Life Sciences Commons^™

Mtorc2 Is Required For Rit-Mediated Oxidative Stress Resistance, Weikang Cai, Douglas A. Andres

Molecular and Cellular Biochemistry Faculty Publications

Rit, a member of the Ras family of GTPases, has been shown to promote cell survival in response to oxidative stress, in part by directing an evolutionarily conserved p38 MAPK-Akt survival cascade. Aberrant Rit signaling has recently been implicated as a driver mutation in human cancer, adding importance to the characterization of critical Rit effector pathways. However, the mechanism by which Rit-p38 signaling regulated Akt activity was unknown. Here, we identify mTORC2 as a critical downstream mediator of Rit-dependent survival signaling in response to reactive oxygen species (ROS) stress. Rit interacts with Sin1 (MAPKAP1), and Rit loss compromises ROS-dependent mTORC2 …

Transcription Of The Streptococcus Pyogenes Hyaluronic Acid Capsule Biosynthesis Operon Is Regulated By Previously Unknown Upstream Elements, Marina Falaleeva, Oliwia W. Zurek, Robert L. Watkins, Robert W. Reed, Hadeel Ali, Paul Sumby, Jovanka M. Voyich, Natalia Korotkova

Molecular and Cellular Biochemistry Faculty Publications

The important human pathogen Streptococcus pyogenes (group A Streptococcus [GAS]) produces a hyaluronic acid (HA) capsule that plays critical roles in immune evasion. Previous studies showed that the hasABC operon encoding the capsule biosynthesis enzymes is under the control of a single promoter, P1, which is negatively regulated by the two-component regulatory system CovR/S. In this work, we characterize the sequence upstream of P1 and identify a novel regulatory region controlling transcription of the capsule biosynthesis operon in the M1 serotype strain MGAS2221. This region consists of a promoter, P2, which initiates transcription of a novel small RNA, HasS, an …

Deficiency Of Kruppel-Like Factor Klf4 In Myeloid-Derived Suppressor Cells Inhibits Tumor Pulmonary Metastasis In Mice Accompanied By Decreased Fibrocytes, Y. Shi, L. Ou, S. Han, M. Li, M. M. O. Pena, E. A. Pena, Chunming Liu, M. Nagarkatti, D. Fan, W. Ai

Molecular and Cellular Biochemistry Faculty Publications

The importance of immunosuppressive myeloid-derived suppressor cells (MDSCs) bearing monocyte markers in tumor metastasis has been well established. Recently, it was reported that these cells possess phenotypic plasticity and differentiate into fibrocytes, very distinct cells that are precursors of tumorigenic myofibroblasts. However, the importance of this transdifferentiation in tumor metastasis has not been explored. Here, we describe the role of MDSC-derived fibrocytes in tumor metastasis that is regulated by Kruppel-like factor 4 (KLF4), a transcription factor that is critical to monocyte differentiation and to promotion of cancer development. Using mouse metastasis models of melanoma and breast cancer, we found that …

Egfr Phosphorylates And Inhibits Lung Tumor Suppressor Gprc5a In Lung Cancer, Xiaofeng Lin, Shuangshuang Zhong, Xiaofeng Ye, Yueling Liao, Feng Yao, Xiaohua Yang, Beibei Sun, Jie Zhang, Qi Li, Yong Gao, Yifan Wang, Jingyi Liu, Baohui Han, Y. Eugene Chin, Binhua P. Zhou, Jiong Deng

Molecular and Cellular Biochemistry Faculty Publications

BACKGROUND: GPRC5A is a retinoic acid inducible gene that is preferentially expressed in lung tissue. Gprc5a- knockout mice develop spontaneous lung cancer, indicating Gprc5a is a lung tumor suppressor gene. GPRC5A expression is frequently suppressed in majority of non-small cell lung cancers (NSCLCs), however, elevated GPRC5A is still observed in a small portion of NSCLC cell lines and tumors, suggesting that the tumor suppressive function of GPRC5A is inhibited in these tumors by an unknown mechanism.

METHODS: In this study, we examined EGF receptor (EGFR)-mediated interaction and tyrosine phosphorylation of GPRC5A by immunoprecipitation (IP)-Westernblot. Tyrosine phosphorylation of GPRC5A by EGFR …

A Tale Of Two Trials: The Impact Of 5Α-Reductase Inhibition On Prostate Cancer (Review), John M. Lacy, Natasha Kyprianou

Molecular and Cellular Biochemistry Faculty Publications

The use of 5α-reductase inhibitors (5α-RIs) as prostate cancer chemoprevention agents is controversial. Two large randomized trials, the Prostate Cancer Prevention Trial (PCPT) and the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) Trial, have both shown a decreased incidence of prostate cancer in patients administered with 5α-RIs. Both studies showed, however, an increased risk of higher-grade prostate cancer. Numerous studies have since analyzed the inherent biases in these landmark studies and have used mathematical modeling to estimate the true incidence of prostate cancer and the risk for high-grade prostate cancer in patients undergoing 5α-RI treatment. All primary publications associated …

Platelet Secretion And Hemostasis Require Syntaxin-Binding Protein Stxbp5, Shaojing Ye, Yunjie Huang, Smita Joshi, Jinchao Zhang, Fanmuyi Yang, Guoying Zhang, Susan S. Smyth, Zhenyu Li, Yoshimi Takai, Sidney W. Whiteheart

Molecular and Cellular Biochemistry Faculty Publications

Genome-wide association studies (GWAS) have linked genes encoding several soluble NSF attachment protein receptor (SNARE) regulators to cardiovascular disease risk factors. Because these regulatory proteins may directly affect platelet secretion, we used SNARE-containing complexes to affinity purify potential regulators from human platelet extracts. Syntaxin-binding protein 5 (STXBP5; also known as tomosyn-1) was identified by mass spectrometry, and its expression in isolated platelets was confirmed by RT-PCR analysis. Coimmunoprecipitation studies showed that STXBP5 interacts with core secretion machinery complexes, such as syntaxin-11/SNAP23 heterodimers, and fractionation studies suggested that STXBP5 also interacts with the platelet cytoskeleton. Platelets from Stxbp5 KO mice had …

Huwe1 Is A Molecular Link Controlling Raf-1 Activity Supported By The Shoc2 Scaffold, Eun Ryoung Jang, Ping Shi, Jamal Bryant, Jing Chen, Vikas Dukhande, Matthew S. Gentry, Hyein Jang, Myoungkun Jeoung, Emilia Galperin

Molecular and Cellular Biochemistry Faculty Publications

Scaffold proteins play a critical role in controlling the activity of the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway. Shoc2 is a leucine-rich repeat scaffold protein that acts as a positive modulator of ERK1/2 signaling. However, the precise mechanism by which Shoc2 modulates the activity of the ERK1/2 pathway is unclear. Here we report the identification of the E3 ubiquitin ligase HUWE1 as a binding partner and regulator of Shoc2 function. HUWE1 mediates ubiquitination and, consequently, the levels of Shoc2. Additionally, we show that both Shoc2 and HUWE1 are necessary to control the levels and ubiquitination of the Shoc2 signaling partner, …

Repair Of O6-Methylguanine Adducts In Human Telomeric G-Quadruplex Dna By O6-Alkylguanine-Dna Alkyltransferase, Lance M. Hellman, Tyler J. Spear, Colton J. Koontz, Manana Melikishvili, Michael G. Fried

Molecular and Cellular Biochemistry Faculty Publications

O⁶-alkylguanine-DNA alkyltransferase (AGT) is a single-cycle DNA repair enzyme that removes pro-mutagenic O⁶-alkylguanine adducts from DNA. Its functions with short single-stranded and duplex substrates have been characterized, but its ability to act on other DNA structures remains poorly understood. Here, we examine the functions of this enzyme on O⁶-methylguanine (6mG) adducts in the four-stranded structure of the human telomeric G-quadruplex. On a folded 22-nt G-quadruplex substrate, binding saturated at 2 AGT:DNA, significantly less than the ~ 5 AGT:DNA found with linear single-stranded DNAs of similar length, and less than the value found with the …

Paramyxovirus Glycoprotein Incorporation, Assembly And Budding: A Three Way Dance For Infectious Particle Production, Farah El Najjar, Anthony P. Schmitt, Rebecca Ellis Dutch

Molecular and Cellular Biochemistry Faculty Publications

Paramyxoviruses are a family of negative sense RNA viruses whose members cause serious diseases in humans, such as measles virus, mumps virus and respiratory syncytial virus; and in animals, such as Newcastle disease virus and rinderpest virus. Paramyxovirus particles form by assembly of the viral matrix protein, the ribonucleoprotein complex and the surface glycoproteins at the plasma membrane of infected cells and subsequent viral budding. Two major glycoproteins expressed on the viral envelope, the attachment protein and the fusion protein, promote attachment of the virus to host cells and subsequent virus-cell membrane fusion. Incorporation of the surface glycoproteins into infectious …

Development And In Silico Evaluation Of Large-Scale Metabolite Identification Methods Using Functional Group Detection For Metabolomics, Joshua M. Mitchell, Teresa W-M Fan, Andrew N. Lane, Hunter N. B. Moseley

Molecular and Cellular Biochemistry Faculty Publications

Large-scale identification of metabolites is key to elucidating and modeling metabolism at the systems level. Advances in metabolomics technologies, particularly ultra-high resolution mass spectrometry (MS) enable comprehensive and rapid analysis of metabolites. However, a significant barrier to meaningful data interpretation is the identification of a wide range of metabolites including unknowns and the determination of their role(s) in various metabolic networks. Chemoselective (CS) probes to tag metabolite functional groups combined with high mass accuracy provide additional structural constraints for metabolite identification and quantification. We have developed a novel algorithm, Chemically Aware Substructure Search (CASS) that efficiently detects functional groups within …

The Human Metapneumovirus Small Hydrophobic Protein Has Properties Consistent With Those Of A Viroporin And Can Modulate Viral Fusogenic Activity, Cyril Masante, Farah El Najjar, Andres Chang, Angela Jones, Carole L. Moncman, Rebecca Ellis Dutch

Molecular and Cellular Biochemistry Faculty Publications

Human metapneumovirus (HMPV) encodes three glycoproteins: the glycoprotein, which plays a role in glycosaminoglycan binding, the fusion (F) protein, which is necessary and sufficient for both viral binding to the target cell and fusion between the cellular plasma membrane and the viral membrane, and the small hydrophobic (SH) protein, whose function is unclear. The SH protein of the closely related respiratory syncytial virus has been suggested to function as a viroporin, as it forms oligomeric structures consistent with a pore and alters membrane permeability. Our analysis indicates that both the full-length HMPV SH protein and the isolated SH protein transmembrane …

Amino Acid Racemase Enzyme Assays, Atanas D. Radkov, Luke A. Moe

Plant and Soil Sciences Faculty Publications

Amino acid racemases are enzymes that invert the α-carbon stereochemistry of amino acids (AAs), interconverting amino acids between their L- and D-enantiomers in a reversible reaction. In bacteria, they are known to have catabolic physiological functions but are also involved in the synthesis of many D-AAs, including D-glutamate and D-alanine, which are necessary components of the peptidoglycan layer of the bacterial cell wall. As such, amino acid racemases represent significant targets for the development of bactericidal compounds. Amino acid racemases are also regarded by the biotechnological industry as important catalysts for the production of economically relevant D-AAs. Here, we provide …

Control Of Cellular Motility By Neuropilin-Mediated Physical Interactions, Xiaobo Li, Matthew W. Parker, Craig W. Vander Kooi

Molecular and Cellular Biochemistry Faculty Publications

The neuropilin (Nrp) family consists of multifunctional cell surface receptors with critical roles in a number of different cell and tissue types. A core aspect of Nrp function is in ligand-dependent cellular migration, where it controls the multistep process of cellular motility through integration of ligand binding and receptor signaling. At a molecular level, the role of Nrp in migration is intimately connected to the control of adhesive interactions and cytoskeletal reorganization. Here, we review the physiological role of Nrp in cellular adhesion and motility in the cardiovascular and nervous systems. We also discuss the emerging pathological role of Nrp …

Acetobixan, An Inhibitor Of Cellulose Synthesis Identified By Microbial Bioprospecting, Ye Xia, Lei Lei, Chad Brabham, Jozsef Stork, James R. Strickland, Adam Ladak, Ying Gu, Ian Wallace, Seth Debolt

Horticulture Faculty Publications

In plants, cellulose biosynthesis is an essential process for anisotropic growth and therefore is an ideal target for inhibition. Based on the documented utility of small-molecule inhibitors to dissect complex cellular processes we identified a cellulose biosynthesis inhibitor (CBI), named acetobixan, by bio-prospecting among compounds secreted by endophytic microorganisms. Acetobixan was identified using a drug-gene interaction screen to sift through hundreds of endophytic microbial secretions for one that caused synergistic reduction in root expansion of the leaky AtcesA6prc1-1 mutant. We then mined this microbial secretion for compounds that were differentially abundant compared with Bacilli that failed to mimic CBI action …

Expression, Purification And Characterization Of Soluble Red Rooster Laforin As A Fusion Protein In Escherichia Coli, M. Kathryn Brewer, Satrio Husodo, Vikas V. Dukhande, Mary Beth Johnson, Matthew S. Gentry

Molecular and Cellular Biochemistry Faculty Publications

BACKGROUND: The gene that encodes laforin, a dual-specificity phosphatase with a carbohydrate-binding module, is mutated in Lafora disease (LD). LD is an autosomal recessive, fatal progressive myoclonus epilepsy characterized by the intracellular buildup of insoluble, hyperphosphorylated glycogen-like particles, called Lafora bodies. Laforin dephosphorylates glycogen and other glucans in vitro, but the structural basis of its activity remains unknown. Recombinant human laforin when expressed in and purified from E. coli is largely insoluble and prone to aggregation and precipitation. Identification of a laforin ortholog that is more soluble and stable in vitro would circumvent this issue.

RESULTS: In this study, we …

Sudemycin E Influences Alternative Splicing And Changes Chromatin Modifications, Paolo Convertini, Manli Shen, Philip M. Potter, Gustavo Palacios, Chandraiah Lagisetti, Pierre De La Grange, Craig Horbinski, Yvonne N. Fondufe-Mittendorf, Thomas R. Webb, Stefan Stamm

Molecular and Cellular Biochemistry Faculty Publications

Sudemycin E is an analog of the pre-messenger RNA splicing modulator FR901464 and its derivative spliceostatin A. Sudemycin E causes the death of cancer cells through an unknown mechanism. We found that similar to spliceostatin A, sudemycin E binds to the U2 small nuclear ribonucleoprotein (snRNP) component SF3B1. Native chromatin immunoprecipitations showed that U2 snRNPs physically interact with nucleosomes. Sudemycin E induces a dissociation of the U2 snRNPs and decreases their interaction with nucleosomes. To determine the effect on gene expression, we performed genome-wide array analysis. Sudemycin E first causes a rapid change in alternative pre-messenger RNA splicing, which is …

Use Of Synthetic Isoprenoids To Target Protein Prenylation And Rho Gtpases In Breast Cancer Invasion, Min Chen, Teresa Knifley, Thangaiah Subramanian, H. Peter Spielmann, Kathleen L. O'Connor

Molecular and Cellular Biochemistry Faculty Publications

Dysregulation of Ras and Rho family small GTPases drives the invasion and metastasis of multiple cancers. For their biological functions, these GTPases require proper subcellular localization to cellular membranes, which is regulated by a series of post-translational modifications that result in either farnesylation or geranylgeranylation of the C-terminal CAAX motif. This concept provided the rationale for targeting farnesyltransferase (FTase) and geranylgeranyltransferases (GGTase) for cancer treatment. However, the resulting prenyl transferase inhibitors have not performed well in the clinic due to issues with alternative prenylation and toxicity. As an alternative, we have developed a unique class of potential anti-cancer therapeutics called …

Computational Design Of The Affinity And Specificity Of A Therapeutic T Cell Receptor, Brian G. Pierce, Lance M. Hellman, Moushumi Hossain, Nishant K. Singh, Craig W. Vander Kooi, Zhiping Weng, Brian M. Baker

Molecular and Cellular Biochemistry Faculty Publications

T cell receptors (TCRs) are key to antigen-specific immunity and are increasingly being explored as therapeutics, most visibly in cancer immunotherapy. As TCRs typically possess only low-to-moderate affinity for their peptide/MHC (pMHC) ligands, there is a recognized need to develop affinity-enhanced TCR variants. Previous in vitro engineering efforts have yielded remarkable improvements in TCR affinity, yet concerns exist about the maintenance of peptide specificity and the biological impacts of ultra-high affinity. As opposed to in vitro engineering, computational design can directly address these issues, in theory permitting the rational control of peptide specificity together with relatively controlled increments in affinity. …

The Chromatin Architectural Proteins Hmgd1 And H1 Bind Reciprocally And Have Opposite Effects On Chromatin Structure And Gene Regulation, Narasimharao Nalabothula, Graham Mcvicker, John Maiorano, Rebecca Martin, Jonathan K. Pritchard, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

BACKGROUND: Chromatin architectural proteins interact with nucleosomes to modulate chromatin accessibility and higher-order chromatin structure. While these proteins are almost certainly important for gene regulation they have been studied far less than the core histone proteins.

RESULTS: Here we describe the genomic distributions and functional roles of two chromatin architectural proteins: histone H1 and the high mobility group protein HMGD1 in Drosophila S2 cells. Using ChIP-seq, biochemical and gene specific approaches, we find that HMGD1 binds to highly accessible regulatory chromatin and active promoters. In contrast, H1 is primarily associated with heterochromatic regions marked with repressive histone marks. We find …

Characterization Of Jabba, A Ricin-Resistant Mutant Of Leishmania Donovani, Megan Rhea Phillips

Theses and Dissertations--Molecular and Cellular Biochemistry

The abundant cell-surface lipophosphoglycan (LPG) of Leishmania parasites plays a central role throughout the eukaryote’s life cycle. A number of LPG-defective mutants and their complementing genes have been isolated and have proven invaluable in assessing the importance of LPG and related glycoconjugates in parasite virulence. While ricin agglutination selection protocols frequently result in lpg- mutants, one L. donovani variant we isolated, named JABBA, was found to be lpg+. Procyclic (logarithmic) JABBA expresses significant amounts of a large-sized LPG, larger than observed from procyclic wild-type but similar in size to LPG from wild-type from metacyclic (stationary) phase.

Structural analysis of …

Molecular Mechanism Of Human Mismatch Repair Initiation, Sanghee Lee

Theses and Dissertations--Nutritional Sciences

DNA mismatch repair (MMR) is a highly conserved pathway that maintains genomic stability primarily by correcting mismatches generated during DNA replication. MMR deficiency leads to microsatellite instability (MSI), which is a hallmark of HNPCC (Hereditary Nonpolyposis Colorectal Cancer). Human mismatch repair is initiated by MutSα, a heterodimer of MSH2 and MSH6 subunits. Mismatch binding by MutSα triggers a series of downstream MMR events including interacting and communicating with other MMR proteins. The ATPase domain of MutSα is situated in the C-termini of its both subunits, and ATP binding is required for dissociation of MutSα from a mismatch. In eukaryotic cells, …

Use Of Genomic Tools To Discover The Cause Of Champagne Dilution Coat Color In Horses And To Map The Genetic Cause Of Extreme Lordosis In American Saddlebred Horses, Deborah G. Cook

Theses and Dissertations--Veterinary Science

Champagne dilution of coat color in horses is caused by dominant gene action. Three sire families were identified as segregating for this trait. Genome wide linkage analysis using 104 microsatellite DNA markers was used to map the gene to ECA14 (LOD > 11.0). Four genes, namely SPARC, SLC36A1, SLC36A2 and SLC36A3, were selected from the region implicated by linkage and their exons sequenced. DNA sequences were compared for two homozygotes for Champagne dilution, two heterozygotes and two horses without dilution. A single base change in exon 2 of SLC36A1 was found unique to horses exhibiting Champagne dilution. This change in base …

The Role Of Angiotensinogen In Atherosclerosis And Obesity, Congqing Wu

Theses and Dissertations--Nutritional Sciences

Angiotensinogen is the only known precursor in the renin-angiotensin system, a hormonal system best known as an essential regulator of blood pressure and fluid homeostasis. Angiotensinogen is sequentially cleaved by renin and angiotensin- converting enzyme to generate angiotensin II. As the major effector peptide, angiotensin II mainly function through angiotensin type 1 receptor.

Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and more recently renin inhibitors are widely known as the 3 classic renin-angiotensin system inhibitory drugs against hypertension and atherosclerosis. Here, we developed an array of regents to explore the effects of angiotensinogen inhibition. First, we demonstrated that genetic deficiency of …

Transmural Heterogeneity Of Cellular Level Cardiac Contractile Properties In Aging And Heart Failure, Premi Haynes

Theses and Dissertations--Physiology

The left ventricle of the heart relaxes when it fills with blood and contracts to eject blood into circulation to meet the body’s metabolic demands. Dysfunction in either relaxation or contraction of the left ventricle can lead to heart failure. Transmural heterogeneity is thought to contribute to normal ventricular wall motion but it is not well understood how transmural modifications affect the failing left ventricle. The overall hypothesis of this dissertation is that normal left ventricles exhibit transmural heterogeneity in cellular level contractile properties and with aging and heart failure there are region-specific changes in cellular level contractile mechanisms.

Age …

Structural Mechanisms Of Glucan Phosphatase Activity In Starch Metabolism, David A. Meekins

Theses and Dissertations--Molecular and Cellular Biochemistry

Starch is a water-insoluble glucose biopolymer used as an energy cache in plants and is synthesized and degraded in a diurnal cycle. Reversible phosphorylation of starch granules regulates the solubility and, consequentially, the bioavailability of starch glucans to degradative enzymes. Glucan phosphatases release phosphate from starch glucans and their activity is essential to the proper diurnal metabolism of starch. Previously, the structural basis of glucan phosphatase activity was entirely unknown. The work in this dissertation outlines the structural mechanism of activity of two plant glucan phosphatases called Starch EXcess4 (SEX4) and Like Sex Four2 (LSF2). The crystal structures of SEX4 …

Molecular Mechanisms Of Neuropilin-Ligand Binding, Matthew W. Parker

Theses and Dissertations--Molecular and Cellular Biochemistry

Neuropilin (Nrp) is an essential cell surface receptor with dual functionality in the cardiovascular and nervous systems. The first identified Nrp-ligand family was the Semaphorin-3 (Sema3) family of axon repulsion molecules. Subsequently, Nrp was found to serve as a receptor for the vascular endothelial growth factor (VEGF) family of pro-angiogenic cytokines. In addition to its physiological role, VEGF signaling via Nrp directly contributes to cancer stemness, growth, and metastasis. Thus, the Nrp/VEGF signaling axis is a promising anti-cancer therapeutic target. Interestingly, it has recently been shown that Sema3 and VEGF are functionally opposed to one another, with Sema3 possessing potent …

Leptin Resistance Induced Obesity And Diabetes Promote Neuropathological Changes In The Aging Brain, Thomas Platt

Theses and Dissertations--Molecular and Cellular Biochemistry

The aging brain is prone to the development of pathology and dementia. With a rapidly growing elderly population diagnoses of neurodegenerative diseases, such as Alzheimer’s disease (AD), frontotemporal dementia (FTD), and Parkinson’s disease are on the rise. Additionally, diabetes and obesity are linked to an increased risk of dementia. The convergence of this increasingly aged population with the obesity and diabetes epidemic give rise to new concerns regarding the future of prevention and treatment of neurodegenerative diseases. Our lab has previously shown that leptin, an adipokine involved in signaling satiety to the hypothalamus, can modulate the generation of the amyloid …

Investigating Structure And Protein-Protein Interactions Of Key Post-Type Ii Pks Tailoring Enzymes, Theresa E. Downey

Theses and Dissertations--Pharmacy

Type II polyketide synthase (PKS) produced natural products have proven to be an excellent source of pharmacologically relevant molecules due to their rich biological activities and chemical scaffolds. Type II-PKS manufactured polyketides share similar polycyclic aromatic backbones leaving their diversity to stem from various chemical additions and alterations facilitated by post-PKS tailoring enzymes. Evidence suggests that post-PKS tailoring enzymes form complexes in order to facilitate the highly orchestrated process of biosynthesis. Thus, protein-protein interactions between these enzymes must play crucial roles in their structures and functions. Despite the importance of these interactions little has been done to study them. In …

The Differences Between Iron And Iron-Substituted Manganese Superoxide Dismutase With Respect To Hydrogen Peroxide Treatment, Jianing Wang

Theses and Dissertations--Chemistry

Iron-substituted manganese superoxide dismutase (Fe(Mn)SOD) was produced using an in vivo preparation method. It’s an inactive enzyme in catalyzing superoxide radical dismutation owing to the mis-incorporation of Fe in the active site evolved to use Mn. To investigate the possible toxicity of human Fe(Mn)SOD proposed by Yamakura, we studied the properties of Fe(Mn)SOD upon H₂O₂ treatment and compared to that of FeSOD. It’s found that the responses to H₂O₂ treatment were different, including the changes of optical spectra, variations of active site coordination and secondary structures. Fe³⁺ reduction was not observed in Fe(Mn)SOD …

Nuclear Import And Interactions Of Potato Yellow Dwarf Virus Nucleocapsid, Matrix, And Phosphoprotein, Gavin Lloyd Franklin Anderson

Theses and Dissertations--Plant Pathology

Potato yellow dwarf virus (PYDV) is the type species of the genus Nucleorhabdovirus and, like all members of this genus, replication and morphogenesis occurs inside the nuclei of infected cells. Protein localization prediction algorithms failed to identify a nuclear localization signal (NLS) in PYDV nucleocapsid (N) protein, although PYDV-N has been shown to localize exclusively to the nucleus when expressed as a green fluorescent protein (GFP):N fusion in plant cells. Deletion analysis and alanine-scanning mutagenesis identified two amino acid motifs, ⁴¹⁹QKR⁴²¹ and ⁴³²KR⁴³³, that were shown to be essential for nuclear import and interaction with …