Molecular Biology Commons^™

Discovery Of Marinopyrrole A (Maritoclax) As A Selective Mcl-1 Antagonist That Overcomes Abt-737 Resistance By Binding To And Targeting Mcl-1 For Proteasomal Degradation*, Kenichiro Doi, Rongshi Li, Shen-Shu Sung, Hongwei Wu, Yan Liu, Wanda Manieri, Gowdahalli Krishnegowda, Andy Awwad, Alden Dewey, Xin Liu, Shantu Amin, Chunwei Cheng, Yong Qin, Ernst Schonbrunn, Gary W. Daughdrill, Thomas P. Loughran Jr., Said M. Sebti, Hong-Gang Wang

Molecular Biosciences Faculty Publications

The anti-apoptotic Bcl-2 family of proteins, including Bcl-2, Bcl-XL and Mcl-1, are well-validated drug targets for cancer treatment. Several small molecules have been designed to interfere with Bcl-2 and its fellow pro-survival family members. While ABT-737 and its orally active analog ABT-263 are the most potent and specific inhibitors to date that bind Bcl-2 and Bcl-XL with high affinity but have a much lower affinity for Mcl-1, they are not very effective as single agents in certain cancer types because of elevated levels of Mcl-1. Accordingly, compounds that specifically target Mcl-1 may overcome this resistance. In this study, we identified …

In Vivo Display: A Selection And Its Derivatives For Antimicrobial Peptide Lead Identification, Wesley David Colangelo

Wayne State University Dissertations

The rise of antibiotic resistance necessitates new approaches for the isolation of new antimicrobials with novel inhibitory mechanisms, bypassing the development of rapid resistance by modification of pre-existing resistance mechanisms. In response, we have developed a series of systems for the rapid isolation and identification of peptides that inhibit the growth of Escherichia coli and other bacteria, termed in vivo display (IVD).

IVD harnesses the cellular processes of E. coli for the expression of a library of random peptides at the terminus of a display protein. A library of 12-amino acid random peptide sequences was added to either the C- …

Methamphetamine Administration Targets Multiple Immune Subsets And Induces Phenotypic Alterations Suggestive Of Immunosuppression., Robert Z. Harms, Brenda M. Morsey, Craig W. Boyer, Howard S. Fox, Nora E. Sarvetnick

Journal Articles: Regenerative Medicine

Methamphetamine (Meth) is a widely abused stimulant and its users are at increased risk for multiple infectious diseases. To determine the impact of meth on the immune system, we utilized a murine model that simulates the process of meth consumption in a typical addict. Our phenotypic analysis of leukocytes from this dose escalation model revealed that meth affected key immune subsets. Meth administration led to a decrease in abundance of natural killer (NK) cells and the remaining NK cells possessed a phenotype suggesting reduced responsiveness. Dendritic cells (DCs) and Gr-1(high) monocytes/macrophages were also decreased in abundance while Gr-1(low) monocytes/macrophages appear …

An Ims/Atp Assay For The Detection Of Mycobacterium Tuberculosis In Urine, Dawn M. Hunter, Daniel V. Lim

Molecular Biosciences Faculty Publications

Background. Although sputum smears are the gold standard for diagnosis of tuberculosis, sensitivity in HIV/TB coinfection cases is low, indicating a need for alternative methods. Urine is being increasingly evaluated. Materials and Methods. A novel method for detecting Mycobacterium tuberculosis (MTB) in synthetic urine using a combined IMS/ATP assay was evaluated. Preliminary work established standard ATP conditions and the sensitivity and specificity of the MTB antibody. Eighty-four blinded samples in four replicate assays were evaluated for the presence of MTB using labeled immunomagnetic beads for capture. Beads were separated, washed, and resuspended in broth and added to a …

Identification Of New Cell Size Control Genes In S. Cerevisiae, Huzefa Dungrawala, Hui Hua, Jill Wright, Lesley Abraham, Thivakorn Kasemsri, Anthony Mcdowell, Jessica Stilwell, Brandt L. Schneider

Molecular Biosciences Faculty Publications

Cell size homeostasis is a conserved attribute in many eukaryotic species involving a tight regulation between the processes of growth and proliferation. In budding yeast S. cerevisiae, growth to a “critical cell size” must be achieved before a cell can progress past START and commit to cell division. Numerous studies have shown that progression past START is actively regulated by cell size control genes, many of which have implications in cell cycle control and cancer. Two initial screens identified genes that strongly modulate cell size in yeast. Since a second generation yeast gene knockout collection has been generated, we screened …

The Two-Component Signal Transduction System Arlrs Regulates Staphylococcus Epidermidis Biofilm Formation In An Ica-Dependent Manner, Yang Wu, Jiaxue Wang, Tao Xu, Jingran Liu, Wenqi Yu, Qiang Lou, Tao Zhu, Nianan He, Haijing Ben, Jian Hu, Friedrich Götz, Di Qu

Molecular Biosciences Faculty Publications

Due to its ability to form biofilms on medical devices, Staphylococcus epidermidis has emerged as a major pathogen of nosocomial infections. In this study, we investigated the role of the two-component signal transduction system ArlRS in regulating S. epidermidis biofilm formation. An ArlRS-deficient mutant, WW06, was constructed using S. epidermidis strain 1457 as a parental strain. Although the growth curve of WW06 was similar to that of SE1457, the mutant strain was unable to form biofilms in vitro. In a rabbit subcutaneous infection model, sterile disks made of polymeric materials were implanted subcutaneously followed with inoculation of WW06 or SE1457. …

Wipi-1 Positive Autophagosome-Like Vesicles Entrap Pathogenic Staphylococcus Aureus For Lysosomal Degradation, Mario Mauthe, Wenqi Yu, Oleg Krut, Martin Krönke, Friedrich Götz, Horst Robenek, Tassula Proikas-Cezanne

Molecular Biosciences Faculty Publications

Invading pathogens provoke the autophagic machinery and, in a process termed xenophagy, the host cell survives because autophagy is employed as a safeguard for pathogens that escaped phagosomes. However, some pathogens can manipulate the autophagic pathway and replicate within the niche of generated autophagosome-like vesicles. By automated fluorescence-based high content analyses, we demonstrate that Staphylococcus aureus strains (USA300, HG001, SA113) stimulate autophagy and become entrapped in intracellular PtdIns(3)P-enriched vesicles that are decorated with human WIPI-1, an essential PtdIns(3)P effector of canonical autophagy and membrane protein of both phagophores and autophagosomes. Further, agr-positive S. aureus (USA300, HG001) strains were more efficiently …

Template-Based Structure Prediction And Classification Of Transcription Factors In Arabidopsis Thaliana, Tao Lu, Yuedong Yang, Bo Yao, Song Liu, Yaoqi Zhou, Chi Zhang

School of Biological Sciences: Faculty Publications

Transcription factors (TFs) play important roles in plants. However, there is no systematic study of their structures and functions of most TFs in plants. Here, we performed template-based structure prediction for all TFs in Arabidopsis thaliana, with their full-length sequences as well as C-terminal and N-terminal regions. A total of 2,918 model structures were obtained with a high confidence score. We find that TF families employ only a smaller number of templates for DNA-binding domains (DBD) but a diverse number of templates for transcription regulatory domains (TRD). Although TF families are classified according to DBD, their sizes have a significant …

Theoretical Justification For Bond Valence -- Bond Length Empirical Correlations, F. D. Hardcastle, S. Laffoon

Journal of the Arkansas Academy of Science

Bond valence – bond length empirical correlations are of great interest in chemistry, biology, geology and materials science because they offer a quick and convenient way of checking and evaluating molecular structures. Linus Pauling’s relationship is the most commonly used, but is a two-parameter fit where R0 and b must be optimized. In this study, a simplified quantum-mechanical approach was used to derive Pauling’s empirical bond valence – bond length relationship. A covalency factor was also introduced to account for the difference in “softness” between cation and anion (resulting in increased orbital overlap). An expression for the b parameter was …

A Proposal To Test The Effects Of Factor Ecat1 On Pluripotency, From Reprogramming To Differentiation Of Human Somatic Cells, Vritti R. Goel

CMC Senior Theses

The field of stem cell research has been growing more because of the interest in using stem cells to cure diseases and heal injuries. Human embryonic stem cells, because of the controversy surrounding them—and subsequently the difficulties in acquiring samples of the existing aging cell lines—can only be used in limited capacities. While the development of induced pluripotent stem cells in the last decade has allowed the field to progress closer to medical treatments, the low efficiency of reprogramming a somatic cell to a pluripotent state, and the vast molecular and genomic differences between human embryonic stem cells and human …

Cloning Of The Gene, Purification As Recombinant Protein And Functional Characterization Of Leishmania Mexicana Cytochrome B5 Reductase, Ala Azhari

USF Tampa Graduate Theses and Dissertations

Leishmania are protozoan parasites that are transmitted by a sand fly vector. These parasites affect not only humans but also wild animals including domestic dogs and rodents, which form an additional challenge and public health problem to control the disease. Leishmaniasis is an important disease with worldwide distribution, including Saudi Arabia, the Middle East, and other tropical and subtropical areas around the world. Due to the expansion of irrigation and agricultural activities, more exposure to sand fly occurs, which leads to the expansion of leishmaniasis infections as newly emerging disease.

Emerging drug resistance in leishmaniasis is an additional problem, contributed …

Determination Of An Interaction Between Nipped B-Like Protein And Mll, Adam Robert Marek

Master's Theses

The Mixed Lineage Leukemia (MLL) protein serves as a positive transcriptional regulator during hematopoietic and embryonic development. The MLL gene can undergo chromosomal translocations producing leukemia-causing fusions that retain the MLL amino-terminus, including the repression domain. A recent yeast two-hybrid screening used the MLL repression domain as bait and yielded nine positive clones of Nipped B-like (NIPBL).

NIPBL is a crucial member of the cohesin complex, which functions in the segregation of sister chromatids during cell division. However, recent evidence suggests the cohesin complex can also function as a transcriptional regulator.

In this study, we wanted to confirm this interaction …

Characterization Of The Coca Chemokine Receptor Four Agonist Activity Of Ubiquitin, Daniel M. Staren

Master's Theses

Ubiquitin has previously been identified as another natural agonist of CXC chemokine receptor 4 (CXCR4). In addition, recent evidence suggests that ubiquitin may activate CXCR4 through a binding site on the receptor, which is distinct from the binding site for the cognate ligand stromal cell-derived factor (SDF)-1α. The cellular consequences of ubiquitin induced CXCR4 activation, however, are still poorly defined and a side-by-side comparison of CXCR4 mediated functions after activation with SDF-1α and ubiquitin is lacking. Such information will be instrumental to better understand the physiological function of CXCR4 and to further define its role as a therapeutic target in …

Disrupting Cxcr2 Macromolecular Complex Pdz-Domain Interactions During Inflammatory Chemotaxis, Marcello Castelvetere

Wayne State University Theses

Neutrophils are the body's first responders to inflammation, being the most abundant white blood cell type in circulation and they quickly initiate an immune response through chemokine signaling. Inflammatory chemokines signal via their receptor CXCR2, which initiates an inflammatory response, recruiting leukocytes to sites of inflammation. Chemokine signaling is important for proper host protection, yet uncontrolled activity is responsible for a variety of pathological conditions: including rheumatoid arthritis, ischemia-reperfusion injury, arteriosclerosis, multiple sclerosis, psoriasis, inflammatory bowel disease, and allergic reactions.

In this report I show a CXCR2 macromolecular signaling complex exists in neutrophils, containing NHERF1 and PLCβ2. I also demonstrate …

Modulation Of Anti-Tumor Immune Response By Tgf-Β-Inducible Early Gene 1 (Tieg1), Andi Cani

Wayne State University Theses

Cancer immunotherapy has had limited clinical efficacy partly because regulatory T cells (Treg) suppress the immune response to tumor-associated antigens. Inducible regulatory T cells (iTreg), which are converted from naïve CD4 T cells by TGF-β, an abundant cytokine in the tumor microenvironment, may contribute to this immune suppression. Induction of Foxp3 by TGF-β is mediated by the transcription factor TIEG1 and abrogation of this protein prevents Foxp3 expression. We are testing the hypothesis that blockade of TIEG1 to prevent iTreg conversion will enhance immune response in DNA vaccination to the tumor associated antigen Her-2. Wild type and TIEG1 knockout mice …

A Study Of The Effects Of Inosine Incorporation Into Dna Due To Defects In Purine Biosynthesis In Escherichia Coli, Jonathan Spence Church

Legacy Theses & Dissertations (2009 - 2024)

Deamination of purine bases can result in the formation of xanthine and hypoxanthine which can be miscoding and mutagenic in DNA. There are several mechanisms for the introduction of deaminated bases into DNA including simple hydrolysis, nitrosative chemistry and through the action of deaminase enzymes. A fourth method was recently presented which describes how deaminated purines can be incorporated into DNA due to defects in purine biosynthesis. Using fluctuation analysis, spontaneous mutation rates were studied in bacterial mutants that were deficient in specific genes involved in purine biosynthesis and dNTP precursor pool maintenance, including purA (adenylosuccinate synthetase), guaA (GMP synthetase), …

Characterization Of The Calmodulin-Ryanodine Receptor Interaction By Cryo-Electron Microscopy, Xiaojun Huang

Legacy Theses & Dissertations (2009 - 2024)

Ryanodine receptor (RyR) is a key player in excitation-contraction coupling (E-C coupling). Calmodulin (CaM) is one of the important regulatory factors of RyR. Two mammalian RyR isoforms, RyR1 and RyR2, are highly enriched in skeletal and cardiac muscle, respectively. Apo-calmodulin weakly activates RyR1 but inhibits RyR2, whereas Ca2+-calmodulin inhibits both the isoforms. Previous cryo-electron microscopy studies showed distinctly different binding locations on RyR1 for the two states of calmodulin. However, recent studies employing fluorescence resonance energy transfer appeared to challenge these findings. In chapter 1, using cryo-electron microscopy, we have determined that a mutant calmodulin, which is incapable of binding …

The Role Of Chromatin And Cofactors In The Transcriptional Memory Effect Exerted In Saccharomyces Cerevisiae, Emily Leigh Paul

Legacy Theses & Dissertations (2009 - 2024)

Abf1 and Rap1 are functionally similar general regulatory factors (GRFs) found in Saccharomyces cerevisiae . Abf1, in its role as a transcriptional activator, exerts a memory effect on some genes under its control. This effect results in transcription levels remaining steady when Abf1 dissociates from its binding site in a conditional mutant. In contrast, Rap1 fails to elicit the same effect on its regulatory targets. Transcriptional memory effects have been observed in many fields of study, including immunology, cancer, and stem cells, and conservation of transcription machinery will allow studies in yeast to be applied to higher organisms.

Inhibition Of Glutamate Receptors By Constructing Bipartite Rna Aptamers, Jeffrey Hebert

Legacy Theses & Dissertations (2009 - 2024)

The relationship of excessive activity of AMPA-type glutamate receptors, and cell death, has long provided researchers a means of investigating neurodegenerative disorders, such as Parkinson's Disease (PD) and amyotrophic lateral sclerosis (ALS). Inhibitors of AMPA receptor channels, including chemical and nucleic acid molecules such as RNA aptamers, have served as potential therapeutic agents and treatment of neurodegenerative disorders. In this study, building bipartite aptamers to enhance inhibitory potency, as compared with a monomeric aptamer of AMPA receptor, is described. An enhanced potency is due, at least in part; to the proximity effect in bipartite structures or binding of a monomeric …

The Role Of Ess1 In Survival, Morphogenetic Switching And Transcription In The Fungal Pathogen Candida Albicans, Dhanushki Poornima Samaranayake

Legacy Theses & Dissertations (2009 - 2024)

Candida albicans is a fungal pathogen that causes serious infections among immune-compromised patients and premature infants. C. albicans can become drug resistant, therefore, identifying new antifungal drug targets is an important goal. Here, we study a peptidyl-prolyl cis/trans isomerase called Ess1 as a potential drug target. Ess1 is conserved among pathogenic fungi, and therefore, potential inhibitors of Ess1 should display a broad spectrum of activity. We confirm that Ess1 is essential for growth in Candida albicans, but unlike the previously published find, deleting one copy of the C. albicans ESS1 gene did not affect morphogenetic switching. However, further reducing activity …