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Following the Arp2/3-based processes in plant cells
Fišerová, Jindřiška ; Opatrný, Zdeněk (advisor) ; Binarová, Pavla (referee) ; Dráber, Pavel (referee)
1. ABSTRACT An actin cytoskeleton comprises an essential cytoskeletal structure that organizes a cytoplasm during number of processes occurring in animal and plant cells, such as cell division and growth, formation of membrane protrusions and cellular movement or cytoplasmic streaming. A dynamic actin net and an exact spatial and temporal actin filament organization is, therefore, necessary for correct growth processes and development of multicellular organism. Depolymerization and re-establishment of actin arrays is mediated by actin associated proteins. Among them, an Arp2/3 complex (actin related protein 2 and 3) plays an important role as a catalyst of the actin filament nucleation and, thus, enables the formation of dynamic actin network. In non-plant cells, Arp2/3 complex-dependent polymerization of actin filaments is required for movement of whole cells (fibroblasts or keratocytes), it drives organels and pathogens throughout the cell or mediates endocytic processes. The role of the Arp2/3 complex in non-motile plant cells is despite the considerable effort over last three years far from being understood. Unlike animals, where loss-of-function mutations in the Arp2/3 complex are lethal, only limited number of cell types show significant phenotype in Arabidopsis mutants. The evidence exists that the...
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Nuclear transport: its regulation and role in plant cells
Bokvaj, Pavel ; Schwarzerová, Kateřina (advisor) ; Fišerová, Jindřiška (referee)
The nucleocytoplasmic transport represents a crucial checkpoint of all signal pathways leading to the gene expression, the cell cycle maintenance, and RNA export processes. It is mediated by nuclear pore complexes (NPC) anchored in double nuclear membrane. The NPC structure and the basic architecture of the transport regulations are evolutionarily highly conserved across eukaryotic kingdoms; however, some significant differences and specifics exist in plants. In this thesis, I describe the contemporary level of our knowledge of the nucleocytoplasmic transport regulation and its actors in animalia generally and in planta in detail.
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Regulation of HOX genes expression in hematopoesis and leukemogenesis
Rejlová, Kateřina ; Starková, Júlia (advisor) ; Machová Poláková, Kateřina (referee) ; Fišerová, Jindřiška (referee)
HOX gene expression is tightly regulated during hematopoiesis and it is gradually decreased during the differentiation of hematopoietic cells. By contrast in case of leukemic blasts the expression of HOX genes is often disrupted and dysregulated. Especially in acute myeloid leukemia (AML) different expression of HOX genes was described between different subtypes classified according to cytogenetics and molecular genetics. In this study, the cohort of childhood AML patients were screened for HOX gene expression and based on these valuesdivided into five clusters using unsupervised hierarchical clustering characterized mainly by presence or absence of the typical molecular aberrations. HOX gene expression was also tested in the healthy counterpart of hematologic cells equivalent to the particular morphological stages of leukemic cells. Based on these results, HOX gene expression directly or indirectly participate in leukemogenesis and it not only copies the developmental/morphological stage in which the hematopoietic cell was stopped during differentiation. It this thesis/study it was concluded that the HOX gene expression is dependent on the presence of specific molecular aberration. In the second part of our study, we investigated the HOX gene transcription regulation in AML patients with PML-RARα...
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Following the Arp2/3-based processes in plant cells
Fišerová, Jindřiška ; Opatrný, Zdeněk (advisor) ; Binarová, Pavla (referee) ; Dráber, Pavel (referee)
1. ABSTRACT An actin cytoskeleton comprises an essential cytoskeletal structure that organizes a cytoplasm during number of processes occurring in animal and plant cells, such as cell division and growth, formation of membrane protrusions and cellular movement or cytoplasmic streaming. A dynamic actin net and an exact spatial and temporal actin filament organization is, therefore, necessary for correct growth processes and development of multicellular organism. Depolymerization and re-establishment of actin arrays is mediated by actin associated proteins. Among them, an Arp2/3 complex (actin related protein 2 and 3) plays an important role as a catalyst of the actin filament nucleation and, thus, enables the formation of dynamic actin network. In non-plant cells, Arp2/3 complex-dependent polymerization of actin filaments is required for movement of whole cells (fibroblasts or keratocytes), it drives organels and pathogens throughout the cell or mediates endocytic processes. The role of the Arp2/3 complex in non-motile plant cells is despite the considerable effort over last three years far from being understood. Unlike animals, where loss-of-function mutations in the Arp2/3 complex are lethal, only limited number of cell types show significant phenotype in Arabidopsis mutants. The evidence exists that the...
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Actin isoforms in the plant cell
Šlajcherová, Kateřina ; Schwarzerová, Kateřina (advisor) ; Fišerová, Jindřiška (referee)
The thesis deals with a question of redundancy in plant actin isotypes, especially in a case of Arabidopsis thaliana. Available proofs both confirm and disprove the redundancy of actin isotypes. Similarities and differences in gene structure are considered, as well as gene and protein sequence, expression, expression regulation and function. Despite conserved features as the gene structure, protein sequence, or higher similarity among ortologues than paralogues, there are differences in actin gene families such as the regulation of genes expression, the structure and function of non-coding sequences, or expression patterns. Moreover, actin isotypes divergetion times correlate with important events in plant evolution history. The thesis also deals with diverse functions of actin isotypes in plants. In addition, directions for future research are provided as well.
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Nuclear transport: its regulation and role in plant cells
Bokvaj, Pavel ; Fišerová, Jindřiška (referee) ; Schwarzerová, Kateřina (advisor)
The nucleocytoplasmic transport represents a crucial checkpoint of all signal pathways leading to the gene expression, the cell cycle maintenance, and RNA export processes. It is mediated by nuclear pore complexes (NPC) anchored in double nuclear membrane. The NPC structure and the basic architecture of the transport regulations are evolutionarily highly conserved across eukaryotic kingdoms; however, some significant differences and specifics exist in plants. In this thesis, I describe the contemporary level of our knowledge of the nucleocytoplasmic transport regulation and its actors in animalia generally and in planta in detail.
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