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Modulation of DNA Binding Affinity of Transcription Factors FOXO and p53 Through Protein-protein Interactions
Hofmanová, Adéla ; Obšil, Tomáš (advisor) ; Pavlíček, Jiří (referee)
5 Abstract The forkhead box "O" (FOXO) proteins are a subclass of the Forkhead family of transcription factors that play a critical role in a variety of cellular processes such as response to cellular stress, gluconeogenesis, cell cycle control, apoptosis, senescence, and repair of DNA damage. They are generally considered to be tumor suppressors. However, it has been shown that they can promote tumorigenesis and induce resistance to the chemotherapeutic agents. Despite many years of research into the biological role of FOXO proteins, a number of questions remain to be answered. For example, whether the slight structural differences observed in the otherwise highly homologous DNA-binding domains of individual FOXO transcription factors affect their DNA binding affinity. Furthermore, it is unclear how protein-protein interactions affect DNA binding affinity of FOXO proteins. Recent study has described the interaction of FOXO transcription factors with the p53 protein. Protein p53 is called the guardian of the genome due to its ability to mediate the response to acute DNA damage. The interaction of FOXO and p53 proteins appears to have a major effect on the DNA binding affinity of both these proteins. Based on this, DNA-binding domains of the human transcription factors FOXO1, FOXO3 and FOXO4 (FOXO1(144-270),...
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Experimental verification of in silico predicted protein binder to FOXO4 transcription factor and transcriptome analysis of bladder cancer
Tauš, Petr ; Drbal, Karel (advisor) ; Převorovský, Martin (referee)
This diploma thesis includes an experimental and a bioinformatic part. The two parts are linked together through the subject of transcription factors of 'forkhead box O' (FOXO) family. FOXO transcription factors have a key role in many cellular processes including cell cycle regulation, apoptosis and metabolism. For a long time, they have been considered strictly as the tumor-suppressors yet a growing number of evidence is pointing out to their pro-tumorigenic role. In consequence FOXO transcription factors are studied intensively as potential therapeutic targets in cancer. In the past decade, in silico prediction of protein-protein interactions has become popular in basic research as well as in drug development. Nonetheless, the predicted structures are still far from fitting to the expected behavior of the respective biomolecules. In the experimental part of this thesis, I verified the interaction of four in silico predicted protein binders based on naturally occurring PDZ domain with FOXO4 using microscale thermophoresis. Non-invasive bladder tumors represent a heterogeneous disease where reliable prediction of tumor aggressiveness is still lacking despite an intensive research. In the bioinformatic part of this thesis, I described the cellular composition of the tumor microenvironment and demonstrated...
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Experimental verification of in silico predicted protein binder to FOXO4 transcription factor and transcriptome analysis of bladder cancer
Tauš, Petr ; Drbal, Karel (advisor) ; Převorovský, Martin (referee)
This diploma thesis includes an experimental and a bioinformatic part. The two parts are linked together through the subject of transcription factors of 'forkhead box O' (FOXO) family. FOXO transcription factors have a key role in many cellular processes including cell cycle regulation, apoptosis and metabolism. For a long time, they have been considered strictly as the tumor-suppressors yet a growing number of evidence is pointing out to their pro-tumorigenic role. In consequence FOXO transcription factors are studied intensively as potential therapeutic targets in cancer. In the past decade, in silico prediction of protein-protein interactions has become popular in basic research as well as in drug development. Nonetheless, the predicted structures are still far from fitting to the expected behavior of the respective biomolecules. In the experimental part of this thesis, I verified the interaction of four in silico predicted protein binders based on naturally occurring PDZ domain with FOXO4 using microscale thermophoresis. Non-invasive bladder tumors represent a heterogeneous disease where reliable prediction of tumor aggressiveness is still lacking despite an intensive research. In the bioinformatic part of this thesis, I described the cellular composition of the tumor microenvironment and demonstrated...
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Úloha Mst1 / FoxO dráhy při indukci apoptosy
Lettlová, Sandra ; Bezouška, Karel (advisor) ; Liberda, Jiří (referee)
Vitamin E analogue -tocopheryl succinate (-TOS) from the group of mitocans, the drugs targeting mitochondria, is a selective inducer of apoptosis in various cancer cell types, which involves the accumulation of reactive oxygen species (ROS). It was found that ROS generation causes p53-independent upregulation of the pro-apoptotic protein Noxa that induces apoptosis by displacement of the BH3-only protein Bak from its inactive complex with the anti-apoptotic protein Mcl-1 to form a pore in outer mitochondrial membrane. Current research has demonstrated that generation of ROS causes activation of Mst1, a component of the Hippo pathway that presents a universal size-control mechanism in all metazoans, whose deregulation is linked to tumorigenesis. Treatment of Jurkat cells with - TOS revealed that activated Mst1 kinase phosphorylates the Forkhead box O1 (FoxO1) transcription factor that then translocates to the nucleus and activates transcription of genes important for apoptosis induction, including NOXA. This explains the p53 independent apoptosis induction and presents Mst1-FoxO1-Noxa as a new pathway involved in the process. Current research has also documented that activated Mst1 kinase controls the expression of the c-MYC oncogene and its target genes, whose products are involved in glucose...
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