Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik
Permanent URI for this collectionhttps://hdl.handle.net/11147/9
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Article Citation - WoS: 48Citation - Scopus: 52Boron Stress Activates the General Amino Acid Control Mechanism and Inhibits Protein Synthesis(Public Library of Science, 2011) Uluışık, İrem; Kaya, Alaattin; Fomenko, Dmitri E.; Karakaya, Hüseyin Çağlar; Carlson, Bradley A.; Gladyshev, Vadim N.; Koç, AhmetBoron is an essential micronutrient for plants, and it is beneficial for animals. However, at high concentrations boron is toxic to cells although the mechanism of this toxicity is not known. Atr1 has recently been identified as a boron efflux pump whose expression is upregulated in response to boron treatment. Here, we found that the expression of ATR1 is associated with expression of genes involved in amino acid biosynthesis. These mechanisms are strictly controlled by the transcription factor Gcn4 in response to boron treatment. Further analyses have shown that boron impaired protein synthesis by promoting phosphorylation of eIF2α in a Gcn2 kinase dependent manner. The uncharged tRNA binding domain (HisRS) of Gcn2 is necessary for the phosphorylation of eIF2α in the presence of boron. We postulate that boron exerts its toxic effect through activation of the general amino acid control system and inhibition of protein synthesis. Since the general amino acid control pathway is conserved among eukaryotes, this mechanism of boron toxicity may be of general importance.Article Citation - WoS: 7Citation - Scopus: 7The Roles of Thiol Oxidoreductases in Yeast Replicative Aging(Elsevier Ltd., 2010) Hacıoğlu, Elise; Esmer, Işıl; Fomenko, Dmitri E.; Gladyshev, Vadim N.; Koç, AhmetThiol-based redox reactions are involved in the regulation of a variety of biological functions, such as protection against oxidative stress, signal transduction and protein folding. Some proteins involved in redox regulation have been shown to modulate life span in organisms from yeast to mammals. To assess the role of thiol oxidoreductases in aging on a genome-wide scale, we analyzed the replicative life span of yeast cells lacking known and candidate thiol oxidoreductases. The data suggest the role of several pathways in controlling yeast replicative life span, including thioredoxin reduction, protein folding and degradation, peroxide reduction, PIP3 signaling, and ATP synthesis. © 2010 Elsevier Ireland Ltd.