Medicine and Health Sciences Commons^™

Disordered Clock Protein Interactions And Charge Blocks Turn An Hourglass Into A Persistent Circadian Oscillator, Meaghan S Jankowski, Daniel Griffith, Divya G Shastry, Jacqueline F Pelham, Garrett M Ginell, Joshua Thomas, Pankaj Karande, Alex S Holehouse, Jennifer M Hurley

2020-Current year OA Pubs

Organismal physiology is widely regulated by the molecular circadian clock, a feedback loop composed of protein complexes whose members are enriched in intrinsically disordered regions. These regions can mediate protein-protein interactions via SLiMs, but the contribution of these disordered regions to clock protein interactions had not been elucidated. To determine the functionality of these disordered regions, we applied a synthetic peptide microarray approach to the disordered clock protein FRQ in Neurospora crassa. We identified residues required for FRQ's interaction with its partner protein FRH, the mutation of which demonstrated FRH is necessary for persistent clock oscillations but not repression of …

Using Protein Language Models For Protein Interaction Hot Spot Prediction With Limited Data, Karen Sargsyan, Carmay Lim

Journal Articles

BACKGROUND: Protein language models, inspired by the success of large language models in deciphering human language, have emerged as powerful tools for unraveling the intricate code of life inscribed within protein sequences. They have gained significant attention for their promising applications across various areas, including the sequence-based prediction of secondary and tertiary protein structure, the discovery of new functional protein sequences/folds, and the assessment of mutational impact on protein fitness. However, their utility in learning to predict protein residue properties based on scant datasets, such as protein-protein interaction (PPI)-hotspots whose mutations significantly impair PPIs, remained unclear. Here, we explore the …

Hawks And Doves: Perceptions And Reality Of Faculty Evaluations, Jillian Zavodnick, Jonathan Doroshow, Sarah Rosenberg, Joshua Banks, Benjamin E. Leiby, Nina Mingioni

Department of Medicine Faculty Papers

OBJECTIVES: Internal medicine clerkship grades are important for residency selection, but inconsistencies between evaluator ratings threaten their ability to accurately represent student performance and perceived fairness. Clerkship grading committees are recommended as best practice, but the mechanisms by which they promote accuracy and fairness are not certain. The ability of a committee to reliably assess and account for grading stringency of individual evaluators has not been previously studied.

METHODS: This is a retrospective analysis of evaluations completed by faculty considered to be stringent, lenient, or neutral graders by members of a grading committee of a single medical college. Faculty evaluations …

Directed Mutational Scanning Reveals A Balance Between Acidic And Hydrophobic Residues In Strong Human Activation Domains, Max V Staller, Eddie Ramirez, Sanjana R Kotha, Alex S Holehouse, Rohit V Pappu, Barak A Cohen

2020-Current year OA Pubs

Acidic activation domains are intrinsically disordered regions of the transcription factors that bind coactivators. The intrinsic disorder and low evolutionary conservation of activation domains have made it difficult to identify the sequence features that control activity. To address this problem, we designed thousands of variants in seven acidic activation domains and measured their activities with a high-throughput assay in human cell culture. We found that strong activation domain activity requires a balance between the number of acidic residues and aromatic and leucine residues. These findings motivated a predictor of acidic activation domains that scans the human proteome for clusters of …

Functional Replacement Of Myostatin With Gdf-11 In The Germline Of Mice., Se-Jin Lee, Adam Lehar, Renata Rydzik, Daniel W Youngstrom, Shalender Bhasin, Yewei Liu, Emily L Germain-Lee

Faculty Research 2022

BACKGROUND: Myostatin (MSTN) is a transforming growth factor-ß superfamily member that acts as a major regulator of skeletal muscle mass. GDF-11, which is highly related to MSTN, plays multiple roles during embryonic development, including regulating development of the axial skeleton, kidneys, nervous system, and pancreas. As MSTN and GDF-11 share a high degree of amino acid sequence identity, behave virtually identically in cell culture assays, and utilize similar regulatory and signaling components, a critical question is whether their distinct biological functions result from inherent differences in their abilities to interact with specific regulatory and signaling components or whether their distinct …

Expanding The Landscape Of Amino Acid-Rich Antimicrobial Peptides: Definition, Deployment In Nature, Implications For Peptide Design And Therapeutic Potential, Aaron P. Decker, Abraham F. Mechesso, Guangshun Wang

Journal Articles: Pathology and Microbiology

Unlike the α-helical and β-sheet antimicrobial peptides (AMPs), our knowledge on amino acid-rich AMPs is limited. This article conducts a systematic study of rich AMPs (>25%) from different life kingdoms based on the Antimicrobial Peptide Database (APD) using the program R. Of 3425 peptides, 724 rich AMPs were identified. Rich AMPs are more common in animals and bacteria than in plants. In different animal classes, a unique set of rich AMPs is deployed. While histidine, proline, and arginine-rich AMPs are abundant in mammals, alanine, glycine, and leucine-rich AMPs are common in amphibians. Ten amino acids (Ala, Cys, Gly, His, …

Integrating Genomics And Metabolomics For Scalable Non-Ribosomal Peptide Discovery., Bahar Behsaz, Edna Bode, Alexey Gurevich, Yan-Ni Shi, Florian Grundmann, Deepa Acharya, Andrés Mauricio Caraballo-Rodríguez, Amina Bouslimani, Morgan Panitchpakdi, Annabell Linck, Changhui Guan, Julia Oh, Pieter C Dorrestein, Helge B Bode, Pavel A Pevzner, Hosein Mohimani

Faculty Research 2021

Non-Ribosomal Peptides (NRPs) represent a biomedically important class of natural products that include a multitude of antibiotics and other clinically used drugs. NRPs are not directly encoded in the genome but are instead produced by metabolic pathways encoded by biosynthetic gene clusters (BGCs). Since the existing genome mining tools predict many putative NRPs synthesized by a given BGC, it remains unclear which of these putative NRPs are correct and how to identify post-assembly modifications of amino acids in these NRPs in a blind mode, without knowing which modifications exist in the sample. To address this challenge, here we report NRPminer, …

Impaired Eif5a Function Causes A Mendelian Disorder That Is Partially Rescued In Model Systems By Spermidine., Víctor Faundes, Martin D. Jennings, Siobhan Crilly, Sarah Legraie, Sarah E. Withers, Sara Cuvertino, Sally J. Davies, Andrew G L Douglas, Andrew E. Fry, Victoria Harrison, Jeanne Amiel, Daphné Lehalle, William G. Newman, Patricia Newkirk, Judith Ranells, Miranda Splitt, Laura A. Cross, Carol J. Saunders, Bonnie Sullivan, Jorge L. Granadillo, Christopher T. Gordon, Paul R. Kasher, Graham D. Pavitt, Siddharth Banka

Manuscripts, Articles, Book Chapters and Other Papers

The structure of proline prevents it from adopting an optimal position for rapid protein synthesis. Poly-proline-tract (PPT) associated ribosomal stalling is resolved by highly conserved eIF5A, the only protein to contain the amino acid hypusine. We show that de novo heterozygous EIF5A variants cause a disorder characterized by variable combinations of developmental delay, microcephaly, micrognathia and dysmorphism. Yeast growth assays, polysome profiling, total/hypusinated eIF5A levels and PPT-reporters studies reveal that the variants impair eIF5A function, reduce eIF5A-ribosome interactions and impair the synthesis of PPT-containing proteins. Supplementation with 1 mM spermidine partially corrects the yeast growth defects, improves the polysome profiles …

On The Roles Of Intrinsically Disordered Proteins And Regions In Cell Communication And Signaling, Sarah E. Bondos, A. Keith Dunker, Vladimir N. Uversky

Molecular Medicine Faculty Publications

For proteins, the sequence → structure → function paradigm applies primarily to enzymes, transmembrane proteins, and signaling domains. This paradigm is not universal, but rather, in addition to structured proteins, intrinsically disordered proteins and regions (IDPs and IDRs) also carry out crucial biological functions. For these proteins, the sequence → IDP/IDR ensemble → function paradigm applies primarily to signaling and regulatory proteins and regions. Often, in order to carry out function, IDPs or IDRs cooperatively interact, either intra- or inter-molecularly, with structured proteins or other IDPs or intermolecularly with nucleic acids. In this IDP/IDR thematic collection published in Cell Communication …

Deficient Histone H3 Propionylation By Brpf1-Kat6 Complexes In Neurodevelopmental Disorders And Cancer., Kezhi Yan, Justine Rousseau, Keren Machol, Laura A. Cross, Katherine E. Agre, Cynthia Forster Gibson, Anne Goverde, Kendra Engleman, Hannah Verdin, Elfride De Baere, Lorraine Potocki, Dihong Zhou, Maxime Cadieux-Dion, Gary A. Bellus, Monisa D. Wagner, Rebecca J. Hale, Natacha Esber, Alan F. Riley, Benjamin D. Solomon, Megan T. Cho, Kirsty Mcwalter, Roy Eyal, Meagan K. Hainlen, Bryce A. Mendelsohn, Hillary M. Porter, Brendan C. Lanpher, Andrea M. Lewis, Juliann Savatt, Isabelle Thiffault, Bert Callewaert, Philippe M. Campeau, Xiang-Jiao Yang

Manuscripts, Articles, Book Chapters and Other Papers

Lysine acetyltransferase 6A (KAT6A) and its paralog KAT6B form stoichiometric complexes with bromodomain- and PHD finger-containing protein 1 (BRPF1) for acetylation of histone H3 at lysine 23 (H3K23). We report that these complexes also catalyze H3K23 propionylation in vitro and in vivo. Immunofluorescence microscopy and ATAC-See revealed the association of this modification with active chromatin. Brpf1 deletion obliterates the acylation in mouse embryos and fibroblasts. Moreover, we identify BRPF1 variants in 12 previously unidentified cases of syndromic intellectual disability and demonstrate that these cases and known BRPF1 variants impair H3K23 propionylation. Cardiac anomalies are present in a subset of the …

The Zinc Transporter Zipt-7.1 Regulates Sperm Activation In Nematodes, Yanmei Zhao, Chieh-Hsiang Tan, Amber Krauchunas, Andrea Scharf, Nicholas Dietrich, Kurt Warnhoff, Zhiheng Yuan, Marina Druzhinina, Sam Guoping Gu, Long Miao, Andrew Singson, Ronald E Ellis, Kerry Kornfeld

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Sperm activation is a fascinating example of cell differentiation, in which immotile spermatids undergo a rapid and dramatic transition to become mature, motile sperm. Because the sperm nucleus is transcriptionally silent, this transition does not involve transcriptional changes. Although Caenorhabditis elegans is a leading model for studies of sperm activation, the mechanisms by which signaling pathways induce this transformation remain poorly characterized. Here we show that a conserved transmembrane zinc transporter, ZIPT-7.1, regulates the induction of sperm activation in Caenorhabditis nematodes. The zipt-7.1 mutant hermaphrodites cannot self-fertilize, and males reproduce poorly, because mutant spermatids are defective in responding to activating …

Sooty Mangabey Genome Sequence Provides Insight Into Aids Resistance In A Natural Siv Host, David Palesch, Steven E. Bosinger, Gregory K. Tharp, Thomas H. Vanderford, Mirko Paiardini, Ann Chahroudi, Zachary P. Johnson, Frank Kirchhoff, Beatrice H. Hahn, Robert B. Norgren, Nirav B. Patel, Donald L. Sodora, Reem A. Dawoud, Caro-Beth Stewart, Sara M. Seepo, R. Alan Harris, Yue Liu, Muthuswamy Raveendran, Yi Han, Adam English, Gregg W.C. Thomas, Matthew W. Hahn, Lenore Pipes, Christopher E. Mason, Donna M. Muzny, Richard A. Gibbs, Daniel Sauter, Kim Worley, Jeffrey Rogers, Guido Silvestri

Journal Articles: Genetics, Cell Biology & Anatomy

In contrast to infections with human immunodeficiency virus (HIV) in humans and simian immunodeficiency virus (SIV) in macaques, SIV infection of a natural host, sooty mangabeys (Cercocebus atys), is non-pathogenic despite high viraemia. Here we sequenced and assembled the genome of a captive sooty mangabey. We conducted genome-wide comparative analyses of transcript assemblies from C. atys and AIDS-susceptible species, such as humans and macaques, to identify candidates for host genetic factors that influence susceptibility. We identified several immune-related genes in the genome of C. atys that show substantial sequence divergence from macaques or humans. One of these sequence divergences, a …

Acquisition Of Functions On The Outer Capsid Surface During Evolution Of Double-Stranded Rna Fungal Viruses, Carlos P. Mata, Daniel Luque, Josué Gómez-Blanco, Javier M. Rodríguez, José M. González, Nobuhiro Suzuki, Said A. Ghabrial, José L. Carrascosa, Benes L. Trus, José R. Castón

Plant Pathology Faculty Publications

Unlike their counterparts in bacterial and higher eukaryotic hosts, most fungal viruses are transmitted intracellularly and lack an extracellular phase. Here we determined the cryo-EM structure at 3.7 Å resolution of Rosellinia necatrix quadrivirus 1 (RnQV1), a fungal double-stranded (ds)RNA virus. RnQV1, the type species of the family Quadriviridae, has a multipartite genome consisting of four monocistronic segments. Whereas most dsRNA virus capsids are based on dimers of a single protein, the ~450-Å-diameter, T = 1 RnQV1 capsid is built of P2 and P4 protein heterodimers, each with more than 1000 residues. Despite a lack of sequence similarity between …

Genetic Signatures For Helicobacter Pylori Strains Of West African Origin, Kennady K. Bullock, Carrie L. Shaffer, Andrew W. Brooks, Ousman Secka, Mark H. Forsyth, Mark S. Mcclain, Timothy L. Cover

Veterinary Science Faculty Publications

Helicobacter pylori is a genetically diverse bacterial species that colonizes the stomach in about half of the human population. Most persons colonized by H. pylori remain asymptomatic, but the presence of this organism is a risk factor for gastric cancer. Multiple populations and subpopulations of H. pylori with distinct geographic distributions are recognized. Genetic differences among these populations might be a factor underlying geographic variation in gastric cancer incidence. Relatively little is known about the genomic features of African H. pylori strains compared to other populations of strains. In this study, we first analyzed the genomes of …

Mechanism Of Transcription Anti-Termination In Human Mitochondria., Hauke S Hillen, Andrey V Parshin, Karen Agaronyan, Yaroslav I Morozov, James J Graber, Aleksandar Chernev, Kathrin Schwinghammer, Henning Urlaub, Michael Anikin, Patrick Cramer, Dmitry Temiakov

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

In human mitochondria, transcription termination events at a G-quadruplex region near the replication origin are thought to drive replication of mtDNA by generation of an RNA primer. This process is suppressed by a key regulator of mtDNA-the transcription factor TEFM. We determined the structure of an anti-termination complex in which TEFM is bound to transcribing mtRNAP. The structure reveals interactions of the dimeric pseudonuclease core of TEFM with mobile structural elements in mtRNAP and the nucleic acid components of the elongation complex (EC). Binding of TEFM to the DNA forms a downstream "sliding clamp," providing high processivity to the EC. …

Characterization Of A Far-Red Analog Of Ghrelin For Imaging Ghs-R In P19-Derived Cardiomyocytes., Gregory A F Douglas, Rebecca Mcgirr, Carlie L Charlton, Dov B Kagan, Lisa M Hoffman, Leonard G Luyt, Savita Dhanvantari

Lisa Hoffman

Ghrelin and its receptor, the growth hormone secretagogue receptor (GHS-R), are expressed in the heart, and may function to promote cardiomyocyte survival, differentiation and contractility. Previously, we had generated a truncated analog of ghrelin conjugated to fluorescein isothiocyanate for the purposes of determining GHS-R expression in situ. We now report the generation and characterization of a far-red ghrelin analog, [Dpr(3)(octanoyl), Lys(19)(Cy5)]ghrelin (1-19), and show that it can be used to image changes in GHS-R in developing cardiomyocytes. We also generated the des-acyl analog, des-acyl [Lys(19)(Cy5)]ghrelin (1-19) and characterized its binding to mouse heart sections. Receptor binding affinity of Cy5-ghrelin as …

Functional Local Renin-Angiotensin System In Human And Rat Periodontal Tissue, Carlos Ferreira Santos, Ana Carolina Morandini, Thiago José Dionísio, Flávio A. Faria, Marta C. Lima, Caio M. Figueiredo, Bella L. Colombini-Ishikiriama, Carla Renata Sipert, Rubens P. Maciel, Ana P. Akashi, Gabriela P. Souza, Gustavo P. Garlet, Camila O. Rodini, Sandra L. Amaral, Christiane Becari, Maria C. Salgado, Eduardo B. Oliveira, Isaac Matus, Daniela N. Didier, Andrew S. Greene

Ana Carolina Morandini

The initiation or progression of periodontitis might involve a local renin-angiotensin system (RAS) in periodontal tissue. The aim of this study was to further characterize the local RAS in human and rat periodontal tissues between healthy and periodontally-affected tissue. Components of the RAS were investigated using in vitro, ex vivo and in vivo experiments involving both human and Wistar rat periodontium. Although not upregulated when challenged with P. gingivalis-lipopolysaccharide, human gingival and periodontal ligament fibroblasts expressed RAS components. Likewise, healthy and inflamed human gingiva expressed RAS components, some of which were shown to be functional, yet no differences in expression …

Allelic Variation In Cxcl16 Determines Cd3+ T Lymphocyte Susceptibility To Equine Arteritis Virus Infection And Establishment Of Long-Term Carrier State In The Stallion, Sanjay Sarkar, Ernest Bailey, Yun Young Go, R. Frank Cook, Ted Kalbfleisch, John E. Eberth, R. Lakshman Chelvarajan, Kathleen M. Shuck, Sergey Artiushin, Peter J. Timoney, Udeni B. R. Balasuriya

Maxwell H. Gluck Equine Research Center Faculty Publications

Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory, systemic, and reproductive disease of horses and other equid species. Following natural infection, 10–70% of the infected stallions can become persistently infected and continue to shed EAV in their semen for periods ranging from several months to life. Recently, we reported that some stallions possess a subpopulation(s) of CD3⁺ T lymphocytes that are susceptible to in vitro EAV infection and that this phenotypic trait is associated with long-term carrier status following exposure to the virus. In contrast, stallions not possessing the CD3⁺ T …

Modeling And Re-Engineering Of Azotobacter Vinelandii Alginate Lyase To Enhance Its Catalytic Efficiency For Accelerating Biofilm Degradation, Chul Ho Jang, Yu Lan Piao, Xiaoqin Huang, Eun Jeong Yoon, So Hee Park, Kyoung Lee, Chang-Guo Zhan, Hoon Cho

Molecular Modeling and Biopharmaceutical Center Faculty Publications

Alginate is known to prevent elimination of Pseudomonas aeruginosa biofilms. Alginate lyase (AlgL) might therefore facilitate treatment of Pseudomonas aeruginosa-infected cystic fibrosis patients. However, the catalytic activity of wild-type AlgL is not sufficiently high. Therefore, molecular modeling and site-directed mutagenesis of AlgL might assist in enzyme engineering for therapeutic development. AlgL, isolated from Azotobacter vinelandii, catalyzes depolymerization of alginate via a β-elimination reaction. AlgL was modeled based on the crystal structure template of Sphingomonas AlgL species A1-III. Based on this computational analysis, AlgL was subjected to site-directed mutagenesis to improve its catalytic activity. The k_cat/K …

Equine Arteritis Virus Uses Equine Cxcl16 As An Entry Receptor, Sanjay Sarkar, Lakshman Chelvarajan, Yun Young Go, Frank Cook, Sergey Artiushin, Shankar Mondal, Kelsi Anderson, John E. Eberth, Peter J. Timoney, Theodore S. Kalbfleisch, Ernest F. Bailey, Udeni B. R. Balasuriya

Veterinary Science Faculty Publications

Previous studies in our laboratory have identified equine CXCL16 (EqCXCL16) to be a candidate molecule and possible cell entry receptor for equine arteritis virus (EAV). In horses, the CXCL16 gene is located on equine chromosome 11 (ECA11) and encodes a glycosylated, type I transmembrane protein with 247 amino acids. Stable transfection of HEK-293T cells with plasmid DNA carrying EqCXCL16 (HEK-EqCXCL16 cells) increased the proportion of the cell population permissive to EAV infection from < 3% to almost 100%. The increase in permissiveness was blocked either by transfection of HEK-EqCXCL16 cells with small interfering RNAs (siRNAs) directed against EqCXCL16 or by pretreatment with guinea pig polyclonal antibody against EqCXCL16 protein (Gp anti-EqCXCL16 pAb). Furthermore, using a virus overlay protein-binding assay (VOPBA) in combination with far-Western blotting, gradient-purified EAV particles were shown to bind directly to the EqCXCL16 protein in vitro. The binding of biotinylated virulent EAV strain Bucyrus at 4°C was significantly higher in HEK-EqCXCL16 cells than nontransfected HEK-293T cells. Finally, the results demonstrated …

Mechanistic Binding Insights For 1-Deoxy-D-Xylulose-5-Phosphatesynthase, The Enzyme Catalyzing The First Reaction Of Isoprenoid Biosynthesis In The Malaria-Causing Protists, Plasmodium Falciparum And Plasmodium Vivax, Matthew R. Battistini, Christopher Shoji, Sumit Handa, Leonid Breydo, David J. Merkler

Chemistry Faculty Publications

We have successfully truncated and recombinantly-expressed 1-deoxy-D-xylulose-5-phosphate synthase (DXS) from both Plasmodium vivax and Plasmodium falciparum. We elucidated the order of substrate binding for both of these ThDP-dependent enzymes using steady-state kinetic analyses, dead-end inhibition, and intrinsic tryptophan fluorescence titrations. Both enzymes adhere to a random sequential mechanism with respect to binding of both substrates: pyruvate and D-glyceraldehyde-3-phosphate. These findings are in contrast to other ThDP-dependent enzymes, which exhibit classical ordered and/or ping-pong kinetic mechanisms. A better understanding of the kinetic mechanism for these two Plasmodial enzymes could aid in the development of novel DXS-specific inhibitors that might prove useful …

Variants In Cxcr4 Associate With Juvenile Idiopathic Arthritis Susceptibility., Terri H. Finkel, Jin Li, Zhi Wei, Wei Wang, Haitao Zhang, Edward M. Behrens, Emma L. Reuschel, Sophie Limou, Carol Wise, Marilynn Punaro, Mara L. Becker, Jane E. Munro, Berit Flatø, Øystein Førre, Susan D. Thompson, Carl D. Langefeld, David N. Glass, Joseph T. Glessner, Cecilia E. Kim, Edward Frackelton, Debra K. Shivers, Kelly A. Thomas, Rosetta M. Chiavacci, Cuiping Hou, Kexiang Xu, James Snyder, Haijun Qiu, Frank Mentch, Kai Wang, Cheryl A. Winkler, Benedicte A. Lie, Justine A. Ellis, Hakon Hakonarson

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease among children, the etiology of which involves a strong genetic component, but much of the underlying genetic determinants still remain unknown. Our aim was to identify novel genetic variants that predispose to JIA.

METHODS: We performed a genome-wide association study (GWAS) and replication in a total of 1166 JIA cases and 9500 unrelated controls of European ancestry. Correlation of SNP genotype and gene expression was investigated. Then we conducted targeted resequencing of a candidate locus, among a subset of 480 cases and 480 controls. SUM test was performed …

Structures Of Eccb1 And Eccd1 From The Core Complex Of The Mycobacterial Esx-1 Type Vii Secretion System, Jonathan Mark Wagner, Sum Chan, Timothy J. Evans, Sara Kahng, Jennifer Kim, Mark A. Arbing, David Eisenberg, Konstantin V. Korotkov

Molecular and Cellular Biochemistry Faculty Publications

Background: The ESX-1 type VII secretion system is an important determinant of virulence in pathogenic mycobacteria, including Mycobacterium tuberculosis. This complicated molecular machine secretes folded proteins through the mycobacterial cell envelope to subvert the host immune response. Despite its important role in disease very little is known about the molecular architecture of the ESX-1 secretion system.

Results: This study characterizes the structures of the soluble domains of two conserved core ESX-1 components – EccB₁ and EccD₁. The periplasmic domain of EccB₁ consists of 4 repeat domains and a central domain, which together form a quasi …

Hypoacetylation, Hypomethylation, And Dephosphorylation Of H2b Histones And Excessive Histone Deacetylase Activity In Du-145 Prostate Cancer Cells, Shundong Cang, Xiaobin Xu, Yuehua Ma, Delong Liu, Jenwei Chiao

NYMC Faculty Publications

BACKGROUND: Hypoacetylation on histone H3 of human prostate cancer cells has been described. Little is known about the modifications of other histones from prostate cancer cells.

METHODS: Histones were isolated from the prostate cancer cell line DU-145 and the non-malignant prostatic cell line RC170N/h. Post-translational modifications of histone H2B were determined by liquid chromatography-mass spectrometry (LC-MS)/MS.

RESULTS: The histone H2B of the prostate cancer cell line DU-145 was found to have hypoacetylation, hypomethylation, and dephosphorylation as compared to the non-malignant prostatic cell line RC170N/h. H2B regained acetylation on multiple lysine residues, phosphorylation on Thr19, and methylation on Lys23 and Lys43 …

West African Anopheles Gambiae Mosquitoes Harbor A Taxonomically Diverse Virome Including New Insect-Specific Flaviviruses, Mononegaviruses, And Totiviruses, Joseph R. Fauver, Nathan D. Grubaugh, Benjamin J. Krajacich, James Weger-Lucarelli, Steven M. Lakin, Lawrence S. Fakoli, Fatorma K. Bolay, Joseph W. Diclaro, Kounbobr Roch Dabiré, Brian D. Foy, Doug E. Brackney, Gregory D. Ebel, Mark D. Stenglein

Journal Articles: Epidemiology

Anopheles gambiae are a major vector of malaria in sub-Saharan Africa. Viruses that naturally infect these mosquitoes may impact their physiology and ability to transmit pathogens. We therefore used metagenomics sequencing to search for viruses in adult Anopheles mosquitoes collected from Liberia, Senegal, and Burkina Faso. We identified a number of virus and virus-like sequences from mosquito midgut contents, including 14 coding-complete genome segments and 26 partial sequences. The coding-complete sequences define new viruses in the order Mononegavirales, and the families Flaviviridae, and Totiviridae. The identification of a flavivirus infecting Anopheles mosquitoes broadens our understanding of the evolution and host …

Structural Characterization Of Cals8, A Tdp-Α-D-Glucose Dehydrogenase Involved In Calicheamicin Aminodideoxypentose Biosynthesis, Shanteri Singh, Karolina Michalska, Lance Bigelow, Michael Endres, Madan K. Kharel, Gyorgy Babnigg, Ragothaman M. Yennamalli, Craig A. Bingman, Andrzej Joachimiak, Jon S. Thorson, George N. Phillips Jr.

Center for Pharmaceutical Research and Innovation Faculty Publications

Classical UDP-glucose 6-dehydrogenases (UGDHs; EC 1.1.1.22) catalyze the conversion of UDP-α-d-glucose (UDP-Glc) to the key metabolic precursor UDP-α-d-glucuronic acid (UDP-GlcA) and display specificity for UDP-Glc. The fundamental biochemical and structural study of the UGDH homolog CalS8 encoded by the calicheamicin biosynthetic gene is reported and represents one of the first studies of a UGDH homolog involved in secondary metabolism. The corresponding biochemical characterization of CalS8 reveals CalS8 as one of the first characterized base-permissive UGDH homologs with a >15-fold preference for TDP-Glc over UDP-Glc. The corresponding structure elucidations of apo-CalS8 and the CalS8·substrate·cofactor ternary complex (at 2.47 and 1.95 Å …

Naturally Occurring Deletion Mutants Of The Pig-Specific, Intestinal Crypt Epithelial Cell Protein Clca4b Without Apparent Phenotype., Stephanie Plog, Nikolai Klymiuk, Stefanie Binder, Matthew J. Van Hook, Wallace B. Thoreson, Achim D. Gruber, Lars Mundhenk

Journal Articles: Ophthalmology

The human CLCA4 (chloride channel regulator, calcium-activated) modulates the intestinal phenotype of cystic fibrosis (CF) patients via an as yet unknown pathway. With the generation of new porcine CF models, species-specific differences between human modifiers of CF and their porcine orthologs are considered critical for the translation of experimental data. Specifically, the porcine ortholog to the human CF modulator gene CLCA4 has recently been shown to be duplicated into two separate genes, CLCA4a and CLCA4b. Here, we characterize the duplication product, CLCA4b, in terms of its genomic structure, tissue and cellular expression patterns as well as its in vitro electrophysiological …

Deubiquitinase Usp47/Ubp64e Regulates Β-Catenin Ubiquitination And Degradation And Plays A Positive Role In Wnt Signaling, Jiandang Shi, Yajuan Liu, Xuehe Xu, Wen Zhang, Tianxin Yu, Jianhang Jia, Chunming Liu

Markey Cancer Center Faculty Publications

Wnt signaling plays important roles in development and tumorigenesis. A central question about the Wnt pathway is the regulation of β-catenin. Phosphorylation of β-catenin by CK1α and GSK3 promotes β-catenin binding to β-TrCP, leading to β-catenin degradation through the proteasome. The phosphorylation and ubiquitination of β-catenin have been well characterized; however, it is unknown whether and how a deubiquitinase is involved. In this study, by screening RNA interference (RNAi) libraries, we identified USP47 as a deubiquitinase that prevents β-catenin ubiquitination. Inactivation of USP47 by RNAi increased β-catenin ubiquitination, attenuated Wnt signaling, and repressed cancer cell growth. Furthermore, USP47 deubiquitinates itself, …

Human Dna Exonuclease Trex1 Is Also An Exoribonuclease That Acts On Single-Stranded Rna, Fenghua Yuan, Tanmay Dutta, Ling Wang, Lei Song, Liya Gu, Liangyue Qian, Anaid Benitez, Shunbin Ning, Arun Malhotra, Murray P. Deutscher, Yanbin Zhang

Toxicology and Cancer Biology Faculty Publications

3' repair exonuclease 1 (TREX1) is a known DNA exonuclease involved in autoimmune disorders and the antiviral response. In this work, we show that TREX1 is also a RNA exonuclease. Purified TREX1 displays robust exoribonuclease activity that degrades single-stranded, but not double-stranded, RNA. TREX1-D200N, an Aicardi-Goutieres syndrome disease-causing mutant, is defective in degrading RNA. TREX1 activity is strongly inhibited by a stretch of pyrimidine residues as is a bacterial homolog, RNase T. Kinetic measurements indicate that the apparent K_m of TREX1 for RNA is higher than that for DNA. Like RNase T, human TREX1 is active in degrading native …

Molecular Basis Of Rna Recognition By The Embryonic Polarity Determinant Mex-5, John Pagano, Brian Farley, Lisa Mccoig, Sean Ryder

Sean P. Ryder

Embryonic development requires maternal proteins and RNA. In Caenorhabditis elegans, a gradient of CCCH tandem zinc finger (TZF) proteins coordinates axis polarization and germline differentiation. These proteins govern expression from maternal mRNAs by an unknown mechanism. Here we show that the TZF protein MEX-5, a primary anterior determinant, is an RNA-binding protein that recognizes linear RNA sequences with high affinity but low specificity. The minimal binding site is a tract of six or more uridines within a 9-13-nucleotide window. This sequence is remarkably abundant in the 3'-untranslated region of C. elegans transcripts, demonstrating that MEX-5 alone cannot specify mRNA target …