Biochemistry Commons^™

Identification Of Disufide Bond Formation Between Mitoneet And Glutamate Dehydrogenase 1, Morgan E. Roberts, Jacquelyn P. Crail, Megan M. Laffoon, William G. Fernandez, Michael A. Menze, Mary E. Konkle

Faculty Research & Creative Activity

MitoNEET is a protein that was identified as a drug target for diabetes, but its cellular function as well as its role in diabetes remains elusive. Protein pull-down experiments identified glutamate dehydrogenase 1 (GDH1) as a potential binding partner. GDH1 is a key metabolic enzyme with emerging roles in insulin regulation. MitoNEET forms a covalent complex with GDH1 through disulfide bond formation and acts as an activator. Proteomic analysis identified the specific cysteine residues that participate in the disulfide bond. This is the first report that effectively links mitoNEET to activation of the insulin regulator GDH1.

Identification Of Disulfide Bond Formation Between Mitoneet And Glutamate Dehydrogenase 1, Morgan E. Roberts, Jacquelyn P. Crail, Megan M. Laffoon, William G. Fernandez, Michael A. Menze, Mary E. Konkle

Faculty Research & Creative Activity

MitoNEET is a protein that was identified as a drug target for diabetes, but its cellular function as well as its role in diabetes remains elusive. Protein pull-down experiments identified glutamate dehydrogenase 1 (GDH1) as a potential binding partner. GDH1 is a key metabolic enzyme with emerging roles in insulin regulation. MitoNEET forms a covalent complex with GDH1 through disulfide bond formation and acts as an activator. Proteomic analysis identified the specific cysteine residues that participate in the disulfide bond. This is the first report that effectively links mitoNEET to activation of the insulin regulator GDH1.

Mechanisms For Regulation Of Plant Kinesins, Anindya Ganguly, Ram Dixit

Biology Faculty Publications & Presentations

Throughout the eukaryotic world, kinesins serve as molecular motors for the directional transport of cellular cargo along microtubule tracks. Plants contain a large number of kinesins that have conserved as well as specialized functions. These functions depend on mechanisms that regulate when, where and what kinesins transport. In this review, we highlight recent studies that have revealed conserved modes of regulation between plant kinesins and their non-photosynthetic counterparts. These findings lay the groundwork for understanding how plant kinesins are differentially engaged in various cellular processes that underlie plant growth and development.

Identification Of Disufide Bond Formation Between Mitoneet And Glutamate Dehydrogenase 1., Morgan Roberts, Jacquelyn Crail, Megan Laffoon, William Fernandez, Michael Menze, Mary Konkle

Faculty Scholarship

MitoNEET is a protein that was identified as a drug target for diabetes, but its cellular function as well as its role in diabetes remains elusive. Protein pull-down experiments identified glutamate dehydrogenase 1 (GDH1) as a potential binding partner. GDH1 is a key metabolic enzyme with emerging roles in insulin regulation. MitoNEET forms a covalent complex with GDH1 through disulfide bond formation and acts as an activator. Proteomic analysis identified the specific cysteine residues that participate in the disulfide bond. This is the first report that effectively links mitoNEET to activation of the insulin regulator GDH1.

Mutational Analysis Of The Rotavirus Nsp4 Enterotoxic Domain That Binds To Caveolin-1, Judith M. Ball, Megan E. Schroeder, Cecelia V. Williams, Friedhelm Schroeder, Rebecca D. Parr

Faculty Publications

Background: Rotavirus (RV) nonstructural protein 4 (NSP4) is the first described viral enterotoxin, which induces early secretory diarrhea in neonatal rodents. Our previous data show a direct interaction between RV NSP4 and the structural protein of caveolae, caveolin-1 (cav-1), in yeast and mammalian cells. The binding site of cav-1 mapped to the NSP4 amphipathic helix, and led us to examine which helical face was responsible for the interaction.

Methods: A panel of NSP4 mutants were prepared and tested for binding to cav-1 by yeast two hybrid and direct binding assays. The charged residues of the NSP4 amphipathic helix were changed …

Microtubule Severing At Crossover Sites By Katanin Generates Ordered Cortical Microtubule Arrays In Arabidopsis, Quan Zhang, Erica Fishel, Tyler Bertroche, Ram Dixit

Biology Faculty Publications & Presentations

Highlights

• Severing primarily depolymerizes the overlying CMT at crossover sites
• Severing probability increases nonlinearly with crossover time
• Katanin localizes to crossover sites and is required for severing
• Loss of katanin activity prevents the formation of coaligned CMT arrays

Summary
The noncentrosomal cortical microtubules (CMTs) of land plants form highly ordered parallel arrays that mediate cell morphogenesis by orienting cellulose deposition [1, 2 and 3]. Since new CMTs initiate from dispersed cortical sites at random orientations [4], parallel array organization is hypothesized to require selective pruning of CMTs that are not in the dominant orientation. Severing of CMTs at crossover sites …

Mscs-Like Mechanosensitive Channels In Plants And Microbes, Margaret E. Wilson, Grigory Maksaev, Elizabeth S. Haswell

Biology Faculty Publications & Presentations

The challenge of osmotic stress is something all living organisms must face as a result of environmental dynamics. Over the past three decades, innovative research and cooperation across disciplines have irrefutably established that cells utilize mechanically gated ion channels to release osmolytes and prevent cell lysis during hypoosmotic stress. Early electrophysiological analysis of the inner membrane of Escherichia coli identified the presence of three distinct mechanosensitive activities. The subsequent discoveries of the genes responsible for two of these activities, the mechanosensitive channels of large (MscL) and small (MscS) conductance, led to the identification of two diverse families of mechanosensitive channels. …

Preservation Of Biosignature Molecules In Potential Sample Return Container Of The Mars 2020 Mission, Kimberly E. Lykens, Fei Chen Ph.D

STAR Program Research Presentations

Preservation of Biosignature Molecules in Potential Sample Return Container of the Mars 2020 Mission

Kimberly Lykens¹ and Fei Chen²

¹Wittenberg University, Springfield, Ohio 45501 ²Jet Propulsion Laboratory, Pasadena, California, 91109

One requirement for sustainable life on terrestrial planets includes the presence of organic polymers, compounds that are essential for major biological functions such as replication and catalysis. An identified goal of the Mars mission in the year 2020 is to implement a sample-return to identify and validate signs of life on Mars through the discovery of biosignature molecules in Martian core samples. Martian core samples recovered …

Immunomodulatory Activity Of Sambucus Mexicana And Trichostema Lanatum On Lps Stimulated Raw 264.7 Macrophage Cells, Victoria Hester, P. Matthew Joyner

Featured Research

Chumash medicinal plants Sambucus mexicana (Mexican elderberry) and Trichostema lanatum (woolly blue curls) were tested for immunomodulatory activity. Anti-inflammatory effects were determined by treating LPS induced RAW 264.7 macrophage cells with plant extracts and measuring the levels of cytokines: tumor necrosis factor alpha (TNF-alpha) and interleukin 10 (IL-10). We hypothesized that both plants would exert immunomodulatory activity by reducing the pro-inflammatory production of TNF-alpha or by promoting M2 polarization with a concurrent increase in IL-10 production. At concentration 0.01 mg/mL woolly blue curls and Mexican elderberry demonstrated anti-inflammatory activity by reducing the concentration of TNF-alpha in vitro, while levels of …

An Ethnobotanical Approach To Finding Antimicrobial Compounds In Wooly Blue Curls (Trichostema Lanatum) Using A Kirby-Bauer Disc Diffusion Assay, Matthew C. Fleming, P. Matthew Joyner

Featured Research

Plants can be an important source of creativity and production of new drugs. In this study, extracts of wooly blue curls (Trichostema lanatum) were made using DMSO and tested for antimicrobial activity on a panel of bacteria commonly found in separate ecological niches. Wooly blue curls (WBC) was chosen due to its being recorded as a strong disinfectant by the Chumash people. It was found that WBC does exhibit antimicrobial activity against gram positive bacteria and not against gram negative bacteria. However, gram negative bacteria with reduced drug efflux function became susceptible to the WBC extract.

Role Of Nucleation In Cortical Microtubule Array Organization: Variations On A Theme, Erica A. Fishel, Ram Dixit

Biology Faculty Publications & Presentations

The interphase cortical microtubules (CMTs) of plant cells form strikingly ordered arrays in the absence of a dedicated microtubule-organizing center. Considerable research effort has focused on activities such as bundling and severing that occur after CMT nucleation and are thought to be important for generating and maintaining ordered arrays. In this review, we focus on how nucleation affects CMT array organization. The bulk of CMTs are initiated from γ-tubulin-containing nucleation complexes localized to the lateral walls of pre-existing CMTs. These CMTs grow either at an acute angle or parallel to the pre-existing CMT. Although the impact of microtubule-dependent nucleation is …

Patatin-Related Phospholipase Pplaiiiδ Increases Seed Oil Content With Long-Chain Fatty Acids In Arabidopsis, Maoyin Li, Sung Bahn, Chuchuan Fan, Jia Li, Tien Phan, Michael Ortiz, Mary Roth, Ruth Welti, Jan Jaworski, Xuemin Wang

Biology Department Faculty Works

The release of fatty acids from membrane lipids has been implicated in various metabolic and physiological processes, but in many cases, the enzymes involved and their functions in plants remain unclear. Patatin-related phospholipase As (pPLAs) constitute a major family of acyl-hydrolyzing enzymes in plants. Here, we show that pPLAIIId promotes the production of triacylglycerols with 20- and 22-carbon fatty acids in Arabidopsis (Arabidopsis thaliana). Of the four pPLAIIIs (a, b, g, d), only pPLAIIId gene knockout results in a decrease in seed oil content, and pPLAIIId is most highly expressed in developing embryos. The overexpression of pPLAIIId increases the content …

Evolutionary And Molecular Analysis Of Conserved Vertebrate Immunity To Fungi, Erin Carter

Honors College

The innate immune system is highly conserved amongst all multicellular organisms. Yet a constant battle exists between host cells and pathogens due to the rapid evolution of immune system components. Functional genomics and in silico methods can be employed to elucidate the evolutionary patterns of vertebrate immunity to pathogenic fungi such as Candida albicans, an opportunistic fungal pathogen that can cause lethal candidiasis in the immunocompromised. Mammals such as humans and mice possess conserved C-type lectin receptors that recognize the C. albicans cell wall. However, these receptors have not been identified in fish. Here I describe how we identified potential …

Activities Of Methionine-Γ-Lyase In The Acidophilic Archaeon “Ferroplasma Acidarmanus” Strain Fer1, M. Khan, Madeline Lopez-Munoz, Charles Kaspar, Kai Hung

Faculty Research & Creative Activity

Biogeochemical processes on exposed pyrite ores result in extremely high levels of sulfuric acid at these locations. Acidophiles that thrive in these conditions must overcome significant challenges, including an environment with proton concentrations at pH 3 or below. The role of sulfur metabolism in the archaeon “Ferroplasma acidarmanus” strain fer1’s ability to thrive in this environment was investigated due to its growth-dependent production of methanethiol, a volatile organic sulfur compound. Two putative sequences for methionine- γ-lyase (EC 4.4.1.11), an enzyme known to carry out α,γ-elimination on L-methionine to produce methanethiol, were identified in fer1. Bioinformatic analyses identified a conserved pyridoxal-5′-phosphate …

Activities Of Methionine-Γ-Lyase In The Acidophilic Archaeon “Ferroplasma Acidarmanus” Strain Fer1, M. A. Khan, Madeline M. Lopez-Munoz, Charles W. Kaspar, Kai F. Hung

Faculty Research & Creative Activity

Biogeochemical processes on exposed pyrite ores result in extremely high levels of sulfuric acid at these locations. Acidophiles that thrive in these conditions must overcome significant challenges, including an environment with proton concentrations at pH 3 or below. The role of sulfur metabolism in the archaeon “Ferroplasma acidarmanus” strain fer1’s ability to thrive in this environment was investigated due to its growth-dependent production of methanethiol, a volatile organic sulfur compound. Two putative sequences for methionine- γ-lyase (EC 4.4.1.11), an enzyme known to carry out α,γ-elimination on L-methionine to produce methanethiol, were identified in fer1. Bioinformatic analyses identified a conserved pyridoxal-5′-phosphate …

Psychosine, The Cytotoxic Sphingolipid That Accumulates In Globoid Cell Leukodystrophy, Alters Membrane Architecture, Jacqueline Hawkins-Salsbury, Archana Parameswar, Xuntian Jiang, Paul Schlesinger, Ernesto Bongarzone, Daniel Ory, Alexei Demchenko, Mark Sands

Chemistry & Biochemistry Faculty Works

Globoid cell leukodystrophy (GLD) is a neurological disease caused by deficiency of the lysosomal enzyme galactosylceramidase (GALC). In the absence of GALC, the cytotoxic glycosphingolipid, psychosine (psy), accumulates in the nervous system. Psychosine accumulation preferentially affects oligodendrocytes, leading to progressive demyelination and infiltration of activated monocytes/macrophages into the CNS. GLD is characterized by motor defects, cognitive deficits, seizures, and death by 2–5 years of age. It has been hypothesized that psychosine accumulation, primarily within lipid rafts, results in the pathogenic cascade in GLD. However, the mechanism of psychosine toxicity has yet to be elucidated. Therefore, we synthesized the enantiomer of …

Aβ Alters The Dna Methylation Status Of Cell-Fate Genes In An Alzheimer’S Disease Model, Gary D. Isaacs, Noor Taher, Courtney Mckenzie, Rebecca Garrett, Matthew Baker, Nena Fox

Faculty Publications and Presentations

Alzheimer’s disease (AD) is characterized by neurofibrillary tangles and extracellular amyloid-β plaques (Aβ). Despite ongoing research, some ambiguity remains surrounding the role of Aβ in the pathogenesis of this neurodegenerative disease. While several studies have focused on the mutations associated with AD, our understanding of the epigenetic contributions to the disease remains less clear. To that end, we determined the changes in DNA methylation in differentiated human neurons with and without Aβ treatment. We isolated the DNA from neurons treated with Aβ or vehicle, and digested the two samples with either a methylation-sensitive (HpaII) or a methylation-insensitive (MspI) restriction endonuclease. …

Acyl-Lipid Metabolism, Younghua Li-Beisson, Basil Shorrosh, Fred Beisson, Mats X. Andersson, Vincent Arondel, Philip D. Bates, Sébastien Baud, David Bird, Allan Debono, Timothy P. Durrett, Rochus B. Franke, Ian A. Graham, Kenta Katayama, Amélie A. Kelly, Tony Larson, Jonathan E. Markham, Martine Miquel, Isabel Molina, Ikuo Nishida, Owen Rowland, Lacey Samuels, Katherine M. Schmid, Hajime Wada, Ruth Welti, Changcheng Xu, Rémi Zallot, John Ohlrogge

Scholarship and Professional Work - LAS

Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes …

Using Stable Isotope Analysis Of Zooplankton To Document Trophic And Biogeochemical Changes In The San Francisco Estuary, Steven C. Westbrook, Julien Moderan

STAR Program Research Presentations

Zooplankton represent a vital link between phytoplankton and fish, like the endangered Delta Smelt. Human interferences (nitrates from waste water, flow alteration, invasive species introduction…) have altered the structure of the San Francisco Estuary (SFE) ecosystem. We use stable isotope analysis to improve our knowledge of the planktonic food web in the SFE and gain insights into its evolution over the past decades. We use the ratios of certain isotopes (Nitrogen, Carbon, Sulfur, etc.) in different species of zooplankton to tell us what it is feeding on as well as the trophic level it feeds in. My research focused on …

Solid-Phase Organic Matter Reduction Regulates Anaerobic Decomposition In Bog Soil, Jason K. Keller, Kimberly K. Takagi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peatlands store globally significant amounts of carbon and are important sources of the greenhouse gas methane (CH4) to the atmosphere. However, for reasons which are not well understood, many peatland soils produce smaller amounts of CH4 than theoretically predicted, and carbon dioxide (CO2) produced during anaerobic decomposition in peatland soils cannot be accounted for by commonly measured microbial processes. Here we show that the reduction of solid-phase organic matter (i.e., humic substances) suppresses CH4 production in a bog soil and can be responsible for 33–61% of the total carbon mineralization in this soil. These results demonstrate that the reduction of …