Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik
Permanent URI for this collectionhttps://hdl.handle.net/11147/9
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Conference Object Jak/Stat Signalling Pathway Genes in the Regulation of Tyrosine Kinase Inhibitors Induced and Clinical Process in Chronic Myeloid Leukemia Patients(Elsevier, 2014) Kiraz, Yağmur; Kartal Yandım, Melis; Kozanoğlu, İlknur; Özdoğu, Hakan; Pişkin, I.; Özcan, Mehmet Ali; Saydam, Göksel; Şahin, Fahri; Avcu, Ferit; Ural, Ali Uğur; Ünal, Ali; Baran, Yusuf[No abstract available]Conference Object Citation - WoS: 2Incorporation of Equisetum Arvense Extract Into Silk Fibroin-Hyaluronic Acid Sponge Matrices for Wound Dressing Applications(Elsevier, 2012) Uslu, Mehmet Emin; Erdoğan, İpek; Bayraktar, OğuzEquisetum arvense extract has frequently been investigated for its antioxidant capacity, antimicrobial and antitumor properties. However, one of the challenges in natural compound investi-gations is to maintain the stability of polyphenolic compounds during their storage and applications. For this purpose extracts can be incorporated into different forms of biomaterial. In this research silk fibroin (SF) and hyaluronic acid (HA) was used as sponge matri-ces for wound dressing application.Article Citation - WoS: 24Citation - Scopus: 23Polyethers Isolated From the Marine Actinobacterium Streptomyces Cacaoi Inhibit Autophagy and Induce Apoptosis in Cancer Cells(Elsevier, 2019) Khan, Nasar; Yılmaz, Sinem; Aksoy, Semiha; Uzel, Ataç; Tosun, Çiğdem; Ballar Kırmızıbayrak, Petek; Bedir, ErdalPolyether compounds, a large group of biologically active metabolites produced by Streptomyces species have been reported to show a variety of bioactivity such as antibacterial, antifungal, antiparasitic, antiviral, and tumour cell cytotoxicity. Since some of these compounds target cancer stem cells and multi-drug resistant cancer cells, this family of compounds have become of high interest. In this study, three polyether-type metabolites (1-3), one of which was a new natural product (3), were isolated from the marine derived Streptomyces cacaoi via antimicrobial activity-guided fractionation studies. As several polyether compounds with structural similarity such as monensin have been linked with autophagy and cell death, we first assessed the cytotoxicity of these three compounds. Compounds 2 and 3, but not 1, were found to be cytotoxic in several cell lines with a higher potency towards cancer cells. Furthermore, 2 and 3 caused accumulation of both autophagy flux markers LC3-II and p62 along with cleavage of caspase-3, caspase-9 and poly (ADP-ribose) polymerase 1 (PARP-1). Interestingly, prolonged treatment of the compounds caused a dramatic downregulation of the proteins related to autophagasome formation in a dose dependent manner. Our findings provide insights on the molecular mechanisms of the polyether-type polyketides, and signify their potency as chemotherapeutic agents through inhibiting autophagy and inducing apoptosis.Article Citation - WoS: 9Citation - Scopus: 10Characterization of Long Living Yeast Deletion Mutants That Lack Mitochondrial Metabolism Genes Dss1, Ppa2 and Afg3(Elsevier, 2019) Muid, Khandaker Ashfaqul; Kimyon, Önder; Reza, Shahadat Hasan; Karakaya, Hüseyin Çağlar; Koç, AhmetMolecular mechanisms of aging and longevity are still mostly unknown. Mitochondria play central roles in cellular metabolism and aging. In this study, we identified three deletion mutants of mitochondrial metabolism genes (ppa2 Delta, dss1 Delta, and afg3 Delta) that live longer than wild-type cells. These long-lived cells harbored significantly decreased amount of mitochondria] DNA (mtDNA) and reactive oxygen species (ROS). Compared to the serpentine nature of wild-type mitochondria, a different dynamics and distribution pattern of mitochondria were observed in the mutants. Both young and old long-lived cells produced relatively low but adequate levels of ATP for cellular activities. The status of the retrograde signaling was checked by expression of CIT2 gene and found activated in long-lived mutants. The mutant cells were also profiled for their gene expression patterns, and genes that were differentially regulated were determined. All long-lived cells comprised similar pleiotropic phenotype regarding mitochondrial dynamics and functions. Thus, this study suggests that DSS1, PPA2, and AFG3 genes modulate the lifespan by altering the mitochondrial morphology and functions.Correction Citation - WoS: 1Citation - Scopus: 2Corrigendum To “the Importance of Boron in Biological Systems” [j. Trace Elem. Med. Biol. 45 (2018) 156–162](Elsevier, 2019) Uluışık, İrem; Karakaya, Hüseyin Çağlar; Koç, Ahmet[No abstract available]Article Citation - WoS: 179Citation - Scopus: 229Health Benefits and Bioactive Compounds of Eggplant(Elsevier, 2018) Gürbüz, Nergiz; Uluışık, Selman; Frary, Anne; Frary, Amy; Doğanlar, SamiEggplant is a vegetable crop that is grown around the world and can provide significant nutritive benefits thanks to its abundance of vitamins, phenolics and antioxidants. In addition, eggplant has potential pharmaceutical uses that are just now becoming recognized. As compared to other crops in the Solanaceae, few studies have investigated eggplant's metabolic profile. Metabolomics and metabolic profiling are important platforms for assessing the chemical composition of plants and breeders are increasingly concerned about the nutritional and health benefits of crops. In this review, the historical background and classification of eggplant are shortly explained; then the beneficial phytochemicals, antioxidant activity and health effects of eggplant are discussed in detail.Article Citation - WoS: 18Citation - Scopus: 21Molecular Genetic Diversity in the Origanum Genus: Est-Ssr and Srap Marker Analyses of the 22 Species in Eight Sections That Naturally Occur in Turkey(Elsevier, 2018) Taşcıoğlu, Tülin; Sadıkoğlu, Narin; Doğanlar, Sami; Frary, AnneOriganum (L.) is a genus of herbaceous perennials with culinary and medicinal uses with many species found in the Mediterranean region. The taxonomic classification of species belonging to this genus has been studied using morphological, biochemical and genetic diversity analyses. In this study, the genetic diversity of 22 Turkish Origanum species (including 24 taxa from eight sections) was examined with 46 herbarium specimens from the Mediterranean, Eastern Anatolian, Central Anatolian, and Black Sea regions of Turkey. Molecular marker data were generated from 25 SRAP primer pairs and six EST-SSR primers which produced 325 alleles. Dendrogram, principal coordinate and population structure analyses revealed the relationships among Origanum sections, species and individuals. Gene flow (PhiPT and Nm) was also studied for a deeper understanding of the relationships and hybridization patterns between sections and species. Molecular separation of the Origanums roughly corresponded to the taxonomy that Ietswaart proposed in 1980 but also suggested that hybridization among sections and species may result in convergence and/or divergence of different sections and species.Article Citation - WoS: 54Citation - Scopus: 58Murine Sialidase Neu3 Facilitates Gm2 Degradation and Bypass in Mouse Model of Tay-Sachs Disease(Elsevier, 2018) Seyrantepe, Volkan; Akyıldız Demir, Seçil; Timur, Zehra Kevser; Von Gerichten, Johanna; Marsching, Christian; Erdemli, Esra; Öztaş, Emin; Takahashi, Kohta; Yamaguchi, Kazunori; Ateş, Nurselin; Dönmez Demir, Buket; Dalkara, Turgay; Erich, Katrin; Hopf, Carsten; Sandhoff, Roger; Miyagi, TaekoTay-Sachs disease is a severe lysosomal storage disorder caused by mutations in Hexa, the gene that encodes for the α subunit of lysosomal β-hexosaminidase A (HEXA), which converts GM2 to GM3 ganglioside. Unexpectedly, Hexa−/− mice have a normal lifespan and show no obvious neurological impairment until at least one year of age. These mice catabolize stored GM2 ganglioside using sialidase(s) to remove sialic acid and form the glycolipid GA2, which is further processed by β-hexosaminidase B. Therefore, the presence of the sialidase (s) allows the consequences of the Hexa defect to be bypassed. To determine if the sialidase NEU3 contributes to GM2 ganglioside degradation, we generated a mouse model with combined deficiencies of HEXA and NEU3. The Hexa−/− Neu3−/− mice were healthy at birth, but died at 1.5 to 4.5 months of age. Thin-layer chromatography and mass spectrometric analysis of the brains of Hexa−/− Neu3−/− mice revealed the abnormal accumulation of GM2 ganglioside. Histological and immunohistochemical analysis demonstrated cytoplasmic vacuolation in the neurons. Electron microscopic examination of the brain, kidneys and testes revealed pleomorphic inclusions of many small vesicles and complex lamellar structures. The Hexa−/− Neu3−/− mice exhibited progressive neurodegeneration with neuronal loss, Purkinje cell depletion, and astrogliosis. Slow movement, ataxia, and tremors were the prominent neurological abnormalities observed in these mice. Furthermore, radiographs revealed abnormalities in the skeletal bones of the Hexa−/− Neu3−/− mice. Thus, the Hexa−/− Neu3−/− mice mimic the neuropathological and clinical abnormalities of the classical early-onset Tay-Sachs patients, and provide a suitable model for the future pre-clinical testing of potential treatments for this condition.Article Citation - WoS: 53Citation - Scopus: 581.55 Å-Resolution Structure of Ent-Copalyl Diphosphate Synthase and Exploration of General Acid Function by Site-Directed Mutagenesis(Elsevier, 2014) Köksal, Mustafa; Christianson, David W.; Peters, Reuben John; Potter, KevinBackground The diterpene cyclase ent-copalyl diphosphate synthase (CPS) catalyzes the first committed step in the biosynthesis of gibberellins. The previously reported 2.25 Å resolution crystal structure of CPS complexed with (S)-15-aza-14,15-dihydrogeranylgeranyl thiolodiphosphate (1) established the αβγ domain architecture, but ambiguities regarding substrate analog binding remained. Method Use of crystallization additives yielded CPS crystals diffracting to 1.55 Å resolution. Additionally, active site residues that hydrogen bond with D379, either directly or through hydrogen bonded water molecules, were probed by mutagenesis. Results This work clarifies structure-function relationships that were ambiguous in the lower resolution structure. Well-defined positions for the diphosphate group and tertiary ammonium cation of 1, as well as extensive solvent structure, are observed. Conclusions Two channels involving hydrogen bonded solvent and protein residues lead to the active site, forming hydrogen bonded "proton wires" that link general acid D379 with bulk solvent. These proton wires may facilitate proton transfer with the general acid during catalysis. Activity measurements made with mutant enzymes indicate that N425, which donates a hydrogen bond directly to D379, and T421, which hydrogen bonds with D379 through an intervening solvent molecule, help orient D379 for catalysis. Residues involved in hydrogen bonds with the proton wire, R340 and D503, are also important. Finally, conserved residue E211, which is located near the diphosphate group of 1, is proposed to be a ligand to Mg2 + required for optimal catalytic activity. General significance This work establishes structure-function relationships for class II terpenoid cyclases.