Biochemistry, Biophysics, and Structural Biology Commons^™

Role Of Notch Signaling In T Cell Polarization, Shilpa Keerthivasan

Dissertations

The differentiation of CD4+ T cells to different effector lineages in response to pathogenic stimuli is the core of the adaptive immune system. One of the effector subsets recently discovered is Thelper 17 (Th17) and it plays a predominant role in autoimmune diseases and inflammatory disorders.

In my thesis, I aimed to study the role of Notch cell surface receptors in Th17 differentiation. Using in vitro Th17 differentiation assays of human naïve CD4+ T cells, I have shown that Notch signaling, particularly Notch1, plays a crucial role in Th17 polarization. By using pharmacological inhibitors and specific knockdown of Notch1, I …

The Specific Role Of The Mll Cxxc Domain In Mll Fusion Protein Function, Laurie Ellen Risner

Dissertations

The MLL gene was first identified because it is involved in chromosome translocations which produce novel fusion proteins that cause leukemia. The CXXC domain of MLL is a cysteine rich DNA binding domain with specificity for binding unmethylated CpG-containing DNA. The CXXC domain is retained in oncogenic MLL fusions, and is absolutely required for the fusions to cause leukemia. This project explored the role of the CXXC domain by introducing structure-informed point mutations within the MLL CXXC domain that disrupt DNA binding, and by performing domain swap experiments in which different CXXC domains from other proteins, including DNMT1, CGBP and …

Repression Of Protein Kinase C Delta In Human Squamous Cell Carcinomas By Ras, Fyn And Nf-Kappa B Signaling, Vipin Yadav

Dissertations

The delta isoform of Protein Kinase C (PKC-delta) is widely expressed in many normal tissues, including epidermal keratinocytes, and has a critical role in UV-induced apoptosis. However, PKC-delta is frequently lost in chemically or UV-induced mouse skin tumors, as well as in human cutaneous squamous cell carcinomas (SCC). Furthermore, re-expression of PKC-delta in human SCC lines is sufficient to induce apoptosis and suppress tumorigenicity, making PKC-delta a potential tumor suppressor gene for SCCs. The objective of this dissertation is to investigate the mechanism of PKC-delta loss in human SCCs.

To determine the mechanism of PKC-delta loss in human SCCs, we …

Notch-1 Specifically Activates Erk1/2 In Multiple Breast Cancer Subtypes, Allison Schuyler Rogowski

Master's Theses

Notch-1 is a cell fate regulatory protein and a potent breast oncogene. Notch-1 and its ligand Jagged-1 are over-expressed in human breast cancers that are associated with poor overall survival (Reedijk, Odorcic et al. 2005). Deregulated Notch signaling may contribute to tumorigenesis by increasing proliferation, inhibiting differentiation, and preventing apoptosis (Miele, Golde et al. 2006). The mitogen-activated protein kinase (MAPK) pathway is a critical cell signaling pathway that has been implicated in the development and progression of cancer (Hanahan and Weinberg 2000). Four major MAPK pathways are involved in both cell growth and apoptosis. The regulation of these pathways is …

Wee1 Is A Biological Target Of The Mir-17-92 Cluster In Leukemia, Sonia Susan Olikara

Master's Theses

MicroRNAs are noncoding RNAs that bind to the 3' untranslated region of their mRNA targets, which causes downregulation of target gene expression. Previous studies have shown that the miR-17-92 cluster, which encodes six miRNAs, is overexpressed in leukemias arising from chromosomal translocations of the Mixed Lineage Leukemia (MLL) gene. In the present study, prediction algorithms identified WEE1, a kinase that inhibits cell cycle progression, as a possible target of five of the six miRNAs. Through luciferase reporter assays, we found that miR-17, miR-20a, and miR-18a specifically target nucleotides 465 to 487 of the 3' UTR of WEE1, while miR-19a and …

Performance Screening Of Chemostat Adapted Recombinant Zymomonas Mobilis Strains, Deirdre M. Beard, Nancy Dowe

STAR Program Research Presentations

Corn stover biomass can be pretreaed and hydrolyzed into soluble sugars to be fermented by microorganisms to ethanol. NREL has developed a recombinant bacteria Zymomonas mobilis 8b that metabolizes both five and six carbon sugars. During pretreatment, toxic inhibitors such as furfural and acetate are produced. NREL has made an attempt to adapt two sub-strains of Z. mobilis 8b to acetate and furfural by using a chemostat method. During the chemostat process, cultures were frozen back in glycerol and saved. In this study, those frozen cultures were revived and analyzed for performance in environments with varying concentrations of furfural and …

Caffeine Metabolism And Cytochrome P450 Enzyme Mrna Expression Levels Of Genetically Diverse Inbred Mouse Strains, Neal Addicott, Michael Malfatti, Gabriela G. Loots

STAR Program Research Presentations

Cytochrome P450 (CYP) enzymes activate or eliminate medications and other xenobiotics, and Caffeine has been used as an indicator of activity for some CYPs. The natural genetic variation in the human population for caffeine metabolizing CYPs does not yet have an established animal model for comparison, but the natural variation in inbred mouse strains presents an attractive starting point. The project gave four different strains of mice a 40mg/kg dose of caffeine and sampled blood and liver tissue after 30 minutes. Samples were analyzed using High Performance Liquid Chromatography (HPLC), reverse transcription PCR (rtPCR), and quantitative PCR (qPCR). The DBA/2J …

Better Biomolecule Thermodynamics From Kinetics, Kiran Girdhar, Gregory Scott, Yann R. Chemla, Martin Gruebele

Chemistry and Biochemistry

Protein stability is measured by denaturation: When solvent conditions are changed (e.g., temperature, denaturant concentration, or pH) the protein population switches between thermodynamic states. The resulting denaturation curves have baselines. If the baselines are steep, nonlinear, or incomplete, it becomes difficult to characterize protein denaturation. Baselines arise because the chromophore probing denaturation is sensitive to solvent conditions, or because the thermodynamic states evolve structurally when solvent conditions are changed, or because the barriers are very low (downhill folding). Kinetics can largely eliminate such baselines: Relaxation of chromophores, or within thermodynamic states, is much faster than the transition over activation …

Microfluidic Paper-Based Analytical Devices: From Pocket To Paper-Based Elisa, Andres W. Martinez

Chemistry and Biochemistry

Microfluidic paper-based analytical devices (microPADs) began as a simple idea with an ambitious goal. The idea was to make microfluidic devices out of paper instead of plastic or glass. The goal was to develop low-cost and portable paper-based diagnostic devices to improve healthcare in developing countries. Over the past 6 years, many developments have been made in the emerging field of paper-based microfluidic devices. Reviewing the development of these devices in the Whitesides group at Harvard University (Cambridge, MA, USA) can provide some insight into the future of the field and encourage scientists from a variety of backgrounds to contribute …

Changes In Apparent Molar Water Volume And Dkp Solubility Yield Insights On The Hofmeister Effect, Daryl K. Eggers, A. Y. Payumo, R. M. Huijon, D. D. Mansfield, L. M. Belk, A. K. Bui, A. E. Knight

Faculty Publications, Chemistry

This study examines the properties of a 4 × 2 matrix of aqueous cations and anions at concentrations up to 8.0 M. The apparent molar water volume, as calculated by subtracting the mass and volume of the ions from the corresponding solution density, was found to exceed the molar volume of ice in many concentrated electrolyte solutions, underscoring the nonideal behavior of these systems. The solvent properties of water were also analyzed by measuring the solubility of diketopiperazine (DKP) in 2.000 M salt solutions prepared from the same ion combinations. Solution rankings for DKP solubility were found to parallel the …

Novel Application Of Query-Based Qualitative Predictors For Characterization Of Solvent Accessible Residues In Conjunction With Protein Sequence Homology. Proceedings Of The 22nd International Workshop On Database And Expert Systems Applications, D Rose, R Nepal, S Gholizadeh, R Mishra, R Lau, Brooke Lustig

Faculty Publications, Chemistry

No abstract provided.

Rnai Screening Reveals Requirement For Host Cell Secretory Pathway In Infection By Diverse Families Of Negative-Strand Rna Viruses, Debasis Panda, Anshuman Das, Phat X. Dinh, Sakthivel Subramaniam, Debasis Nayak, Nicholas J. Barrows, James L. Pearson, Jesse Thompson, David L. Kelly, Istvan Ladunga, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Negative-strand (NS) RNA viruses comprise many pathogens that cause serious diseases in humans and animals. Despite their clinical importance, little is known about the host factors required for their infection. Using vesicular stomatitis virus (VSV), a prototypic NS RNA virus in the family Rhabdoviridae, we conducted a human genomewide siRNA screen and identified 72 host genes required for viral infection. Many of these identified genes were also required for infection by two other NS RNA viruses, the lymphocytic choriomeningitis virus of the Arenaviridae family and human parainfluenza virus type 3 of the Paramyxoviridae family. Genes affecting different stages of …

Carbenoxolone Blocks The Light-Evoked Rise In Intracellular Calcium In Isolated Melanopsin Ganglion Cell Photoreceptors, Jayne R. Bramley, Erin M. Wiles, Patricia J. Sollars, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: Retinal ganglion cells expressing the photopigment melanopsin are intrinsically photosensitive (ipRGCs). These ganglion cell photoreceptors send axons to several central targets involved in a variety of functions. Within the retina ipRGCs provide excitatory drive to dopaminergic amacrine cells via glutamatergic signals and ipRGCs are coupled to widefield GABAergic amacrine cells via gap junctions. However, the extent to which ipRGCs are coupled to other retinal neurons in the ganglion cell layer via gap junctions is unclear. Carbenoxolone, a widely employed gap junction inhibitor, greatly reduces the number of retinal neurons exhibiting non-rod, non-cone mediated light-evoked Ca²⁺ signals suggesting extensive …

Y-Like Retinal Ganglion Cells Innervate The Dorsal Raphe Nucleus In The Mongolian Gerbil (Meriones Unguiculatus), Liju Luan, Chaoran Ren, Benson Wui-Man Lau, Jian Yang, Gary E. Pickard, Kwok-Fai So, Mingliang Pu

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: The dorsal raphe nucleus (DRN) of the mesencephalon is a complex multi-functional and multi-transmitter nucleus involved in a wide range of behavioral and physiological processes. The DRN receives a direct input from the retina. However little is known regarding the type of retinal ganglion cell (RGC) that innervates the DRN. We examined morphological characteristics and physiological properties of these DRN projecting ganglion cells.

Methodology/Principal Findings: The Mongolian gerbils are highly visual rodents with a diurnal/crepuscular activity rhythm. It has been widely used as experimental animals of various studies including seasonal affective disorders and depression. Young adult gerbils were used …

Challenges And Opportunities For Toxicology In Mexico, Rodrigo Franco, Balam Muñoz

School of Veterinary and Biomedical Sciences: Faculty Publications

We have developed this Special Issue titled “Challenges and Opportunities for Toxicology in Mexico” with the aim to highlight not only the challenges toxicology research faces in Mexico, but also the efforts and drive towards cutting edge research to address them. Altogether, this special issue should be a valuable source of information for all readers with an interest in toxicology and human health.

Mexico is an important economy worldwide and is a major exporter of several supplies and commodities. Because of this, its industry is a source of occupational exposure to several chemical derivatives (Nieusma 2011). The situation of occupational …

Roles Of The 15-Kda Selenoprotein (Sep15) In Redox Homeostasis And Cataract Development Revealed By The Analysis Of Sep 15 Knockout Mice, Marina V. Kasaikina, Dmitri E. Fomenko, Vyacheslav M. Labunskyy, Salil A. Lachke, Wenya Qiu, Juliet A. Moncaster, Jie Zhang, Mark W. Wojnarowicz, Sathish Kumar Natarajan, Mikalai I. Malinouski, Ulrich Schweizer, Petra A. Tsuji, Bradley A. Carlson, Richard L. Maas, Marjorie F. Lou, Lee E. Goldstein, Dolph L. Hatfield, Vadim N. Gladyshev

School of Veterinary and Biomedical Sciences: Faculty Publications

The 15-kDa selenoprotein (Sep15) is a thioredoxin-like, endoplasmic reticulum-resident protein involved in the quality control of glycoprotein folding through its interaction with UDP-glucose:glycoprotein glucosyltransferase. Expression of Sep15 is regulated by dietary selenium and the unfolded protein response, but its specific function is not known. In this study, we developed and characterized Sep15 KO mice by targeted removal of exon 2 of the Sep15 gene coding for the cysteinerich UDP-glucose:glycoprotein glucosyltransferase-binding domain. These KO mice synthesized a mutant mRNA, but the shortened protein product could be detected neither in tissues nor in Sep15 KO embryonic fibroblasts. Sep15 KO mice were viable …

Intrinsically Photosensitive Retinal Ganglion Cells, Gary E. Pickard, Patricia J. Sollars

School of Veterinary and Biomedical Sciences: Faculty Publications

Intrinsically photosensitive retinal ganglion cells (ipRGCs) respond to light in the absence of all rod and cone photoreceptor input. The existence of these ganglion cell photoreceptors, although predicted from observations scattered over many decades, was not established until it was shown that a novel photopigment, melanopsin, was expressed in retinal ganglion cells of rodents and primates. Phototransduction in mammalian ipRGCs more closely resembles that of invertebrate than vertebrate photoreceptors and appears to be mediated by transient receptor potential channels. In the retina, ipRGCs provide excitatory drive to dopaminergic amacrine cells and ipRGCs are coupled to GABAergic amacrine cells via gap …

Characterization Of Poly (Rc) Binding Protein (Pcbp2) And Frataxin, Sudipa Ghimire-Rijal

Wayne State University Theses

Iron is a micronutrient that acts as a cofactor in many prosthetic groups involving itself in almost every biological process. Iron is the key component in our body fluid, flowing in our veins all the time. Iron deficiency disorders affects more than 9 million people worldwide. Similarly, a high level of iron is associated with various disorders which suggest that in order for body to function properly level of iron should be tightly regulated. Many iron binding proteins help in maintaining cellular iron homeostasis by keeping iron in reduced form.

Working on the hypothesis that Poly (rC) Binding Protein family …

Investigating The Bacterial Predator Bdellovibrio’S Ability To Degrade Aspartate, Scott Anderson

Summer Research

Bdellovibrio bacteriovorus is a predatory Gram-negative Deltaproteobacterium that attacks and invades larger Gram-negative bacteria devouring them from within (Sockett, 2004). Enzymatic results obtained in the 1970s suggest that Bdellovibrio relies on its tricarboxylic acid (TCA) cycle and the oxidation of prey cell derived amino acids (Hespell, 1976). However, annotation of the published genome of Bdellovibrio HD100 revealed that it lacked numerous genes involved with the degradation of amino acids (Rendulic, 2004). Thus it is of great interest to determine if Bdellovibrio can degrade amino acids. If it can, new genes related to the degradation of amino acids will be discovered …

Thiol Peroxidases Mediate Specific Genome-Wide Regulation Of Gene Expression In Response To Hydrogen Peroxide, Dmitri E. Fomenko, Ahmet Koc, Natalia Agisheva, Michael Jacobsen, Alaattin Kaya, Mikalai Malinouski, Julian C. Rutherford, Kam-Leung Siu, Dong-Yan Jin, Dennis R. Winge, Vadim N. Gladyshev

Department of Biochemistry: Faculty Publications

Hydrogen peroxide is thought to regulate cellular processes by direct oxidation of numerous cellular proteins, whereas antioxidants, most notably thiol peroxidases, are thought to reduce peroxides and inhibit H₂O₂ response. However, thiol peroxidases have also been implicated in activation of transcription factors and signaling. It remains unclear if these enzymes stimulate or inhibit redox regulation and whether this regulation is widespread or limited to a few cellular components. Herein, we found that Saccharomyces cerevisiae cells lacking all eight thiol peroxidases were viable and withstood redox stresses. They transcriptionally responded to various redox treatments, but were unable to …