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Role of DD- and DED-containing adaptor proteins in apoptotic signaling
Čaja, Fabián ; Anděra, Ladislav (advisor) ; Janštová, Vanda (referee)
Proteins containing a bundle of six anti-paralel α-helices in so-called "death domain" (DD) and similar structures (DED, CARD) represent important players in apoptotic signaling. To DD/DED/CARD domains-containing proteins belong pro- apoptotic membrane receptors from the TNFR superfamily, then adaptor proteins and enzymes as proteases or kinases. These pro-apoptotic "death receptors" interact with adaptor proteins and initiator caspases containing DDs or DEDs and activate apoptotic signaling cascade. DEDs and DDs are in addition found in many proteins participating in activation of caspases or other non-apoptotic signaling. Many experimental models document that defects in and deregulations of proteins containing DDs and DEDs can have severe if not lethal consequences for an organism. Abberations in these proteins in many cases could lead to cancerogenesis, immunodeficiencies or developmental defects.
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Preparation of strategy for studying interaction of human constitutive androstane receptor with steroid receptor coactivator-1
Šachová, Ivana ; Martin, Jan (advisor) ; Mladěnka, Přemysl (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy Candidate: Ivana Šachová Supervisors: PharmDr. Jan Martin, PhD., Dipl. Ing. Mgr. Ferdinand Molnár, PhD. Title of diploma thesis: Preparation of strategy for studying interaction of human constitutive androstane receptor with steroid receptor coactivator-1 The aim of this study was to express wild type and mutated synthetic human SRC1 central domains in E. coli BL21 DE3 cells. Expressed recombinant proteins were purified afterwards and used for investigation of SRC1-CAR protein interaction using pull down experiments. The constitutive androstane receptor (CAR), a nuclear receptor (NR), is a transcriptional regulator, which influences the expression of various proteins, such as enzymes of biotransformation and transporters important for metabolism of both endogenous and exogenous compounds. CAR can be fully active only in presence of coactivators, such as steroid receptor coactivator-1 (SRC1). The most important fragment of SRC1 for binding to NRs is the central domain, made of three α-helical Leu-X-X-Leu-Leu (LXXLL) L1, L2, L3 motifs, in where L is a leucine and X represents any amino acid. hSRC1, as well as hCAR, can be successfully produced by expression of cDNA of interest in E. coli strains. In case of SRC1,...
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Analogues of IGF-1 for the study of interactions of the hormone with the receptors for IGF-1 and insulin
Macháčková, Kateřina ; Jiráček, Jiří (advisor) ; Obšilová, Veronika (referee) ; Šulc, Miroslav (referee)
Insulin/IGF system is a complex network of three similar hormones (insulin, IGF-1 and IGF-2) and their three similar receptors (IR-A, IR-B and IGF-1R,), which play important roles in maintaining basal energy homeostasis of the organism, in growth, development, life-span but also in development of diseases such as diabetes mellitus, cancer, acromegaly or Laron dwarfism. Despite structural similarities between family members, each member have its unique role in the system. Identification of structural determinants in insulin and IGFs that trigger their specific signalling pathways is important for rational drug design for safer treatment of diabetes or for more efficient combating of cancer or growth-related disorders. In this thesis, we focused on identification of such structural determinants in IGF-1. Comparison of our data with parallel studies with IGF-2 and insulin could give a more complex picture of the problem. First of all, we developed necessary methodologies for the preparation of IGF-1 analogues. We developed a new methodology for the total chemical synthesis of IGF-1 analogues based on the solid-phase synthesis of fragments and their ligation by a CuI -catalyzed cycloaddition of azides and alkynes. In parallel, we developed a procedure for a recombinant production of IGF- 1 and its...
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Study of structure and interaction of human lymphocyte receptors
Bláha, Jan ; Vaněk, Ondřej (advisor) ; Šulc, Miroslav (referee) ; Obšil, Tomáš (referee)
Natural killer (NK) cells are an essential part of immune system, providing self-surveillance of virally infected, stress transformed or cancerous cells. NKR-P1 receptors and their ligands from clec2 gene family represent an alternate missing-self recognition system of NK cells based on interaction of highly related C-type lectin-like receptors. Human NKR-P1 has been described more than twenty years ago but still remains the sole human orthologue of this receptor family, particularly numerous in rodents. On binding to its cognate ligand LLT1, NKR-P1 can relay inhibitory or co-stimulatory signals. Although being interesting targets for their potential role in tumor immune evasion and autoimmunity, nature of their interaction is still unclear. To elucidate the architecture of their interaction, we developed a generally applicable method for recombinant expression of human NKR-P1 and LLT1 and their homologues based on transfection of HEK293S GnTI- cells. Further, we described a stabilizing mutation His176Cys, that enables for expression of highly stable and soluble LLT1. Finally, we have crystallized LLT1 and human NKR-P1 in different glycosylation states both as individuals and in complex. While both structures of LLT1 and NKR-P1 follow the classical C-type lectin-like superfamily fold, contrary to...
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Interaction of retroviral env glycoproteins with receptors and virus entry into the cell
Přikryl, David ; Pečenka, Vladimír (advisor) ; Horníková, Lenka (referee)
Humankind has adjusted many animals, plants and bacteria to serve their needs. Now the time has come to exploit also viruses. The most significant applications for them seem to lie in the sphere of human health. Particularly the family of retroviruses represent a perfekt vectors for gene delivery to cure genetic diseases or to destroy undesirable, e.g. cancer cells. In order to efficiently use these vehicles, a series of problems must be overcome and some segments of retroviral life cycle must be more deeply explored. This work describes some of them along with possible ways to solve them. The first described area is nonspecific adsorption of virions on the cell surface, the second is securing effective interaction between envelope glycoproteins and receptors highly specific for the targeted cell type and finally driven fusion of membranes. Key words: retrovirus, adsorption, env, receptor, phusion
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Structural biology of complex of rat NK cell receptors NKR-P1B and Clrb
Dvorská, Anna ; Vaněk, Ondřej (advisor) ; Ingr, Marek (referee)
The Natural Killer (NK) cells have an important role in the nonspecific immunity of the or- ganism. They have the ability to identify and to kill tumor cells and cells infected by a virus without preceding sensitization by antigen. Their function is directed by the amount of sti- mulation and inhibition receptors interacting with ligands on the tumor or infected cell. This thesis focuses on the preparation and the study of the complex of rat NK cellular inhi- bition receptor NKR-P1B ("natural killer cell receptor - protein 1B") and its ligand Clrb ("C-type lectin-related ligand b"). The Clrb initiates the inhibition of NKR-P1B, meaning that if the cell express Clrb, it won't be destroyed. If the cell gets infected by the rat cytome- galovirus, it loses Clrb from its surface and its destruction is therefore no longer prevented. Cells infected with this virus defend themselves from destruction by expression of the viral gene of C-type lectin RCTL, which is a homolog of Clrb. Transient transfection of human embryonic kidney 293 cell line with simple glycosylation (HEK293S GnTI− ) was used for the recombinant preparation of the soluble form of these two receptors of the rat NK cells. The native forms of the receptors - disulfidic homo- dimers - were prepared as the fusion construct with IgG Fc (using...
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Preparation of expression vectors for receptor NKp30 and its ligands B7-H6 and BAG-6
Pažický, Samuel ; Vaněk, Ondřej (advisor) ; Milichovský, Jan (referee)
NK cells, the cells of non-adaptive imune system, are able to recognise viraly infected or oncogenous cells by many inhibiting and activating receptors that are expressed on their surface and eliminate them consequently. For NKp30, activating receptor of NK cells included in NCR (Natural Killer Cell Receptors) family, lately there were identified several ligands, including membrane protein B7-H6 expressed on oncogenous cells surface and BAG- 6, cell core protein with wide spectrum of functions. Aim of this thesis was preparation of expression vectors coding for receptor NKp30 and his ligands B7-H6 and BAG-6, enabling expression of these proteins in HEK293 cell line. Keywords: NK cell, plasmid, receptor, NKp30, B7-H6, BAG-6
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Mechanisms of action of bisphenol A with emphasis on metabolism and fertility
Houška, Jakub ; Daňková, Pavlína (advisor) ; Novák, Jan (referee)
Bisphenol A is an endocrine disruptor, a chemical which is found in environment and also in water and food consumed by people and which disrupts endocrine system of humans and other organisms. Being endocrine disruptor it has a wide scale of negative effects on human health. I have attempted reviewing the molecular mechanism of its action with special respect to obesity and reproduction in this paper including interactions of bisphenol with specific receptors, its impact on enzyme synthesis and also on epigenetic mechanisms as DNA methylation or changes in miRNA expression. Possible ways of elimination of bisphenol A effects are examined in the end of this work. Keywords bisphenol A, molecular mechanisms, obesity, fertility, receptor, epigenetic mechanisms, elimination of effects
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Biophysical characterization of the CAR/RXR protein complex with its binding partners
Duchoslav, Vojtěch ; Bouřa, Evžen (advisor) ; Pavlíček, Jiří (referee)
The constitutive androstane receptor (CAR) plays an important role as a xenosensor in the organism and is therefore widely expressed in the kidney, liver, gallbladder and in the small intestine epithelium, where the biotransformation of xenobiotic occurs. CAR is also an important factor in the elimination of bile acids and bilirubin. CAR has also been shown to have an important role in regulation of glucose and lipid metabolism. Impairment of lipid and glucose metabolism is a common cause of cardiovascular and metabolic diseases such as atherosclerosis, type 2 diabetes, obesity and insulin resistance. These diseases are called metabolic syndrome and result in severe organ damage. CAR respective its complex with RXRα (retinoid X receptor α) has become a promising biological target for drug discovery for metabolic syndrome. The major aim of this study was a structural characterization of the CAR/RXRα protein complex together with the agonist IV676*HCl, which would describe in detail the interaction of this small molecule with the receptor. Obtained structural information would be used to design improved agonists.
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