Medical Microbiology Commons^™

Hyperphosphorylation Of The Group A Streptococcal Control Of Virulence Regulator Increases Promoter Occupancy Specifically At Virulence Factor-Encoding Genes, Nicola Horstmann, Chau Nguyen Tran, Anthony R Flores, Samuel A Shelburne

Faculty, Staff and Student Publications

The control of virulence two-component gene regulatory system (CovRS) is critical to the pathogenesis of many medically important streptococci. In emm1 group A streptococci (GAS), CovR directly binds the promoters of numerous GAS virulence factor-encoding genes. Elimination of CovS phosphatase activity increases CovR phosphorylation (CovR~P) levels and abrogates GAS virulence. Given the emm type-specific diversity of CovRS function, in this study we used chromatin immunoprecipitation sequencing (ChIP-seq) to define global CovR DNA occupancy in the wild-type emm3 strain MGAS10870 (medium CovR~P) and its CovS phosphatase-negative derivative 10870-CovS-T284A (high CovR~P). In the wild-type emm3 strain, 89% of the previously identified emm1 …

Poly(A)-Binding Protein Is An Ataxin-2 Chaperone That Regulates Biomolecular Condensates, Steven Boeynaems, Yanniv Dorone, Yanrong Zhuang, Victoria Shabardina, Guozhong Huang, Anca Marian, Garam Kim, Anushka Sanyal, Nesli-Ece Şen, Daniel Griffith, Roberto Docampo, Keren Lasker, Iñaki Ruiz-Trillo, Georg Auburger, Alex S Holehouse, Edor Kabashi, Yi Lin, Aaron D Gitler

Duncan NRI Faculty and Staff Publications

Biomolecular condensation underlies the biogenesis of an expanding array of membraneless assemblies, including stress granules (SGs) which form under a variety of cellular stresses. Advances have been made in understanding the molecular grammar of a few scaffold proteins that make up these phases, but how the partitioning of hundreds of SG proteins is regulated remains largely unresolved. While investigating the rules that govern the condensation of ataxin-2, a SG protein implicated in neurodegenerative disease, we unexpectedly identified a short 14aa sequence that acts as a condensation switch and is conserved across the eukaryote lineage. We identify poly(A)-binding proteins as unconventional …

Genotype-Degree Of Hemolysis Correlation In Hereditary Spherocytosis, Yimeng Shi, Yuan Li, Xiawan Yang, Xiaoxia Li, Guangxin Peng, Xin Zhao, Xu Liu, Yufei Zhao, Jing Hu, Xiangrong Hu, Baohang Zhang, Kang Zhou, Yang Yang, Youzhen Xiong, Jianping Li, Huihui Fan, Wenrui Yang, Lei Ye, Liping Jing, Li Zhang, Fengkui Zhang

Faculty, Staff and Student Publications

BACKGROUND: Hereditary spherocytosis (HS) is a common inherited hemolytic anemia, caused by mutations in five genes that encode erythrocyte membrane skeleton proteins. The red blood cell (RBC) lifespan could directly reflect the degree of hemolysis. In the present cohort of 23 patients with HS, we performed next-generation sequencing (NGS) and Levitt's carbon monoxide (CO) breath test to investigate the potential genotype-degree of hemolysis correlation.

RESULTS: In the present cohort, we identified 8 ANK1,9 SPTB,5 SLC4A1 and 1 SPTA1 mutations in 23 patients with HS, and the median RBC lifespan was 14(8-48) days. The median RBC lifespan of patients with ANK1, …

An Unknown Essential Function Of Trna Splicing Endonuclease Is Linked To The Integrated Stress Response And Intron Debranching, Jennifer E Hurtig, Ambro Van Hoof

Faculty, Staff and Student Publications

tRNA splicing endonuclease (TSEN) has a well-characterized role in transfer RNA (tRNA) splicing but also other functions. For yeast TSEN, these other functions include degradation of a subset of mRNAs that encode mitochondrial proteins and an unknown essential function. In this study, we use yeast genetics to characterize the unknown tRNA-independent function(s) of TSEN. Using a high-copy suppressor screen, we found that sen2 mutants can be suppressed by overexpression of SEN54. This effect was seen both for tRNA-dependent and tRNA-independent functions indicating that SEN54 is a general suppressor of sen2, likely through structural stabilization. A spontaneous suppressor screen identified mutations …

Differential Spatial Gene And Protein Expression Associated With Recurrence Following Chemoradiation For Localized Anal Squamous Cell Cancer, Sharia Hernandez, Prajnan Das, Emma B Holliday, Li Shen, Wei Lu, Benny Johnson, Craig A Messick, Cullen M Taniguchi, John Skibber, Ethan B Ludmir, Y Nancy You, Grace Li Smith, Brian Bednarski, Larisa Kostousov, Eugene J Koay, Bruce D Minsky, Matthew Tillman, Shaelynn Portier, Cathy Eng, Albert C Koong, George J Chang, Wai Chin Foo, Jing Wang, Luisa Solis Soto, Van K Morris

Faculty, Staff and Student Publications

The identification of transcriptomic and protein biomarkers prognosticating recurrence risk after chemoradiation of localized squamous cell carcinoma of the anus (SCCA) has been limited by a lack of available fresh tissue at initial presentation. We analyzed archival FFPE SCCA specimens from pretreatment biopsies prior to chemoradiation for protein and RNA biomarkers from patients with localized SCCA who recurred (N = 23) and who did not recur (N = 25). Tumor cells and the tumor microenvironment (TME) were analyzed separately to identify biomarkers with significantly different expression between the recurrent and non-recurrent groups. Recurrent patients had higher mean protein expression of …

Structure-Based Regulatory Role For The 5'Utr Of Rcnmv Rna2, Jennifer S H Im, Jasmine R Sheppard, K Andrew White

Faculty, Staff and Student Publications

Red clover necrotic mosaic virus (RCNMV) is a segmented positive-strand RNA virus consisting of RNA1 and RNA2. Previous studies demonstrated that efficient translation of RCNMV RNA2 requires de novo synthesis of RNA2 during infections, suggesting that RNA2 replication is required for its translation. We explored a potential mechanism underlying the regulation of replication-associated translation of RNA2 by examining RNA elements in its 5' untranslated region (5'UTR). Structural analysis of the 5'UTR suggested that it can form two mutually exclusive configurations: a more thermodynamically stable conformation, termed the 5'-basal stem structure (5'BS), in which 5'-terminal sequences are base paired, and an …

Enhancer-Promoter Entanglement Explains Their Transcriptional Interdependence, Anil K Panigrahi, David M Lonard, Bert W O'Malley

Faculty, Staff and Students Publications

Enhancers not only activate target promoters to stimulate messenger RNA (mRNA) synthesis, but they themselves also undergo transcription to produce enhancer RNAs (eRNAs), the significance of which is not well understood. Transcription at the participating enhancer-promoter pair appears coordinated, but it is unclear why and how. Here, we employ cell-free transcription assays using constructs derived from the human GREB1 locus to demonstrate that transcription at an enhancer and its target promoter is interdependent. This interdependence is observable under conditions where direct enhancer-promoter contact (EPC) takes place. We demonstrate that transcription activation at a participating enhancer-promoter pair is dependent on i) …

Conformational Rearrangements In The Sensory Rcsf/Omp Complex Mediate Signal Transduction Across The Bacterial Cell Envelope, Sarah R Lach, Santosh Kumar, Seonghoon Kim, Wonpil Im, Anna Konovalova

Faculty, Staff and Student Publications

Timely detection and repair of envelope damage are paramount for bacterial survival. The Regulator of Capsule Synthesis (Rcs) stress response can transduce the stress signals across the multilayered gram-negative cell envelope to regulate gene expression in the cytoplasm. Previous studies defined the overall pathway, which begins with the sensory lipoprotein RcsF interacting with several outer membrane proteins (OMPs). RcsF can also interact with the periplasmic domain of the negative regulator IgaA, derepressing the downstream RcsCDB phosphorelay. However, how the RcsF/IgaA interaction is regulated at the molecular level to activate the signaling in response to stress remains poorly understood. In this …

Cell-Type-Specific Aging Clocks To Quantify Aging And Rejuvenation In Neurogenic Regions Of The Brain, Matthew T Buckley, Eric D Sun, Benson M George, Ling Liu, Nicholas Schaum, Lucy Xu, Jaime M Reyes, Margaret A Goodell, Irving L Weissman, Tony Wyss-Coray, Thomas A Rando, Anne Brunet

Faculty, Staff and Students Publications

The diversity of cell types is a challenge for quantifying aging and its reversal. Here we develop 'aging clocks' based on single-cell transcriptomics to characterize cell-type-specific aging and rejuvenation. We generated single-cell transcriptomes from the subventricular zone neurogenic region of 28 mice, tiling ages from young to old. We trained single-cell-based regression models to predict chronological age and biological age (neural stem cell proliferation capacity). These aging clocks are generalizable to independent cohorts of mice, other regions of the brains, and other species. To determine if these aging clocks could quantify transcriptomic rejuvenation, we generated single-cell transcriptomic datasets of neurogenic …

Modified Messengers: Flatworm Stem Cells And Regeneration Are Guarded By Rna Methylation, Blair W Benham-Pyle

Faculty, Staff and Students Publications

The contribution of RNA modifications to whole-body regeneration remains unclear. In this issue, Dagan et al (2022) show that m6a mRNA pathway components are critically required for stem cell differentiation, survival, and tissue renewal in the planarian Schmidtea mediterranea.

Discovery Of An Orally Active Benzoxaborole Prodrug Effective In The Treatment Of Chagas Disease In Non-Human Primates, Angel M Padilla, Wei Wang, Tsutomu Akama, David S Carter, Eric Easom, Yvonne Freund, Jason S Halladay, Yang Liu, Sarah A Hamer, Carolyn L Hodo, Gregory K Wilkerson, Dylan Orr, Brooke White, Arlene George, Huifeng Shen, Yiru Jin, Michael Zhuo Wang, Susanna Tse, Robert T Jacobs, Rick L Tarleton

Faculty, Staff and Student Publications

Trypanosoma cruzi, the agent of Chagas disease, probably infects tens of millions of people, primarily in Latin America, causing morbidity and mortality. The options for treatment and prevention of Chagas disease are limited and underutilized. Here we describe the discovery of a series of benzoxaborole compounds with nanomolar activity against extra- and intracellular stages of T. cruzi. Leveraging both ongoing drug discovery efforts in related kinetoplastids, and the exceptional models for rapid drug screening and optimization in T. cruzi, we have identified the prodrug AN15368 that is activated by parasite carboxypeptidases to yield a compound that targets the messenger RNA …

Exome Sequencing Identifies Genetic Variants In Anophthalmia And Microphthalmia, Jingjing Li, Wei Yang, Yuejun Jessie Wang, Chen Ma, Cynthia J Curry, Daniel Mcgoldrick, Deborah A Nickerson, Jessica X Chong, Elizabeth E Blue, James C Mullikin, Jennita Reefhuis, Wendy N Nembhard, Paul A Romitti, Martha M Werler, Marilyn L Browne, Andrew F Olshan, Richard H Finnell, Marcia L Feldkamp, Faith Pangilinan, Lynn M Almli, Mike J Bamshad, Lawrence C Brody, Mary M Jenkins, Gary M Shaw, University Of Washington Center For Mendelian Genomics, Nisc Comparative Sequencing Program, National Birth Defects Prevention Study

Faculty, Staff and Students Publications

Anophthalmia and microphthalmia (A/M) are rare birth defects affecting up to 2 per 10,000 live births. These conditions are manifested by the absence of an eye or reduced eye volumes within the orbit leading to vision loss. Although clinical case series suggest a strong genetic component in A/M, few systematic investigations have been conducted on potential genetic contributions owing to low population prevalence. To overcome this challenge, we utilized DNA samples and data collected as part of the National Birth Defects Prevention Study (NBDPS). The NBDPS employed multi-center ascertainment of infants affected by A/M. We performed exome sequencing on 67 …

Genomic Features Underlie The Co-Option Of Sva Transposons As Cis-Regulatory Elements In Human Pluripotent Stem Cells, Samantha M Barnada, Andrew Isopi, Daniela Tejada-Martinez, Clément Goubert, Sruti Patoori, Luca Pagliaroli, Mason Tracewell, Marco Trizzino

Department of Biochemistry and Molecular Biology Faculty Papers

Domestication of transposable elements (TEs) into functional cis-regulatory elements is a widespread phenomenon. However, the mechanisms behind why some TEs are co-opted as functional enhancers while others are not are underappreciated. SINE-VNTR-Alus (SVAs) are the youngest group of transposons in the human genome, where ~3,700 copies are annotated, nearly half of which are human-specific. Many studies indicate that SVAs are among the most frequently co-opted TEs in human gene regulation, but the mechanisms underlying such processes have not yet been thoroughly investigated. Here, we leveraged CRISPR-interference (CRISPRi), computational and functional genomics to elucidate the genomic features that underlie SVA domestication …

The Ep300/Tp53 Pathway, A Suppressor Of The Hippo And Canonical Wnt Pathways, Is Activated In Human Hearts With Arrhythmogenic Cardiomyopathy In The Absence Of Overt Heart Failure, Leila Rouhi, Siyang Fan, Sirisha M Cheedipudi, Aitana Braza-Boïls, Maria Sabater Molina, Yan Yao, Matthew J Robertson, Cristian Coarfa, Juan R Gimeno, Pilar Molina, Priyatansh Gurha, Esther Zorio, Ali J Marian

Faculty, Staff and Students Publications

AIMS: Arrhythmogenic cardiomyopathy (ACM) is a primary myocardial disease that typically manifests with cardiac arrhythmias, progressive heart failure, and sudden cardiac death (SCD). ACM is mainly caused by mutations in genes encoding desmosome proteins. Desmosomes are cell-cell adhesion structures and hubs for mechanosensing and mechanotransduction. The objective was to identify the dysregulated molecular and biological pathways in human ACM in the absence of overt heart failure.

METHODS AND RESULTS: Transcriptomes in the right ventricular endomyocardial biopsy samples from three independent individuals carrying truncating mutations in the DSP gene and five control samples were analysed by RNA-Seq (discovery group). These cases …

Systems Biology Approach To Functionally Assess The Clostridioides Difficile Pangenome Reveals Genetic Diversity With Discriminatory Power, Charles J Norsigian, Heather A Danhof, Colleen K Brand, Firas S Midani, Jared T Broddrick, Tor C Savidge, Robert A Britton, Bernhard O Palsson, Jennifer K Spinler, Jonathan M Monk

Faculty, Staff and Students Publications

Combatting Clostridioides difficile infections, a dominant cause of hospital-associated infections with incidence and resulting deaths increasing worldwide, is complicated by the frequent emergence of new virulent strains. Here, we employ whole-genome sequencing, high-throughput phenotypic screenings, and genome-scale models of metabolism to evaluate the genetic diversity of 451 strains of C. difficile. Constructing the C. difficile pangenome based on this set revealed 9,924 distinct gene clusters, of which 2,899 (29%) are defined as core, 2,968 (30%) are defined as unique, and the remaining 4,057 (41%) are defined as accessory. We develop a strain typing method, sequence typing by accessory genome (STAG), …

Perturbed Hematopoiesis In Individuals With Germline Dnmt3a Overgrowth Tatton-Brown-Rahman Syndrome, Ayala Tovy, Carina Rosas, Amos S Gaikwad, Geraldo Medrano, Linda Zhang, Jaime M Reyes, Yung-Hsin Huang, Tastuhiko Arakawa, Kristen Kurtz, Shannon E Conneely, Anna G Guzman, Rogelio Aguilar, Anne Gao, Chun-Wei Chen, Jean J Kim, Melissa T Carter, Amaia Lasa-Aranzasti, Irene Valenzuela, Lionel Van Maldergem, Lorenzo Brunetti, M John Hicks, Andrea N Marcogliese, Margaret A Goodell, Rachel E Rau

Faculty, Staff and Students Publications

Tatton-Brown-Rahman syndrome (TBRS) is an overgrowth disorder caused by germline heterozygous mutations in the DNA methyltransferase DNMT3A. DNMT3A is a critical regulator of hematopoietic stem cell (HSC) differentiation and somatic DNMT3A mutations are frequent in hematologic malignancies and clonal hematopoiesis. Yet, the impact of constitutive DNMT3A mutation on hematopoiesis in TBRS is undefined. In order to establish how constitutive mutation of DNMT3A impacts blood development in TBRS we gathered clinical data and analyzed blood parameters in 18 individuals with TBRS. We also determined the distribution of major peripheral blood cell lineages by flow cytometric analyses. Our analyses revealed non-anemic macrocytosis, …

A Non-Coding Insertional Mutation Of Grhl2 Causes Gene Over-Expression And Multiple Structural Anomalies Including Cleft Palate, Spina Bifida And Encephalocele, Georgia Pitsava, Marcia L Feldkamp, Nathan Pankratz, John Lane, Denise M Kay, Kristin M Conway, Charlotte Hobbs, Gary M Shaw, Jennita Reefhuis, Mary M Jenkins, Lynn M Almli, Cynthia Moore, Martha Werler, Marilyn L Browne, Chris Cunniff, Andrew F Olshan, Faith Pangilinan, Lawrence C Brody, Robert J Sicko, Richard H Finnell, Michael J Bamshad, Daniel Mcgoldrick, Deborah A Nickerson, James C Mullikin, Paul A Romitti, James L Mills

Faculty, Staff and Students Publications

BACKGROUND: Sacral agenesis (SA) consists of partial or complete absence of the caudal end of the spine and often presents with additional birth defects. Several studies have examined gene variants for syndromic forms of SA, but only one has examined exomes of children with non-syndromic SA.

METHODS: Using buccal cell specimens from families of children with non-syndromic SA, exomes of 28 child-parent trios (eight with and 20 without a maternal diagnosis of pregestational diabetes) and two child-father duos (neither with diagnosis of maternal pregestational diabetes) were exome sequenced.

RESULTS: Three children had heterozygous missense variants in ID1 (Inhibitor of DNA …

Decidualization Of Human Endometrial Stromal Cells Requires Steroid Receptor Coactivator-3, Vineet K Maurya, Maria M Szwarc, David M Lonard, William E Gibbons, San-Pin Wu, Bert W O'Malley, Francesco J Demayo, John P Lydon

Faculty, Staff and Students Publications

Steroid receptor coactivator-3 (SRC-3; also known as NCOA3 or AIB1) is a member of the multifunctional p160/SRC family of coactivators, which also includes SRC-1 and SRC-2. Clinical and cell-based studies as well as investigations on mice have demonstrated pivotal roles for each SRC in numerous physiological and pathophysiological contexts, underscoring their functional pleiotropy. We previously demonstrated the critical involvement of SRC-2 in murine embryo implantation as well as in human endometrial stromal cell (HESC) decidualization, a cellular transformation process required for trophoblast invasion and ultimately placentation. We show here that, like SRC-2, SRC-3 is expressed in the epithelial and stromal …

Hypermethylation Of Pi3k-Akt Signalling Pathway Genes Is Associated With Human Neural Tube Defects, Tian Tian, Xinyuan Lai, Kuanhui Xiang, Xiao Han, Shengju Yin, Robert M Cabrera, John W Steele, Yunping Lei, Xuanye Cao, Richard H Finnell, Linlin Wang, Aiguo Ren

Faculty, Staff and Students Publications

Neural tube defects (NTDs) are a group of common and severe congenital malformations. The PI3K-AKT signalling pathway plays a crucial role in the neural tube development. There is limited evidence concerning any possible association between aberrant methylation in PI3K-AKT signalling pathway genes and NTDs. Therefore, we aimed to investigate potential associations between aberrant methylation of PI3K-AKT pathway genes and NTDs. Methylation studies of PI3K-AKT pathway genes utilizing microarray genome-methylation data derived from neural tissues of ten NTD cases and eight non-malformed controls were performed. Targeted DNA methylation analysis was subsequently performed in an independent cohort of 73 NTD cases and …

Modeling Nonsegmented Negative-Strand Rna Virus (Nnsv) Transcription With Ejective Polymerase Collisions And Biased Diffusion, Felipe-Andrés Piedra, David Henke, Anubama Rajan, Donna M Muzny, Harsha Doddapaneni, Vipin K Menon, Kristi L Hoffman, Matthew C Ross, Sara J Javornik Cregeen, Ginger Metcalf, Richard A Gibbs, Joseph F Petrosino, Vasanthi Avadhanula, Pedro A Piedra

Faculty, Staff and Students Publications

Infections by non-segmented negative-strand RNA viruses (NNSV) are widely thought to entail gradient gene expression from the well-established existence of a single promoter at the 3' end of the viral genome and the assumption of constant transcriptional attenuation between genes. But multiple recent studies show viral mRNA levels in infections by respiratory syncytial virus (RSV), a major human pathogen and member of NNSV, that are inconsistent with a simple gradient. Here we integrate known and newly predicted phenomena into a biophysically reasonable model of NNSV transcription. Our model succeeds in capturing published observations of respiratory syncytial virus and vesicular stomatitis …

Lysergic Acid Diethylamide Induces Increased Signalling Entropy In Rats’ Prefrontal Cortex, Aurora Savino, Charles D. Nichols

School of Graduate Studies Faculty Publications

Psychedelic drugs are gaining attention from the scientific community as potential new compounds for the treatment of psychiatric diseases such as mood and substance use disorders. The 5-HT2A receptor has been identified as the main molecular target, and early studies pointed to an effect on the expression of neuroplasticity genes. Analysing RNA-seq data from the prefrontal cortex of rats chronically treated with lysergic acid diethylamide (LSD), we describe the psychedelic-induced rewiring of gene co-expression networks, which become less centralised but more complex, with an overall increase in signalling entropy typical of highly plastic systems. Intriguingly, signalling entropy mirrors, at the …

Trypanosoma Cruzi Modulates Piwi-Interacting Rna Expression In Primary Human Cardiac Myocytes During The Early Phase Of Infection, Kayla J. Rayford, Ayorinde Cooley, Ashutosh Arun, Girish Rachakonda, Yulia Kleschenko, Fernando Villalta, Siddharth Pratap, Maria F. Lima, Pius N. Nde

Publications and Research

Trypanosoma cruzi dysregulates the gene expression profile of primary human cardiomyocytes (PHCM) during the early phase of infection through a mechanism which remains to be elucidated. The role that small non-coding RNAs (sncRNA) including PIWI-interacting RNA (piRNA) play in regulating gene expression during the early phase of infection is unknown. To understand how T. cruzi dysregulate gene expression in the heart, we challenged PHCM with T. cruzi trypomastigotes and analyzed sncRNA, especially piRNA, by RNA-sequencing. The parasite induced significant differential expression of host piRNAs, which can target and regulate the genes which are important during the early infection phase. An …

Tumor Somatic Mutations Also Existing As Germline Polymorphisms May Help To Identify Functional Snps From Genome-Wide Association Studies, Ivan P Gorlov, Xiangjun Xia, Spiridon Tsavachidis, Olga Y Gorlova, Christopher I Amos

Faculty, Staff and Students Publications

We hypothesized that a joint analysis of cancer risk-associated single-nucleotide polymorphism (SNP) and somatic mutations in tumor samples can predict functional and potentially causal SNPs from GWASs. We used mutations reported in the Catalog of Somatic Mutations in Cancer (COSMIC). Confirmed somatic mutations were subdivided into two groups: (1) mutations reported as SNPs, which we call mutational/SNPs and (2) somatic mutations that are not reported as SNPs, which we call mutational/noSNPs. It is generally accepted that the number of times a somatic mutation is reported in COSMIC correlates with its selective advantage to tumors, with more frequently reported mutations being …

Cyclin D1 Integrates G9a-Mediated Histone Methylation., Zhiping Li, Xuanmao Jiao, Gabriele Di Sante, Adam Ertel, Mathew C. Casimiro, Min Wang, Sanjay Katiyar, Xiaoming Ju, D. V. Klopfenstein, Aydin Tozeren, William Dampier, Iouri Chepelev, Albert Jeltsch, Richard G. Pestell

Department of Cancer Biology Faculty Papers

Lysine methylation of histones and non-histone substrates by the SET domain containing protein lysine methyltransferase (KMT) G9a/EHMT2 governs transcription contributing to apoptosis, aberrant cell growth, and pluripotency. The positioning of chromosomes within the nuclear three-dimensional space involves interactions between nuclear lamina (NL) and the lamina-associated domains (LAD). Contact of individual LADs with the NL are dependent upon H3K9me2 introduced by G9a. The mechanisms governing the recruitment of G9a to distinct subcellular sites, into chromatin or to LAD, is not known. The cyclin D1 gene product encodes the regulatory subunit of the holoenzyme that phosphorylates pRB and NRF1 thereby governing cell-cycle …

Antibody Epitope Specificity For Dsdna Phosphate Backbone Is An Intrinsic Property Of The Heavy Chain Variable Germline Gene Segment Used, Tatjana Srdic-Rajic, Heinz Kohler, Vladimir Jurisic, Radmila Metlas

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Analysis of protein sequences by the informational spectrum method (ISM) enables characterization of their specificity according to encoded information represented with defined frequency (F). Our previous data showed that F(0.367) is characteristic for variable heavy chain (VH) domains (a combination of variable (V), diversity (D) and joining (J) gene segments) of the anti-phosphocholine (PC) T15 antibodies and mostly dependent on the CDR2 region, a site for PC phosphate group binding. Because the T15 dsDNA-reactive U4 mutant also encodes F(0.367), we hypothesized that the same frequency may also be characteristic for anti-DNA antibodies. Data obtained from an analysis of 60 spontaneously …

N-Terminal Domain Of Human Uracil Dna Glycosylase (Hung2) Promotes Targeting To Uracil Sites Adjacent To Ssdna-Dsdna Junctions, Brian P Weiser, Gaddiel Rodriguez, Philip A Cole, James T Stivers

Rowan-Virtua School of Osteopathic Medicine Departmental Research

The N-terminal domain (NTD) of nuclear human uracil DNA glycosylase (hUNG2) assists in targeting hUNG2 to replication forks through specific interactions with replication protein A (RPA). Here, we explored hUNG2 activity in the presence and absence of RPA using substrates with ssDNA-dsDNA junctions that mimic structural features of the replication fork and transcriptional R-loops. We find that when RPA is tightly bound to the ssDNA overhang of junction DNA substrates, base excision by hUNG2 is strongly biased toward uracils located 21 bp or less from the ssDNA-dsDNA junction. In the absence of RPA, hUNG2 still showed an 8-fold excision bias …

A Systems Biology Approach For Predicting Essential Genes And Deciphering Their Dynamics Under Stress In Streptococcus Sanguinis, Fadi El-Rami

Theses and Dissertations

Infectious diseases are the top leading cause of death worldwide. Identifying essential genes, genes indispensable for survival, has been proven indispensable in defining new therapeutic targets against pathogens, major elements of the minimal set genome to be harnessed in synthetic biology, and determinants of evolutionary relationships of phylogenetically distant species. Thus, essentiality studies promise valuable revenues that can decipher much of biological complexities.

Taking advantage of the available microbial sequences and the essentiality studies conducted in various microbial models, we proposed a framework for the prediction of essential genes based on our experimentally verified knowledge of the pathways involved in …

Signaling Through Lrg1, Rho1 And Pkc1 Governs Candida Albicans Morphogenesis In Response To Diverse Cues, Jinglin L. Xie, Nora Grahl, Trevor Sless, Michelle Leach, Sang Hu Kim, Deborah Hogan

Dartmouth Scholarship

The capacity to transition between distinct morphological forms is a key virulence trait for diverse fungal pathogens. A poignant example of a leading opportunistic fungal pathogen of humans for which an environmentally responsive developmental program underpins virulence is Candida albicans. C. albicans mutants that are defective in the transition between yeast and filamentous forms typically have reduced virulence. Although many positive regulators of C. albicans filamentation have been defined, there are fewer negative regulators that have been implicated in repression of filamentation in the absence of inducing cues. To discover novel negative regulators of filamentation, we screened …

Requirements For Pseudomonas Aeruginosa Type I-F Crispr-Cas Adaptation Determined Using A Biofilm Enrichment Assay, Gary E. Heussler, Jon L. Miller, Courtney E. Price, Alan J. Collins

Dartmouth Scholarship

CRISPR (clustered regularly interspaced short palindromic repeat)-Cas (CRISPR-associated protein) systems are diverse and found in many archaea and bacteria. These systems have mainly been characterized as adaptive immune systems able to protect against invading mobile genetic elements, including viruses. The first step in this protection is acquisition of spacer sequences from the invader DNA and incorporation of those sequences into the CRISPR array, termed CRISPR adaptation. Progress in understanding the mechanisms and requirements of CRISPR adaptation has largely been accomplished using overexpression of cas genes or plasmid loss assays; little work has focused on endogenous CRISPR-acquired immunity from viral predation. …

The Role Of Collagen Interacting Proteins In The Pathogenesis Of Filifactor Alocis, Ozioma Salomey Chioma

Loma Linda University Electronic Theses, Dissertations & Projects

Filifactor alocis is a Gram-positive, asaccharolytic; obligate anaerobe that has emerged as a potential periodontal pathogen due to its presence in high numbers in patients who have periodontal disease and least detection in healthy individuals (Kumar et al., 2003, Kumar et al., 2006, Wade, 2011). There is compelling evidence in the literature that demonstrates that F. alocis has virulence properties that may play an important role in infection-induced periodontitis (Abusleme et al., 2013, Griffen et al., 2012, Hutter et al., 2003, Khader et al., 2006, Siqueira and Rocas, 2003, Siqueira et al., 2009). However, there is a gap in our …