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: 3Citation - Scopus: 5A Novel Thermophilic Hemoprotein Scaffold for Rational Design of Biocatalysts(Springer Verlag, 2018) Efua Aggrey Fynn, Joana; Sürmeli, Nur BaşakHemoproteins are commonly found in nature, and involved in many important cellular processes such as oxygen transport, electron transfer, and catalysis. Rational design of hemoproteins can not only inspire novel biocatalysts but will also lead to a better understanding of structure-function relationships in native hemoproteins. Here, the heme nitric oxide/oxygen-binding protein from Caldanaerobacter subterraneus subsp. tengcongensis (TtH-NOX) is used as a novel scaffold for oxidation biocatalyst design. We show that signaling protein TtH-NOX can be reengineered to catalyze H2O2 decomposition and oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) by H2O2. In addition, the role of the distal tyrosine (Tyr140) in catalysis is investigated. The mutation of Tyr140 to alanine hinders the catalysis of the oxidation reactions. On the other hand, the mutation of Tyr140 to histidine, which is commonly observed in peroxidases, leads to a significant increase of the catalytic activity. Taken together, these results show that, while the distal histidine plays an important role in hemoprotein reactions with H2O2, it is not always essential for oxidation activity. We show that TtH-NOX protein can be used as an alternative scaffold for the design of novel biocatalysts with desired reactivity or functionality. H-NOX proteins are homologous to the nitric oxide sensor soluble guanylate cyclase. Here, we show that the gas sensor protein TtH-NOX shows limited capacity for catalysis of redox reactions and it can be used as a novel scaffold in biocatalysis design. [GRAPHICS] .Article Citation - WoS: 10Citation - Scopus: 13Analysis of European Hazelnut (corylus Avellana) Reveals Loci for Cultivar Improvement and the Effects of Domestication and Selection on Nut and Kernel Traits(Springer Verlag, 2019) Frary, Amy; Öztürk, Süleyman Can; Balık, Hüseyin İrfan; Kayalak Balık, Selda; Kızılcı, Gökhan; Doğanlar, Sami; Frary, AnneTurkey is a rich source of European hazelnut (Corylus avellana) germplasm with nearly 400 accessions in the national collection. This genetic material encompasses cultivars, landraces and wild genotypes which were characterized for 12 nut and 13 kernel traits over 2years in the 1990s. Analysis of these attributes revealed both the positive and negative impacts that human selection and breeding have had on hazelnut. Thus, while selection has resulted in larger nuts and kernels, cultivars have fewer nuts per cluster and kernels with larger internal cavities. Breeding has also resulted in a propensity for cultivars to have higher proportions of double kernels and empty nuts, two traits which reduce quality and yield. In addition, it is clear that while selection has successfully increased hazelnut fat content it has not impacted overall flavor, a much more complex trait. The nut and kernel phenotypic data were combined with genotypic data from 406 simple sequence repeat marker alleles for association mapping of the quantitative trait loci (QTL) for the traits. A total of 78 loci were detected in the population with the highest proportions for nut (24%) and kernel (26%) appearance parameters followed by quality (19%), shell thickness (16%) and yield-related (15%) traits. It is hoped that some of the identified QTL will be useful for future breeding of hazelnut for improved nut and kernel yield and quality.Article Citation - WoS: 12Citation - Scopus: 18Synergistic Antimicrobial Effects of Activated Lactoferrin and Rosemary Extract in Vitro and Potential Application in Meat Storage(Springer Verlag, 2020) Soyer, Ferda; Keman, Deniz; Eroğlu, Erdal; Türe, HasanThis study aimed to explore the antimicrobial effects of activated lactoferrin (ALF) and rosemary extract (RE) on Escherichia coli O157:H7, Salmonella Enteritidis and Listeria monocytogenes, and to investigate their application potential in the meat storage. Minimum inhibitory concentrations (MICs) of ALF, RE and ALF-RE combinations were determined via microtiter plate assay. MICs of ALF were 1% for E. coli O157:H7; 0.5% for S. Enteritidis and 0.1% for L. monocytogenes. While 15% RE inhibited L. monocytogenes; 30% RE partially inhibited E. coli O157:H7 and S. Enteritidis growth. Synergistic effect of ALF and RE on the inhibition of E. coli O157:H7 increased the activity of ALF two to three folds. Food application of antimicrobials was performed by dipping of meat samples. Both ALF and RE were found effective in the prevention of L. monocytogenes growth about two logs. According to the data, choice of natural antimicrobials may be promising in food preservation.Article Citation - WoS: 15Citation - Scopus: 19Genome-Wide Association Mapping of Yield Components and Drought Tolerance-Related Traits in Cotton(Springer Verlag, 2018) Akköse Baytar, Asena; Peynircioğlu, Ceng; Sezener, Volkan; Başal, Hüseyin; Frary, Anne; Frary, Amy; Doğanlar, SamiDrought causes serious yield losses in cotton production throughout the world. Association mapping allows identification and localization of the genes controlling drought-related traits which will be helpful in cotton breeding. In the present study, genetic diversity analysis and association mapping of yield and drought traits were performed on a panel of 99 upland cotton genotypes using 177 SSR (simple sequence repeat) markers. Yield parameters and drought tolerance-related traits were evaluated for two seasons under two watering regimes: water-stressed and well-watered. The traits included seed cotton yield (SCY), lint yield (LY), lint percentage (LP), water-use efficiency (WUE), yield potential (YP), yield reduction (YR), yield index (YI), drought sensitivity index (DSI), stress tolerance index (STI), harmonic mean (HM), and geometric mean productivity (GMP). The genotypes with the least change in seed cotton yield under drought stress were Zeta 2, Delcerro, Nazilli 87, and DAK 66/3 which were also the most water-use efficient cultivars. The average genetic diversity of the panel was 0.38. The linkage disequilibrium decayed relatively rapidly at 20–30 cM (r 2 ≥ 0.5). We identified 30 different SSR markers associated with the traits. Fifteen and 23 SSR markers were linked to the traits under well-watered and water-stress conditions, respectively. To our knowledge, most of these quantitative yield and drought tolerance-associated loci were newly identified. The genetic diversity and association mapping results should facilitate the development of drought-tolerant cotton lines with high yield in molecular breeding programs.Article Citation - Scopus: 8The Second Case of Saposin a Deficiency and Altered Autophagy(Springer Verlag, 2018) Köse, Melis; Akyıldız Demir, Seçil; Akıncı, Gülçin; Eraslan, Cenk; Yılmaz, Ünsal; Ceylaner, Serdar; Sözmen Yıldırım, Eser; Seyrantepe, VolkanKrabbe disease is a lysosomal storage disease caused by galactosylceramidase deficiency, resulting in neurodegeneration with a rapid clinical downhill course within the first months of life in the classic infantile form. This process may be triggered by the accumulation of galactosylceramide (GalCer) in nervous tissues. Both the enzyme galactosylceramidase and its in vivo activator molecule, saposin A, are essential during GalCer degradation. A clinical manifestation almost identical to Krabbe disease is observed when, instead of the galactosylceramidase protein, the saposin A molecule is defective. Saposin A results from posttranslational processing of the precursor molecule, prosaposin, encoded by the PSAP gene. Clinical and neuroimaging findings in a 7-month-old child strongly suggested Krabbe disease, but this condition was excluded by enzymatic and genetic testing. However, at whole exome sequencing, the previously undescribed homozygous, obviously pathogenic PSAP gene NM_002778.3: c.209T>G(p.Val70Gly) variant was determined in the saposin A domain of the PSAP gene. Fibroblast studies showed GalCer accumulation and the activation of autophagy for the first time in a case of human saposin A deficiency. Our patient represents the second known case in the literature and provides new information concerning the pathophysiology of saposin A deficiency and its intralysosomal effects.Article Citation - WoS: 11Citation - Scopus: 14Categorization of Species Based on Their Micrornas Employing Sequence Motifs, Information-Theoretic Sequence Feature Extraction, and K-Mers(Springer Verlag, 2017) Yousef, Malik; Nigatu, Dawit; Levy, Dalit; Allmer, Jens; Henkel, WernerBackground: Diseases like cancer can manifest themselves through changes in protein abundance, and microRNAs (miRNAs) play a key role in the modulation of protein quantity. MicroRNAs are used throughout all kingdoms and have been shown to be exploited by viruses to modulate their host environment. Since the experimental detection of miRNAs is difficult, computational methods have been developed. Many such tools employ machine learning for pre-miRNA detection, and many features for miRNA parameterization have been proposed. To train machine learning models, negative data is of importance yet hard to come by; therefore, we recently started to employ pre-miRNAs from one species as positive data versus another species’ pre-miRNAs as negative examples based on sequence motifs and k-mers. Here, we introduce the additional usage of information-theoretic (IT) features. Results: Pre-miRNAs from one species were used as positive and another species’ pre-miRNAs as negative training data for machine learning. The categorization capability of IT and k-mer features was investigated. Both feature sets and their combinations yielded a very high accuracy, which is as good as the previously suggested sequence motif and k-mer based method. However, for obtaining a high performance, a sufficiently large phylogenetic distance between the species and sufficiently high number of pre-miRNAs in the training set is required. To examine the contribution of the IT and k-mer features, an information gain-based feature ranking was performed. Although the top 3 are IT features, 80% of the top 100 features are k-mers. The comparison of all three individual approaches (motifs, IT, and k-mers) shows that the distinction of species based on their pre-miRNAs k-mers are sufficient. Conclusions: IT sequence feature extraction enables the distinction among species and is less computationally expensive than motif calculations. However, since IT features need larger amounts of data to have enough statistics for producing highly accurate results, future categorization into species can be effectively done using k-mers only. The biological reasoning for this is the existence of a codon bias between species which can, at least, be observed in exonic miRNAs. Future work in this direction will be the ab initio detection of pre-miRNA. In addition, prediction of pre-miRNA from RNA-seq can be done.Article Citation - WoS: 18Citation - Scopus: 29Cry1ac-Mediated Resistance To Tomato Leaf Miner (tuta Absoluta) in Tomato(Springer Verlag, 2017) Şelale, Hatice; Dağlı, Fatih; Mutlu, Nedim; Doğanlar, Sami; Frary, AnneTomato leaf miner (Tuta absoluta) is a major pest of tomato in regions with hot climates such as South America and the Mediterranean. This insect feeds on almost every part of the plant and forms galleries while feeding on the plant’s inner tissues. Thus, it can cause plant death and is costly and difficult to control with chemical sprays. In this study, we transferred a modified Bacillus thuringiensis cry1Ac gene to tomato plants via Agrobacterium tumefaciens mediated transformation. Introduction of the cry1Ac gene to the tomato genome was confirmed with PCR and Southern blot analysis in 12 independent events. Insertion sites of the transgene in the tomato genome were determined with TAIL-PCR (thermal asymmetric interlaced polymerase chain reaction) for four selected transgenic lines. Cry1Ac gene expression was verified at both the transcriptional and translational levels, with RT-qPCR and Western blot analyses, respectively. Expression of the Cry1Ac protein in tomato resulted in T. absoluta mortality rates of 38–100% depending on transgenic line. In addition, gallery formation was reduced in 57–100% of the transgenic plants. Moreover, it was found that a single copy of the gene in the hemizygous condition is sufficient to confer tolerance to leaf miner. This is the first reported development of tomato plants resistant to T. absoluta. These transgenic plants are promising for development of commercial tomato cultivars resistant to leaf miner, which will limit the use of environmentally harmful chemicals for control of this pest.Article Citation - WoS: 17Citation - Scopus: 20Molecular Genetic Diversity of the Turkish National Hazelnut Collection and Selection of a Core Set(Springer Verlag, 2017) Öztürk, Süleyman Can; Balık, Hüseyin İrfan; Kayalak Balık, Selda; Kızılcı, Gökhan; Duyar, Ömür; Doğanlar, Sami; Frary, AnneEuropean hazelnut (Corylus avellana L.) is an economically and nutritionally important nut crop with wild and cultivated populations found throughout Europe and in parts of Asia. This study examined the molecular genetic diversity and population structure of 402 genotypes including 143 wild individuals, 239 landraces, and 20 cultivars from the Turkish national hazelnut collection using simple sequence repeat (SSR) markers. A total of 30 SSR markers yielded 407 polymorphic fragments. Diversity analysis of the Turkish hazelnut genotypes indicated that they fell into three subpopulations according to ad hoc statistics and neighbor-joining algorithm. Although all cultivars clustered together, they overlapped with the wild accessions and landraces. Thus, the dendrogram, principal coordinate, and population structure analyses suggest that they share the same gene pool. A total of 78 accessions were selected as a core set to encompass the molecular genetic and morphological diversity present in the national collection. This core set should have priority in preservation efforts and in trait characterization.Article Citation - WoS: 4Citation - Scopus: 6Dishevelled Proteins and Cyld Reciprocally Regulate Each Other in Cml Cell Lines(Springer Verlag, 2017) Çalışkan, Ceyda; Pehlivan, Melek; Yüce, Zeynep; Sercan, OgünDishevelled (Dvl) proteins are activated by Wnt pathway stimulation and have crucial roles in the regulation of β-catenin destruction complex. CYLD is a tumor suppressor and a deubiquitination enzyme. CYLD negatively regulates the Wnt/β-catenin signaling pathway by deubiquitinating Dvl proteins. Loss of function and mutations of CYLD were linked to different types of solid tumors. Loss of function in CYLD is associated with Dvl hyper ubiquitination, resulting in the transmission of Wnt signaling to downstream effectors. β-catenin upregulation is observed during disease progression in chronic myeloid leukemia (CML). Deregulated Dvl signaling may be a reason for β-catenin activation in CML; and CYLD may contribute to Dvl deregulation. First, we evaluated mRNA expression in three CML cell lines and mRNA expression of the CYLD gene was found to be present in all (K562, MEG01, KU812). Unlike solid tumors sequencing revealed no mutations in the coding sequences of the CYLD gene. DVL genes were silenced by using a pool of siRNA oligonucleotides and gene expression differences in CYLD was determined by RT-PCR and western blot. CYLD protein expression decreased after Dvl silencing. An opposite approach of overexpressing Dvl proteins resulted in upregulated CYLD expression. While previous reports have described CYLD as a regulator of DVL proteins; our data suggests the presence of a more complicated reciprocal regulatory mechanism in CML cell lines.Article Citation - WoS: 20Citation - Scopus: 24Newly Developed Ssr Markers Reveal Genetic Diversity and Geographical Clustering in Spinach (spinacia Oleracea)(Springer Verlag, 2017) Göl, Şurhan; Göktay, Mehmet; Allmer, Jens; Doğanlar, Sami; Frary, AnneSpinach is a popular leafy green vegetable due to its nutritional composition. It contains high concentrations of vitamins A, E, C, and K, and folic acid. Development of genetic markers for spinach is important for diversity and breeding studies. In this work, Next Generation Sequencing (NGS) technology was used to develop genomic simple sequence repeat (SSR) markers. After cleaning and contig assembly, the sequence encompassed 2.5% of the 980 Mb spinach genome. The contigs were mined for SSRs. A total of 3852 SSRs were detected. Of these, 100 primer pairs were tested and 85% were found to yield clear, reproducible amplicons. These 85 markers were then applied to 48 spinach accessions from worldwide origins, resulting in 389 alleles with 89% polymorphism. The average gene diversity (GD) value of the markers (based on a GD calculation that ranges from 0 to 0.5) was 0.25. Our results demonstrated that the newly developed SSR markers are suitable for assessing genetic diversity and population structure of spinach germplasm. The markers also revealed clustering of the accessions based on geographical origin with clear separation of Far Eastern accessions which had the overall highest genetic diversity when compared with accessions from Persia, Turkey, Europe, and the USA. Thus, the SSR markers have good potential to provide valuable information for spinach breeding and germplasm management. Also they will be helpful for genome mapping and core collection establishment.