Biochemistry, Biophysics, and Structural Biology Commons^™

Copper–Zinc Superoxide Dismutase-Deficient Mice Show Increased Susceptibility To Experimental Autoimmune Encephalomyelitis Induced With Myelin Oligodendrocyte Glycoprotein 35–55, Chandirasegara Massilamany, Arunakumar Gangaplara, Heejeong Kim, Charlotte Standord, Govardhan Rathnaiah, David Steffen, Jaekwon Lee, Jay Reddy

School of Veterinary and Biomedical Sciences: Faculty Publications

In this report, we have addressed the role of copper–zinc superoxide dismutase (SOD1) deficiency in the mediation of central nervous system autoimmunity. We demonstrate that SOD1-deficient C57Bl/6 mice develop more severe autoimmune encephalomyelitis induced with myelin oligodendrocyte glycoprotein (MOG) 35–55, compared with wild type mice. This alteration in the disease phenotype was not due to aberrant expansion of MOG-specific T cells nor their ability to produce inflammatory cytokines; rather lymphocytes generated in SOD1-deficient mice were more prone to spontaneous cell death when compared with their wild type littermate controls. The data point to a role for SOD1 in the maintenance …

Rhodotorula Minuta Fungemia In A Ewe Lamb, C G. Chitko-Mckown, K A. Leymaster, M. P. Heaton, D D. Griffin, J K. Veatch, S A. Jones, M. L. Clawson

School of Veterinary and Biomedical Sciences: Faculty Publications

An 8-month-old crossbred ewe, normal upon physical examination, was humanely euthanized for tissue collection. After approximately 3 weeks in tissue culture, fungi began budding out of cells obtained from the choroid plexus. After an additional 3 weeks, budding was observed in kidney cell cultures and eventually in monocyte cultures as well. Serum from the lamb was submitted to the Veterinary Diagnostic Laboratory at Colorado State University for fungal diagnosis and was found negative for Aspergillus, Blastomyces, Coccidioidomycosis and Histoplasmosis. DNA was isolated from fungi collected from tissue culture supernatants and used in a set of pan-fungal PCR assays with DNA …

Posttranslational Modification Of Vesicular Stomatitis Virus Glycoprotein, But Not Jnk Inhibition, Is The Antiviral Mechanism Of Sp600125, Sabrina Marozin, Jennifer Altomonte, Sibylle Apfel, Phat X. Dinh, Enrico De Toni, Antonia Rizzani, Andreas Nüssler, Nobuyuki Kato, Roland M. Schmid, Asit K. Pattnaik, Oliver Eberta

School of Veterinary and Biomedical Sciences: Faculty Publications

Vesicular stomatitis virus (VSV), a negative-sense single-stranded-RNA rhabdovirus, is an extremely promising oncolytic agent for cancer treatment. Since oncolytic virotherapy is moving closer to clinical application, potentially synergistic combinations of oncolytic viruses and molecularly targeted antitumor agents are becoming a meaningful strategy for cancer treatment. Mitogenactivated protein kinase (MAPK) inhibitors have been shown to impair liver cell proliferation and tumor development, suggesting their potential use as therapeutic agents for hepatocellular carcinoma (HCC). In this work, we show that the impairment of MAPK in vitro did not interfere with the oncolytic properties of VSV in HCC cell lines. Moreover, the administration …

Identification Of Amino Acid Residues Important For Anti-Ifn Activity Of Porcine Reproductive And Respiratory Syndrome Virus Non-Structural Protein 1, Lalit Beura, Sakthivel Subramaniam, Hiep Vu, Byungjoon Kwon, Asit K. Pattnaik, Fernando A. Osorio

School of Veterinary and Biomedical Sciences: Faculty Publications

The non-structural protein 1 (nsp1) of porcine reproductive and respiratory syndrome virus is partly responsible for inhibition of type I interferon (IFN) response by the infected host. By performing alanine-scanning mutagenesis, we have identified amino acid residues in nsp1α and nsp1β~ (the proteolytic products of nsp1) that when substituted with alanine(s) exhibited significant relief of IFNsuppression. A mutant virus (16-SA, in which residues 16-20 of nsp1β were substituted with alanines) encoding mutant nsp1β recovered from infectious cDNA clone was shown to be attenuated for growth in vitro and induced significantly higher amount of type I IFN transcripts in infected macrophages. …

Glycosyl-Phosphatidylinositol (Gpi)-Anchored Membrane Association Of The Porcine Reproductive And Respiratory Syndrome Virus Gp4 Glycoprotein And Its Co-Localization With Cd163 In Lipid Rafts, Yijun Du, Asit K. Pattnaik, Cheng Song, Dongwan Yoo, Gang Li

School of Veterinary and Biomedical Sciences: Faculty Publications

The porcine reproductive and respiratory syndrome virus (PRRSV) glycoprotein 4 (GP4) resembles a typical type I membrane protein in its structure but lacks a hydrophilic tail at the C-terminus, suggesting that GP4 may be a lipid-anchored membrane protein. Using the human decay-accelerating factor (DAF; CD55), a known glycosyl-phosphatidylinositol (GPI) lipid-anchored protein, chimeric constructs were made to substitute the GPI-anchor domain of DAF with the putative lipid-anchor domain of GP4, and their membrane association and lipase cleavage were determined in cells. The DAF-GP4 fusion protein was transported to the plasma membrane and was cleaved by phosphatidylinositol-specific phospholipase C (PI-PLC), indicating that …

A Single Amino Acid Change Resulting In Loss Of Fluorescence Of Egfp In A Viral Fusion Protein Confers Fitness And Growth Advantage To The Recombinant Vesicular Stomatitis Virus, Phat X. Dinh, Debasis Panda, Phani B. Das, Subash C. Das, Anshuman Das, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Using a recombinant vesicular stomatitis virus encoding eGFP fused in-frame with an essential viral replication protein, the phosphoprotein P, we show that during passage in culture, the virus mutates the nucleotide C289 within eGFP of the fusion protein PeGFP to A or T, resulting in R97S/C amino acid substitution and loss of fluorescence. The resultant non-fluorescent virus exhibits increased fitness and growth advantage over its fluorescent counterpart. The growth advantage of the non-fluorescent virus appears to be due to increased transcription and replication activities of the PeGFP protein carrying the R97S/C substitution. Further, our results show that the R97S/C mutation …

Amino Acid Residues In The Non-Structural Protein 1 Of Porcine Reproductive And Respiratory Syndrome Virus Involved In Down-Regulation Of Tnf-Cx Expression In Vitro And Attenuation In Vivo, Sakthivel Subramaniam, Lalit Beura, Byungjoon Kwon, Asit K. Pattnaik, Fernando A. Osorio

School of Veterinary and Biomedical Sciences: Faculty Publications

Porcine reproductive and respiratory syndrome virus (PRRSV) suppresses tumor necrosis factor-alpha (TNF-α) production at both transcriptional and post-transcriptional levels by its non-structural proteins 1α and 1β (Nsp1α and Nsp1β). To identifY the amino acid residues responsible for this activity, we generated several alanine substitution mutants of Nsp1α and Nsp1β. Examination of the mutant proteins revealed that Nsp1α residues Gly90, Asn91 , Arg97, Argl 00 and Arg124 were necessary for TNF-α promoter suppression, whereas several amino acids spanning the entire Nsp1β ~ were found to be required for this activity. Two mutant viruses, with mutations at Nsp1α Gly90 or Nsp1β residues …

Fusion Of A Fluorescent Protein To The Pul25 Minor Capsid Protein Of Pseudorabies Virus Allows Live-Cell Capsid Imaging With Negligible Impact On Infection, Kevin P. Bohannon, Patricia J. Sollars, Gary E. Pickard, Gregory A. Smith

School of Veterinary and Biomedical Sciences: Faculty Publications

In order to resolve the location and activity of submicroscopic viruses in living cells, viral proteins are often fused to fluorescent proteins (FPs) and visualized by microscopy. In this study, we describe the fusion of FPs to three proteins of pseudorabies virus (PRV) that allowed imaging of capsids in living cells. Included in this study are the first recombinant PRV strains expressing FP–pUL25 fusions based on a design applied to herpes simplex virus type 1 by Homa and colleagues. The properties of each reporter virus were compared in both in vitro and in vivo infection models. PRV strains expressing FP–pUL25 …

Staphylococcal Response To Oxidative Stress, Rosmarie Gaupp, Nagender Ledala, Greg A. Somerville

School of Veterinary and Biomedical Sciences: Faculty Publications

Staphylococci are a versatile genus of bacteria that are capable of causing acute and chronic infections in diverse host species. The success of staphylococci as pathogens is due in part to their ability to mitigate endogenous and exogenous oxidative and nitrosative stress. Endogenous oxidative stress is a consequence of life in an aerobic environment; whereas, exogenous osidative and nitrosative stress are often due to the bacteria's interaction with host immune systems. To overcome the deleterious effects of oxidative and nitrosative stress, staphylococci have evolved protection, detoxification, and repair mechanisms that are controlled by a network of regulators. In this review, …

Udp-Glucose Dehydrogenase Polymorphisms From Patients With Congenital Heart Valve Defects Disrupt Enzyme Stability And Quaternary Assembly, Annastasia S. Hyde, Erin L. Farmer, Katherine E. Easley, Kristy Van Lammeren, Vincent M. Christoffels, Joseph J. Barycki, Jeroen Bakkers, Melanie A. Simpson

Department of Biochemistry: Faculty Publications

Background: UDP-glucose dehydrogenase (UGDH) polymorphisms were identified in a screen of candidate genes for heart valve defects.

Results: Two individual mutants fail to rescue cardiac valve defects in UGDH-deleted zebrafish and have reduced stability in vitro.

Conclusion: UGDH loss of function mutations result in a subset of human congenital cardiac valve defects caused by reduced enzyme activity during morphogenesis.

Significance: Screening these alleles could predict valve defects.

Genome, Functional Gene Annotation, And Nuclear Transformation Of The Heterokont Oleaginous Alga Nannochloropsis Oceanica Ccmp1779, Astrid Vieler, Guangxi Wu, Chia-Hong Tsai, Blair Bullard, Adam J. Cornish, Christopher Harvey, Ida-Barbara Reca, Chelsea Thornburg, Rujira Achawanantakun, Christopher J. Buehl, Michael S. Campbell, David Cavalier, Kevin L. Childs, Teresa J. Clark, Rahul Deshpande, Erika Erickson, Ann Armenia Ferguson, Witawas Handee, Que Kong, Xiaobo Li, Bensheng Liu, Steven Lundback, Cheng Peng, Rebecca Roston, Michigan State University, Jeffrey P. Simpson, Allan Terbush, Jaruswan Warakanont, Simone Zäuner, Eva M. Farre, Eric L. Hegg, Ning Jiang, Min-Hao Kuo, Yan Lu, Krishna K. Niyogi, John Ohlrogge, Katherine W. Osteryoung, Yair Shachar-Hill, Barbara B. Sears, Yanni Sun, Hideki Takahashi, Mark Yandell, Shin-Han Shiu, Christoph Benning

Department of Biochemistry: Faculty Publications

Unicellular marine algae have promise for providing sustainable and scalable biofuel feedstocks, although no single species has emerged as a preferred organism. Moreover, adequate molecular and genetic resources prerequisite for the rational engineering of marine algal feedstocks are lacking for most candidate species. Heterokonts of the genus Nannochloropsis naturally have high cellular oil content and are already in use for industrial production of high-value lipid products. First success in applying reverse genetics by targeted gene replacement makes Nannochloropsis oceanica an attractive model to investigate the cell and molecular biology and biochemistry of this fascinating organism group. Here we present the …

Cellular Responses Of Candida Albicans To Phagocytosis And The Extracellular Activities Of Neutrophils Are Critical To Counteract Carbohydrate Starvation, Oxidative And Nitrosative Stress, Pedro Miramón, Christine Dunker, Hanna Windecker, Iryna Bohovych, Alistair J.P. Brown, Oliver Kurzai, Bernhard Hube

Department of Biochemistry: Faculty Publications

Neutrophils are key players during Candida albicans infection. However, the relative contributions of neutrophil activities to fungal clearance and the relative importance of the fungal responses that counteract these activities remain unclear. We studied the contributions of the intra- and extracellular antifungal activities of human neutrophils using diagnostic Green Fluorescent Protein (GFP)-marked C. albicans strains. We found that a carbohydrate starvation response, as indicated by upregulation of glyoxylate cycle genes, was only induced upon phagocytosis of the fungus. Similarly, the nitrosative stress response was only observed in internalised fungal cells. In contrast, the response to oxidative stress was observed in …

Small But Crucial: The Novel Small Heat Shock Protein Hsp21 Mediates Stress Adaptation And Virulence In Candida Albicans, Francois L. Mayer, Duncan Wilson, Ilse D. Jacobsen, Pedro Miramón, Silvia Slesiona, Iryna Bohovych, Alistair J.P. Brown, Bernhard Hube

Department of Biochemistry: Faculty Publications

Small heat shock proteins (sHsps) have multiple cellular functions. However, the biological function of sHsps in pathogenic microorganisms is largely unknown. In the present study we identified and characterized the novel sHsp Hsp21 of the human fungal pathogen Candida albicans. Using a reverse genetics approach we demonstrate the importance of Hsp21 for resistance of C. albicans to specific stresses, including thermal and oxidative stress. Furthermore, a hsp21∆/∆ mutant was defective in invasive growth and formed significantly shorter filaments compared to the wild type under various filamentinducing conditions. Although adhesion to and invasion into human-derived endothelial and oral epithelial cells …

Oligomerization Of Heme O Synthase In Cytochrome Oxidase Biogenesis Is Mediated By Cytochrome Oxidase Assembly Factor Coa2, Oleh Khalimonchuk, Hyung Kim, Talina Watts, Xochitl Perez-Martinez, Dennis R. Winge

Department of Biochemistry: Faculty Publications

The synthesis of the heme a cofactor used in cytochrome c

oxidase (CcO) is dependent on the sequential action of heme o

synthase (Cox10) and heme a synthase (Cox15). The active state of

Cox10 appears to be a homo-oligomeric complex,andformation of

this complex is dependent on the newly synthesized CcO subunit

Cox1 and the presence of an early Cox1 assembly intermediate.

Cox10 multimerization is triggered by progression of Cox1 from

the early assembly intermediate todownstreamintermediates.The

CcOassembly factor Coa2 appears important in coupling the presence

of newly synthesized Cox1 to Cox10 oligomerization. Cells

lacking Coa2 are impaired in Cox10 complex formation …

Selective Oma1 Protease-Mediated Proteolysis Of Cox1 Subunit Of Cytochrome Oxidase In Assembly Mutants, Oleh Khalimonchuk, Mi-Young Jeong, Talina Watts, Elliott Ferris, Dennis R. Winge

Department of Biochemistry: Faculty Publications

Background: Yeast lacking Coa2 are deficient in cytochrome c oxidase due to Cox1 degradation.

Results: Oma1 mediates Cox1 degradation in coa2∆ cells but not other mutants stalled in oxidase biogenesis.

Conclusion: Impaired hemylation of Cox1 in coa2∆ cells leads to misfolding and facile degradation by Oma1.

Significance: Oma1 functions in quality control of cytochrome oxidase assembly.

The Evolutionary Rewiring Of Ubiquitination Targets Has Reprogrammed The Regulation Of Carbon Assimilation In The Pathogenic Yeast Candida Albicans, Doblin Sandai, Zhikang Yin, Laura Selway, David Stead, Janet Walker, Michelle D. Leach, Iryna Bohovych, Iuliana V. Ene, Stavroula Kastora, Susan Budge, Carol A. Munro, Frank C. Odds, Neil A.R. Gow, Alistair J.P. Brown

Department of Biochemistry: Faculty Publications

Microbes must assimilate carbon to grow and colonize their niches. Transcript profiling has suggested that Candida albicans, a major pathogen of humans, regulates its carbon assimilation in an analogous fashion to the model yeast Saccharomyces cerevisiae, repressing metabolic pathways required for the use of alterative nonpreferred carbon sources when sugars are available. However, we show that there is significant dislocation between the proteome and transcriptome in C. albicans. Glucose triggers the degradation of the ICL1 and PCK1 transcripts in C. albicans, yet isocitrate lyase (Icl1) and phosphoenolpyruvate carboxykinase (Pck1) are stable and are retained. Indeed, numerous …

Role Of Apoptosis-Inducing Factor, Proline Dehydrogenase, And Nadph Oxidase In Apoptosis And Oxidative Stress, Sathish Kumar Natarajan, Donald F. Becker

Department of Biochemistry: Faculty Publications

Flavoproteins catalyze a variety of reactions utilizing flavin mononucleotide or flavin adenine dinucleotide as cofactors. The oxidoreductase properties of flavoenzymes implicate them in redox homeostasis, oxidative stress, and various cellular processes, including programmed cell death. Here we explore three critical flavoproteins involved in apoptosis and redox signaling, ie, apoptosis-inducing factor (AIF), proline dehydrogenase, and NADPH oxidase. These proteins have diverse biochemical functions and influence apoptotic signaling by unique mechanisms. The role of AIF in apoptotic signaling is two-fold, with AIF changing intracellular location from the inner mitochondrial membrane space to the nucleus upon exposure of cells to apoptotic stimuli. In …

Late-Stage Maturation Of The Rieske Fe/S Protein: Mzm1 Stabilizes Rip1 But Does Not Facilitate Its Translocation By The Aaa Atpase Bcs1, Tie-Zhong Cui, Pamela M. Smith, Jennifer L. Fox, Oleh Khalimonchuk, Dennis R. Winge

Department of Biochemistry: Faculty Publications

The final step in the assembly of the ubiquinol-cytochrome c reductase or bc₁ complex involves the insertion of the Rieske Fe/S cluster protein, Rip1. Maturation of Rip1 occurs within the mitochondrial matrix prior to its translocation across the inner membrane (IM) in a process mediated by the Bcs1 ATPase and subsequent insertion into the bc₁ complex. Here we show that the matrix protein Mzm1 functions as a Rip1 chaperone, stabilizing Rip1 prior to the translocation step. In the absence of Mzm1, Rip1 is prone to either proteolytic degradation or temperature-induced aggregation. A series of Rip1 truncations were engineered …

Substrate Channeling In Proline Metabolism, Benjamin W. Arentson, Nikhilesh Sanyal, Donald F. Becker

Department of Biochemistry: Faculty Publications

Proline metabolism is an important pathway that has relevance in several cellular functions such as redox balance, apoptosis, and cell survival. Results from different groups have indicated that substrate channeling of proline metabolic intermediates may be a critical mechanism. One intermediate is pyrroline-5-carboxylate (P5C), which upon hydrolysis opens to glutamic semialdehyde (GSA). Recent structural and kinetic evidence indicate substrate channeling of P5C/ GSA occurs in the proline catabolic pathway between the proline dehydrogenase and P5C dehydrogenase active sites of bifunctional proline utilization A (PutA). Substrate channeling in PutA is proposed to facilitate the hydrolysis of P5C to GSA which is …

Glutaredoxin 1 Protects Dopaminergic Cells By Increased Protein Glutathionylation In Experimental Parkinson's Disease, Humberto Rodriguez-Rocha, Aracely Garcia Garcia, Laura Zavala-Flores, Sumin Li, Nandakumar Madayiputhiya, Rodrigo Franco

Department of Biochemistry: Faculty Publications

Aims: Chronic exposure to environmental toxicants, such as paraquat, has been suggested as a risk factor for Parkinson's disease (PD). Although dopaminergic cell death in PD is associated with oxidative damage, the molecular mechanisms involved remain elusive. Glutaredoxins (GRXs) utilize the reducing power of glutathione to modulate redox-dependent signaling pathways by protein glutathionylation. We aimed to determine the role of GRX1 and protein glutathionylation in dopaminergic cell death. Results: In dopaminergic cells, toxicity induced by paraquat or 6-hydroxydopamine (6-OHDA) was inhibited by GRX1 overexpression, while its knock-down sensitized cells to paraquat-induced cell death. Dopaminergic cell death was paralleled by protein …