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The Role of FBH1 in Maintenance of Genome Stability
Šimandlová, Jitka ; chevelev, Igor (advisor) ; Kratochvíl, Lukáš (referee)
The genome is constantly threatened by various damaging agents and maintaining its integrity is crucial for all organisms. Several repair pathways have been implicated in the removal of different types of lesions from DNA. Among them, homologous recombination (HR) plays a key role in repair of double-strand breaks. HR is a highly important repair mechanism which has to be tightly regulated to prevent excessive HR events. These events could interfere with other DNA repair pathways, generate toxic intermediates, or block the progression of the replication fork. Therefore, it is not surprising that cells have evolved mechanisms that counteract inappropriate HR events. As it has been shown recently, cells possess DNA helicases capable of preventing excessive recombination. A novel human DNA helicase, hFBH1, belonging to the superfamily I has been shown to function as pro- and anti- recombinase. Similar to the two members of RecQ family, BLM and RECQL5, FBH1 disrupts Rad51 from nucleofilament. However, FBH1 might also promote initiation of HR. The FBH1 helicase possesses additional high conserved F-box motif which allows it to act within a Skp1-Cullin-F-box, SCF, complex as ubiquitin ligase and target proteins for degradation.
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Studium funkce AtAFB4
Zelinka, Radim
Despite the fact, that research on apical dominance started before more than 100 years ago, this economically important phenomenon is not fully understood yet. One of the genes involved in this regulation in the model plant Pisum sativum is PsMS2, that was cloned recently and it came out i tis an ortholog of the auxin F-box receptor AtAFB4. The aim of this bachelor thesis was to prepare hybrids of the Arabidopsis mutant afb4 with plants expressing the GFP gene for green fluorescent protein fused to genes of the PIN family (1,2,3,4,7) under native promoters. T1 plans from all five crosses were test-ed preliminary using the selection gene for resistance to the herbicide sulphadiazine contained in the genome of male plants and more than 50 % of T1 plants from all lines survived without any symptoms of damage. In further cultivation of the surviving plants strong phenotype resembling the afb4 mutation of the male plants was observed in all plants. From the above-mentioned facts we can conclude that we have obtained hybrids bearing the intended genetic information. These prepared plants will be used in further studies on the influence of the afb4 mutation on the changes of PIN membrane transporters and further characteristics, like changes in auxin transport, reaction to exogenous application of auxin and strigolactone, etc.
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The Role of FBH1 in Maintenance of Genome Stability
Šimandlová, Jitka ; Kratochvíl, Lukáš (referee) ; chevelev, Igor (advisor)
The genome is constantly threatened by various damaging agents and maintaining its integrity is crucial for all organisms. Several repair pathways have been implicated in the removal of different types of lesions from DNA. Among them, homologous recombination (HR) plays a key role in repair of double-strand breaks. HR is a highly important repair mechanism which has to be tightly regulated to prevent excessive HR events. These events could interfere with other DNA repair pathways, generate toxic intermediates, or block the progression of the replication fork. Therefore, it is not surprising that cells have evolved mechanisms that counteract inappropriate HR events. As it has been shown recently, cells possess DNA helicases capable of preventing excessive recombination. A novel human DNA helicase, hFBH1, belonging to the superfamily I has been shown to function as pro- and anti- recombinase. Similar to the two members of RecQ family, BLM and RECQL5, FBH1 disrupts Rad51 from nucleofilament. However, FBH1 might also promote initiation of HR. The FBH1 helicase possesses additional high conserved F-box motif which allows it to act within a Skp1-Cullin-F-box, SCF, complex as ubiquitin ligase and target proteins for degradation.
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