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Articles 361 - 390 of 654

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Mechanism-Informed Refinement Reveals Altered Substrate-Binding Mode For Catalytically Competent Nitroreductase, Warintra Pitsawong, Chad A. Haynes, Ronald L. Koder, David W. Rodgers, Anne-Frances Miller Jul 2017

Mechanism-Informed Refinement Reveals Altered Substrate-Binding Mode For Catalytically Competent Nitroreductase, Warintra Pitsawong, Chad A. Haynes, Ronald L. Koder, David W. Rodgers, Anne-Frances Miller

Chemistry Faculty Publications

Nitroreductase from Enterobacter cloacae (NR) reduces diverse nitroaromatics including herbicides, explosives and prodrugs, and holds promise for bioremediation, prodrug activation and enzyme-assisted synthesis. We solved crystal structures of NR complexes with bound substrate or analog for each of its two half-reactions. We complemented these with kinetic isotope effect (KIE) measurements elucidating H-transfer steps essential to each half-reaction. KIEs indicate hydride transfer from NADH to the flavin consistent with our structure of NR with the NADH analog nicotinic acid adenine dinucleotide (NAAD). The KIE on reduction of p-nitrobenzoic acid (p-NBA) also indicates hydride transfer, and requires revision of …

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Mutations In The Transmembrane Domain And Cytoplasmic Tail Of Hendra Virus Fusion Protein Disrupt Virus-Like-Particle Assembly, Nicolás P. Cifuentes-Muñoz, Weina Sun, Greeshma Ray, Phuong Tieu Schmitt, Stacy Webb, Kathleen Gibson, Rebecca Ellis Dutch, Anthony P. Schmitt Jul 2017

Mutations In The Transmembrane Domain And Cytoplasmic Tail Of Hendra Virus Fusion Protein Disrupt Virus-Like-Particle Assembly, Nicolás P. Cifuentes-Muñoz, Weina Sun, Greeshma Ray, Phuong Tieu Schmitt, Stacy Webb, Kathleen Gibson, Rebecca Ellis Dutch, Anthony P. Schmitt

Molecular and Cellular Biochemistry Faculty Publications

Hendra virus (HeV) is a zoonotic paramyxovirus that causes deadly illness in horses and humans. An intriguing feature of HeV is the utilization of endosomal protease for activation of the viral fusion protein (F). Here we investigated how endosomal F trafficking affects HeV assembly. We found that the HeV matrix (M) and F proteins each induced particle release when they were expressed alone but that their coexpression led to coordinated assembly of virus-like particles (VLPs) that were morphologically and physically distinct from M-only or F-only VLPs. Mutations to the F protein transmembrane domain or cytoplasmic tail that disrupted endocytic trafficking …

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Crystal Structure Of Yersinia Pestis Virulence Factor Yfea Reveals Two Polyspecific Metal-Binding Sites, Christopher D. Radka, Lawrence J. Delucas, Landon S. Wilson, Matthew B. Lawrenz, Robert D. Perry, Stephen G. Aller Jul 2017

Crystal Structure Of Yersinia Pestis Virulence Factor Yfea Reveals Two Polyspecific Metal-Binding Sites, Christopher D. Radka, Lawrence J. Delucas, Landon S. Wilson, Matthew B. Lawrenz, Robert D. Perry, Stephen G. Aller

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Gram-negative bacteria use siderophores, outer membrane receptors, inner membrane transporters and substrate-binding proteins (SBPs) to transport transition metals through the periplasm. The SBPs share a similar protein fold that has undergone significant structural evolution to communicate with a variety of differentially regulated transporters in the cell. In Yersinia pestis, the causative agent of plague, YfeA (YPO2439, y1897), an SBP, is important for full virulence during mammalian infection. To better understand the role of YfeA in infection, crystal structures were determined under several environmental conditions with respect to transition-metal levels. Energy-dispersive X-ray spectroscopy and anomalous X-ray scattering data show that …

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Igf-1 Mediated Neurogenesis Involves A Novel Rit1/Akt/Sox2 Cascade, Sajad Mir, Weikang Cai, Shaun W. Carlson, Kathryn E. Saatman, Douglas A. Andres Jun 2017

Igf-1 Mediated Neurogenesis Involves A Novel Rit1/Akt/Sox2 Cascade, Sajad Mir, Weikang Cai, Shaun W. Carlson, Kathryn E. Saatman, Douglas A. Andres

Molecular and Cellular Biochemistry Faculty Publications

Insulin-like growth factor 1 (IGF-1) is known to have diverse effects on brain structure and function, including the promotion of stem cell proliferation and neurogenesis in the adult dentate gyrus. However, the intracellular pathways downstream of the IGF-1 receptor that contribute to these diverse physiological actions remain relatively uncharacterized. Here, we demonstrate that the Ras-related GTPase, RIT1, plays a critical role in IGF-1-dependent neurogenesis. Studies in hippocampal neuronal precursor cells (HNPCs) demonstrate that IGF-1 stimulates a RIT1-dependent increase in Sox2 levels, resulting in pro-neural gene expression and increased cellular proliferation. In this novel cascade, RIT1 stimulates Akt-dependent phosphorylation of …

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Exploring Cancer Metabolism Using Stable Isotope-Resolved Metabolomics (Sirm), Ronald C. Bruntz, Andrew N. Lane, Richard M. Higashi, Teresa W. -M. Fan Jun 2017

Exploring Cancer Metabolism Using Stable Isotope-Resolved Metabolomics (Sirm), Ronald C. Bruntz, Andrew N. Lane, Richard M. Higashi, Teresa W. -M. Fan

Center for Environmental and Systems Biochemistry Faculty Publications

Metabolic reprogramming is a hallmark of cancer. The changes in metabolism are adaptive to permit proliferation, survival, and eventually metastasis in a harsh environment. Stable isotope-resolved metabolomics (SIRM) is an approach that uses advanced approaches of NMR and mass spectrometry to analyze the fate of individual atoms from stable isotope-enriched precursors to products to deduce metabolic pathways and networks. The approach can be applied to a wide range of biological systems, including human subjects. This review focuses on the applications of SIRM to cancer metabolism and its use in understanding drug actions.

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A Comparison Of Nucleosome Organization In Drosophila Cell Lines, Rebecca L. Martin, John Maiorano, Greg J. Beitel, John F. Marko, Graham Mcvicker, Yvonne N. Fondufe-Mittendorf Jun 2017

A Comparison Of Nucleosome Organization In Drosophila Cell Lines, Rebecca L. Martin, John Maiorano, Greg J. Beitel, John F. Marko, Graham Mcvicker, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Changes in the distribution of nucleosomes along the genome influence chromatin structure and impact gene expression by modulating the accessibility of DNA to transcriptional machinery. However, the role of genome-wide nucleosome positioning in gene expression and in maintaining differentiated cell states remains poorly understood. Drosophila melanogastercell lines represent distinct tissue types and exhibit cell-type specific gene expression profiles. They thus could provide a useful tool for investigating cell-type specific nucleosome organization of an organism’s genome. To evaluate this possibility, we compared genome-wide nucleosome positioning and occupancy in five different Drosophila tissue-specific cell lines, and in reconstituted chromatin, and then …

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C/D-Box Snornas Form Methylating And Non-Methylating Ribonucleoprotein Complexes: Old Dogs Show New Tricks, Marina Falaleeva, Justin R. Welden, Marilyn J. Duncan, Stefan Stamm Jun 2017

C/D-Box Snornas Form Methylating And Non-Methylating Ribonucleoprotein Complexes: Old Dogs Show New Tricks, Marina Falaleeva, Justin R. Welden, Marilyn J. Duncan, Stefan Stamm

Molecular and Cellular Biochemistry Faculty Publications

C/D box snoRNAs (SNORDs) are an abundantly expressed class of short, non‐coding RNAs that have been long known to perform 2′‐O‐methylation of rRNAs. However, approximately half of human SNORDs have no predictable rRNA targets, and numerous SNORDs have been associated with diseases that show no defects in rRNAs, among them Prader‐Willi syndrome, Duplication 15q syndrome and cancer. This apparent discrepancy has been addressed by recent studies showing that SNORDs can act to regulate pre‐mRNA alternative splicing, mRNA abundance, activate enzymes, and be processed into shorter ncRNAs resembling miRNAs and piRNAs. Furthermore, recent biochemical studies have shown that a given SNORD …

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Desulfination By 2′-Hydroxybiphenyl-2-Sulfinate Desulfinase Proceeds Via Electrophilic Aromatic Substitution By The Cysteine-27 Proton, Inacrist Geronimo, Shawn R. Nigam, Christina M. Payne May 2017

Desulfination By 2′-Hydroxybiphenyl-2-Sulfinate Desulfinase Proceeds Via Electrophilic Aromatic Substitution By The Cysteine-27 Proton, Inacrist Geronimo, Shawn R. Nigam, Christina M. Payne

Chemical and Materials Engineering Faculty Publications

Biodesulfurization is an attractive option for enzymatically removing sulfur from the recalcitrant thiophenic derivatives that comprise the majority of organosulfur compounds remaining in hydrotreated petroleum products. Desulfurization in the bacteria Rhodococcus erythropolis follows a four-step pathway culminating in C–S bond cleavage in the 2′-hydroxybiphenyl-2-sulfinate (HBPS) intermediate to yield 2-hydroxybiphenyl and bisulfite. The reaction, catalyzed by 2′-hydroxybiphenyl-2-sulfinate desulfinase (DszB), is the rate-limiting step and also the least understood, as experimental evidence points to a mechanism unlike that of other desulfinases. On the basis of structural and biochemical evidence, two possible mechanisms have been proposed: nucleophilic addition and electrophilic aromatic substitution. Density …

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Microarray Dataset Of Transient And Permanent Dna Methylation Changes In Hela Cells Undergoing Inorganic Arsenic-Mediated Epithelial-To-Mesenchymal Transition, Meredith Eckstein, Matthew Rea, Yvonne N. Fondufe-Mittendorf May 2017

Microarray Dataset Of Transient And Permanent Dna Methylation Changes In Hela Cells Undergoing Inorganic Arsenic-Mediated Epithelial-To-Mesenchymal Transition, Meredith Eckstein, Matthew Rea, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

The novel dataset presented here represents the results of the changing pattern of DNA methylation profiles in HeLa cells exposed to chronic low dose (0.5 µM) sodium arsenite, resulting in epithelial-to-mesenchymal transition, as well as DNA methylation patterns in cells where inorganic arsenic has been removed. Inorganic arsenic is a known carcinogen, though not mutagenic. Several mechanisms have been proposed as to how inorganic arsenic drives carcinogenesis such as regulation of the cell׳s redox potential and/or epigenetics. In fact, there are gene specific studies and limited genome-wide studies that have implicated epigenetic factors such as DNA methylation in inorganic arsenic-mediated …

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Discovery Of A Diaminopyrimidine Flt3 Inhibitor Active Against Acute Myeloid Leukemia, Jamie A. Jarusiewicz, Jae Yoon Jeon, Michele C. Connelly, Yizhe Chen, Lei Yang, Sharyn D. Baker, R. Kiplin Guy May 2017

Discovery Of A Diaminopyrimidine Flt3 Inhibitor Active Against Acute Myeloid Leukemia, Jamie A. Jarusiewicz, Jae Yoon Jeon, Michele C. Connelly, Yizhe Chen, Lei Yang, Sharyn D. Baker, R. Kiplin Guy

Pharmaceutical Sciences Faculty Publications

Profiling of the kinase-binding capabilities of an aminopyrimidine analogue detected in a cellular screen of the St. Jude small-molecule collection led to the identification of a novel series of FMS-like tyrosine kinase 3 (FLT3) inhibitors. Structure–activity relationship studies led to the development of compounds exhibiting good potency against MV4-11 and MOLM13 acute myelogenous leukemia cells driven by FLT3, regardless of their FLT3 mutation status. In vitro pharmacological profiling demonstrated that compound 5e shows characteristics suitable for further preclinical development.

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The Foxo Transcription Factor Controls Insect Growth And Development By Regulating Juvenile Hormone Degradation In The Silkworm, Bombyx Mori, Baosheng Zeng, Yuping Huang, Jun Xu, Takahiro Shiotsuki, Hua Bai, Subba Reddy Palli, Yongping Huang, Anjiang Tan May 2017

The Foxo Transcription Factor Controls Insect Growth And Development By Regulating Juvenile Hormone Degradation In The Silkworm, Bombyx Mori, Baosheng Zeng, Yuping Huang, Jun Xu, Takahiro Shiotsuki, Hua Bai, Subba Reddy Palli, Yongping Huang, Anjiang Tan

Entomology Faculty Publications

Forkhead box O (FOXO) functions as the terminal transcription factor of the insulin signaling pathway and regulates multiple physiological processes in many organisms, including lifespan in insects. However, how FOXO interacts with hormone signaling to modulate insect growth and development is largely unknown. Here, using the transgene-based CRISPR/Cas9 system, we generated and characterized mutants of the silkworm Bombyx mori FOXO (BmFOXO) to elucidate its physiological functions during development of this lepidopteran insect. The BmFOXO mutant (FOXO-M) exhibited growth delays from the first larval stage and showed precocious metamorphosis, pupating at the end of the fourth instar (trimolter) rather …

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Genetic Metabolic Complementation Establishes A Requirement For Gdp-Fucose In Leishmania, Hongjie Guo, Natalia M. Novozhilova, Giulia Bandini, Salvatore J. Turco, Michael A. L. Ferguson, Stephen M. Beverley May 2017

Genetic Metabolic Complementation Establishes A Requirement For Gdp-Fucose In Leishmania, Hongjie Guo, Natalia M. Novozhilova, Giulia Bandini, Salvatore J. Turco, Michael A. L. Ferguson, Stephen M. Beverley

Molecular and Cellular Biochemistry Faculty Publications

To survive in its sand fly vector, the trypanosomatid protozoan parasite Leishmania first attaches to the midgut to avoid excretion, but eventually it must detach for transmission by the next bite. In Leishmania major strain Friedlin, this is controlled by modifications of the stage-specific adhesin lipophosphoglycan (LPG). During differentiation to infective metacyclics, d-arabinopyranose (d-Arap) caps the LPG side-chain galactose residues, blocking interaction with the midgut lectin PpGalec, thereby leading to parasite detachment and transmission. Previously, we characterized two closely related L. major genes (FKP40 and AFKP80) encoding bifunctional proteins with kinase/pyrophosphorylase activities required for salvage and …

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Perspectives And Expectations In Structural Bioinformatics Of Metalloproteins, Sen Yao, Robert M. Flight, Eric C. Rouchka, Hunter N. B. Moseley May 2017

Perspectives And Expectations In Structural Bioinformatics Of Metalloproteins, Sen Yao, Robert M. Flight, Eric C. Rouchka, Hunter N. B. Moseley

Molecular and Cellular Biochemistry Faculty Publications

Recent papers highlight the presence of large numbers of compressed angles in metal ion coordination geometries for metalloprotein entries in the worldwide Protein Data Bank, due mainly to multidentate coordination. The prevalence of these compressed angles has raised the controversial idea that significantly populated aberrant or even novel coordination geometries may exist. Some of these papers have undergone severe criticism, apparently due to views held that only canonical coordination geometries exist in significant numbers. While criticism of controversial ideas is warranted and to be expected, we believe that a line was crossed where unfair criticism was put forth to discredit …

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Melatonin And Its Metabolites Protect Human Melanocytes Against Uvb-Induced Damage: Involvement Of Nrf2-Mediated Pathways, Zorica Janjetovic, Stuart G. Jarrett, Elizabeth F. Lee, Cory Duprey, Russel J. Reiter, Andrzej T. Slominski Apr 2017

Melatonin And Its Metabolites Protect Human Melanocytes Against Uvb-Induced Damage: Involvement Of Nrf2-Mediated Pathways, Zorica Janjetovic, Stuart G. Jarrett, Elizabeth F. Lee, Cory Duprey, Russel J. Reiter, Andrzej T. Slominski

Toxicology and Cancer Biology Faculty Publications

Ultraviolet light (UV) is an inducer of reactive oxygen species (ROS) as well as 6-4-photoproducts and cyclobutane pyrimidine dimers (CPD) in the skin, which further cause damage to the skin cells. Irradiation of cultured human melanocytes with UVB stimulated ROS production, which was reduced in cells treated with melatonin or its metabolites: 6-hydroxymelatonin (6-OHM), N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK), N-acetylserotonin (NAS), and 5-methoxytryptamine (5-MT). Melatonin and its derivatives also stimulated the expression of NRF2 (nuclear factor erythroid 2 [NF-E2]-related factor 2) and its target enzymes and proteins that play an important role in cell protection from different damaging factors including UVB. Silencing …

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Oxidation Of Substituted Catechols At The Air-Water Interface: Production Of Carboxylic Acids, Quinones, And Polyphenols, Elizabeth A. Pillar, Marcelo I. Guzman Apr 2017

Oxidation Of Substituted Catechols At The Air-Water Interface: Production Of Carboxylic Acids, Quinones, And Polyphenols, Elizabeth A. Pillar, Marcelo I. Guzman

Chemistry Faculty Publications

Anthropogenic activities contribute benzene, toluene, and anisole to the environment, which in the atmosphere are converted into the respective phenols, cresols, and methoxyphenols by fast gas-phase reaction with hydroxyl radicals (HO(•)). Further processing of the latter species by HO(•) decreases their vapor pressure as a second hydroxyl group is incorporated to accelerate their oxidative aging at interfaces and in aqueous particles. This work shows how catechol, pyrogallol, 3-methylcatechol, 4-methylcatechol, and 3-methoxycatechol (all proxies for oxygenated aromatics derived from benzene, toluene, and anisole) react at the air-water interface with increasing O3(g) during τc ≈ 1 μs contact time and contrasts their …

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Reactivity Of Ketyl And Acetyl Radicals From Direct Solar Actinic Photolysis Of Aqueous Pyruvic Acid, Alexis J. Eugene, Marcelo I. Guzman Mar 2017

Reactivity Of Ketyl And Acetyl Radicals From Direct Solar Actinic Photolysis Of Aqueous Pyruvic Acid, Alexis J. Eugene, Marcelo I. Guzman

Chemistry Faculty Publications

The variable composition of secondary organic aerosols (SOA) contributes to the large uncertainty for predicting radiative forcing. A better understanding of the reaction mechanisms leading to aerosol formation such as for the photochemical reaction of aqueous pyruvic acid (PA) at λ ≥ 305 nm can contribute to constrain these uncertainties. Herein, the photochemistry of aqueous PA (5-300 mM) continuously sparged with air is re-examined in the laboratory under comparable irradiance at 38° N at noon on a summer day. Several analytical methods are employed to monitor the time series of the reaction, including (1) the derivatization of carbonyl (C═O) functional …

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Editorial: Platelet Secretion, Brian Storrie, Sidney W. Whiteheart Mar 2017

Editorial: Platelet Secretion, Brian Storrie, Sidney W. Whiteheart

Molecular and Cellular Biochemistry Faculty Publications

No abstract provided.

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Aberrant Coordination Geometries Discovered In The Most Abundant Metalloproteins, Sen Yao, Robert M. Flight, Eric C. Rouchka, Hunter N. B. Moseley Mar 2017

Aberrant Coordination Geometries Discovered In The Most Abundant Metalloproteins, Sen Yao, Robert M. Flight, Eric C. Rouchka, Hunter N. B. Moseley

Molecular and Cellular Biochemistry Faculty Publications

Metalloproteins bind and utilize metal ions for a variety of biological purposes. Due to the ubiquity of metalloprotein involvement throughout these processes across all domains of life, how proteins coordinate metal ions for different biochemical functions is of great relevance to understanding the implementation of these biological processes. Toward these ends, we have improved our methodology for structurally and functionally characterizing metal binding sites in metalloproteins. Our new ligand detection method is statistically much more robust, producing estimated false positive and false negative rates of ∼0.11% and ∼1.2%, respectively. Additional improvements expand both the range of metal ions and their …

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Zhx2 (Zinc Fingers And Homeoboxes 2) Regulates Major Urinary Protein Gene Expression In The Mouse Liver, Jieyun Jiang, Kate Townsend Creasy, Justin Purnell, Martha L. Peterson, Brett T. Spear Mar 2017

Zhx2 (Zinc Fingers And Homeoboxes 2) Regulates Major Urinary Protein Gene Expression In The Mouse Liver, Jieyun Jiang, Kate Townsend Creasy, Justin Purnell, Martha L. Peterson, Brett T. Spear

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The mouse major urinary proteins (Mups) are encoded by a large family of highly related genes clustered on chromosome 4. Mups, synthesized primarily and abundantly in the liver and secreted through the kidneys, exhibit male-biased expression. Mups bind a variety of volatile ligands; these ligands, and Mup proteins themselves, influence numerous behavioral traits. Although urinary Mup protein levels vary between inbred mouse strains, this difference is most pronounced in BALB/cJ mice, which have dramatically low urinary Mup levels; this BALB/cJ trait had been mapped to a locus on chromosome 15. We previously identified Zhx2 (zinc fingers and homeoboxes 2) as …

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Epigenomic Reprogramming In Inorganic Arsenic-Mediated Gene Expression Patterns During Carcinogenesis, Meredith Eckstein, Rebekah Eleazer, Matthew Rea, Yvonne N. Fondufe-Mittendorf Mar 2017

Epigenomic Reprogramming In Inorganic Arsenic-Mediated Gene Expression Patterns During Carcinogenesis, Meredith Eckstein, Rebekah Eleazer, Matthew Rea, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Arsenic is a ubiquitous metalloid that is not mutagenic but is carcinogenic. The mechanism(s) by which arsenic causes cancer remain unknown. To date, several mechanisms have been proposed, including the arsenic-induced generation of reactive oxygen species (ROS). However, it is also becoming evident that inorganic arsenic (iAs) may exert its carcinogenic effects by changing the epigenome, and thereby modifying chromatin structure and dynamics. These epigenetic changes alter the accessibility of gene regulatory factors to DNA, resulting in specific changes in gene expression both at the levels of transcription initiation and gene splicing. In this review, we discuss recent literature reports …

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The Mirnaome Of Catharanthus Roseus: Identification, Expression Analysis, And Potential Roles Of Micrornas In Regulation Of Terpenoid Indole Alkaloid Biosynthesis, Ethan M. Shen, Sanjay Kumar Singh, Jayadri S. Ghosh, Barunava Patra, Priyanka Paul, Ling Yuan, Sitakanta Pattanaik Feb 2017

The Mirnaome Of Catharanthus Roseus: Identification, Expression Analysis, And Potential Roles Of Micrornas In Regulation Of Terpenoid Indole Alkaloid Biosynthesis, Ethan M. Shen, Sanjay Kumar Singh, Jayadri S. Ghosh, Barunava Patra, Priyanka Paul, Ling Yuan, Sitakanta Pattanaik

Plant and Soil Sciences Faculty Publications

MicroRNAs (miRNAs) regulate numerous crucial biological processes in plants. However, information is limited on their involvement in the biosynthesis of specialized metabolites in plants, including Catharanthus roseus that produces a number of pharmaceutically valuable, bioactive terpenoid indole alkaloids (TIAs). Using small RNA-sequencing, we identified 181 conserved and 173 novel miRNAs (cro-miRNAs) in C. roseus seedlings. Genome-wide expression analysis revealed that a set of cro-miRNAs are differentially regulated in response to methyl jasmonate (MeJA). In silico target prediction identified 519 potential cro-miRNA targets that include several auxin response factors (ARFs). The presence of cleaved transcripts of miRNA-targeted ARFs in C. roseus …

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Calcium's Role As Nuanced Modulator Of Cellular Physiology In The Brain, Hilaree N. Frazier, Shaniya Maimaiti, Katie L. Anderson, Lawrence D. Brewer, John C. Gant, Nada M. Porter, Olivier Thibault Feb 2017

Calcium's Role As Nuanced Modulator Of Cellular Physiology In The Brain, Hilaree N. Frazier, Shaniya Maimaiti, Katie L. Anderson, Lawrence D. Brewer, John C. Gant, Nada M. Porter, Olivier Thibault

Pharmacology and Nutritional Sciences Faculty Publications

Neuroscientists studying normal brain aging, spinal cord injury, Alzheimer’s disease (AD) and other neurodegenerative diseases have focused considerable effort on carefully characterizing intracellular perturbations in calcium dynamics or levels. At the cellular level, calcium is known for controlling life and death and orchestrating most events in between. For many years, intracellular calcium has been recognized as an essential ion associated with nearly all cellular functions from cell growth to degeneration. Often the emphasis is on the negative impact of calcium dysregulation and the typical worse-case-scenario leading inevitably to cell death. However, even high amplitude calcium transients, when executed acutely can …

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Hendra Virus Fusion Protein Transmembrane Domain Contributes To Pre-Fusion Protein Stability, Stacy Webb, Tamas Nagy, Hunter Moseley, Michael G. Fried, Rebecca Ellis Dutch Feb 2017

Hendra Virus Fusion Protein Transmembrane Domain Contributes To Pre-Fusion Protein Stability, Stacy Webb, Tamas Nagy, Hunter Moseley, Michael G. Fried, Rebecca Ellis Dutch

Molecular and Cellular Biochemistry Faculty Publications

Enveloped viruses utilize fusion (F) proteins studding the surface of the virus to facilitate membrane fusion with a target cell membrane. Fusion of the viral envelope with a cellular membrane is required for release of viral genomic material, so the virus can ultimately reproduce and spread. To drive fusion, the F protein undergoes an irreversible conformational change, transitioning from a metastable pre-fusion conformation to a more thermodynamically stable post-fusion structure. Understanding the elements that control stability of the pre-fusion state and triggering to the post-fusion conformation is important for understanding F protein function. Mutations in F protein transmembrane (TM) domains …

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Oled Loki As A Catalyst For Tertiary Amine And Hydroxamate Glycosylation, Ryan R. Hughes, Khaled A. Shaaban, Jianjun Zhang, Hongnan Cao, George N. Phillips Jr., Jon S. Thorson Feb 2017

Oled Loki As A Catalyst For Tertiary Amine And Hydroxamate Glycosylation, Ryan R. Hughes, Khaled A. Shaaban, Jianjun Zhang, Hongnan Cao, George N. Phillips Jr., Jon S. Thorson

Center for Pharmaceutical Research and Innovation Faculty Publications

We describe the ability of an engineered glycosyltransferase (OleD Loki) to catalyze the N‐glycosylation of tertiary‐amine‐containing drugs and trichostatin hydroxamate glycosyl ester formation. As such, this study highlights the first bacterial model catalyst for tertiary‐amine N‐glycosylation and further expands the substrate scope and synthetic potential of engineered OleDs. In addition, this work could open the door to the discovery of similar capabilities among other permissive bacterial glycosyltransferases.

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Dual-Functional-Tag-Facilitated Protein Labeling And Immobilization, Xinyi Zhang, Wei Lu, Kevin Kwan, Dibakar Bhattacharyya, Yinan Wei Feb 2017

Dual-Functional-Tag-Facilitated Protein Labeling And Immobilization, Xinyi Zhang, Wei Lu, Kevin Kwan, Dibakar Bhattacharyya, Yinan Wei

Chemistry Faculty Publications

An important strategy in the construction of biomimetic membranes and devices is to use natural proteins as the functional components for incorporation in a polymeric or nanocomposite matrix. Toward this goal, an important step is to immobilize proteins with high efficiency and precision without disrupting the protein function. Here, we developed a dual-functional tag containing histidine and the non-natural amino acid azidohomoalanine (AHA). AHA is metabolically incorporated into the protein, taking advantage of the Met-tRNA and Met-tRNA synthetase. Histidine in the tag can facilitate metal-affinity purification, whereas AHA can react with an alkyne-functionalized probe or surface via well-established click chemistry. …

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The Molecular Basis Of Talin2'S High Affinity Toward Β1-Integrin, Yaxia Yuan, Liqing Li, Yanyan Zhu, Lei Qi, Latifeh Azizi, Vesa P. Hytönen, Chang-Guo Zhan, Cai Huang Feb 2017

The Molecular Basis Of Talin2'S High Affinity Toward Β1-Integrin, Yaxia Yuan, Liqing Li, Yanyan Zhu, Lei Qi, Latifeh Azizi, Vesa P. Hytönen, Chang-Guo Zhan, Cai Huang

Molecular Modeling and Biopharmaceutical Center Faculty Publications

Talin interacts with β-integrin tails and actin to control integrin activation, thus regulating focal adhesion dynamics and cell migration. There are two talin genes, Tln1 and Tln2, which encode talin1 and talin2, and it is generally believed that talin2 functions redundantly with talin1. However, we show here that talin2 has a higher affinity to β1-integrin tails than talin1. Mutation of talin2 S339 to leucine, which can cause Fifth Finger Camptodactyly, a human genetic disease, completely disrupted its binding to β–integrin tails. Also, substitution of talin1 C336 with Ser enhanced the affinity of talin1, whereas substitution of talin2 S339 with …

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Genome-Wide Dna Methylation Reprogramming In Response To Inorganic Arsenic Links Inhibition Of Ctcf Binding, Dnmt Expression And Cellular Transformation, Matthew Rea, Meredith Eckstein, Rebekah Eleazer, Caroline Smith, Yvonne N. Fondufe-Mittendorf Feb 2017

Genome-Wide Dna Methylation Reprogramming In Response To Inorganic Arsenic Links Inhibition Of Ctcf Binding, Dnmt Expression And Cellular Transformation, Matthew Rea, Meredith Eckstein, Rebekah Eleazer, Caroline Smith, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Chronic low dose inorganic arsenic (iAs) exposure leads to changes in gene expression and epithelial-to-mesenchymal transformation. During this transformation, cells adopt a fibroblast-like phenotype accompanied by profound gene expression changes. While many mechanisms have been implicated in this transformation, studies that focus on the role of epigenetic alterations in this process are just emerging. DNA methylation controls gene expression in physiologic and pathologic states. Several studies show alterations in DNA methylation patterns in iAs-mediated pathogenesis, but these studies focused on single genes. We present a comprehensive genome-wide DNA methylation analysis using methyl-sequencing to measure changes between normal and iAs-transformed cells. …

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Novel Interconnections In Lipid Metabolism Revealed By Overexpression Of Sphingomyelin Synthase-1, Gergana M. Deevska, Patrick P. Dotson Ii, Alexander A. Karakashian, Giorgis Isaac, Mark Wrona, Samuel B. Kelly, Alfred H. Merrill Jr., Mariana N. Nikolova‑Karakashian Jan 2017

Novel Interconnections In Lipid Metabolism Revealed By Overexpression Of Sphingomyelin Synthase-1, Gergana M. Deevska, Patrick P. Dotson Ii, Alexander A. Karakashian, Giorgis Isaac, Mark Wrona, Samuel B. Kelly, Alfred H. Merrill Jr., Mariana N. Nikolova‑Karakashian

Physiology Faculty Publications

This study investigates the consequences of elevating sphingomyelin synthase 1 (SMS1) activity, which generates the main mammalian sphingolipid, sphingomyelin. HepG2 cells stably transfected with SMS1 (HepG2-SMS1) exhibit elevated enzyme activity in vitro and increased sphingomyelin content (mainly C22:0- and C24:0-sphingomyelin) but lower hexosylceramide (Hex-Cer) levels. HepG2-SMS1 cells have fewer triacylglycerols than controls but similar diacylglycerol acyltransferase activity, triacylglycerol secretion, and mitochondrial function. Treatment with 1 mm palmitate increases de novo ceramide synthesis in both cell lines to a similar degree, causing accumulation of C16:0-ceramide (and some C18:0-, C20:0-, and C22:0-ceramides) as well as C16:0- and C18:0-Hex-Cers. In these experiments, the …

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Omecamtiv Mecarbil Enhances The Duty Ratio Of Human Β-Cardiac Myosin Resulting In Increased Calcium Sensitivity And Slowed Force Development In Cardiac Muscle, Anja M. Swenson, Wanjian Tang, Cheavar A. Blair, Christopher M. Fetrow, William C. Unrath, Michael J. Previs, Kenneth S. Campbell, Christopher M. Yengo Jan 2017

Omecamtiv Mecarbil Enhances The Duty Ratio Of Human Β-Cardiac Myosin Resulting In Increased Calcium Sensitivity And Slowed Force Development In Cardiac Muscle, Anja M. Swenson, Wanjian Tang, Cheavar A. Blair, Christopher M. Fetrow, William C. Unrath, Michael J. Previs, Kenneth S. Campbell, Christopher M. Yengo

Physiology Faculty Publications

The small molecule drug omecamtiv mecarbil (OM) specifically targets cardiac muscle myosin and is known to enhance cardiac muscle performance, yet its impact on human cardiac myosin motor function is unclear. We expressed and purified human β-cardiac myosin subfragment 1 (M2β-S1) containing a C-terminal Avi tag. We demonstrate that the maximum actin-activated ATPase activity of M2β-S1 is slowed more than 4-fold in the presence of OM, whereas the actin concentration required for half-maximal ATPase was reduced dramatically (30-fold). We find OM does not change the overall actin affinity. Transient kinetic experiments suggest that there are …

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Functional And Structural Studies On The Neisseria Gonorrhoeae Gmha, The First Enzyme In The Glycero-Manno-Heptose Biosynthesis Pathways, Demonstrate A Critical Role In Lipooligosaccharide Synthesis And Gonococcal Viability, Igor H. Wierzbicki, Ryszard A. Zielke, Konstantin V. Korotkov, Aleksandra E. Sikora Jan 2017

Functional And Structural Studies On The Neisseria Gonorrhoeae Gmha, The First Enzyme In The Glycero-Manno-Heptose Biosynthesis Pathways, Demonstrate A Critical Role In Lipooligosaccharide Synthesis And Gonococcal Viability, Igor H. Wierzbicki, Ryszard A. Zielke, Konstantin V. Korotkov, Aleksandra E. Sikora

Molecular and Cellular Biochemistry Faculty Publications

Sedoheptulose-7-phosphate isomerase, GmhA, is the first enzyme in the biosynthesis of nucleotide-activated-glycero-manno-heptoses and an attractive, yet underexploited, target for development of broad-spectrum antibiotics. We demonstrated that GmhA homologs in Neisseria gonorrhoeae and N. meningitidis (hereafter called GmhAGC and GmhANM, respectively) were interchangeable proteins essential for lipooligosaccharide (LOS) synthesis, and their depletion had adverse effects on neisserial viability. In contrast, the Escherichia coli ortholog failed to complement GmhAGC depletion. Furthermore, we showed that GmhAGC is a cytoplasmic enzyme with induced expression at mid-logarithmic phase, upon iron deprivation and anaerobiosis, and conserved in contemporary gonococcal …

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