|
|
Role of TCTP1 in plant reproduction
Pitoňak, Oliver ; Hafidh, Said (advisor) ; Lafon Placette, Clément (referee)
TCTP is a conserved eukaryotic protein involved in regulation of multiple cellular processes, such as translation, cell cycle and cell death. Apart from its intracellular functions, TCTP is secreted and participates in human immune response. Dimerization via a terminal cysteine residue is critical for its extracellular function. Multiple sequence alignment of eukaryotic TCTPs revealed that terminal cysteine residue is conserved not only in animals but also in green plant lineage. In contrast to animal model organisms, knowledge about TCTP in plants is limited. Arabidopsis thaliana genome harbors two TCTP paralogs, TCTP1 and TCTP2. TCTP1 expression is highly upregulated in pollen. Previously published studies pointed to its role in embryo development, pollen tube growth and targeting. Using mutant characterization and analysis of subcellular localization, the role of TCTP1 in plant reproduction was investigated in this thesis. Recombinant Arabidopsis thaliana TCTP1 protein was produced along with its potential interacting partners BRL2 and TTL3 in heterologous Escherichia coli system. tctp-1 T- DNA line characterization pointed to TCTP1 role in pollen tube growth. It was expressed in mature pollen and pollen tube under native promoter and localized to the cytoplasm. Recombinant AtTCTP1 formed dimers...
|
|
|
Functional characterization of Alba-family genes in Arabidopsis thaliana
Kočová, Helena ; Honys, David (advisor) ; Fischer, Lukáš (referee)
(anglicky) Alba-family proteins were identified in Archaea and Eucarya and are classified among the oldest and the most conserved nucleic acid-binding proteins. The binding preferences and roles differ among certain evolution clades. In Crenarchaea they represent chromatin-binding proteins, while their role in RNA metabolism is suggested in Euryarchaea and Eukaryotes. ALBA proteins are well characterized in human, where they play a role in the RNAse P/MRP complex and in unicellular parasites, such as Plasmodium and Trypanosoma, where an involvement in the life cycle regulation is confirmed. In plants, their role is not yet well understood. The aim of this thesis is to increase a knowledge about the Alba-family proteins in the model plant Arabidopsis thaliana. Based on a minimal changes to development and reproduction in single mutants and high sequence similarity, a functional redundancy of the proteins was assumed. For better understanding of the ALBA proteins function, three smaller members of the family were edited by the same metod. The obtained triple mutant showed delay in flowering. ALBA dimer formation was confirmed in many organisms. BiFC method was used to determine Arabidopsis ALBA homodimerization. The data analysis showed potential homodimerization in most of them.
|
|
| |
|
|
Characterization of the PTEN domain of selected Arabidopsis class II formins
Přerostová, Sylva ; Cvrčková, Fatima (advisor) ; Havelková, Lenka (referee)
Formins are proteins facilitating formation of actin filaments. They affect structure of cytoskeleton and participate in cytokinesis and tip growth. There are 2 classes of formins in Arabidopsis thaliana, which include FH1 and FH2 (Formin Homology 1 and 2) domain. Formins of the class I have usually a transmembrane domain on N-terminus. Due to this fact they can interact with membranes. Some formins from the class II include PTEN domain (Phosphatase and Tensin Homolog) derived from sequences of PTEN proteins which has lost the function of phosphatase. It is assumed this domain can bind on a membrane via the phosphatase section or C2 domain. This thesis was focused on the formin AtFH13 from the class II in Arabidopsis thaliana and on its PTEN domain. There were analyzed differences between mutants and wild-types in length of roots in seedlings and in size of seeds and seed coats, and observed the effect of dexamethasone on the length of roots on AtFH13. PTEN domain of the formin was isolated from cDNA, cloned to a vector and fused with YFP. The tagged protein was visualized by the method of transient expression in epidermal cells in the leaves of Nicotiana benthamiana. No big differences were observed between plants mutant in the gene AtFH13 and wild-type in choice parameters. Dexamethasone did't influence...
|
guest ::
