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Polymerase substrate specificity

Aleksei Agapov, Daria Esyunina, Danil Pupov, Andrey Kulbachinskiy
The Gre-family transcription factors bind within the secondary channel of bacterial RNA polymerase (RNAP) directly modulating its catalytic activities. Universally conserved Gre factors activate RNA cleavage by RNAP, by chelating catalytic metal ions in the RNAP active site, and facilitate both promoter escape and transcription elongation. Gfh factors are Deinococcus/Thermus -specific homologues of Gre factors whose transcription functions remain poorly understood. Recently, we found that Gfh1 and Gfh2 proteins from Deinococcus radiodurans dramatically stimulate RNAP pausing during transcription elongation in the presence of Mn(2+) but not Mg(2+) ions...
October 17, 2016: Biochemical Journal
Lional Rajappa-Titu, Takuma Suematsu, Paola Munoz-Tello, Marius Long, Özlem Demir, Kevin J Cheng, Jason R Stagno, Hartmut Luecke, Rommie E Amaro, Inna Aphasizheva, Ruslan Aphasizhev, Stéphane Thore
Terminal uridyltransferases (TUTases) execute 3' RNA uridylation across protists, fungi, metazoan and plant species. Uridylation plays a particularly prominent role in RNA processing pathways of kinetoplastid protists typified by the causative agent of African sleeping sickness, Trypanosoma brucei In mitochondria of this pathogen, most mRNAs are internally modified by U-insertion/deletion editing while guide RNAs and rRNAs are U-tailed. The founding member of TUTase family, RNA editing TUTase 1 (RET1), functions as a subunit of the 3' processome in uridylation of gRNA precursors and mature guide RNAs...
October 15, 2016: Nucleic Acids Research
Naotaka Nakazawa, Aneesh R Sathe, G V Shivashankar, Michael P Sheetz
Substrate rigidity affects many physiological processes through mechanochemical signals from focal adhesion (FA) complexes that subsequently modulate gene expression. We find that shuttling of the LIM domain (domain discovered in the proteins, Lin11, Isl-1, and Mec-3) protein four-and-a-half LIM domains 2 (FHL2) between FAs and the nucleus depends on matrix mechanics. In particular, on soft surfaces or after the loss of force, FHL2 moves from FAs into the nucleus and concentrates at RNA polymerase (Pol) II sites, where it acts as a transcriptional cofactor, causing an increase in p21 gene expression that will inhibit growth on soft surfaces...
October 14, 2016: Proceedings of the National Academy of Sciences of the United States of America
Hirofumi Sawai
It has been shown that necroptosis-caspase-independent programmed necrotic cell death-can be induced by treatment with tumor necrosis factor (TNF) in the L929 murine fibrosarcoma cell line, even in the absence of a caspase inhibitor. Although it was reported that necrostatin-1-a specific inhibitor of necroptosis-inhibited TNF-induced necroptosis in L929 cells, it has not been elucidated whether the cells eventually die by apoptosis in the presence of necrostatin-1. In this paper, induction of apoptosis was demonstrated in TNF-treated L929 cells in the presence of necrostatin-1...
October 7, 2016: International Journal of Molecular Sciences
Kewen Cheng, Daodong Pan, Jun Teng, Li Yao, Yingwang Ye, Feng Xue, Fan Xia, Wei Chen
Rapid detection of pathogens is of great significance for food safety and disease diagnosis. A new colorimetric method for rapid and easy detection of Vibrio parahaemolyticus (V. parahaemolyticus or Vp) has been developed in this research. A specific sequence was designed and integrated with the forward primer for molecular detection of Vp. This specific sequence was tested and treated as the horseradish peroxidase (HRP)-mimicking DNAzyme and could be amplified during the polymerase chain reaction (PCR) process...
2016: Sensors
Sandra C Koch, Nina Simon, Charlotte Ebert, Thomas Carell
Nucleotide excision repair (NER) is a highly versatile and efficient DNA repair process, which is responsible for the removal of a large number of structurally diverse DNA lesions. Its extreme broad substrate specificity ranges from DNA damages formed upon exposure to ultraviolet radiation to numerous bulky DNA adducts induced by mutagenic environmental chemicals and cytotoxic drugs used in chemotherapy. Defective NER leads to serious diseases, such as xeroderma pigmentosum (XP). Eight XP complementation groups are known of which seven (XPA-XPG) are caused by mutations in genes involved in the NER process...
January 2016: Quarterly Reviews of Biophysics
Ana Miriam Saldaña-Cruz, Lilia Carolina León-Moreno, José Sánchez-Corona, Daniel Alejandro Márquez-de Santiago, Francisco Mendoza-Carrera, Xochitl Helga Castro-Martínez, Alejandra Guadalupe García-Zapién, María Cristina Morán-Moguel, Silvia Esperanza Flores-Martínez
AIMS: Polymorphisms in the CYP2C9 and CYP2C19 genes confer potential risk for specific adverse drug reactions and therapeutic effect failure. Their frequencies differ among ethnic groups. This study was aimed to describe the distribution of CYP2C9 and CYP2C19 alleles and haplotypes in four Mestizo populations from Western Mexico and their comparison with the reported data from other ethnic groups. METHODS: The CYP2C alleles (CYP2C9*2, CYP2C9*3, CYP2C19*2, and CYP2C19*3) were genotyped using polymerase chain reaction-restriction fragment length polymorphisms analyses using DNA samples from 477 healthy Mestizo individuals of Colima (n = 100), Jalisco (n = 147), Michoacán (n = 117), and Nayarit (n = 113)...
September 12, 2016: Genetic Testing and Molecular Biomarkers
Carly E Winton, Brian L Gilmore, Andrew C Demmert, Vasilea Karageorge, Zhi Sheng, Deborah F Kelly
Recent advances in the development of functional materials offer new tools to dissect human health and disease mechanisms. The use of tunable surfaces is especially appealing as substrates can be tailored to fit applications involving specific cell types or tissues. Here we use tunable materials to facilitate the three-dimensional (3D) analysis of BRCA1 gene regulatory complexes derived from human cancer cells. We employed a recently developed microchip platform to isolate BRCA1 protein assemblies natively formed in breast cancer cells with and without BRCA1 mutations...
2016: NPJ Breast Cancer
Yongjie Xu, Xintong Bian, Ye Sang, Yujian Li, Dandan Li, Wei Cheng, Yibing Yin, Huangxian Ju, Shijia Ding
A novel G-quadruplex DNAzyme-driven chemiluminescence (CL) imaging method has been developed for ultrasensitive and specific detection of BCR/ABL fusion gene based on bis-three-way junction (bis-3WJ) nanostructure and cascade DNA machineries. Bis-3WJ probes are designed logically to recognize BCR/ABL fusion gene, which forms the stable bis-3WJ nanostructure for the activation of polymerase/nicking enzyme machineries in cascade, resulting in synthesis of DNAzyme subunits. These DNAzyme subunits can form integrated DNAzyme by self-assembly to catalyze CL substrate, thus providing an amplified signal for the sensing events or outputs for AND logic operation...
2016: Scientific Reports
Gernot Längst
Cellular DNA is packaged into chromatin, which is the substrate of all DNA-dependent processes in eukaryotes. The regulation of chromatin requires specialized enzyme activities to allow the access of sequence-specific binding proteins and RNA polymerases. In order to dissect chromatin-dependent features of transcription regulation in detail, in vitro systems to generate defined chromatin templates for transcription are required. I present a protocol that allows the assembly of nucleosomes on ribosomal RNA (rRNA) minigenes by salt gradient dialysis and subsequent sucrose gradient centrifugation...
2016: Methods in Molecular Biology
Ujani Chakraborty, Eric Alani
Mismatch repair (MMR) systems correct DNA mismatches that result from DNA polymerase misincorporation errors. Mismatches also appear in heteroduplex DNA intermediates formed during recombination between nearly identical sequences, and can be corrected by MMR or removed through an unwinding mechanism, known as anti-recombination or heteroduplex rejection. We review studies, primarily in baker's yeast, which support how specific factors can regulate the MMR/anti-recombination decision. Based on recent advances, we present models for how DNA structure, relative amounts of key repair proteins, the timely localization of repair proteins to DNA substrates, and epigenetic marks can modulate this critical decision...
August 28, 2016: FEMS Yeast Research
Satoshi Yuzawa, Kai Deng, George Wang, Edward E K Baidoo, Trent R Northen, Paul D Adams, Leonard Katz, Jay D Keasling
Type I modular polyketide synthases (PKSs) are polymerases that utilize acyl-CoAs as substrates. Each polyketide elongation reaction is catalyzed by a set of protein domains called a module. Each module usually contains an acyltransferase (AT) domain, which determines the specific acyl-CoA incorporated into each condensation reaction. Although successful exchange of individual AT domains can lead to the biosynthesis of a large variety of novel compounds, hybrid PKS modules often show significantly decreased activities...
August 22, 2016: ACS Synthetic Biology
Vito Genna, Pietro Vidossich, Emiliano Ippoliti, Paolo Carloni, Marco De Vivo
The enzymatic polymerization of DNA and RNA is at the basis of genetic inheritance for all living organisms. It is catalyzed by the DNA/RNA polymerase (Pol) superfamily. Here, bioinformatics analysis reveals that the incoming nucleotide substrate always forms an H-bond between its 3'OH and β-phosphate moieties upon formation of the Michaelis complex. This previously unrecognized H-bond implies a novel self-activated mechanism (SAM), which synergistically connects the in situ nucleophile formation with subsequent nucleotide addition and, importantly, nucleic acid translocation...
August 16, 2016: Journal of the American Chemical Society
Atsushi Kawase, Ayumi Handa, Masahiro Iwaki
BACKGROUND AND OBJECTIVES: Various nutrients modulate the expression of transporters; however, the effect of a high-cholesterol (HC) diet on the expression and function of hepatic transporters remains unclear. Here, we examined the effects of an HC diet on drug disposition via hepatic transporters, including organic anion-transporting polypeptide (Oatp), multidrug resistance-associated protein (Mrp), and bile salt export pump (Bsep). METHODS: In situ perfused rat liver system was performed...
August 10, 2016: European Journal of Drug Metabolism and Pharmacokinetics
Yicheng Long, Maria G Abad, Erik D Olson, Elisabeth Y Carrillo, Jane E Jackman
The superfamily of 3'-5' polymerases synthesize RNA in the opposite direction to all other DNA/RNA polymerases, and its members include eukaryotic tRNA(His) guanylyltransferase (Thg1), as well as Thg1-like proteins (TLPs) of unknown function that are broadly distributed, with family members in all three domains of life. Dictyostelium discoideum encodes one Thg1 and three TLPs (DdiTLP2, DdiTLP3 and DdiTLP4). Here, we demonstrate that depletion of each of the genes results in a significant growth defect, and that each protein catalyzes a unique biological reaction, taking advantage of specialized biochemical properties...
September 30, 2016: Nucleic Acids Research
Bethany R Baumgart, Faye Wang, Jae Kwagh, Chris Storck, Catherine Euler, Megan Fuller, Damir Simic, Suresh Sharma, Jamie J Arnold, Craig E Cameron, Terry R Van Vleet, Oliver Flint, Roderick T Bunch, Marc H Davies, Michael J Graziano, Thomas P Sanderson
BMS-986094, the prodrug of a guanosine nucleotide analogue (2'-C-methylguanosine), was withdrawn from clinical trials due to serious safety issues. Nonclinical investigative studies were conducted as a follow up to evaluate the potential for BMS-986094-related mitochondrial-toxicity. In vitro, BMS-986094 was applied to human hepatoma cells (HepG2 and Huh-7) or cardiomyocytes (hiPSCM) up to 19 days to assess mitochondrial DNA content and specific gene expression. There were no mitochondrial DNA changes at concentrations ≤10 µM...
October 2016: Toxicological Sciences: An Official Journal of the Society of Toxicology
Changqing Li, Yannick Debing, Gytis Jankevicius, Johan Neyts, Ivan Ahel, Bruno Coutard, Bruno Canard
UNLABELLED: ADP-ribosylation is a posttranslational protein modification in which ADP-ribose is transferred from NAD(+) to specific acceptors to regulate a wide variety of cellular processes. The macro domain is an ancient and highly evolutionarily conserved protein domain widely distributed throughout all kingdoms of life, including viruses. The human TARG1/C6orf130, MacroD1, and MacroD2 proteins can reverse ADP-ribosylation by acting on ADP-ribosylated substrates through the hydrolytic activity of their macro domains...
October 1, 2016: Journal of Virology
Vijaya Lakshmi Tiruveedi, Swarna Bale, Amit Khurana, Chandraiah Godugu
Tankyrases belong to a group of enzymes called poly ADP ribosyl polymerases (PARPs). With the advent of a new class of small molecule inhibitors of PARP for clinical use like OLAPARIB; that gained accelerated approval by the USFDA in treating ovarian and breast cancers, the horizons of the PARPs as a novel target in various disease conditions has risen. Tankyrases (PARP 5) are yet another class of PARPs that perform poly ADP ribosylation on different substrate proteins aiding in progression of many diseases like cancer, fibrosis, diabetes and neurological disorders even...
July 15, 2016: Current Drug Targets
Michele Benedetti, Alessandro Romano, Federica De Castro, Chiara R Girelli, Daniela Antonucci, Danilo Migoni, Tiziano Verri, Francesco P Fanizzi
In this work, we assessed the capacity of RNA polymerases to use platinated ribonucleotides as substrates for RNA synthesis by testing the incorporation of the model compound [Pt(dien)(N7-5'-GTP)] (dien=diethylenetriamine; GTP=5'-guanosine triphosphate) into a natural RNA sequence. The yield of in vitro transcription operated by T7 RNA polymerase, on the LacZ (Escherichia coli gene encoding for β-galactosidase) sequence, decreases progressively with decreasing the concentration of natural GTP, in favor of the platinated nucleotide, [Pt(dien)(N7-5'-GTP)]...
July 8, 2016: Journal of Inorganic Biochemistry
Li-Juan Wang, Fei Ma, Bo Tang, Chun-Yang Zhang
DNA glycosylase is an initiating enzyme of cellular base excision repair pathway which is responsible for the repair of various DNA lesions and the maintenance of genomic stability, and the dysregulation of DNA glycosylase activity is associated with a variety of human pathology. Accurate detection of DNA glycosylase activity is critical to both clinical diagnosis and therapeutics, but conventional methods for the DNA glycosylase assay are usually time-consuming with poor sensitivity. Here, we demonstrate the base-excision-repair-induced construction of a single quantum dot (QD)-based sensor for highly sensitive measurement of DNA glycosylase activity...
August 2, 2016: Analytical Chemistry
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