Other Biochemistry, Biophysics, and Structural Biology Commons^™

Phenotypic Screening Identifies Brefeldin A/Ascotoxin As An Inducer Of Lipid Storage In The Algae Chlamydomonas Reinhardtii, Nishikant Wase, Boqiang Tu, Paul N. Black, Concetta C. Dirusso

Nishikant Wase

The use of microalgae as a biofuel feedstock is highly desired, but current methods to induce lipid accumulation cause severe stress responses that limit biomass and, thus oil yield. To address these issues, a high throughput screening (HTS) method was devised to identify chemical inducers of growth and lipid accumulation. Optimization was performed to determine the most effective cell density, DMSO and Nile Red (NR) concentrations to monitor growth and lipid accumulation. The method was tested using 1717 compounds from National Cancer Institute (NCI) Diversity Set III and Natural Products Set II in Chlamydomonas reinhardtii. Cells were inoculated at low ...

Lipid Transport Required To Make Lipids Of Photosynthetic Membranes, Evan Labrant, Allison C. Barnes, Rebecca Roston

Biochemistry -- Faculty Publications

Photosynthetic membranes provide much of the usable energy for life on earth. To produce photosynthetic membrane lipids, multiple transport steps are required, including fatty acid export from the chloroplast stroma to the endoplasmic reticulum, and lipid transport from the endoplasmic reticulum to the chloroplast envelope membranes. Transport of hydrophobic molecules through aqueous space is energetically unfavorable and must be catalyzed by dedicated enzymes, frequently on specialized membrane structures. Here, we review photosynthetic membrane lipid transport to the chloroplast in the context of photosynthetic membrane lipid synthesis. We independently consider the identity of transported lipids, the proteinaceous transport components, and membrane ...

Study Of The Visual Adaptation Mechanism In Marine Species With The Change Of Habitation Depth., Demid Osipov, Daniil Moshnikov

The International Student Science Fair 2018

The goal of our work was to determine the principal mechanisms that provide the difference in visual perception of two marine species that live on different depths: T. Pacificus and O. Vulgaris. In nature, visual perception of species that live deeper is shifted towards the blue region. This is related to the fact that red, orange and yellow light is absorbed more strongly by water than the blue light. On the other hand, the visual perception spectrum of an animal is determined by the absorption spectrum of the "light sensor" located in rods and cones of its eye retina. These ...

The Characterization Of The Transcription Factor Msab And Its Role In Staphylococcal Virulence, Justin Batte

Dissertations

Staphylococcus aureus is a common human pathogen that is responsible for a wide range of infections, ranging from relative minor skin infections to life-threatening disease such as bacteremia, septicemia, and endocarditis. S. aureus possesses many different virulent factors that aid in its ability to cause this wide array of infections. One major virulence factor includes the production of capsular polysaccharide (CP). The production of CP plays a major role in the virulence response during infection specifically by providing S. aureus an antiphagocytic mechanism that allows the pathogen to evade phagocytosis during an infection. S. aureus has developed complex genetic regulatory ...

Diurnal And Developmental Differences In Gene Expression Between Adult Dispersing And Flightless Morphs Of The Wing Polymorphic Cricket, Gryllus Firmus: Implications For Life-History Evolution, Anthony J. Zera, Neetha Nanoth Vellichirammal, Jennifer A. Brisson

Anthony Zera Publications

The functional basis of life history adaptation is a key topic of research in life history evolution. Studies of wing polymorphism in the cricket Gryllus firmus have played a prominent role in this field. However, prior in-depth investigations of morph specialization have primarily focused on a single hormone, juvenile hormone, and a single aspect of intermediary metabolism, the fatty-acid biosynthetic component of lipid metabolism. Moreover, the role of diurnal variation in life history adaptation in G. firmus has been understudied, as is the case for organisms in general. Here, we identify genes whose expression differs consistently between the ...

Intraperitoneal Nanotherapy For Metastatic Ovarian Cancer Based On Sirna-Mediated Suppression Of Dj-1 Protein Combined With A Low Dose Of Cisplatin, Canan Schumann, Stephanie Chan, Jess A. Miller, Yuliya Bortnyak, Katherine Carey, Alex Fedchyk, Leon Wong, Tetiana Korzun, Abraham S. Moses, Anna Lorenz, Delany Shea, Olena Taratula, Oleh Khalimonchuk, Oleh Taratula

Biochemistry -- Faculty Publications

Herein, we report an efficient combinatorial therapy for metastatic ovarian cancer based on siRNA-mediated suppression of DJ-1 protein combined with a low dose of cisplatin. DJ-1 protein modulates, either directly or indirectly, different oncogenic pathways that support and promote survival, growth, and invasion of ovarian cancer cells. To evaluate the potential of this novel therapy, we have engineered a cancer-targeted nanoplatform and validated that DJ-1 siRNA delivered by this nanoplatform after intraperitoneal injection efficiently downregulates the DJ-1 protein in metastatic ovarian cancer tumors and ascites. In vivo experiments revealed that DJ-1 siRNA monotherapy outperformed cisplatin alone by inhibiting tumor growth ...

Structural Determinants For The Interactions Of Chemically Modified Nucleic Acids With The Stabilin‑2 Clearance Receptor, Hans Gaus, Colton M. Miller, Punit P. Seth, Edward N. Harris

Biochemistry -- Faculty Publications

The Stabilin receptors are systemic clearance receptors for some classes of chemically modified nucleic acid therapeutics. In this study, the recombinant human secreted ecto-domain of the small isoform of Stabilin-2 (s190) was purified from cell culture and evaluated for direct binding with a multitude of antisense oligonucleotides (ASOs) using a fluorescence polarizationbased assay. The tested ASOs varied in their backbone composition, modification of the ribose 2′ position, overall length of the oligo, and sequence of the nucleotide bases. A fully phosphorothioate (PS) ASO with a 5−10−5 pattern of flanking 2′-O-methoxyethyl modifications was then used to test ...

Recently Discovered Benzo(A)Pyrene Induced Health Effects And Their Threat To The Inland Empire, Quinn Navarro

Armacost Library Undergraduate Research Award (ALURA)

This study investigated recent discoveries of Benzo(a)Pyrene (BaP) in order to determine the current threat BaP poses to residents of Southern California. Literature reviews comprise the research done on BaP-induced health effects. Primary articles reviewed include “Adverse Effect of Sub-Chronic Exposure to Benzo(a)Pyrene and Protective Effect of Butylated Hydroxyanisole on Learning and Memory Ability in Male

Sprague-Dawley Rat” by Xiao Liang (2014), and “Bioaccumulation and oxidative damage in juvenile scallop Chlamys farreri exposed to benzo[a]Pyrene, benzo[b]Fluoranthene and chrysene” by Meng Xiu (2014). These studies conclude that BaP potentially impairs memory and learning ...

Computational Systems Biology Approach For The Study Of Rheumatoid Arthritis: From A Molecular Map To A Dynamical Model, Vidisha Singh, Marek Ostaszewski, George D. Kalliolias, Gilles Chiocchia, Robert Olaso, Elisabeth Petit-Teixeira, Tomáš Helikar, Anna Niarakis

Biochemistry -- Faculty Publications

In this work we present a systematic effort to summarize current biological pathway knowledge concerning Rheumatoid Arthritis (RA). We are constructing a detailed molecular map based on exhaustive literature scanning, strict curation criteria, re-evaluation of previously published attempts and most importantly experts’ advice. The RA map will be web-published in the coming months in the form of an interactive map, using the MINERVA platform, allowing for easy access, navigation and search of all molecular pathways implicated in RA, serving thus, as an on line knowledgebase for the disease. Moreover the map could be used as a template for Omics data ...

Impact Of Phosphoinositides On Regulation Of K-Atp By Atp And Hydrogen Sulfide, Tyler Hendon

Theses and Dissertations

Hydrogen sulfide (H2S) reduces ischemia reperfusion (IR) injury by stimulating adenosine triphosphate (ATP) sensitive potassium channels (KATP) [1-5]. Demonstrating H2S stimulation is unique to KATP, as other inwardly rectifying potassium (Kir) channels demonstrate inhibition or are unaffected [6]. We recently showed that H2S inhibits Kir2 and Kir3 by decreasing channel sensitivity to phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2 or PIP2) [6]. Here, we test the hypothesis that H2S regulation of Kir6.2, a pore-forming subunit of the KATP channel, is also dependent on PIP2. Using whole-cell patch-clamp we show that H2S increases the activity of Kir6.2 channels expressed ...

Mutations In Rhodopsin Transmembrane Helix 5 And Dimerization Interface, Margaret Pinkevitch

Honors Research Projects

G protein coupled receptors (GPCRs) are membrane proteins with many functional roles. This family of receptors is expansive, with several subfamilies. Here, a member of subfamily A, rhodopsin (Rho) is studied. Mutations in rhodopsin have been linked to the disease retinitis pigmentosa (RP). Some of these mutations have been found to disrupt the dimerization/oligomerization of Rho at the TM4/TM5 proposed dimerization interface, causing pathogenesis of RP. In this study, two mutations of transmembrane helix 5 were investigated for changes in dimerization and stability, cell trafficking, and signaling. It was found that the V209M and F220C mutations did not ...

Can A Comprehensive Transition Plan To Barefoot Running Be The Solution To The Injury Epidemic In American Endurance Runners?, Michael A. Scarlett

CMC Senior Theses

Fossils belonging to the genus Homo, dating as far back as two million years ago, exhibit uniquely efficient features suggesting that early humans had evolved to become exceptional endurance runners. Although they did not have the cushion or stability-control features provided in our modern day running shoes, our early human ancestors experienced far less of the running-related injuries we experience today. The injury rate has been estimated as high as 90% annually for Americans training for a marathon and as high as 79% annually for all American endurance runners. There is an injury epidemic in conventionally shod populations that does ...

The Role Of The Metallochaperone Hypa In The Acid Survival And Activities Of Nickel Enzymes In Helicobacter Pylori, Heidi Hu

Doctoral Dissertations

Helicobacter pylori is a bacterium that has colonized the human gastric mucosa of over 50% of the world population. Persistent infection can cause gastritis, peptic ulcers, and cancers. The ability of H. pylori to colonize the acidic environment of the human stomach is dependent on the activity of the nickel containing enzymes, urease and NiFe-hydrogenase. The nickel metallochaperone, HypA, was previously shown to be required for the full activity of both enzymes. In addition to a Ni-binding site, HypA also contains a structural Zn site, which has been characterized to alter its averaged structure depending on pH and the presence ...

Towards The Synthetic Design Of Camelina Oil Enriched In Tailored Acetyl-Triacylglycerols With Medium-Chain Fatty Acids, Sunil Bansal, Hae Jin Kim, Gunnam Na, Megan E. Hamilton, Edgar B. Cahoon, Chaofu Lu, Timothy P. Durrett

Biochemistry -- Faculty Publications

The ability to manipulate expression of key biosynthetic enzymes has allowed the development of genetically modified plants that synthesise unusual lipids that are useful for biofuel and industrial applications. By taking advantage of the unique activities of enzymes from different species, tailored lipids with a targeted structure can be conceived. In this study we demonstrate the successful implementation of such an approach by metabolically engineering the oilseed crop Camelina sativa to produce 3-acetyl-1,2-diacyl-sn-glycerols (acetyl-TAGs) with medium-chain fatty acids (MCFAs). Different transgenic camelina lines that had been genetically modified to produce MCFAs through the expression of MCFA-specific thioesterases ...

Rates And Patterns Of Evolution In A Duplicated Genome In The Family Catostomidae, Megann Michelle Schmidt

Honors Program Theses

First and foremost, I would like to thank Dr. Gary and Myrna Floyd for financial support through their Undergraduate Research Assistantship, and I would also like to thank the University of Northern Iowa Biology Department for their support of undergraduate research. I would like to express my utmost gratitude towards Dr. Peter Berendzen and Zachary Sperstad for their support and guidance throughout this entire project. Additionally, thanks to the Iowa EPSCoR for funding collection of the data set, and thanks to Andrew Simons at the University of Minnesota and Jonathan Armbruster at Auburn University for help in data collection and ...

A Mechanistic Computational Model Reveals That Plasticity Of Cd4+ T Cell Differentiation Is A Function Of Cytokine Composition And Dosage, Bhanwar Lal Puniya, Robert G. Todd, Akram Mohammed, Deborah M. Brown, Matteo Barberis, Tomáš Helikar

Biochemistry -- Faculty Publications

CD4+ T cells provide cell-mediated immunity in response to various antigens. During an immune response, naïve CD4+ T cells differentiate into specialized effector T helper (Th1, Th2, and Th17) cells and induced regulatory (iTreg) cells based on a cytokine milieu. In recent studies, complex phenotypes resembling more than one classical T cell lineage have been experimentally observed. Herein, we sought to characterize the capacity of T cell differentiation in response to the complex extracellular environment. We constructed a comprehensive mechanistic (logical) computational model of the signal transduction that regulates T cell differentiation. The model’s dynamics were characterized and analyzed ...

Total Mercury Determination In Muscle And Liver Tissue Samples From Brazilian Amazon Fish Using Slurry Sampling, João Vitor De Queiroz, José Cavalcante Souza Vieira, Izabela Da Cunha Bataglioli, Alis Correia Bittarello, Camila Pereira Braga, Grasieli De Oliveira, Cilene Do Carmo Federici Padilha, Pedro De Magalhães Padilha

Biochemistry -- Faculty Publications

This paper presents a slurry sampling method for total mercury determination by graphite furnace atomic absorption spectrometry (GFAAS) in tissue of fish from the Amazon. The tissue samples were lyophilized and macerated, and then the slurry samples were prepared by putting 20 mg of tissue, added to a solution containing Triton X-100, Suprapur HNO₃, and zirconium nitrate directly in sampling vials of a spectrometer. Mercury standard solutions were prepared under the same conditions as the slurry samples. The slurry samples and the mercury standard solutions were sonicated for 20 s. Twenty microliters of slurry samples were injected into the ...

Cancerdiscover: An Integrative Pipeline For Cancer Biomarker And Cancer Class Prediction From High-Throughput Sequencing Data, Akram Mohammed, Greyson Biegert, Jiri Adamec, Tomáš Helikar

Biochemistry -- Faculty Publications

Accurate identification of cancer biomarkers and classification of cancer type and subtype from High Throughput Sequencing (HTS) data is a challenging problem because it requires manual processing of raw HTS data from various sequencing platforms, quality control, and normalization, which are both tedious and timeconsuming. Machine learning techniques for cancer class prediction and biomarker discovery can hasten cancer detection and significantly improve prognosis. To date, great research efforts have been taken for cancer biomarker identification and cancer class prediction. However, currently available tools and pipelines lack flexibility in data preprocessing, running multiple feature selection methods and learning algorithms, therefore, developing ...

The Colomoto Interactive Notebook: Accessible And Reproducible Computational Analyses For Qualitative Biological Networks, Aurelien Naldi, Celine Hernandez, Nicolas Levy, Gautier Stoll, Pedro T. Monteiro, Claudine Chaouiya, Tomáš Helikar, Andrei Zinovyev, Laurence Calzone, Sarah Cohen-Boulakia, Denis Thieffry, Loic Pauleve

Biochemistry -- Faculty Publications

Analysing models of biological networks typically relies on workflows in which different software tools with sensitive parameters are chained together,many times with additional manual steps. The accessibility and reproducibility of such workflows is challenging, as publications often overlook analysis details, and because some of these tools may be difficult to install, and/or have a steep learning curve. The CoLoMoTo Interactive Notebook provides a unified environment to edit, execute, share, and reproduce analyses of qualitative models of biological networks. This framework combines the power of different technologies to ensure repeatability and to reduce users’ learning curve of these technologies ...

Simulation Of Stimulation: Cytokine Dosage And Cell Cycle Crosstalk Driving Timing-Dependent T Cell Differentiation, Matteo Barberis, Tomáš Helikar, Paul Verbruggen

Biochemistry -- Faculty Publications

Triggering an appropriate protective response against invading agents is crucial to the effectiveness of human innate and adaptive immunity. Pathogen recognition and elimination requires integration of a myriad of signals from many different immune cells. For example, T cell functioning is not qualitatively, but quantitatively determined by cellular and humoral signals. Tipping the balance of signals, such that one of these is favored or gains advantage on another one, may impact the plasticity of T cells. This may lead to switching their phenotypes and, ultimately, modulating the balance between proliferating and memory T cells to sustain an appropriate immune response ...