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Eukaryotic translation initiation factor 3 and its role in plant translation regulation
Raabe, Karel ; Michailidis, Christos (advisor) ; Retzer, Katarzyna (referee)
After transcription, mRNA translation is another highly regulated process in gene expression. In plants, translation regulation plays an important role during progamic phase, fertilization and seed development, where synthesized transcripts are stored and selectively translated later in development. Translation regulation is also broadly used in stress responses as a fast and flexible tool to change gene expression; therefore, it plays an essential role in the survival strategy of sessile organisms like plants. Both regulation of the global translational rate as well as selective regulation of specific transcripts modulate the final gene expression response. Most of the regulatory mechanisms are concentrated in the stage of initiation, which is facilitated by several translation initiation factors. Eukaryotic translation initiation factor 3 (eIF3) is the largest and most complex of these factors, consisting of 12 conserved subunits. Its key function in the initiation is to scaffold the formation of the translation initiation complex and in the scanning mechanism accuracy. In past decades, additional eIF3 functions were discovered acting upon the whole translation cycle, including its importance in global and specific translation regulation. The aim of this work is to review eIF3 functions and to...
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5' end modification of bacterial RNA
Pinkas, Daniel ; Krásný, Libor (advisor) ; Schierová, Michaela (referee)
Regulation of gene expression is a key feature of all organisms and can occur at several levels ranging from transcription initiation to protein degradation. An important mechanism of this process is regulation of mRNA stability by various modifications. The best known modification is eukaryotic 7mG cap, which protects RNA from RNase degradation. Recently, several new prokaryotic modifications have been discovered thanks to advances in liquid chromatography and mass spectrometry methods. One such a modification is nicotinamide adenine dinucleotide at the 5' end of some RNA. Nicotinamide adenine dinucleotide is analogous to 7mG cap. This study describes this phenomenon in context of bacterial transcription. Powered by TCPDF (www.tcpdf.org)
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Transcription factors driving periodic gene expression during the fission yeast cell cycle
Jordáková, Anna ; Převorovský, Martin (advisor) ; Paleček, Jan (referee)
The fission yeast Schizosaccharomyces pombe plays an important role in elucidation of the mechanisms of cell cycle regulation and characterization of the relevant effector molecules involved. The cell cycle of S. pombe consists of a prolonged period of growth (G2 phase), which is followed by a nuclear division (M phase), a very short G1 phase and DNA replication (S phase). Already during S phase formation of division septum occurs. Cell cycle progression is regulated at multiple levels. Although the yeast S. pombe is an extensively studied model organism, knowledge of the transcriptional network regulating progression through the cell cycle is still incomplete. Transcription factors are very important regulators of gene expression and therefore their characterization is the subject of research. At the transcriptional level, several key transcription factors have been identified that regulate periodically oscillating and interdependent waves of gene expression during the cell cycle. This study summarizes the current state of knowledge in the field of the transcriptional regulation of periodic gene expression in the fission yeast cell cycle.
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Aptamers - binding and regulation abilities of RNA molecules
Oplová, Michaela ; Půta, František (advisor) ; Dzijak, Rastislav (referee)
Aptamers are single stranded ribo- or deoxyribonucleotides usually 20 to 80 nucleotides in length that occupy a complex three-dimensional structures by intramolecular interactions and bind to small target molecules with high affinity and specificity. Aptamers are generated in vitro using revolutionary technology SELEX (systematic evolution of ligand by exponential enrichment) and its modifications. They have recently attracted considerable attention of the scientific and medical community because of the fact that is possible to prepare aptamers binding practically any target molecule and this is making aptamers promising as diagnostic and therapeutic tools. Aptamers also exist naturally; aptamer domains have been found repeatedly as part of the regulatory elements of gene expression in bacteria, where they act as specific receptors for cellular metabolites. Domain TPP has been also found in plants, fungi and green algae.
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