Biochemistry Commons^™

Disruption Of Claudin-Made Tight Junction Barriers By Clostridium Perfringens Enterotoxin: Insights From Structural Biology, Chinemerem P. Ogbu, Sourav Roy, Alex J. Vecchio

Department of Biochemistry: Faculty Publications

Claudins are a family of integral membrane proteins that enable epithelial cell/cell interactions by localizing to and driving the formation of tight junctions. Via claudin self-assembly within the membranes of adjoining cells, their extracellular domains interact, forming barriers to the paracellular transport of small molecules and ions. The bacterium Clostridium perfringens causes prevalent gastrointestinal disorders in mammals by employing an enterotoxin (CpE) that targets claudins. CpE binds to claudins at or near tight junctions in the gut and disrupts their barrier function, potentially by disabling their assembly or via cell signaling means—the mechanism(s) remain unclear. CpE ultimately destroys claudin-expressing cells …

Sesamum Indicum Diet Prevents Hyperlipidemia In Experimental Rats, Muinat M. Adeyanju, Idris A. Saheed, Oluwaseun I. Oyelekan, Taiwo A. Dele-Osibanjo, Ayodeji A. Adelegan, Adekunle J. Raimi, Samuel O. Olalekan, Olugbenga S. Alabi, Khadijat M. Alli

Department of Biochemistry: Faculty Publications

Cardiovascular diseases and metabolic complications caused by hyperlipidemia are the leading cause of death globally. In this study, the hypolipidemic potency of Sesamum indicum (SI) seeds was investigated. Of the thirty-five (35) male rats used in the study, five (5) were randomly selected for baseline measurements and thirty (30) were fed high fat diet (HFD) for four (4) weeks before random assignment into three (3) groups. The experimental group was treated with 50% SI seed, the positive control group was given a hypolipidemic drug, atorvastatin (5 mg/kg/day) while the untreated group served as the negative control. With SI administration, the …

Role Of Specialized Pro-Resolving Mediators In Reducing Neuroinflammation In Neurodegenerative Disorders, Jana Ponce, Arzu Ulu, Corrine Hanson, Erin Cameron-Smith, Jenna Wuebker, John Bertoni, Alfred Fisher, Ka-Chun Siu, Vivien Marmelat, Jiri Adamec, Danish Bhatti

Department of Biochemistry: Faculty Publications

Alzheimer’s disease (AD) and Parkinson’s disease (PD) are neurodegenerative disorders that affect millions of individuals worldwide. As incidence of these conditions increases with age, there will undoubtedly be an increased prevalence of cases in the near future. Neuroinflammation is a hallmark in the development and progression of neurodegenerative diseases and prevention or resolution of chronic neuroinflammation may represent a novel approach to treatment. The present review highlights the potential of the anti-inflammatory and pro-resolving effects of polyunsaturated fatty acid (PUFA)- derived mediators (Specialized Pro-resolving Mediators—SPM) in neurodegenerative disorders. PUFA-derived SPM are biosynthesized in response to chemicals produced from acute inflammatory …

Two Heads Are Better Than One: Current Landscape Of Integrating Qsp And Machine Learning, Tongli Zhang, Ioannis P. Androulakis, Peter Bonate, Limei Cheng, Tomáš Helikar, Jaimit Parikh, Christopher Rackauckas, Kalyanasundaram Subramanian, Carolyn R. Cho

Department of Biochemistry: Faculty Publications

Quantitative systems pharmacology (QSP) modeling is applied to address essential questions in drug development, such as the mechanism of action of a therapeutic agent and the progression of disease. Meanwhile, machine learning (ML) approaches also contribute to answering these questions via the analysis of multi-layer ‘omics’ data such as gene expression, proteomics, metabolomics, and high-throughput imaging. Furthermore, ML approaches can also be applied to aspects of QSP modeling. Both approaches are powerful tools and there is considerable interest in integrating QSP modeling and ML. So far, a few successful implementations have been carried out from which we have learned about …

Metabolic Synergy Between Human Symbionts Bacteroides And Methanobrevibacter, Jennie L. Catlett, Sean Carr, Mikaela Cashman, Megan D. Smith, Mary Walter, Zahmeeth Sakkaff, Christine A. Kelley, Massimiliano Pierobon, Myra B. Cohen, Nicole R. Buan

Department of Biochemistry: Faculty Publications

ABSTRACT Trophic interactions between microbes are postulated to determine whether a host microbiome is healthy or causes predisposition to disease. Two abundant taxa, the Gram-negative heterotrophic bacterium Bacteroides thetaiotaomicron and the methanogenic archaeon Methanobrevibacter smithii, are proposed to have a synergistic metabolic relationship. Both organisms play vital roles in human gut health; B. thetaiotaomicron assists the host by fermenting dietary polysaccharides, whereas M. smithii consumes end-stage fermentation products and is hypothesized to relieve feedback inhibition of upstream microbes such as B. thetaiotaomicron. To study their metabolic interactions, we defined and optimized a coculture system and used software testing …

Arginine Catabolism And Polyamine Biosynthesis Pathway Disparities Within Francisella Tularensis Subpopulations, Yinshi Yue, Bhanwar Lal Puniya, Tomáš Helikar, Benjamin Girardo, Steven H. Hinrichs, Marilyn A. Larson

Department of Biochemistry: Faculty Publications

Francisella tularensis is a highly infectious zoonotic pathogen with as few as 10 organisms causing tularemia, a disease that is fatal if untreated. Although F. tularensis subspecies tularensis (type A) and subspecies holarctica (type B) share over 99.5% average nucleotide identity, notable differences exist in genomic organization and pathogenicity. The type A clade has been further divided into subtypes A.I and A.II, with A.I strains being recognized as some of the most virulent bacterial pathogens known. In this study, we report on major disparities that exist between the F. tularensis subpopulations in arginine catabolism and subsequent polyamine biosynthesis. The genes …

Functional Foods: Promising Therapeutics For Nigerian Children With Sickle Cell Diseases, Oladeji John Alabi, Fikayo Noah Adegboyega, Dolapo Samuel Olawoyin, Oluwakemi Arinola Babatunde

Department of Biochemistry: Faculty Publications

Sickle cell disease (SCD), also known as sickle cell anemia (SCA) is one of the structural hemoglobinopathies that occurs due to a single nucleotide mutation from GAG to GTG, which changes the amino acid of a β-globin chain of hemoglobin (Hb) from glutamate to valine. This singular mutation results to disorderliness in red blood cells (RBCs) with advent of changes in RBC morphology and other pathological conditions. In the 1980s, intermittent red blood cell transfusions, opioids, and penicillin prophylaxis were the only available therapy for SCA and were commonly reserved for acute, life threatening complications. So far, the US Food …

Fish Oil Intake During Gestation And Lactation Attenuated Stz-Induced Diabetes Inmale Offspring Via Activation Of Brown Fat And Modulating Oxylipin Profile, Rong Fan, Shalom Thomas, Mikyoung You, Zhuoheng Li, Brandt Bessell, Bhanwar Lal Puniya, Tomáš Helikar, Zhenhua Liu, Soonkyu Chung

Department of Biochemistry: Faculty Publications

Fish oil (FO) has been demonstrated to activate brown thermogenesis and attenuate inflammation in the brown adipose tissue (BAT). Previously, we have reported thatmaternal FO supplementation promotes BAT activity of the weaned mice pups. However, whether maternal FO intake could confer sustainable metabolic benefits to offspring remains uncovered. Therefore, this study aimed to determine the differential impact of maternal FO during pregnancy versus lactation on BAT transcriptome and evaluate the role of bioactive lipid metabolites derived from maternal FO supplementation on the extended metabolic benefits of older pups in the context of type 1 diabetes (T1D).

Conclusions: Our results suggested …

Recognition Of Extracellular Dna By Type Iv Pili Promotes Biofilm Formation By Clostridioides Difficile, Leslie A. Ronish, Ben Sidner, Yafan Yu, Kurt H. Piepenbrink

Department of Biochemistry: Faculty Publications

Clostridioides difficile is a Gram-positive bacillus, which is a frequent cause of gastrointestinal infections triggered by the depletion of the gut microbiome. Because of the frequent recurrence of these infections after antibiotic treatment, mechanisms of C. difficile persistence and recurrence, including biofilm formation, are of increasing interest. Previously, our group and others found that type IV pili, filamentous helical appendages polymerized from protein subunits, promoted microcolony and biofilm formation in C. difficile. In Gram-negative bacteria, the ability of type IV pili to mediate bacterial self-association has been explained through interactions between the pili of adjacent cells, but type …

Coordination Of Metal Center Biogenesis In Human Cytochrome C Oxidase, Eva Nývltová, Jonathan Dietz, Javier Seravalli, Oleh Khalimonchuk, Antoni Barrientos

Department of Biochemistry: Faculty Publications

Mitochondrial cytochrome c oxidase (CcO) or respiratory chain complex IV is a heme aa3- copper oxygen reductase containing metal centers essential for holo-complex biogenesis and enzymatic function that are assembled by subunit-specific metallochaperones. The enzyme has two copper sites located in the catalytic core subunits. The COX1 subunit harbors the CuB site that tightly associates with heme a3 while the COX2 subunit contains the binuclear CuA site. Here, we report that in human cells the CcO copper chaperones form macromolecular assemblies and cooperate with several twin CX9C proteins to control heme a biosynthesis and coordinate copper transfer sequentially to the …

Building Digital Twins Of The Human Immune System: Toward A Roadmap, Reinhard Laubenbacher, Anna Niarakis, Tomas Helikar, G. An, B. Shapiro, R. S. Malik-Sheriff, T. J. Sego, P. Macklin, J. A. Glazier

Department of Biochemistry: Faculty Publications

Digital twins, customized simulation models pioneered in industry, are beginning to be deployed in medicine and healthcare, with some major successes, for instance in cardiovascular diagnostics and in insulin pump control. Personalized computational models are also assisting in applications ranging from drug development to treatment optimization. More advanced medical digital twins will be essential to making precision medicine a reality. Because the immune system plays an important role in such a wide range of diseases and health conditions, from fighting pathogens to autoimmune disorders, digital twins of the immune system will have an especially high impact. However, their development presents …

Addressing Barriers In Comprehensiveness, Accessibility, Reusability, Interoperability And Reproducibility Of Computational Models In Systems Biology, Anna Niarakis, Dagmar Waltemath, James Glazier, Falk Schreiber, Sarah M. Keating, David Nickerson, Claudine Chaouiya, Anne Siegel, Vincent Noël, Henning Hermjakob, Tomáš Helikar, Sylvain Soliman, Laurence Calzone

Department of Biochemistry: Faculty Publications

Computational models are often employed in systems biology to study the dynamic behaviours of complex systems. With the rise in the number of computational models, finding ways to improve the reusability of these models and their ability to reproduce virtual experiments becomes critical. Correct and effective model annotation in community-supported and standardised formats is necessary for this improvement. Here,we present recent efforts toward a common framework for annotated, accessible, reproducible and interoperable computational models in biology, and discuss key challenges of the field.

Scientists from different systems biology fields have long been developing community-driven guidelines and best practices for annotation, …

Development, Structure, And Mechanism Of Synthetic Antibodies That Target Claudin And Clostridium Perfringens Enterotoxin Complexes, Benjamin J. Orlando, Pawel K. Dominik, Sourav Roy, Chinemerem P. Ogbu, Satchal K. Erramilli, Anthony A. Kossiakoff, Alex J. Vecchio

Department of Biochemistry: Faculty Publications

Strains of Clostridium perfringens produce a two-domain enterotoxin (CpE) that afflicts humans and domesticated animals, causing prevalent gastrointestinal illnesses. CpE’s C-terminal domain (cCpE) binds cell surface receptors, followed by a restructuring of its N-terminal domain to form a membranepenetrating β-barrel pore, which is toxic to epithelial cells of the gut. The claudin family of membrane proteins are known receptors for CpE and also control the architecture and function of cell-cell contacts (tight junctions) that create barriers to intercellular molecular transport. CpE binding and assembly disables claudin barrier function and induces cytotoxicity via β-pore formation, disrupting gut homeostasis; however, a structural …

The Follicular Lymphoma Epigenome Regulates Its Microenvironment, Rada Amin, Mounia S. Braza

Department of Biochemistry: Faculty Publications

Follicular lymphoma (FL) is a B-cell non-Hodgkin lymphoma of germinal center (GC) origin with a distinctive tumor microenvironment (TME) and a unique spectrum of mutations. Despite the important therapeutic advances, FL is still incurable. During B-cell development, the GC reaction is a complex multistep process in which epigenetic regulators dynamically induce or suppress transcriptional programs. In FL, epigenetic gene mutations perturb the regulation of these programs, changing GC B-cell function and skewing differentiation towards tumor cells and altering the microenvironment interactions. FL pathogenesis and malignant transformation are promoted by epigenetic reprogramming of GC B cells that alters the immunological synapse …

Feedlot Diets Containing Different Starch Levels And Additives Change The Cecal Proteome Involved In Cattle’S Energy Metabolism And Inflammatory Response, Leone Campos Rocha, Andrey Sávio De Almeida Assunção, Renata Aparecida Martins, Victor Valério De Carvalho, Alexandre Perdigão2, Marília Afonso Rabelo Buzalaf, Jiri Adamec, Camila Pereira Braga, Danilo Domingues Millen, José Cavalcante Souza Vieira, Pedro De Magalhães Padilha

Department of Biochemistry: Faculty Publications

Diets for feedlot cattle must be a higher energy density, entailing high fermentable carbohydrate content. Feed additives are needed to reduce possible metabolic disorders. This study aimed to analyze the post-rumen effects of different levels of starch (25%, 35%, and 45%) and additives (monensin or a blend of essential oils and exogenous α-amylase) in diets for Nellore feedlot cattle. The cecum tissue proteome was analyzed via two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and then differentially expressed protein spots were identified with liquid chromatography–tandem mass spectrometry (LC–MS/MS). The use of blends of essential oils associated with α-amylase as a feed additive promoted …

Endothelial Cell-Specific Deletion Of A Microrna Accelerates Atherosclerosis, Dafeng Yang, Stefan Haemmig, Jingshu Chen, Michael Mccoy, Henry S. Cheng, Haoyang Zhou, Daniel Pérez-Cremades, Xiao Cheng, Xinghui Sun, Jorge Haneo-Mejia, Shamsudheen K. Vellarikkal, Rajat M. Gupta, Victor Barrera, Mark W. Feinberg

Department of Biochemistry: Faculty Publications

Background and aims: Chronic vascular endothelial inflammation predisposes to atherosclerosis; however, the cell-autonomous roles for endothelial-expressing microRNAs (miRNAs) are poorly understood in this process. MiR-181b is expressed in several cellular constituents relevant to lesion formation. The aim of this study is to examine the role of genetic deficiency of the miR-181b locus in endothelial cells during atherogenesis.

Methods and Results: Using a proprotein convertase subtilisin/kexin type 9 (PCSK9)-induced atherosclerosis mouse model, we demonstrated that endothelial cell (EC)-specific deletion of miR-181a2b2 significantly promoted atherosclerotic lesion formation, cell adhesion molecule expression, and the influx of lesional macrophages in the vessel wall. Yet, …

A Link Between Methylglyoxal And Heart Failure During Hiv-1 Infection, Prasanta K. Dasg, Fadhel A. Alomar, Jesse L. Cox, Joellyn Mcmillan, Bryan T. Hackfort, Edward Makarov, Brenda Morsey, Howard S. Fox, Howard E. Gendelman, Santhi Gorantla, Keshore R. Bidasee

Department of Biochemistry: Faculty Publications

Early-onset heart failure (HF) continues to be a major cause of morbidity and mortality in people living with human immunodeficiency virus type one (HIV-1) infection (PLWH), yet the molecular causes for this remain poorly understood. Herein NOD.Cg- Prkdc^scidIl2rg^tm1Wjl/SzJ humanized mice (Hu-mice), plasma from PLWH, and autopsied cardiac tissues from deceased HIV seropositive individuals were used to assess if there is a link between the glycolysis byproduct methylglyoxal (MG) and HF in the setting of HIV-1 infection. At five weeks post HIV infection, Hu-mice developed grade III-IV diastolic dysfunction (DD) with an associated two-fold increase in plasma …

Charting A New Frontier Integrating Mathematical Modeling In Complex Biological Systems From Molecules To Ecosystems, Katharine A. White, Kira D. Mcentire, Nicole R. Buan, Lecia Robinson, Elisar Barbar

Department of Biochemistry: Faculty Publications

Advances in quantitative biology data collection and analysis across scales (molecular, cellular, organismal, and ecological) have transformed how we understand, categorize, and predict complex biological systems. This surge of quantitative data creates an opportunity to apply, develop, and evaluate mathematical models of biological systems and explore novel methods of analysis. Simultaneously, thanks to increased computational power, mathematicians, engineers, and physical scientists have developed sophisticated models of biological systems at different scales. Novel modeling schemes can offer deeper understanding of principles in biology, but there is still a disconnect between modeling and experimental biology that limits our ability to fully realize …

Characterization Of The Multifunctional Enzyme Proline Utilization A, Yizi Mao

Department of Biochemistry: Dissertations, Theses, and Student Research

Proline is a unique and important amino acid. Proline is a proteogenic amino acid and its metabolism is involved in many critical cellular functions. Therefore, proline metabolism is tightly regulated, and dysfunction of proline metabolism is related to human diseases. The first step of proline oxidization to ∆¹-pyrroline-5-carboxylic acid (P5C) is catalyzed by proline dehydrogenase (PRODH). P5C is then non-enzymatically hydrolyzed to glutamate-γ-semialdehyde (GSA), which can be further oxidized to glutamate by P5C dehydrogenase (P5CDH/GSALDH). In Gram-negative bacteria, the PRODH and P5CDH enzymes are expressed as one polypeptide called proline utilization A (PutA). In some Gram-negative bacteria an …

Reintegrating Biology Through The Nexus Of Energy, Information, And Matter, Kim L. Hoke, Sara L. Zimmer, Adam B. Roddy, Mary Jo Ondrechen, Craig E. Williamson, Nicole R. Buan

Department of Biochemistry: Faculty Publications

Information, energy, and matter are fundamental properties of all levels of biological organization, and life emerges from the continuous flux of matter, energy, and information. This perspective piece defines and explains each of the three pillars of this nexus. We propose that a quantitative characterization of the complex interconversions between matter, energy, and information that compose this nexus will help us derive biological insights that connect phenomena across different levels of biological organization. We articulate examples from multiple biological scales that highlight how this nexus approach leads to a more complete understanding of the biological system. Metrics of energy, information, …

Stabilin Receptors Clear Lps And Control Systemic Inflammation, Fatima Cabral, Mustafa Al-Rahem, John Skaggs, Thushara A. Thomas, Naresh Kumar, Qian Wu, Paolo Fadda, Lianbo Yu, John M. Robinson, Jonghan Kim, Ekta Pandey, Xinghui Sun, Wael N. Jarjour, Murugesan V.S. Rajaram, Edward N. Harris, Latha P. Ganesan

Department of Biochemistry: Faculty Publications

Lipopolysaccharides (LPSs) cause lethal endotoxemia if not rapidly cleared from blood circulation. Liver sinusoidal endothelial cells (LSEC) systemically clear LPS by unknown mechanisms. We discovered that LPS clearance through LSEC involves endocytosis and lysosomal inactivation via Stabilin-1 and 2 (Stab1 and Stab2) but does not involve TLR4. Cytokine production was inversely related to clearance/endocytosis of LPS by LSEC. When exposed to LPS, Stabilin double knockout mice (Stab DK) and Stab1 KO, but not Stab2 KO, showed significantly enhanced systemic inflammatory cytokine production and early death compared with WT mice. Stab1 KO is not significantly different from Stab DK in circulatory …

Mitochondrial Metal Homeostasis: A Look Into Iron And Copper Mobilization Within Mitochondria, Jonathan Dietz

Department of Biochemistry: Dissertations, Theses, and Student Research

Cellular iron and copper homeostasis is interdependent with mitochondrial iron and copper homeostasis. Mitochondria must import iron to form iron-sulfur clusters and heme, while it must import copper for usage and storage. These cofactors are incorporated into mitochondrial proteins that support essential functions, including cellular respiration and maintaining redox homeostasis. In turn, mitochondria also provide heme to the cell and enables the biogenesis of cytosolic iron-sulfur cluster containing proteins, while also providing copper when needed. Due to both metals (and their modified species) reactivity, iron and copper are stored and trafficked within the mitochondria carefully. Although these cofactors are crucial …

Dynamic Evolution And Correlation Between Metabolites And Microorganisms During Manufacturing Process And Storage Of Fu Brick Tea, Jing Li, Ran Xu, Joseph Brake, Lizeng Cheng, Jie Wu, Xiaobin Wu

Department of Biochemistry: Faculty Publications

Fu brick tea (FBT) is one of the major brands of dark tea. Microbial fermentation is considered the key step in the development of the special characteristics of FBT. The systemic corelationship of the microbiome and metabolomics during manufacture of Fu brick tea is not fully understood. In this study, we comprehensively explored the microbiome and metabolite dynamic evolution during the FBT manufacturing processes, and revealed decisive factors for the quality and safety of FBT based on the grouped methods of metabolomics combined with biochemical measurements, microbiome sequencing combined with quantitative polymerase chain reaction (PCR), and multiplex analysis. Both the …

Recent Applications Of Quantitative Systems Pharmacology And Machine Learning Models Across Diseases, Sara Sadat Aghamiri1, Rada Amin, Tomáš Helikar

Department of Biochemistry: Faculty Publications

Quantitative systems pharmacology (QSP) is a quantitative and mechanistic platform describing the phenotypic interaction between drugs, biological networks, and disease conditions to predict optimal therapeutic response. In this meta-analysis study, we review the utility of the QSP platform in drug development and therapeutic strategies based on recent publications (2019–2021). We gathered recent original QSP models and described the diversity of their applications based on therapeutic areas, methodologies, software platforms, and functionalities. The collection and investigation of these publications can assist in providing a repository of recent QSP studies to facilitate the discovery and further reusability of QSP models. Our review …

Purification And Initial Biochemical Characterization Of Atp:Cob(I)Alamin Adenosyltransferase (Eutt) Enzyme Of Salmonella Enterica, Nicole R. Buan, Jorge C. Escalante-Semerena

Department of Biochemistry: Faculty Publications

ATP:cob(I)alamin adenosyltransferase (EutT) of Salmonella enterica was overproduced and enriched to ~70% homogeneity, and its basic kinetic parameters were determined. Abundant amounts of EutT protein were produced, but all of it remained insoluble. Soluble active EutT protein (~70% homogeneous) was obtained after treatment with detergent. Under conditions in which cobalamin (Cbl) was saturating, K_m(ATP) = 10 μM, k_cat = 0.03 s^–1, and V_max = 54.5 nM min^–1. Similarly, under conditions in which MgATPwas saturating,K_m(Cbl)= 4.1μM, k_cat = 0.06 s^–1, andV_{max …}

The Simulation Experiment Description Markup Language (Sed-Ml): Language Specification For Level 1 Version 4, Lucian P. Smith,, Frank T. Bergmann, Alan Garny, Tomáš Helikar, Jonathan Karr, David Nickerson,, Herbert Sauro, Dagmar Waltemath, Matthias König

Department of Biochemistry: Faculty Publications

Computational simulation experiments increasingly inform modern biological research, and bring with them the need to provide ways to annotate, archive, share and reproduce the experiments performed. These simulations increasingly require extensive collaboration among modelers, experimentalists, and engineers. The Minimum Information About a Simulation Experiment (MIASE) guidelines outline the information needed to share simulation experiments. SED-ML is a computer-readable format for the information outlined by MIASE, created as a community project and supported by many investigators and software tools. The first versions of SED-ML focused on deterministic and stochastic simulations of models. Level 1 Version 4 of SED-ML substantially expands these …

Liquid And Semisolid Lubricant Compositions , Methods Of Making , And Uses Thereof, Diana Berman, Kent Dean Chapman, Tervor Bradley Romsdahl, Edgar Benjamin Cahoon, Robert Earl Minto, Chunyu Zhang

Department of Biochemistry: Faculty Publications

Various liquid and semisolid lubricant compositions are provided, in particular lubricant compositions containing oil from the seeds of the Brassicaceae Orychophragmus violaceus, preferably those that have been esterified with one or more fatty acids such as palmitoleic acid, oleic acid, linoleic acid, lauric acid, palmitic acid, stearic acid, or a combination thereof. In various aspects, lubricant compositions are provided that include a petroleum or a synthetic base oil and about 40 % or less by weight of a liquid lubricant composition containing oil from the seeds of the Brassicaceae Orychophragmus violaceus preferably those that have been esterified with one …

Analysis Of Single-Site Cysteine Mutation, I412c, In Human A Glycine Receptor States To Further Refine Structure And Allostery, Leah Engquist

Honors Program: Senior Projects (Public)

The glycine receptor (GlyR) is the major inhibitory receptor in the brain and spinal cord. A member of the pentameric ligand gated ion channel superfamily, crystal structures are available but there are still unresolved areas, specifically the C-terminal tail and TM3-TM4 intracellular loop. Further refinement can provide deeper understanding of the molecular mechanism and allow the creation of novel therapeutics to modulate its function. We propose to insert a single cysteine mutation, I412C, into a Cys null background (C41S/C290A/C345S) to study non- conducting states (resting, desensitized) or with F207G/A288G mutations to study the open state. Purified, reconstituted GlyR is crosslinked …

Mitochondrial Contact Site And Cristae Organizing System (Micos) Machinery Supports Heme Biosynthesis By Enabling Optimal Performance Of Ferrochelatase, Jonathan V. Dietz, Mathilda M. Willoughby, Robert B. Piel, Teresa A. Ross, Iryna Bohovych, Hannah G. Addis, Jennifer L. Fox, William N. Lanzilotta, Harry A. Dailey, James A. Wohlschlegel, Amit R. Reddi, Amy E. Medlock, Oleh Khalimonchuk

Department of Biochemistry: Faculty Publications

Heme is an essential cofactor required for a plethora of cellular processes in eukaryotes. In metazoans the heme biosynthetic pathway is typically partitioned between the cytosol and mitochondria, with the first and final steps taking place in the mitochondrion. The pathway has been extensively studied and its biosynthetic enzymes structurally characterized to varying extents. Nevertheless, understanding of the regulation of heme synthesis and factors that influence this process in metazoans remains incomplete. Therefore, we investigated the molecular organization as well as the physical and genetic interactions of the terminal pathway enzyme, ferrochelatase (Hem15), in the yeast Saccharomyces cerevisiae. Biochemical and …

Hiv-1 Transcription Elongation By Tat-Mediated Recruitment Of P-Tefb, Elizabeth Griggs

Honors Program: Senior Projects (Public)

Over 38.0 million people live with the human immunodeficiency virus (HIV) as of 462019. HIV hijacks the host's cellular machinery to replicate its viral DNA and transcribe the corresponding RNA. HIV-1 transcription relies on both cellular and viral transcription factors for proper regulation. The viral transcriptional activator Tat is a primary regulator. Transcription activation and elongation is controlled through the interaction of Tat with Positive Transcription Elongation Factor b (P-TEFb), a cellular transcriptional activator. The focus of this paper is 1) an in-depth understanding of the interaction between P-TEFb and Tat in HIV transcription, and 2) a review of recent …