TR Dizin İndeksli Yayınlar / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7149
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Article Citation - WoS: 6Citation - Scopus: 8Deep Sequencing Reveals Two Jurkat Subpopulations With Distinct Mirna Profiles During Camptothecin-Induced Apoptosis(TUBITAK, 2018) Erdoğan, İpek; Coşacak, Mehmet İlyas; Nalbant, Ayten; Akgül, BünyaminMicroRNAs (miRNAs) are small noncoding RNAs of about 19-25 nt that regulate gene expression posttranscriptionally under various cellular conditions, including apoptosis. The miRNAs involved in modulation of apoptotic events in T cells are partially known. However, heterogeneity associated with cell lines makes it difficult to interpret gene expression signatures, especially in cancer-related cell lines. Treatment of the Jurkat T-cell leukemia cell line with the universal apoptotic drug, camptothecin, resulted in identification of two Jurkat subpopulations: one that is sensitive to camptothecin and another that is rather intrinsically resistant. We sorted apoptotic Jurkat cells from nonapoptotic ones prior to profiling miRNAs through deep sequencing. Our data showed that a total of 184 miRNAs were dysregulated. Interestingly, the apoptotic and nonapoptotic subpopulations exhibited distinct miRNA expression profiles. In particular, 6 miRNAs were inversely expressed in these two subpopulations. The pyrosequencing results were validated by real-time qPCR. Altogether, these results suggest that miRNAs modulate apoptotic events in T cells and that cellular heterogeneity requires careful interpretation of miRNA expression profiles obtained from drug-treated cell lines.Article Citation - WoS: 3Citation - Scopus: 3Cloning, Expression, and Activity Analysis of Human Cathepsin C in the Yeast Pichia Pastoris(TUBITAK, 2017) Dağlıoğlu, CenkThe yeast Pichia pastoris expression system was investigated for the production of human cathepsin C (CatC) recombinant protein. The full-length CatC cDNA, corresponding to amino acids 12-475, was synthesized from interleukin-2 (IL-2) stimulated human peripheral blood mononuclear cells and subcloned in the pGEM-T cloning vector. After confirming the DNA sequence of the insert, the gene was cloned into the pPICZαA expression vector under the control of the methanol-inducible alcohol oxidase (AOX1) promoter and transformed to P. pastoris X-33 cells. The expressed protein was secreted into the culture medium through the α-factor mating signal sequence of the expression vector. Analysis of the culture supernatant revealed that the recombinant human CatC was secreted as a 58-kDa molecule, indicating that human CatC was accumulated in the culture supernatant as proform composed of the residual propart, the activation peptide, and the heavy and light chains. Extracellular recombinant proCatC was further activated by cysteine endoprotease papain in vitro and its activity was confirmed by assays using a synthetic substrate.Article Citation - WoS: 1Citation - Scopus: 3Detection of the Contamination Sources of Listeria Monocytogenes in Pickled White Cheese Production Process Line and Genotyping With the Pulsed-Field Gel Electrophoresis Method(TUBITAK, 2016) Telli, Nihat; Güner, Ahmet; Soyer Dönmez, Ferda; Özdemir, Özgün ÖyküThis study was conducted to determine the contamination sources, serotyping profiles, and antibiotic resistance patterns of Listeria monocytogenes isolated during the production of pickled white cheese. The genetic-relatedness of the isolates to EGD SLCC (5835) (1/2a, lineage II) and ATCC (13932) (4b, lineage I) reference strains was also determined with pulsed-field gel electrophoresis (PFGE) as a result of digestions with AscI and ApaI enzymes. Samples were collected from 16 different points in the production process of 4 different plants at 3 different times. Among the 192 samples examined, 17 (8.85%) were determined to be contaminated with Listeria spp. Three isolates (3.53%) obtained from raw milk, wall/ground, and press cases were identified as L. monocytogenes via the conventional culture method and confirmed by polymerase chain reaction. These isolates were found to belong to serotype 4b. According to antibiotic resistance testing against 10 antibiotics (ampicillin, gentamicin, erythromycin, tetracycline, chloramphenicol, cefalotin, streptomycin, vancomycin, penicillin, and sulfamethoxazole/trimethoprim), it was determined that isolates from raw milk and press cases were resistant to erythromycin. PPGE band patterns of the isolates displayed indistinguishable with AscI and 80%-94% homology with ApaI. The isolates were observed to display high homology to ATCC (13932) and lower homology to EGD SLCC (5835) obtained by both enzymes.Article Citation - WoS: 5Citation - Scopus: 5Invadopodia: Proteolytic Feet of Cancer Cells(TUBITAK, 2014) Batı, Gizem; Pesen Okvur, DevrimThe leading cause of death in cancer patients is metastasis. Invasion is an integral part of metastasis and is carried out by proteolytic structures called invadopodia at the cellular level. In this introductory review, we start by evaluating the definition of invadopodia. While presenting the upstream signaling events involved, we integrate current models on invadopodia. In addition, we discuss the significance of invadopodia in 2D and 3D and in vivo. We finally point out technical challenges and conclude with open questions in the field. © TÜBİTAK.Article Citation - WoS: 27Citation - Scopus: 36Purification and Biochemical Characterization of an Extracellular Lipase From Psychrotolerant Pseudomonas Fluorescens Ke38(TUBITAK, 2013) Adan Gökbulut, Aysun; Arslanoğlu, AlperAn extracellular lipase producing bacterium was isolated from a soil sample, and identified as a strain of Pseudomonas fluorescens by 16S rRNA gene sequencing. It was named Pseudomonas fluorescens KE38. KE38 showed psychrotolerant properties with an optimum growth temperature of 25 °C. The lipase enzyme secreted by KE38 was purified 41.13-fold with an overall yield of 54.99%, and a specific activity of 337.3 U/mg. The molecular mass of purified lipase was estimated to be approximately 43 kDa by SDS-PAGE. Although the lipase was active at a temperature range of 15-65 °C, it exhibited maximum activity at 45 °C, at pH 8.0. The enzyme exhibited high stability retaining 100% and 70% of its activity after an incubation period of 45 and 100 min at 45 °C and pH 8.0 respectively. It also showed a broad substrate specificity acting on p-nitrophenyl esters with C8-C18 acyl groups as substrates and was activated by Ca2+ and Ni2+ at 1 mM. While the enzyme retained its activity levels in the presence of a variety of organic solvents, DMSO and dimethylformamide enhanced this. High stability, broad substrate specificity and activity at cold temperatures in the presence of organic solvents, and metal ions make the extracellular lipase of KE38 a candidate for industrial applications.Article Citation - WoS: 25Citation - Scopus: 25Application of Est-Ssrs To Examine Genetic Diversity in Eggplant and Its Close Relatives(TUBITAK, 2011) Tümbilen, Yeliz; Frary, Anne; Daunay, Marie Christine; Doğanlar, SamiWithin the genus Solanum, the term 'eggplant' encompasses several cultivated species that are used for food and, to a lesser extent, for medicine. Th e use of one common name to describe more than one species and the existence of many related wild species have led to taxonomic confusion which, in turn, have complicated analyses of evolutionary relationships and genetic diversity within this groups of species. A further challenge for eggplant research is that, despite the fact that the use of molecular markers for phylogenetic studies is well-established, very few studies have described the development of new markers for eggplant. In our work, genic microsatellite (SSR) markers were identified from an expressed sequence tag library of S. melongena and used for analysis of 47 accessions of eggplant and closely related species. Th e markers had very good polymorphism in the 18 species tested including 8 S. melongena accessions. Moreover, genetic analysis performed with these markers showed concordance with previous research and knowledge of eggplant domestication. Th ese markers are expected to be a valuable resource for studies of genetic relationships, fingerprinting, and gene mapping in eggplant.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 SelçukIn 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.