Other Biochemistry, Biophysics, and Structural Biology Commons^™

Evaluation Of Three Herbicide Resistance Genes For Use In Genetic Transformations And For Potential Crop Protection In Algae Production, Andrew J. Bruggeman, Daniel Kuehler, Donald P. Weeks

Department of Biochemistry: Faculty Publications

Genes conferring resistance to the herbicides glyphosate, oxyfluorfen and norflurazon were developed and tested for use as dominant selectable markers in genetic transformation of Chlamydomonas reinhardtii and as potential tools for the protection of commercial-scale algal production facilities against contamination by organisms sensitive to these broad-spectrum herbicides. A synthetic glyphosate acetyltransferase (GAT) gene, when fitted with a strong Chlamydomonas promoter, conferred a 2.79-fold increase in tolerance to the EPSPS inhibitor, glyphosate, in transgenic cells compared with progenitor WT cells. A mutant Chlamydomonas protoporphyrinogen oxidase (protox, PPO) gene previously shown to produce an enzyme insensitive to PPO-inhibiting herbicides, when genetically engineered, …

Saturated Free Fatty Acids Induce Cholangiocyte Lipoapoptosis, Sathish Kumar Natarajan, Sally A. Ingham, Ashley M. Mohr, Cody J. Wehrkamp, Anuttoma Ray, Sohini Roy, Sophie C. Cazanave, Mary Anne Phillippi, Justin L. Mott

Department of Biochemistry: Faculty Publications

Recent studies have identified a cholestatic variant of nonalcoholic fatty liver disease (NAFLD) with portal inflammation and ductular reaction. Based on reports of biliary damage, as well as increased circulating free fatty acids (FFAs) in NAFLD, we hypothesized the involvement of cholangiocyte lipoapoptosis as a mechanism of cellular injury. Here, we demonstrate that the saturated FFAs palmitate and stearate induced robust and rapid cell death in cholangiocytes. Palmitate and stearate induced cholangiocyte lipoapoptosis in a concentration-dependent manner in multiple cholangiocyte-derived cell lines. The mechanism of lipoapoptosis relied on the activation of caspase 3/7 activity. There was also a significant up-regulation …

Xiap Antagonist Embelin Inhibited Proliferation Of Cholangiocarcinoma Cells, Cody J. Wehrkamp, Ashley R. Gutwein, Sathish Kumar Natarajan, Mary Anne Phillippi, Justin L. Mott

Department of Biochemistry: Faculty Publications

Cholangiocarcinoma cells are dependent on antiapoptotic signaling for survival and resistance to death stimuli. Recent mechanistic studies have revealed that increased cellular expression of the E3 ubiquitin-protein ligase X-linked inhibitor of apoptosis (XIAP) impairs TRAIL- and chemotherapy-induced cytotoxicity, promoting survival of cholangiocarcinoma cells. This study was undertaken to determine if pharmacologic antagonism of XIAP protein was sufficient to sensitize cholangiocarcinoma cells to cell death. We employed malignant cholangiocarcinoma cell lines and used embelin to antagonize XIAP protein. Embelin treatment resulted in decreased XIAP protein levels by 8 hours of treatment with maximal effect at 16 hours in KMCH and Mz-ChA-1 …

Evidence That The C‑Terminal Domain Of A Type B Puta Protein Contributes To Aldehyde Dehydrogenase Activity And Substrate Channeling, Min Luo, Shelbi Christgen, Nikhilesh Sanyal, Benjamin W. Arentson, Donald F. Becker, John J. Tanner

Department of Biochemistry: Faculty Publications

Proline utilization A (PutA) is a bifunctional enzyme that catalyzes the oxidation of proline to glutamate. Structures of type A PutAs have revealed the catalytic core consisting of proline dehydrogenase (PRODH) and Δ1- pyrroline-5-carboxylate dehydrogenase (P5CDH) modules connected by a substrate-channeling tunnel. Type B PutAs also have a C-terminal domain of unknown function (CTDUF) that is absent in type A PutAs. Small-angle X-ray scattering (SAXS), mutagenesis, and kinetics are used to determine the contributions of this domain to PutA structure and function. The 1127-residue Rhodobacter capsulatus PutA (RcPutA) is used as a representative CTDUF-containing type B PutA. The reaction progress …

Pharmacokinetic And Biodistribution Assessment Of A Near Infrared-Labeled Psma-Specific Small Molecule In Tumor-Bearing Mice, Joy L. Kovar, Lael L. Cheung, Melanie A. Simpson, D. Michael Olive

Department of Biochemistry: Faculty Publications

Prostate cancer is themost frequently diagnosed cancer in men and often requires surgery. Use of near infrared (NIR) technologies to perform image-guided surgery may improve accurate delineation of tumor margins. To facilitate preclinical testing of such outcomes, here we developed and characterized a PSMA-targeted small molecule, YC-27. IRDye 800CW was conjugated to YC-27 or an anti-PSMA antibody used for reference. Human 22Rv1, PC3M-LN4, and/or LNCaP prostate tumor cells were exposed to the labeled compounds. In vivo targeting and clearance properties were determined in tumor-bearing mice. Organs and tumors were excised and imaged to assess probe localization. YC-27 exhibited a dose …

Ycf1-Mediated Cadmium Resistance In Yeast Is Dependent On Copper Metabolism And Antioxidant Enzymes, Wenzhong Wei, Nathan Smith, Xiaobin Wu, Heejeong Kim, Javier Seravalli, Oleh Khalimonchuk, Jaekwon Lee

Department of Biochemistry: Faculty Publications

Aims: Acquisition and detoxification of metal ions are vital biological processes. Given the requirement of metallochaperones in cellular copper distribution and metallation of cuproproteins, this study investigates whether the metallochaperones also deliver metal ions for transporters functioning in metal detoxification. Results: Resistance to excess cadmium and copper of the yeast Saccharomyces cerevisiae, which is conferred by PCA1 and CaCRP1 metal efflux P-type ATPases, respectively, does not rely on known metallochaperones, Atx1p, Ccs1p, and Cox17p. Copper deficiency induced by the expression of CaCRP1 encoding a copper exporter occurs in the absence of Atx1p. Intriguingly, CCS1 encoding the copper chaperone for superoxide …

Stress Adaptation In A Pathogenic Fungus, Alistair J. P. Brown, Susan Budge, Despoina Kaloriti, Anna Tillmann, Mette D. Jacobsen, Zhikang Yin, Iuliana V. Ene, Iryna Bohovych, Doblin Sandai, Stavroula Kastora, Joanna Potrykus, Elizabeth R. Ballou, Delma S. Childers, Shahida Shahana, Michelle D. Leach

Department of Biochemistry: Faculty Publications

Candida albicans is a major fungal pathogen of humans. This yeast is carried by many individuals as a harmless commensal, but when immune defences are perturbed it causes mucosal infections (thrush). Additionally, when the immune system becomes severely compromised, C. albicans often causes life-threatening systemic infections. A battery of virulence factors and fitness attributes promote the pathogenicity of C. albicans. Fitness attributes include robust responses to local environmental stresses, the inactivation of which attenuates virulence. Stress signalling pathways in C. albicans include evolutionarily conserved modules. However, there has been rewiring of some stress regulatory circuitry such that the roles of …

Proline Biosynthesis Is Required For Endoplasmic Reticulum Stress Tolerance In Saccharomyces Cerevisiae, Xinwen Liang, M. B. Dickman, Donald F. Becker

Department of Biochemistry: Faculty Publications

Background: Proline is an important amino acid for stress resistance in different organisms.

Results: Depletion of proline biosynthesis disrupts redox homeostasis and increases sensitivity to endoplasmic reticulum (ER) stress in yeast.

Conclusion: Proline biosynthesis is critical for maintaining the intracellular redox environment and the UPR during ER stress.

Significance: Proline metabolism is shown to have an important role in ER stress tolerance that was previously unknown.

Protein/Protein Interactions In The Mammalian Heme Degradation Pathway Heme Oxygenase-2, Cytochrome P450 Reductase, And Biliverdin Reductase, Andrea L. M. Spencer, Ireena Bagai, Donald F. Becker, Erik R. P. Zuiderweg, Stephen W. Ragsdale

Department of Biochemistry: Faculty Publications

Background: Heme oxygenase, cytochrome P450 reductase, and biliverdin reductase are the key enzymes in heme degradation.

Results: Specific electrostatic and hydrophobic interactions form the binding interface between heme oxygenase and cytochrome P450 reductase. Conclusion: Heme oxygenase binds cytochrome P450 reductase dynamically and biliverdin reductase very weakly.

Significance: Characterizing interactions among proteins involved in heme degradation are crucial to understanding heme homeostasis.

Mechanisms Underlying The Exquisite Sensitivity Of Candida Albicans To Combinatorial Cationic And Oxidative Stress That Enhances The Potent Fungicidal Activity Of Phagocytes, Despoina Kaloriti, Mette Jacobsen, Zhikang Yin, Miranda Patterson, Anna Tillmann, Deborah A. Smith, Emily Cook, Tao You, Melissa J. Grimm, Iryna Bohovych, Celso Grebogi, Brahm H. Segal, Neil A.R. Gow, Ken Haynes, Janet Quinn, Alistair J.P. Brown

Department of Biochemistry: Faculty Publications

Immune cells exploit reactive oxygen species (ROS) and cationic fluxes to kill microbial pathogens, such as the fungus

Candida albicans. Yet, C. albicans is resistant to these stresses in vitro. Therefore, what accounts for the potent antifungal activity

of neutrophils? We show that simultaneous exposure to oxidative and cationic stresses is much more potent than the individual

stresses themselves and that this combinatorial stress kills C. albicans synergistically in vitro.We also show that the high

fungicidal activity of human neutrophils is dependent on the combinatorial effects of the oxidative burst and cationic fluxes, as

their pharmacological attenuation with …

New Clox Systems For Rapid And Efficient Gene Disruption In Candida Albicans, Shahida Shahana, Delma S. Childers, Elizabeth R. Ballou, Iryna Bohovych, Frank C. Odds, Neil A.R. Gow, Alistair J.P. Brown

Department of Biochemistry: Faculty Publications

Precise genome modification is essential for the molecular dissection of Candida albicans, and is yielding invaluable information about the roles of specific gene functions in this major fungal pathogen of humans. C. albicans is naturally diploid, unable to undergo meiosis, and utilizes a non-canonical genetic code. Hence, specialized tools have had to be developed for gene disruption in C. albicans that permit the deletion of both target alleles, and in some cases, the recycling of the Candida-specific selectable markers. Previously, we developed a tool based on the Cre recombinase, which recycles markers in C. albicans with 90–100% efficiency via …

Oxidative Stress, Redox Signaling, And Autophagy: Cell Death Versus Survival, Juliana Navarro-Yepes, Michaela Burns, Anandhan Annadurai, Oleh Khalimonchuk, Luz Maria Del Razo, Betzabet Quintanilla-Vega, Aglaia Pappa, Mihalis I. Panayiotidis, Rodrigo Franco

Department of Biochemistry: Faculty Publications

Significance: The molecular machinery regulating autophagy has started becoming elucidated, and a number of studies have undertaken the task to determine the role of autophagy in cell fate determination within the context of human disease progression. Oxidative stress and redox signaling are also largely involved in the etiology of human diseases, where both survival and cell death signaling cascades have been reported to be modulated by reactive oxygen species (ROS) and reactive nitrogen species (RNS). Recent Advances: To date, there is a good understanding of the signaling events regulating autophagy, as well as the signaling processes by which alterations in …

Kinetic And Structural Characterization Of Tunnel-Perturbing Mutants In Bradyrhizobium Japonicum Proline Utilization A, Benjamin W. Arentson, Min Luo, Travis A. Pemberton, John J. Tanner, Donald F. Becker

Department of Biochemistry: Faculty Publications

Proline utilization A from Bradyrhizobium japonicum (BjPutA) is a bifunctional flavoenzyme that catalyzes the oxidation of proline to glutamate using fused proline dehydrogenase (PRODH) and Δ¹-pyrroline-5-carboxylate dehydrogenase (P5CDH) domains. Recent crystal structures and kinetic data suggest an intramolecular channel connects the two active sites, promoting substrate channeling of the intermediate Δ¹-pyrroline-5-carboxylate/glutamate-γ-semialdehyde (P5C/GSA). In this work, the structure of the channel was explored by inserting large side chain residues at four positions along the channel in BjPutA. Kinetic analysis of the different mutants revealed replacement of D779 with Tyr (D779Y) or Trp (D779W) significantly decreased the overall …

Biochemical Assay Optimization And Computational Screening Efforts To Identify Potential Luxs Inhibitors, Keeshia Q. Wang

Master's Theses

Quorum sensing (QS) is a process of coordination of bacterial gene expression in response to cell population. System two QS is regulated by the small signaling molecule autoinducer-2 (AI-2) and is implicated in the infectious behaviors of various bacterial species. AI-2 is biosynthesized from S-ribosylhomocysteine (SRH) by the enzyme LuxS and induces interspecies cell-to-cell communication. Inhibition of LuxS would therefore inhibit interspecies QS. Herein, a search for novel molecular species that will competitively bind with SRH in the LuxS binding site is performed in silico. Computational screening results are then validated in vitro using an optimized LuxS inhibition …

Molecular Evolution Of Protein-Rna Mimicry As A Mechanism For Translational Control, Assaf Katz, Lindsey Solden, S. Betty Zou, William Wiley Navarre, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P (EF-P) is a conserved ribosome-binding protein that structurally mimics tRNA to enable the synthesis of peptides containing motifs that otherwise would induce translational stalling, including polyproline. In many bacteria, EF-P function requires post-translational modification with (R)-β-lysine by the lysyl-tRNA synthetase paralog PoxA. To investigate how recognition of EF-P by PoxA evolved from tRNA recognition by aminoacyl-tRNA synthetases, we compared the roles of EF-P/PoxA polar contacts with analogous interactions in a closely related tRNA/synthetase complex. PoxA was found to recognize EF-P solely via identity elements in the acceptor loop, the domain of the protein that interacts with the …

Cytochrome B5 Reductase Encoded By Cbr1 Is Essential For A Functional Male Gametophyte In Arabidopsis, Laura L. Wayne, James G. Wallis, Rajesh Kumar, Jennifer E. Markham, John Browse

Department of Biochemistry: Faculty Publications

In all eukaryotes, NADH:cytochrome b5 reductase provides electrons, via cytochrome b5, for a range of biochemical reactions in cellular metabolism, including for fatty acid desaturation in the endoplasmic reticulum. Studies in mammals, yeast, and in vitro plant systems have shown that cytochrome b5 can, at least in some circumstances, also accept electrons from NADPH:cytochrome P450 reductase, potentially allowing for redundancy in reductase function. Here, we report characterization of three T-DNA insertional mutants of the gene encoding cytochrome b5 reductase in Arabidopsis thaliana, CBR1. The progeny of plants heterozygous for the cbr1-2 allele segregated 6% homozygous mutants, while cbr1-3 and cbr1-4 …

Direction Of Aminoacylated Transfer Rnas Into Antibiotic Synthesis And Peptidoglycan-Mediated Antibiotic Resistance, Jennifer Shepherd, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Prokaryotic aminoacylated‐transfer RNAs often need to be efficiently segregated between translation and other cellular biosynthetic pathways. Many clinically relevant bacteria, including Streptococcus pneumoniae, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa direct some aminoacylated‐tRNA species into peptidoglycan biosynthesis and/or membrane phospholipid modification. Subsequent indirect peptidoglycan cross‐linkage or change in membrane permeability is often a prerequisite for high‐level antibiotic resistance. In Streptomycetes, aminoacylated‐tRNA species are used for antibiotic synthesis as well as antibiotic resistance. The direction of coding aminoacylated‐tRNA molecules away from translation and into antibiotic resistance and synthesis pathways are discussed in this review.

Lipid Ii-Independent Trans Editing Of Mischarged Trnas By The Penicillin Resistance Factor Murm, Jennifer Shepherd, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Streptococcus pneumoniae is a causative agent of nosocomial infections such as pneumonia, meningitis, and septicemia. Penicillin resistance in S. pneumoniae depends in part upon MurM, an aminoacyl-tRNA ligase that attaches l-serine or l-alanine to the stem peptide lysine of Lipid II in cell wall peptidoglycan. To investigate the exact substrates the translation machinery provides MurM, quality control by alanyl-tRNA synthetase (AlaRS) was investigated. AlaRS mischarged serine and glycine to tRNAAla, as observed in other bacteria, and also transferred alanine, serine, and glycine to tRNA^Phe. S. pneumoniae tRNA^Phe has an unusual U4:C69 mismatch in its acceptor stem that …

Diversity Of Plant Methionine Sulfoxide Reductases B And Evolution Of A Form Specific For Free Methionine Sulfoxide, Dung Tien Le, Lionel Tarrago, Yasuko Watanabe, Alaattin Kaya, Byung Cheon Lee, Uyen Tran, Rie Nishiyama, Dmitri E. Fomenko, Vadim N. Gladyshev, Lam-Son Phan Tran

Department of Biochemistry: Faculty Publications

Methionine can be reversibly oxidized to methionine sulfoxide (MetO) under physiological conditions. Organisms evolved two distinct methionine sulfoxide reductase families (MSRA & MSRB) to repair oxidized methionine residues. We found that 5 MSRB genes exist in the soybean genome, including GmMSRB1 and two segmentally duplicated gene pairs (GmMSRB2 and GmMSRB5, GmMSRB3 and GmMSRB4). GmMSRB2 and GmMSRB4 proteins showed MSRB activity toward protein-based MetO with either DTT or thioredoxin (TRX) as reductants, whereas GmMSRB1 was active only with DTT. GmMSRB2 had a typical MSRB mechanism with Cys121 and Cys 68 as catalytic and resolving residues, respectively. Surprisingly, this enzyme also possessed …

A Cell Simulator Platform: The Cell Collective, Tomáš Helikar, B. Kowal, J. A. Rogers

Department of Biochemistry: Faculty Publications

Diseases are often a result of multiple malfunctions in complex, nonlinear biological/biochemical networks. As such, these processes are far more complicated to understand because they tend to give rise to functions that are emergent in nature, i.e., higher-level (mal)functions that are more than the sum of their parts. Systems biology provides a new approach to understanding biological systems and diseases from a holistic perspective.

Divergent Protein Motifs Direct Ef-P Mediated Translational Regulation In Salmonella And Escherichia Coli, Steven J. Hersch, Mengchi Wang, S. Betty Zou, Kyung-Mee Moon, Leonard J. Foster, Michael Ibba, William Wiley Navarre

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P (EF-P) is a universally conserved bacterial translation factor homologous to eukaryotic/archaeal initiation factor 5A. In Salmonella, deletion of the efp gene results in pleiotropic phenotypes, including increased susceptibility to numerous cellular stressors. Only a limited number of proteins are affected by the loss of EF-P, and it has recently been determined that EF-P plays a critical role in rescuing ribosomes stalled at PPP and PPG peptide sequences. Here we present an unbiased in vivo investigation of the specific targets of EF-P by employing stable isotope labeling of amino acids in cell culture (SILAC) to compare the …

Rescuing Acetylcholinesterase From Nerve Agent Inhibition: Protein Dynamics Driven Drug Discovery, Aiyana M. Emigh, Brian Bennion

STAR Program Research Presentations

Severe morbidity and mortality consequences result from irreversible inhibition of human acetylcholinesterase by organophosphates (OPs). Oxime-based reactivators are currently the only available treatments but lack efficacy in the central nervous system (CNS) where the most damage occurs. Computational docking and molecular dynamics (MD) simulations reveal complex structural barriers that may reduce oxime efficacy. These results may guide future drug designs of more effective countermeasures.

Proline Mechanisms Of Stress Survival, Xinwen Liang, Lu Zhang, Sathish Kumar Natarajan, Donald F. Becker

Department of Biochemistry: Faculty Publications

Significance: The imino acid proline is utilized by different organisms to offset cellular imbalances caused by environmental stress. The wide use in nature of proline as a stress adaptor molecule indicates that proline has a fundamental biological role in stress response. Understanding the mechanisms by which proline enhances abiotic/biotic stress response will facilitate agricultural crop research and improve human health. Recent Advances: It is now recognized that proline metabolism propels cellular signaling processes that promote cellular apoptosis or survival. Studies have shown that proline metabolism influences signaling pathways by increasing reactive oxygen species (ROS) formation in the mitochondria …

Reporters For The Analysis Of N-Glycosylation In Candida Albicans, Shahida Shahana, Hector M. Mora-Montes, Luis Castillo, Iryna Bohovych, Chirag C. Sheth, Frank C. Odds, Neil A.R. Gow, Alistair J.P. Brown

Department of Biochemistry: Faculty Publications

A large proportion of Candida albicans cell surface proteins are decorated post-translationally by glycosylation. Indeed N-glycosylation is critical for cell wall biogenesis in this major fungal pathogen and for its interactions with host cells. A detailed understanding of N-glycosylation will yield deeper insights into host-pathogen interactions. However, the analysis of N-glycosylation is extremely challenging because of the complexity and heterogeneity of these structures. Therefore, in an attempt to reduce this complexity and facilitate the analysis of N-glycosylation, we have developed new synthetic C. albicans reporters that carry a single N-linked glycosylation site derived from Saccharomyces cerevisiae Suc₂. These …

Probing Arabidopsis Chloroplast Diacylglycerol Pools By Selectively Targeting Bacterial Diacylglycerol Kinase To Suborganellar Membranes, Bagyalakshmi Muthan, Rebecca Roston, John E. Froehlich, Christoph Benning

Department of Biochemistry: Faculty Publications

Diacylglycerol (DAG) is an intermediate in metabolism of both triacylglycerols and membrane lipids. Probing the steady-state pools of DAG and understanding how they contribute to the synthesis of different lipids is important when designing plants with altered lipid metabolism. However, traditional methods of assaying DAG pools are difficult, because its abundance is low and because fractionation of subcellular membranes affects DAG pools. To manipulate and probe DAG pools in an in vivo context, we generated multiple stable transgenic lines of Arabidopsis (Arabidopsis thaliana) that target an Escherichia coli DAGkinase (DAGK) to each leaflet of each chloroplast envelope membrane. …

A Comprehensive, Multi-Scale Dynamical Model Of Erbb Receptor Signal Transduction In Human Mammary Epithelial Cells, Tomáš Helikar, Naomi Kochi, Bryan Kowal, Manjari Dimri, Mayumi Naramura, Srikumar M. Raja, Vimla Band, Hamid Band, Jim A. Rogers

Department of Biochemistry: Faculty Publications

The non-receptor tyrosine kinase Src and receptor tyrosine kinase epidermal growth factor receptor (EGFR/ErbB1) have been established as collaborators in cellular signaling and their combined dysregulation plays key roles in human cancers, including breast cancer. In part due to the complexity of the biochemical network associated with the regulation of these proteins as well as their cellular functions, the role of Src in EGFR regulation remains unclear. Herein we present a new comprehensive, multi-scale dynamical model of ErbB receptor signal transduction in human mammary epithelial cells. This model, constructed manually from published biochemical literature, consists of 245 nodes representing proteins …

Sbml Qualitative Models: A Model Representation Format And Infrastructure To Foster Interactions Between Qualitative Modelling Formalisms And Tools, Claudine Chaouiya, Duncan Bérenguier, Sarah M. Keating, Aurélien Naldi, Martijn P. Van Iersel, Nicolas Rodriguez, Andreas Dräger, Finja Büchel, Thomas Cokelaer, Bryan Kowal, Benjamin Wicks, Emanuel Gonçalves, Julien Dorier, Michel Page, Pedro T. Monteiro, Axel Von Kamp, Ioannis Xenarios, Hidde De Jong, Michael Hucka, Steffen Klamt, Denis Thieffry, Nicolas Le Novère, Julio Saez-Rodriguez, Tomáš Helikar

Department of Biochemistry: Faculty Publications

Background: Qualitative frameworks, especially those based on the logical discrete formalism, are increasingly used to model regulatory and signalling networks. A major advantage of these frameworks is that they do not require precise quantitative data, and that they are well-suited for studies of large networks. While numerous groups have developed specific computational tools that provide original methods to analyse qualitative models, a standard format to exchange qualitative models has been missing.

Results: We present the Systems Biology Markup Language (SBML) Qualitative Models Package (“qual”), an extension of the SBML Level 3 standard designed for computer representation of qualitative …

Selenodb 2.0: Annotation Of Selenoprotein Genes In Animals And Their Genetic Diversity In Humans, Frederic Romagne, Didac Santesmasses, Louise White, Gaurab K. Sarangi, Marco Mariotti, Ron Hübler, Antje Weihmann, Genis Parra, Vadim N. Gladyshev, Roderic Guigo, Sergi Castellano

Department of Biochemistry: Faculty Publications

SelenoDB (http://www.selenodb.org) aims to provide high-quality annotations of selenoprotein genes, proteins and SECIS elements. Selenoproteins are proteins that contain the amino acid selenocysteine (Sec) and the first release of the database included annotations for eight species. Since the release of SelenoDB 1.0 many new animal genomes have been sequenced. The annotations of selenoproteins in new genomes usually contain many errors in major databases. For this reason, we have now fully annotated selenoprotein genes in 58 animal genomes. We provide manually curated annotations for human selenoproteins, whereas we use an automatic annotation pipeline to annotate selenoprotein genes in other animal genomes. …

Comparative Metabolic Profiling Of Haberlea Rhodopensis, Thellungiella Halophyla, And Arabidopsis Thaliana Exposed To Low Temperature, Maria Benina, Toshihiro Obata, Nikolay Mehterov, Ivan Ivanov, Veselin Petrov, Valentina Toneva, Alisdair R. Fernie, Tsanko S. Gechev

Department of Biochemistry: Faculty Publications

Haberlea rhodopensis is a resurrection species with extreme resistance to drought stress and desiccation but also with ability to withstand low temperatures and freezing stress. In order to identify biochemical strategies which contribute to Haberlea's remarkable stress tolerance, the metabolic reconfiguration of H. rhodopensis during low temperature (4^◦C) and subsequent return to optimal temperatures (21^◦C) was investigated and compared with that of the stress tolerant Thellungiella halophyla and the stress sensitive Arabidopsis thaliana. Metabolic analysis by GC-MS revealed intrinsic differences in the metabolite levels of the three species even at 21^◦C. H. rhodopensis …

Elucidating Causes Of Diporeia Decline In The Great Lakes Via Metabolomics: Physiological Responses After Exposure To Different Stressors, Suman Maity, Amber Jannasch, Jiri Adamec, James M. Watkins, Thomas Nalepa, Tomas O. Höök, Maria S. Sepúlveda

Department of Biochemistry: Faculty Publications

The benthic macroinvertebrate Diporeia spp. have been extirpated from many areas of the Laurentian Great Lakes, but the mechanisms underlying such declines are not fully understood. Diporeia declines coinciding with the invasion of exotic dreissenid mussels (zebra and quagga) have led to the hypothesis that Diporeia declines are a result of decreased food availability from increasing competition with dreissenids for diatoms. There is additional evidence that Diporeia are negatively affected when in close proximity to dreissenids, probably because of exposure to toxins present in the mussels’ pseudofeces. Diporeia are also known to be sensitive to anthropogenic contaminants (such as polychlorinated …