskolin (50 µM), and/or inhibitors of AC/cAMP/PKA, AC/cAMP/MAPK (MEK1/2, p38 MAPK) signaling pathways, PKA inhibitor, KT 5720 (5 μM), an inhibitor of MEK1/2, U0126 (10 μM) and an inhibitor of p38 MAPK, SB202190 (10 μM). The...
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Changes of the intracellular redox state during virus infections
Kompas, Maroš ; Mělková, Zora (advisor) ; Trejbalová, Kateřina (referee)
Viruses are infectious agens, which cause disruption of a host cellular redox homeostasis. This effect is mediated by cellular defense machinery or via viral gene products. In order to restore cellular redox enviroment, activation of cellular adaptive response takes place. That is mediated by transcription factor Nrf2, which leads to upregulation of gene expression of antioxidant enzymes. Under suboptimal redox condition, or by detecting foreign nucleic acid, redox sensitive transcription factor Nf-κB is also being activated, what leads to expresion of proteins mediating cellular imunne responses. It is important to remember that these proteins might show malignant effects to surrounding tissues during long term inflammations. With respect to that, viruses have evolved mechanisms, through which they are able to overcome or hijack these pathways, in order to propagate the infection. Key words: intracellular redox state, ROS, RNS, oxidative stress, antioxidant enzymes, regulation of gene expression, virus infections
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The relationship between splicing and posttranslational modifications of chromatin in Saccharomyces cerevisiae
Kovaľová, Libuša ; Folk, Petr (advisor) ; Čáp, Michal (referee)
Protein Prp45, the yeast ortholog of the human transcription coregulator SNW1/SKIP, has been previously associated only with the regulation of pre-mRNA splicing. However, our laboratory found that protein Prp45 genetically interacts not only with the proteins involved in pre-mRNA splicing, but also with factors important for transcription elongation and with chromatin modifying enzymes. Our data and the information about the human ortholog SNW1/SKIP suggest that Prp45 could serve as a regulator coupling splicing, transcription and chromatin state in S. cerevisiae. The main aim of this diploma thesis was to find out whether the protein Prp45, which is essential for cotranscriptional assembly of the spliceosome, affects posttranslational modifications of chromatin on transcribed genes. Using chromatin immunoprecipitation, the influence of prp45(1-169) mutation on trimethylation of histone H3 at lysine 4 and acetylation of histone H3 at lysines 9, 14 and 18 on transcriptionally active genes was not confirmed. The other aim was to analyse the behavior of cells synchronized by α-factor by using flow cytometry. According to our results, prp45(1-169) mutation leads to the prolongation of the cell cycle. For the purpose of monitoring the dynamics of nucleosomes in S. cerevisiae strains, the system of...
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