|
|
Effectors of RAB GTPases and their role in plant secretion
Růžičková, Martina ; Hála, Michal (advisor) ; Motyka, Václav (referee) ; Klíma, Petr (referee)
Rab GTPases are small signaling molecules that play an important role in vesicle trafficking in eukaryotic cells. Correct signaling through small GTPases allows orchestration of vesicle transport among cellular organelles and also to the cell wall providing cell wall material for cell growth and elongation. Engagement of Rab GTPases in the regulation of endomembrane trafficking is one of the evolutionary conserved aspects of secretion regulation. The network of Rab GTPases interaction includes also various downstream effectors. One of them is the exocyst complex involved in vesicle docking at the plasma membrane. It is a complex composed of eight different subunits (Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70 and Exo84). Exocyst was discovered as Sec4p Rab GTPase effector in yeast and also data from animal models describe the Sec15 exocyst subunit as the Rab-interacting partner, but data from plants are missing. On the other hand, numerous studies identified exocyst role in tip growth of pollen tube and root hairs, seed coat formation, cell plate and cell wall formation, hypocotyl elongation, and importantly also PIN auxin efflux carriers recycling and polar auxin transport. There are two paralogues of SEC15 in the Arabidopsis genome, SEC15a and SEC15b, the previous one already shown to be...
|
|
|
The role of ARPC2 in plant cells
Šlajcherová, Kateřina ; Schwarzerová, Kateřina (advisor) ; Klíma, Petr (referee)
ARPC2 protein localization in a plant cell Kateřina Šlajcherová 1 Abstract Actin cytoskeleton is an ubiquitous structure which plays numerous irreplacable roles. Actin nucleation is, beside formins, performed by ARP2/3 complex (actin-related protein), comprising of seven subunits (ARP2, 3, C1-C5) and activated by protein SCAR/WAVE complex. ARP2/3 complex is attached to the membrane and branches existing microfilaments, apart from nucleating them de novo. ARP2/3 mutants in most organisms show severe defects. However, plant mutants exhibit only mild phenotype, for example, Arabidopsis thaliana ARPC2 mutant (dis2-1) has deformed trichomes and leaf epidermal cells, but its viability is not impaired. The aim of the thesis is to map ARPC2 localization within the cell and broaden our understanding of ARP2/3 complex role in plant cell morphogenesis. Tobacco ARPC2 (NtArpC2) subunit was visualized in Arabidopsis plants, using the GFP fusion protein as well as imunofluorescence and anti-ARPC2 antibody. Experiments were undertaken to collocalize the subunit with actin and microtubular cytoskeleton, with mitochondrions, endosomes and other membrane organelles. The specimens were observed in confocal and TIRF microscope. The GFP-NtARPC2 protein shows as motile dots; their movement, but not their existence, is dependent...
|
|
|
Closer analysis of gene trap line MGT180 and its candidate genes
Šnajdrová, Tereza ; Soukup, Aleš (advisor) ; Klíma, Petr (referee)
Root branching allows plants to explore rhizosphere, to gain efficiently water, mineral nutrients or enter in various biotic interactions. Initiation of lateral root formation is localized to pericycle cells, flanking the xylem poles of diarch vascular bundle in Arabidopsis thaliana. Right in these pericycle cells, there is the expression pattern of the gene trap line MGT180. In this theseis , I have provided the evidence that the expression pattern of MGT180 is related with AT-HOOK MOTIF CONTAINING NUCLEAR LOCALIZED18 (AHL18; At3g60870). AHL18 belongs to a gene family of 29 transcriptional factors of Arabidopsis. AHL18 has not been functionally characterized yet, the analysis of singlemutant ahl18 and some others revealed no significant phenotype. However, one of doublemutants, E15, showed a significant phenotype. This phenotype was evident mainly in the aboveground part of plants, and was not corresponding to any phenotype of AHL mutation described so far. There is a known redundancy among some AHL genes, confirmed by crossing of ahl18 and ahl28 leading to E15 plant. Translation phusion AHL18-mRUBY and AHL22-mRUBY under native promotors should reveal, where these two related proteins act, and if they fiction in autonomous manner or not. Key words Arabidopsis thaliana, lateral root, AHL, pericycle
|
|
| |
|
| |
|
|
Creation of GUI for optimization of electrical machines
Bártková, Tereza ; Klíma, Petr (referee) ; Knebl, Ladislav (advisor)
This work follows the development process of graphical user interface (GUI) spanning from choosing the right tools for implementation to the implementation itself. The purpose of the work was making the optimization program user-friendly by creating a communication layer between the optimization algorithm and the user and demonstrating its functions. First of all, the study of various programming languages and their toolkits regarding GUI programming was undertaken. Python was chosen because the original program is written in it, also software development in Python is probably the quickest one. Furthermore there are analyzed characteristics of this language and PyQt, which is a tool meant for GUI creation. The third chapter introduces very thoroughly the issues of electrical machines and their optimization. Introduction of these issues is followed by brief description of two optimization methods being used in electrical machines optimization. Following chapter introduces the actual machine under the optimization study, on which the final program was tested. Afterwards follows detailed description of application layout created in Qt Designer. New program structure enriched with graphical user interface is described and its functions are shown. Finally there is a guideline on how to use this program and the optimization is executed accordingly. Also, the results of the optimization are analyzed.
|
|
|
Flux switching electric machine
Szabó, Hugo ; Klíma, Petr (referee) ; Ondrůšek, Čestmír (advisor)
The goal of this thesis is to create a literature search about a rotating electrical machine with switching of magnetic flux, to explain its construction concept and its operating behavior, to create an initial concept of generator, calculate chosen construction with finite element method analysis and to compare analysis results with analytical design. To create a concept of the generator one of available designing procedures will be used.
|
|
|
High-speed outer rotor synchronous machine
Král, Radek ; Knebl, Ladislav (referee) ; Klíma, Petr (advisor)
The master thesis deals with the construction and design of a high-speed synchronous machine with an outer rotor. The thesis is organised into three main chapters. The first chapter deals with machine design theory as well as mechanical limits, which are significant for high speed machines. This chapter also provides examples of applications of these electrical machines. In the second chapter, the initial design of the machine is calculated analytically. This machine design is optimised and the third chapter of this work shows the results of simulations using the finite elements method, including the evaluation of these results.
|
|
| |
|
|
Skin effect in high-speed electrical machines.
Klíma, Petr ; Bárta, Jan (referee) ; Mach, Martin (advisor)
This master thesis deals with the suppression of the skin and proximity effects in high-speed machines. The first part summarizes the general knowledge of high-speed machines. The second part is devoted to the principle and possible suppression of consequences caused by skin and proximity effects. The third part shows the simulation results of models of a synchronous machine with permanent magnets. The results of these simulations reveal the consequences of skin and proximity effects. In addition, design measures are proposed to limit these and other undesirable phenomena to achieve the highest possible efficiency.
|
guest ::
RSS feed.