Structural Biology Commons^™

Itraq-Based Proteomics Analysis And Network Integration For Kernel Tissue Development In Maize, Long Zhang, Yongbin Dong, Qilei Wang, Chunguang Du, Wenwei Xiong, Xinyu Li, Sailan Zhu, Yuling Li

Department of Biology Faculty Scholarship and Creative Works

Grain weight is one of the most important yield components and a developmentally complex structure comprised of two major compartments (endosperm and pericarp) in maize (Zea mays L.), however, very little is known concerning the coordinated accumulation of the numerous proteins involved. Herein, we used isobaric tags for relative and absolute quantitation (iTRAQ)-based comparative proteomic method to analyze the characteristics of dynamic proteomics for endosperm and pericarp during grain development. Totally, 9539 proteins were identified for both components at four development stages, among which 1401 proteins were non-redundant, 232 proteins were specific in pericarp and 153 proteins were specific in …

Molecular Mechanisms Of C-Terminal Eps15 Homology Domain Containing (Ehd) Protein Function, Kriti Bahl

Theses & Dissertations

Endocytic trafficking is not only an essential process for the maintenance of cellular homeostasis but also plays a vital role in regulating diverse cellular processes such as signaling, migration and cell division. The C-terminal Eps 15 Homology Domain proteins (EHD1-4) play pivotal roles in regulating distinct steps of endocytic trafficking. Among the EHDs, EHD2 is disparate both in terms of sequence homology (70%) and its subcellular localization at the caveolae. The crystal structure of EHD2 has been solved and it contains an unstructured loop consisting of two proline-phenylalanine (PF) motifs: KPFRKLNPF. However, the other paralogs EHD1, …

Determining The Structure Of Phospholipase C Epsilon, Hannah O'Neill, Monita Sieng, Elisabeth Garland-Kuntz, Angeline Lyon

The Summer Undergraduate Research Fellowship (SURF) Symposium

The phospholipase C (PLC) epsilon subfamily of PLC enzymes are found at highest concentration within the cardiovascular system. Improper functioning of the enzyme, whether due to overstimulation or changes in expression, has far-reaching effects within the human body Stunted heart valve development and cardiac hypertrophy and are two such examples. The mechanisms by which PLC epsilon activity is regulated in these processes remain unknown, as does the physical structure of the enzyme. In this study, we seek to determine the structure of a PLC epsilon fragment that retains enzymatic activity and is amenable to crystallization. Mutagenesis of PLC epsilon cDNA …

Quaternary Interactions And Supercoiling Modulate The Cooperative Dna Binding Of Agt, Manana Melikishvili, Michael G. Fried

Center for Structural Biology Faculty Publications

Human O⁶-alkylguanine-DNA alkyltransferase (AGT) repairs mutagenic O⁶-alkylguanine and O⁴-alkylthymine adducts in single-stranded and duplex DNAs. The search for these lesions, through a vast excess of competing, unmodified genomic DNA, is a mechanistic challenge that may limit the repair rate in vivo. Here, we examine influences of DNA secondary structure and twist on protein–protein interactions in cooperative AGT complexes formed on lesion-free DNAs that model the unmodified parts of the genome. We used a new approach to resolve nearest neighbor (nn) and long-range (lr) components from the ensemble-average cooperativity, ω_ave. We found …

Transcriptomic Differentiation Underlying Marine‐To‐Freshwater Transitions In The South American Silversides Odontesthes Argentinensis And O. Bonariensis (Atheriniformes), Lily Hughes, Gustavo Somoza, Bryan Nguyen, James Bernot, Mariano Gonzalez-Castro, Juan Martin Diaz De Astarloa, Guillermo Orti

Computational Biology Institute

Salinity gradients are critical habitat determinants for freshwater organisms. Silverside fishes in the genus Odontesthes have recently and repeatedly transitioned from marine to freshwater habitats, overcoming a strong ecological barrier. Genomic and transcriptomic changes involved in this kind of transition are only known for a few model species. We present new data and analyses of gene expression and microbiome composition in the gills of two closely related silverside species, marine O. argentinensis and freshwater O. bonariensis and find more than three thousand transcripts differentially expressed, with osmoregulatory/ion transport genes and immune genes showing very different expression patterns across species. Interspecific …

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 …

Conserved Amino Acid Networks Modulate Discrete Functional Properties In An Enzyme Superfamily, Chitra Narayanan, Donald Gagne, Kimberly A. Reynolds, Nicolas Doucet

Advanced Science Research Center

In this work, we applied the sequence-based statistical coupling analysis approach to characterize conserved amino acid networks important for biochemical function in the pancreatic-type ribonuclease (ptRNase) superfamily. This superfamily-wide analysis indicates a decomposition of the RNase tertiary structure into spatially distributed yet physically connected networks of co-evolving amino acids, termed sectors. Comparison of this statistics-based description with new NMR experiments data shows that discrete amino acid networks, termed sectors, control the tuning of distinct functional properties in different enzyme homologs. Further, experimental characterization of evolutionarily distant sequences reveals that sequence variation at sector positions can distinguish homologs with a conserved …

Rnaseq Analysis Of The Drosophila Response To The Entomopathogenic Nematode Steinernema., Shruti Yadav, Sean Daugherty, Amol Carl Shetty, Ioannis Eleftherianos

Computational Biology Institute

Drosophila melanogaster is an outstanding model to study the molecular and functional basis of host-pathogen interactions. Currently, our knowledge of microbial infections in D. melanogaster is well understood; however, the response of flies to nematode infections is still in its infancy. Here, we have used the potent parasitic nematode Steinernema carpocapsae, which lives in mutualism with its endosymbiotic bacteria Xenorhabdus nematophila, to examine the transcriptomic basis of the interaction between D. melanogaster and entomopathogenic nematodes. We have employed next-generation RNA sequencing (RNAseq) to investigate the transcriptomic profile of D. melanogaster larvae in response to infection by S. carpocapsae symbiotic (carrying …

2d Nmr Structural Study Of A Dna Duplex Containing Two Unnatural Base Pairs, Weston Preising

Undergraduate Honors Theses

DNA is the genetic blueprint responsible for the traits of living organisms. The "genetic alphabet" consists of four molecules called nucleobases, represented by the letters A, T, G, and C strung together in a "strand." A DNA duplex consists of two "strands" held together such that A is across from T and G across from C, referred to A-T and G-C "base pairs". Recently, the genetic alphabet or code has been expanded by synthetic biologists in an effort to unveil new insights to the machinery of DNA replication, and potentially develop new medicines to cure diseases like HIV. The new …

Estimation Of The True Evolutionary Distance Under The Fragile Breakage Model., Nikita Alexeev, Max A Alekseyev

Computational Biology Institute

BACKGROUND: The ability to estimate the evolutionary distance between extant genomes plays a crucial role in many phylogenomic studies. Often such estimation is based on the parsimony assumption, implying that the distance between two genomes can be estimated as the rearrangement distance equal the minimal number of genome rearrangements required to transform one genome into the other. However, in reality the parsimony assumption may not always hold, emphasizing the need for estimation that does not rely on the rearrangement distance. The distance that accounts for the actual (rather than minimal) number of rearrangements between two genomes is often referred to …

Characterization Of Genes Involved In Phycobiliprotein Biosynthesis In Fremyella Diplosiphon And Thermosynechococcus Elongatus, Christina M. Kronfel

LSU New Orleans Theses and Dissertations

Cyanobacteria are photosynthetic organisms that efficiently capture light by utilizing the light-harvesting complexes called phycobilisomes. In many cyanobacteria, phycobilisomes are composed of an allophycocyanin core with phycocyanin and phycoerythrin (PE) rods radiating from the core. These phycobiliproteins have multiple bilin chromophores, such as phycoerythrobilin (PEB), covalently attached to specific cysteine (Cys) residues for efficient photosynthetic light capture. Chromophore ligation on phycobiliprotein subunits occurs through bilin lyase catalyzed reactions.

This study mainly focuses on characterizing the roles of enzymes that are involved in the biosynthetic pathway of the phycobiliproteins within two cyanobacteria Thermosynechococcus elongatus and Fremyella diplosiphon. A combination of molecular …

Transcriptomic Effects Of Dispersed Oil In A Non-Model Decapod Crustacean, Hernan Vazquez-Miranda, Brent Thoma, Juliet Wong, Darryl Felder, Keith A. Crandall, Heather Bracken-Grissom

Computational Biology Institute

Background. Oil spills are major environmental disasters. Dispersants help control spills, as they emulsify oil into droplets to speed bioremediation. Although dispersant toxicity is controversial, the genetic consequences and damages of dispersed oil exposure are poorly understood. We used RNA-seq to measure gene expression of flatback mudcrabs (Eurypanopeus depressus, Decapoda, Brachyura, Panopeidae) exposed to dispersed oil.

Methods. Our experimental design included two control types, oil-only, and oil-dispersant treatments with three replicates each. We prepared 100 base pair-ended libraries from total RNA and sequenced them in one Illumina HiSeq2000 lane. We assembled a reference transcriptome with all replicates per treatment, …

Science, Between The Lines: Rosalind Franklin, Rachael Renzi

Senior Honors Projects

The purpose of this paper is to contrast scientific rhetoric with creative biographical writing style. Both forms of communication rely on specific syntax and styles to describe research findings to the appropriate audiences, but the often passive format of scientific literature excludes the passionate reasonings of the researcher. In order to understand why the scientist is kept separate from his or her published findings, I am going to experiment with the two contrasting forms. Throughout the paper, each form will be tested and used at varying levels. Both scientific and creative writing will be mixed. To emphasize the technically dense …

Characterization Of Andrenocortical Tissue Morphology, Histology, And Steroid Synthesis Among Finetooth (Carcharhinus Isodon), Blacktip (Carcharhinus Limbatus), Atlantic Sharpnose (Rhizoprionodon Terraenovae), And Bonnethead (Sphyrna Tiburo) Sharks, Danielle Elizabeth Bailey

Master's Theses

Adrenocortical (interrenal) tissue is composed of steroidogenic cells that produce corticosteroids involved in the stress response and hydromineral balance. Previous research characterizing the elasmobranch interrenal suggests that the number of interrenal bodies that produce the single primary corticosteroid, 1a-hydroxycorticosterone (1a-OHB), varies among species. However, potential species-specific differences in the amount of interrenal tissue and major steroid products produced have been understudied. To address this critical gap in our understanding of elasmobranch biology, this study examined interrenal morphology, cell structure, steroidogenic enzyme distribution (3bHSD), and steroid production in four shark species: Finetooth Carcharhinus isodon, Blacktip Carcharhinus limbatus, Atlantic Sharpnose …

Fret-Based Investigations Of The Structure-Function Relationships In The Nmda Receptor, Drew M. Dolino

Dissertations and Theses (Open Access)

The N-methyl-D-aspartate (NMDA) receptor is one member of a class of proteins known as the ionotropic glutamate receptors. Ionotropic glutamate receptors mediate the majority of excitatory neurotransmission in the central nervous system, with the NMDA receptor standing out among these receptors for its requirement of a co-agonist, its magnesium-block-based coincidence detection, its slow kinetics, its calcium permeability, its allosteric modulation, and its especially important functional roles in synaptic plasticity, excitotoxicity, and more. In recent years, a wealth of structural information has come about describing endpoint structures to high resolution, but such structures are unable to fully resolve the movements …

Validation Of The Pre-B Cell Receptor As A Therapeutic Target In B Cell Precursor Acute Lymphoblastic Leukemia, Michael Frank Erasmus

Biomedical Sciences ETDs

This dissertation is built upon the fundamental idea that the pre-B cell receptor (pre-BCR) is important to leukemia cell survival and a logical therapeutic target in B cell precursor acute lymphoblastic leukemia (BCP-ALL). The pre-BCR is expressed early at a specific stage during B cell development where it plays a central role in survival of healthy B lymphocytes. This receptor is composed of the membrane heavy chain (mIgμ) associated with surrogate light chain components, 5 and VpreB. Through the use of advanced imaging modalities, in particular two-color single particle tracking (SPT), we showed that pre-BCRs formed transient, homotypic interactions. These …

Quantitative Evaluation Of Clinostomum Marginatum Distribution In The Fish Host (Perca Flavescens): Investigation Of The Impact On Functional Performance, Doiba Ki Eshofonie, Precious Freeman

Student Scholar Showcase

Doiba Eshofonie & Precious Freeman

Mentor: Takashi Maie

2017 Student Scholar Showcase

Quantitative evaluation of Clinostomum marginatum distribution in the fish host (Perca flavescens): Investigation of the impact on functional performance

Clinostomum marginatum is a trematode commonly found in freshwater fish. The adult C. marginatum stays in its definitive avian host’s mouth and throat. It releases eggs upon contact in water and the eggs hatch into a free-swimming miracidia, which infects an aquatic snail as the first intermediate host. The miracidia, then, develops into a cercaria and leaves the snail to find a fish as its second intermediate …

Docking Studies Of Isoform-Selectivity Of Phosphatidylinositol 3-Kinase (Pi3k) Inhibitors, Kaitlin Goettsch

UNO Student Research and Creative Activity Fair

Phosphatidylinositol 3-kinases (PI3Ks) and their related pathways are reputed targets for drug-based anticancer therapies. Mutations in PI3K genes, expression, and pathways are frequent among multiple cancer types. Four isoforms of PI3Ks exist: α, β, γ, & δ and studies have identified several ligands for each isoform which are capable of serving as inhibitory therapeutic compounds. However, the biochemical efficacy of these molecules varies and the isoform selectivity is not well understood. In this study, we applied in silico docking methods and free energy calculation methods to estimate the binding of reported PI3K ligands against 5 PI3K structures: PI3Kα (PBD ID: …

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 …

The Temporal Dynamics Of The Tracheal Microbiome In Tracheostomised Patients With And Without Lower Respiratory Infections., Marcos Pérez-Losada, Robert J Graham, Madeline Coquillette, Amenah Jafarey, Eduardo Castro-Nallar, Manuel Aira, Robert J Freishtat, Jonathan M Mansbach

Computational Biology Institute

Background: Airway microbiota dynamics during lower respiratory infection (LRI) are still poorly understood due, in part, to insufficient longitudinal studies and lack of uncontaminated lower airways samples. Furthermore, the similarity between upper and lower airway microbiomes is still under debate. Here we compare the diversity and temporal dynamics of microbiotas directly sampled from the trachea via tracheostomy in patients with (YLRI) and without (NLRI) lower respiratory infections. Methods: We prospectively collected 127 tracheal aspirates across four consecutive meteorological seasons (quarters) from 40 patients, of whom 20 developed LRIs and 20 remained healthy. All aspirates were collected when patients had no …