Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Identification of Mitochondrial Electron Transport Chain Mutations That Effect Ageing(Izmir Institute of Technology, 2009) Hacıoğlu, Elise; Koç, Ahmet; Koç, Ahmet; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyAging can be defined as the loss of cell functionality by accumulation of deleterious effects. Mitochondrial electron transport chain (ETC) is the main site for reactive oxygen species (ROS) production. According to free radical theory of aging, free radicals produced by normal aerobic respiration accumulate by time and can cause aging. Although previous studies have identified that inner mitochondrial membrane complexes I and III are the major sites of ROS production, role of ETC genes in ROS production is a matter of debate. The purpose of the present study was to determine the ETC mutations that affect aging using S.cerevisiae as a model organism. Deletion mutants of S.cerevisiae lacking 73 genes of ETC were analyzed aging and we found out that nine mutants caused reduction in replicative lifespan. In addition to aging profiles, ROS production levels, respiratory competence and oxidative stress tolerance level of these deletion strains were also investigated. In order to verify lifespan modulation by these genes, they were all overexpressed in wild-type cells and aging profile of these cells was analyzed. Most of the cells lived longer than wild type control cells containing sham vector. Our results suggest that some of the ETC genes play important roles in mitochondrial functions and aging. We hope that our results will contribute to the field of aging studies.Master Thesis Characterization of Connexin 26 Mutations Causing Hereditary Skin Disorders(Izmir Institute of Technology, 2013) Meşe Özçivici, Gülistan; Meşe Özçivici, Gülistan; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyConnexins (Cx) are building blocks of gap junctions that provide intercellular communication between adjacent cells. There exist 21 types of connexins in human body which are important for human physiology. Hence, in any case of deficiency or mutation, disorders can occur. For instance, most of the characterized Cx26 mutations are related to deafness; while there are few mutations associated with different skin disorders. One of them is a rare congenital skin disorder; Keratitis- Ichthyosis-Deafness (KID) syndrome. In this study, we aimed to investigate the effects of Cx26 mutations associated with KID syndrome in two gap junctional communication-deficient cell lines; mouse neuroblastoma (N2A) and human cervix carcinoma (HeLa), and also in human keratinocytes (HaCaT). For this purpose, newly identified KID syndrome mutations, A88V, D50A, D50Y, and I30N were characterized. Studies on N2A cells demonstrated that Cx26 mRNA levels of mutants were higher than Cx26 WT, whereas their protein expression were very low compared to Cx26 WT. Moreover, in HeLa cells, mutant proteins were observed to be localized mainly in the cytoplasm. Furthermore, the uptake of fluorescent dyes into the cells through the mutant hemichannels was statistically higher than Cx26 WT hemichannels. For HaCaT cells, mutant proteins did not have any effect on Keratin 10 expression, a marker for suprabasal layers of epidermis. In conclusion, all four mutations caused increased hemichannel activity similar to other analyzed KID syndrome mutations, which provides a further support for the presence of increased hemichannel activity as a mechanism for mutations leading to KID syndrome.