Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik

Permanent URI for this collectionhttps://hdl.handle.net/11147/9

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Institution Author: search.filters.institutionAuthor.Ünlü, Ercan Selçuk

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Now showing 1 - 3 of 3
  • Article
    Citation - WoS: 20
    Citation - Scopus: 20
    Genome-Wide Identification of Genes That Play a Role in Boron Stress Response in Yeast
    (Elsevier Ltd., 2011) Uluışık, İrem; Kaya, Alaattin; Ünlü, Ercan Selçuk; Avşar, Kadir; Karakaya, Hüseyin Çağlar; Yalçın, Talat; Koç, Ahmet
    Boron is an essential micronutrient for plants and it is either necessary or beneficial for animals. Studies identified only few genes related to boron metabolism thus far and details of how boron is imported into cells and used in cell metabolism are largely unknown. In order to identify genes that play roles in boron metabolism, we screened the entire set of yeast haploid deletion mutants and identified 6 mutants that were resistant to toxic levels of boron, and 21 mutants that were highly sensitive to boron treatment. Furthermore, we performed a proteomic approach to identify additional proteins that are significantly up-regulated by boron treatment. Our results revealed many genes and pathways related to boron stress response and suggest a possible link between boron toxicity and translational control.
  • Article
    Citation - WoS: 59
    Citation - Scopus: 60
    Effects of Deleting Mitochondrial Antioxidant Genes on Life Span
    (John Wiley and Sons Inc., 2007) Ünlü, Ercan Selçuk; Koç, Ahmet
    Reactive oxygen species (ROS) damage biomolecules, accelerate aging, and shorten life span, whereas antioxidant enzymes mitigate these effects. Because mitochondria are a primary site of ROS generation and also a primary target of ROS attack, they have become a major focus area of aging studies. Here, we employed yeast genetics to identify mitochondrial antioxidant genes that are important for replicative life span. In our studies, it was found that among the known mitochondrial antioxidant genes (TTR1, CCD1, SOD1, GLO4, TRR2, TRX3, CCS1, SOD2, GRX5, PRX1), deletion of only three genes, SOD1 (Cu, Zn superoxide dismutase), SOD2 (Manganese-containing superoxide dismutase), and CCS1 (Copper chaperone), shortened the life span enormously. The life span decreased 40% for Δsod1 mutant, 72% for Δsod2 mutant, and 50% for Δccs1 mutant. Deletion of the other genes had little or no effect on life span.
  • Article
    Evidence for the Presence of a Second Electron Donor for the Cytoplasmic Thioredoxins in the Yeast Saccharomyces Cerevisiae
    (TUBITAK, 2006) Koç, Ahmet; Karakaya, Hüseyin Çağlar; Ünlü, Ercan Selçuk
    In yeast, the cytoplasmic thioredoxin system is composed of NADPH, thioredoxin reductase-1 (TRR1) and 2 thioredoxin genes (TRX1, TRX2). In this study, using yeast knockout mutants for TRR1, TRX1 and TRX2 genes, the role of the thioredoxin system in methionine sulfoxide reduction was investigated. Cells lacking both TRX1 and TRX2 genes simultaneously were not able to reduce methionine sulfoxides to methionine; however, mutants missing the TRR1 gene were able to reduce methionine sulfoxides to methionine, which showed that electrons could be transferred from NADPH to thioredoxins in the absence of TRR1. Similar results were observed for 3-phosphoadenosine 5-phosphosulfate reduction in the inorganic sulfate assimilation pathway. Results from both assays suggested that yeast cells have additional cytoplasmic thioredoxin reductase activity that could compensate for methionine sulfoxide reduction and sulfate assimilation in the absence of TRR1. This report also constitutes the first evidence that thioredoxins are the in vivo electron donors for methionine sulfoxide reductases in yeast.