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Pathophysiology of primary congenital and early-onset non-autoimmune hypothyroidism
Al Taji, Eva ; Lebl, Jan (advisor) ; Dvořáková, Marcela (referee) ; Jiskra, Jan (referee) ; Stárka, Luboslav (referee)
Background: Thyroid dysgenesis (TD) and thyroid dyshormonogenesis clinically manifest as permanent primary congenital hypothyroidism (CH) and only rarely as non-congenital, postnatal non-autoimmune hypothyroidism. As basic molecular events underlying the regulation of thyroid development, growth and function were clarified in the last decade, molecular pathogenesis of TD and dyshormonogenesis has been intensively studied. Candidate genes for TD and dyshormonogenesis had been described and their mutations were subsequently detected in several patients with non-syndromic and syndromic CH. Nevertheless, no systematic population-based phenotype-focused molecular genetic analysis had been performed and concerning TD, the data regarded only a few individual patients. Aim: The aim of this extensive study was to identify monogenic forms of TD and dyshormonogenesis in a population-based cohort of Czech patients mostly with CH. Systematic mutation screening was based on a detailed clinical information and phenotype description, and thus focused on clinically defined subgroups of patients matching the phenotypes of already known candidate gene mutations.
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The TUB3 intron splicing in PRP45 mutant cells
Konířová, Jana ; Půta, František (advisor) ; Zimmermannová, Olga (referee)
Protein Prp45, an essential factor of the yeast Saccharomyces cerevisiae, is implicated in pre-mRNA splicing. A truncated version of the PRP45 gene, prp45(1-169), which exhibits a temperature sensitivity, was previously prepared in our laboratory. The aim of this work is to contribute to better understanding of prp45(1-169) mutant phenotype. We tested the prp45(1-169) strain for its response to microtubule inhibitor benomyl and then we found that TUB3 overexpression from plasmid rescues discovered prp45(1-169) mutant cells hypersensitivity to benomyl. In addition, we studied the influence of TUB1, TUB3, and COF1 intron deletion on prp45(1-169) strain temperature sensitivity. Using RT-qPCR method we found that prp45(1-169) mutation results in the distinctive increase of pre-mRNA level for all tested genes, that could implicate that pre-mRNA splicing in these cells is affected before first transesterication.
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Characterization of membrane protein DREPP
Vosolsobě, Stanislav ; Schwarzerová, Kateřina (advisor) ; Cvrčková, Fatima (referee)
Proteins of DREPP family (20-25 kDa, syn. PCaP1 in Arabidopsis thaliana) first appeared in ferns and we have shown that several independent duplications of DREPP protein occurred during evolution of large families (Poaceae, Brassicaceae, Solanaceae and Asteraceae) and in group Coniferophyta. Secondary losses of one paralogue occurred in subfamilies Pooideae and Solanoideae.We have also detected two large-scale modification of DREEP protein in Asparagales and Brassicaceae (this divergent paralogue was previously described as MAP18 protein). We have examined colinearity of chromosome fragments in vicinity both PCaP1 and MAP18 paralogues in Arabidopsis thaliana and we hypothesize that MAP18 gene arose during genome duplication on the origin of Brassicaceae family. DREPP protein was previously identified in detergent-resistant membrane microdomain fraction and a myristyl anchor was shown to be necessary for their membrane localization. Membrane association was shown to be modified by the interaction of unique N-terminal domain with PtdInsPs, which was inhibited by binding of Ca-calmodulin (Nagasaki et al., 2008). The mutation of Gly2 by Ala in the myristilation site, or C-terminal GFP-fusion (GFP-DREPP), affect membrane association in Arabidopsis thaliana (Nagasaki et al., 2008). Several DREPP paralogues in...
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Molecular Genetic Analysis in Patients Suspected of Cryptic Rearrangements.
Šolc, Roman ; Hirschfeldová, Kateřina (advisor) ; Vícha, Aleš (referee)
Such chromosomal rearrangements, which cannot be detected by using of cytogenetic banding of metaphase chromosomes, i.e. chromosomes smaller than 3 - 5 Mb, and therefore modern molecular genetic methods are used to detect them, are called "cryptic rearrangements". Their important role in human pathology is more and more significant. By using of the multiplex ligation-probe dependent amplification method (MLPA) we examined a group of 50 probands with idiopathic mental retardation. A cryptic rearrangement was found at 8 probands (16 %), at 6 of them it was demonstrably causal. Then we examined a group of 40 probands suspected of gene SHOX pathology. A cryptic rearrangement was found at 17 probands (42.5 %) and at 8 of them it was demonstrably causal. Presence of small deletion founded isolated at 7 probands was verified in a population set, but without a positive result. An analysis of mutations was made too.
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HIV - 1 Protease: Insights into Drug Resistance Development
Grantz Šašková, Klára ; Konvalinka, Jan (advisor) ; Forstová, Jitka (referee) ; Dohnálek, Jan (referee) ; Schiffer, Celia (referee)
Amino acid changes within HIV protease or its substrate that decrease the susceptibility to protease inhibitors represent a highly complex issue still not yet fully understood. Various mechanisms by which this often complicated pattern of mutations influence drug binding needs to be analyzed on a molecular level by a series of methods including experiments with recombinant viruses, biochemical enzyme analysis, structural and thermodynamical studies or molecular dynamics. Each result may help to complete the overall picture of protease inhibitor resistance evolution and therefore contribute to the design of more powerful 3rd generation HIV/AIDS drugs. This thesis presents several analyses of HIV resistance development on molecular level. We have focused on the nelfinavir resistance pathway, lopinavir mutation score, emergence of amino acid insertions in HIV protease gene and their contribution to protease inhibitor resistance and finally we analyzed a highly mutated protease species isolated from patients failing darunavir therapy. Since we are able to accomplish a wide combination of techniques, we could explain and put together some pieces of viral evolution considering the final steps of HIV life cycle and also provide knowledge necessary for novel inhibitor design. Aims of the Project There were...
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Molecular- genetic analysis of the Thyroid carcinomas
Sýkorová, Vlasta ; Bendlová, Běla (advisor) ; Zamrazil, Václav (referee) ; Peterka, Miroslav (referee)
Introduction: Thyroid cancer represents more than 90% of endocrine tumors and its incidence, predominantly of papillary thyroid carcinoma (PTC), is still increasing in the Czech Republic. Several genetic changes are known, but thein impact to phenotype is still controversial. Aims: To study of the genetic causes (RET/PTC, BRAF and RAS alterations) and the role of RET polymorphisms in thyroid cancer (predominantly PTC), and to correlate genotype with phenotype. Subjects and Methods: Overall 234 PTC tissues, 8 poorly differentiated carcinomas, 3 anaplastic carcinomas, 23 medullary carcinomas, 6 follicular carcinomas and one follicular adenoma were analyzed. Samples of fresh frozen thyroid tissues, fine-needle aspiration biopsies and paraffin-embedded formalin-fixed tissue sections of patients with thyroid cancer and blood samples of healthy controls were used for analysis. The expression of RET/PTC rearrangements was detected on agarose gel. Five RET polymorphisms were analyzed using specific TaqMan probes. Detection of mutations in the BRAF gene and three RAS genes was performed by direct sequencing. Presence of alteration was correlated with clinicopathological parameters. Results: We found out that some RET polymophisms are associated with development of RET/PTC rearrangements in PTC and proved,...
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The role of Prp45p in mRNA expression and maturation
Abrhámová, Kateřina ; Půta, František (advisor) ; Pichová, Alena (referee) ; Janderová, Blanka (referee)
Prp45p of Saccharomyces cerevisiae and Snw1p of Schizosaccharomyces pombe are essential proteins, which share extensive homology with the mammalian transcription regulator and splicing factor SNW/SKIP. We have analyzed the essential function of these proteins in both yeasts and found a mutation (prp45(1-169)) that exhibited temperature sensitivity. The mutant strain harboring the corresponding chromosomal deletion shows temperature sensitive phenotype and hypersensitivity to cycloheximide, hydroxyurea, calcofluor white, and to microtubule inhibitors. At 30řC, the cells are often elongated, deformed, and larger than wt. After synchronization prp45(1-169) cells stop their growth with 2N DNA content at 37řC. We found that the temperature sensitivity is not overcome and the hypersensitivity to microtubule destabilizing drugs is only partially suppressed by the excision of intron from TUB1 gene. This distinguishes prp45(1-169) from those splicing factor's mutants that cause tubulin-dependent G2/M arrest, which can be relieved by the expression of intronless tub1. We performed analysis of splicing in vitro and found that splicing of optimal substrates is not impaired. We also compared the content and stability of RNA in wt-cells and in prp45(1-169) cells at variol temperatures using microarrays. The...
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Alterations of the oncogenic properties of tumor cell lines by modulating oncogene expression. Example of v-src transformed chicken cell lines
Kovářová, Denisa ; Hejnar, Jiří (advisor) ; Španielová, Hana (referee)
4 Alterations of the oncogenic properties of tumor cell lines by modulating oncogene expression. Example of v-src transformed chicken cell lines Abstract v-Src protein tyrosine kinase is the product of the transforming gene transduced by avian Rous sarcoma virus. In contrast to proto-oncogene c-src, v-src lacks the negative-regulatory C-terminal domain and consequently shows a higher level of activity and transforming ability. In addition, v-Src contains point mutations throughout its coding region that probably contribute to the high level of intrinsic kinase activity. Long terminal repeats (LTR) comprise strong promoter-enhancer sequences and ensure efficient expression of the v-src gene. v-Src protein has a strong transforming potential in vitro and induces tumor development and growth in vivo. Moreover, it is implicated in metastatic formation. In several cancer types the elevated c-Src kinase activity caused pleiotropic cellular responses inducing transformation and metastasis. The aim of this diploma work was to reveal the role of v-Src in mediating tumor and metastatic progression in chicken cell lines PR9692 and PR9692-E9. Despite the low propensity of the chicken cells to immortalization, comparatively high immoratlization efficiency was observed in cells from ex vivo tumours growing progressively...
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Structural-Functional Correlations of Hydroxymethylbilane synthase
Douděrová, Dana
Acute intermittent porphyria (AIP) is an autosomal dominantly inherited disorder, classified as acute hepatic porphyria. It is characterized by a deficiency of hydroxymethylbilane synthase (HMBS, EC 4.3.1.8), the third enzyme in heme biosynthesis. Clinical features include gastrointestinal, neurologic and cardiovascular symptoms, but the most common clinical presentation is abdominal pain caused by neurovisceral crises. The purpose of this study was first to perform molecular analysis of the AIP patients. Once a mutation is detected in a patient, molecular testing is offered to family members. In each affected family, this becomes an important tool for individualised medicine, allowing for careful drug prescription; in addition, it is very important for the asymptomatic carriers to be warned of precipitating factors, thus avoiding an acute attack. The proper DNA diagnostics can be achieved by a combination of a robust and effective pre-screening method and a confirmatory DNA sequencing step. We decided to establish a new generation pre-screening method, which will be highly sensitive and relatively time- and cost-effective. Our method of choice was high-resolution melting (HRM) analysis using the LightScanner instrument. Another important aspect of this project was to study the molecular...
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