Mayada çeşitli farklılaşma sinyallerinin TPS1 ve NTH1 genleri transkripsiyonuna etkilerinin araştırılması
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Date
2021-02-12
Authors
Peters, Thomas Saah
Journal Title
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Publisher
Bursa Uludağ Üniversitesi
Abstract
Saccharomyces cerevisiae, haploid veya diploid olarak bulunabilen tek hücreli ökaryotik bir organizmadır. Tek hücreli olmasına rağmen, bazı çevresel koşulların etkisi ile farklı gelişim süreçleri göstermektedir. Bu süreçler sporülasyon ve psödohifsel gelişmelerdir. Diploid mayalarda azot açlığının Ras2 membran proteini tarafından kontrol edildiği bilinmektedir. Azot açlığı durumunda aktif hale gelen Ras2 proteini, protein kinaz A yolu aracılığıyla, enzimleri ve transkripsiyon faktörlerini kodlayan çok sayıda genin aktivitesini değiştirmektedir. Sonuç olarak, diploid mayalar üreme şeklini değiştirmekte ve psödohifsel üremeye geçmektedir. Ras2 ve diğer bazı mutasyonlara sahip sigma suşu, haploid olsa dahi, pseudohif oluşturmaktadır. Trehaloz, S. cerevisiae için önemli bir disakkarittir ve depo karbonhidrattır. Stres koruma faktörü olmakla birlikte hücreye glikoz girişini kontrol etmektedir. TPS1 ve − genleri de trehaloz metabolizmasında biyosentez ve katabolizmada işlev gören enzimleri kodlamaktadır. Bu tez çalışmasında, S. cerevisiae'de görülen apoptoz, otofaji, pseudohifsel gelişim gibi farklı hücresel süreçlerinin TPS1 ve NTH1 genlerinin transkripsiyonu üzerine etkileri araştırıldı. Farklı genetik özelliklere sahip suşlara transforme edilen TPS1-LacZ ve NTH1-LacZ gen füzyonlarının transkripsiyon seviyeleri β-galaktozidaz enzim tayin methoduyla belirlendi. Apoptoz koşulları aktive edildiğinde TPS1 ve NTH1 gen ekspresyonunun 2 kat baskıladığı görüldü. Ancak, otofaji koşullarının aktive edilmesi ile hem TPS1 ve hem de NTH1 geni trasnkripsiyonunda farklı seviyelerde aktivasyon olduğu bulundu. Diploid maya hücresinde sporulasyon aktivasyonunda NTH1 geni transkripsiyonunda önemli bir azalma olduğu tayin edildi. NTH1 ve TPS1 gen transkripsiyonlarının S. cerevisiae’nın farklı hücresel gelişim veya farklılaşma süreçlerinden farklı şekillerde etkilendiği görülmektedir.
Saccharomyces cerevisiae is a unicellular eukaryotic organism that can be found as haploid or diploid. Although it has a single cell, it shows different developmental processes under the influence of some environmental conditions. These processes are sporulation and pseudohyphal developments. It is known that nitrogen starvation in diploid yeasts is controlled by the Ras2 membrane protein. The Ras2 protein, which is activated in nitrogen starvation, changes the activity of many genes encoding enzymes and transcription factors through the protein kinase A pathway. As a result, diploid yeasts change their growth pattern and pass on to pseudohyphal reproduction. Sigma strain with ras2 and some other mutations produces pseudohyphae even though it is haploid. Trehalose is an important disaccharide and storage carbohydrate for S.cerevisiae. Although it is a stress protection factor, it controls the entry of glucose into the cell. TPS1 and NTH1 genes also encode enzymes that function in biosynthesis and catabolism in trehalose metabolism. In this thesis study, the effects of different cellular processes such as apoptosis, autophagy, pseudohyphal development seen in S. cerevisiae on the transcription of TPS1 and NTH1 genes were investigated. The transcription levels of TPS1-LacZ and NTH1-LacZ gene fusions transformed into strains with different genetic characteristics were determined by the β-galactosidase enzyme assay method. When the apoptosis conditions were activated, it was observed that TPS1 and NTH1 gene expression was suppressed 2-fold. However, different levels of activation were found in both TPS1 and NTH1 gene transcription by activating autophagy conditions. A significant decrease in NTH1 gene transcription in sporulation activation in diploid yeast cell was determined. It is seen that NTH1 and TPS1 gene transcriptions are affected differently by different cellular development or differentiation processes of S. cerevisiae.
Saccharomyces cerevisiae is a unicellular eukaryotic organism that can be found as haploid or diploid. Although it has a single cell, it shows different developmental processes under the influence of some environmental conditions. These processes are sporulation and pseudohyphal developments. It is known that nitrogen starvation in diploid yeasts is controlled by the Ras2 membrane protein. The Ras2 protein, which is activated in nitrogen starvation, changes the activity of many genes encoding enzymes and transcription factors through the protein kinase A pathway. As a result, diploid yeasts change their growth pattern and pass on to pseudohyphal reproduction. Sigma strain with ras2 and some other mutations produces pseudohyphae even though it is haploid. Trehalose is an important disaccharide and storage carbohydrate for S.cerevisiae. Although it is a stress protection factor, it controls the entry of glucose into the cell. TPS1 and NTH1 genes also encode enzymes that function in biosynthesis and catabolism in trehalose metabolism. In this thesis study, the effects of different cellular processes such as apoptosis, autophagy, pseudohyphal development seen in S. cerevisiae on the transcription of TPS1 and NTH1 genes were investigated. The transcription levels of TPS1-LacZ and NTH1-LacZ gene fusions transformed into strains with different genetic characteristics were determined by the β-galactosidase enzyme assay method. When the apoptosis conditions were activated, it was observed that TPS1 and NTH1 gene expression was suppressed 2-fold. However, different levels of activation were found in both TPS1 and NTH1 gene transcription by activating autophagy conditions. A significant decrease in NTH1 gene transcription in sporulation activation in diploid yeast cell was determined. It is seen that NTH1 and TPS1 gene transcriptions are affected differently by different cellular development or differentiation processes of S. cerevisiae.
Description
Keywords
Apoptoz, Maya, Otofaji, Transkripsiyon, Trehaloz, Apoptosis, Autophagy, Trehalose, Transcription, Yeast
Citation
Peters, T. S. (2021). Mayada çeşitli farklılaşma sinyallerinin TPS1 ve NTH1 genleri transkripsiyonuna etkilerinin araştırılması. Yayınlanmamış yüksek lisans tezi. Bursa Uludağ Üniversitesi Fen Bilimleri Enstitüsü.