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: 4
    Citation - Scopus: 3
    Boron Stress Signal Is Transmitted Through the Tor Pathway
    (Elsevier, 2023) Uluışık, İrem; Koç, Ahmet
    Although boron is an essential element for many organisms, an excess amount of it can cause toxicity, and the mechanism behind this toxicity is not yet fully understood. The Gcn4 transcription factor plays a crucial role in the boron stress response by directly activating the expression of the boron efflux pump Atr1. More than a dozen transcription factors and multiple cell signaling pathways have roles in regulating the Gcn4 transcription factor under various circumstances. However, it is unknown which pathways or factors mediate boron signaling to Gcn4. Using the yeast Saccharomyces cerevisiae as a model, we analyzed the factors that converge on the Gcn4 transcription factor to assess their possible roles in boron stress signaling. Our findings show that the GCN system is activated by uncharged tRNA stress in response to boron treatment and that GCN1, which plays a role in transferring uncharged tRNAs to Gcn2, is necessary for the kinase activity of Gcn2. The SNF and PKA pathways were not involved in mediating boron stress, even though they interact with Gcn4. Mutations in TOR pathway genes, such as GLN3 and TOR1, abolished Gcn4 and ATR1 activation in response to boric acid treatment. Therefore, our study suggests that the TOR pathway must be functional to form a proper response against boric acid stress.
  • Article
    Citation - WoS: 11
    Citation - Scopus: 14
    Proteomic Changes During Boron Tolerance in Barley (hordeum Vulgare) and the Role of Vacuolar Proton-Translocating Atpase Subunit E
    (Türkiye Klinikleri Journal of Medical Sciences, 2011) Atik, Ahmet Emin; Bozdağ, Gönensin Ozan; Akıncı, Ersin; Kaya, Alaattin; Koç, Ahmet; Yalçın, Talat; Karakaya, Hüseyin Çağlar
    Boron is an essential micronutrient for plants and animals; however, it can be toxic when present at high concentrations. The purpose of this study was to understand the mechanisms of boron tolerance in the Turkish barley (Hordeum vulgare) Anadolu cultivar. For this purpose, 2-dimensional electrophoresis (2-DE) was used to screen differentially expressed proteins for both control and boron-stressed Anadolu barley genotypes. Seven proteins were revealed by 2-DE: 1) ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCo large chain), 2) TLP5, a thaumatin-like protein, 3) PR5, a basic pathogenesis-related protein, 4) a RNase S-like protein, 5) a PSI type III chlorophyll a/b-binding protein, 6) a light-harvesting complex I LHC I, and 7) the vacuolar proton-translocating ATPase subunit E protein. These were found to be upregulated in response to boron treatment. Even though the protein encoded by the V-ATPase subunit E gene was overexpressed, its transcript level was downregulated by boron treatment. Heterologous expression of the barley V-ATPase subunit E gene in yeast provided boron resistance to yeast cells. These results indicated that the V-ATPase subunit E gene was functional and conferred tolerance to toxic boron levels in yeast and might play a role in the overall boron tolerance of barley. © TÜBITAK.