Genetic Processes Commons^™

Mecp2 Interacts With The Super Elongation Complex To Regulate Transcription, Jun Young Sonn, Wonho Kim, Marta Iwanaszko, Yuki Aoi, Yan Li, Guantong Qi, Luke Parkitny, Janice L Brissette, Lorin Weiner, Juan Botas, Ismael Al-Ramahi, Ali Shilatifard, Huda Y Zoghbi

Faculty, Staff and Students Publications

Loss-of-function mutations in methyl-CpG binding protein 2 (MECP2) cause Rett syndrome. While we know that MeCP2 binds to methylated cytosines on DNA, the full breadth of the molecular mechanisms by which MeCP2 regulates gene expression remains incompletely understood. Here, using a genetic modifier screen, we identify the super elongation complex, a P-TEFb–containing elongation factor that releases promoter-proximally paused RNA polymerase II, as a genetic interactor of MECP2. MeCP2 physically interacts with SEC subunits and directly binds AFF4, the scaffold of the SEC, via the transcriptional repression domain. Furthermore, MeCP2 facilitates the binding of AFF4 on a subset …

Transcription-Replication Collisions Trigger High-Fidelity Replication Reset, Matthew B Cooke, Kobie T Welch, Laura Deus Ramirez, Katelin M Hagstrom, Alice X Wen, Jennifer A Halliday, Susan M Rosenberg, Christophe Herman

Faculty, Staff and Students Publications

Double-stranded DNA ends arise from external agents or cellular processes like transcription-replication collisions (TRCs), threatening genome stability. Here, we performed genomic CRISPRi screens to uncover DNA end formation factors in Escherichia coli. We discovered that translation-transcription decoupling causes DNA end formation through a TRC-dependent pathway, which is lethal when DNA end processing by RecBCD is disrupted, but not when recombination is disrupted. We find that TRCs cause replisome stalling followed by "rear-ending" from trailing replisomes which generates free DNA ends, rather than strand breaks. Surprisingly, these DNA ends are resolved through a process we call "replication reset", where the stalled …

Dna Methylation And Machine Learning: Challenges And Perspective Toward Enhanced Clinical Diagnostics, Erfan Aref-Eshghi, Arash B Abadi, Mohammad-Erfan Farhadieh, Amirreza Hooshmand, Fatemeh Ghasemi, Leila Youssefian, Hassan Vahidnezhad, Taylor Martin Kerrins, Xiaonan Zhao, Mahdi Akbarzadeh, Hakon Hakonarson, Amir Hossein Saeidian

Faculty, Staff and Students Publications

DNA methylation is an epigenetic modification that regulates gene expression by adding methyl groups to DNA, affecting cellular function and disease development. Machine learning, a subset of artificial intelligence, analyzes large datasets to identify patterns and make predictions. Over the past two decades, advances in bioinformatics technologies for arrays and sequencing have generated vast amounts of data, leading to the widespread adoption of machine learning methods for analyzing complex biological information for medical problems. This review explores recent advancements in DNA methylation studies that leverage emerging machine learning techniques for more precise, comprehensive, and rapid patient diagnostics based on DNA …

Improved Allele Frequencies In Gnomad Through Local Ancestry Inference, Pragati Kore, Michael W Wilson, Grace Tiao, Katherine Chao, Philip W Darnowsky, Nicholas A Watts, Jessica Honorato Mauer, Samantha M Baxter, Genome Aggregation Database Consortium, Heidi L Rehm, Mark J Daly, Konrad J Karczewski, Elizabeth G Atkinson

Faculty, Staff and Students Publications

The Genome Aggregation Database (gnomAD) is a foundational resource for allele frequency data, widely used in genomic research and clinical interpretation. However, traditional estimates rely on individual-level genetic ancestry groupings that may obscure variation in recently admixed populations. To improve resolution, we applied local ancestry inference (LAI) to over 27 million variants in two admixed groups: Admixed American (n = 7612) and African/African American (n = 20,250), deriving ancestry-specific allele frequencies. We show that 78.5% and 85.1% of variants in these groups, respectively, exhibit at least a twofold difference in ancestry-specific frequencies. Moreover, 81.49% of variants with LAI information would …

Β-Catenin Functions As A Molecular Adapter For Disordered Cbaf Interactions, Yuen San Chan, Qinyu Gao, Sarah A Robinson, Wenzhi Wang, Ruzena Filandrova, Lisa-Maria Weinhold, Mario Loeza Cabrera, Miao Zhang, Chandra Shekar R Ambati, Antonio M Lerario, Nagireddy Putluri, Katja Kiseljak-Vassiliades, Margaret E Wierman, Mouhammed Amir Habra, Gary D Hammer, Vaclav Veverka, Katerina Cermakova, H Courtney Hodges

Faculty, Staff and Students Publications

BAF (SWI/SNF) chromatin remodelers engage binding partners to generate site-specific DNA accessibility. However, the basis for interaction between BAF and divergent binding partners has remained unclear. Here, we tested the hypothesis that scaffold proteins augment BAF's binding repertoire by examining β-catenin (CTNNB1) and steroidogenic factor 1 (SF-1, NR5A1), a transcription factor central to steroid production in human cells. BAF inhibition rapidly opposed SF-1/β-catenin enhancer occupancy, impairing SF-1 target activation and SF-1/β-catenin autoregulation. These effects arise due to β-catenin's role as a molecular adapter between SF-1 and an intrinsically disordered region (IDR) of the canonical BAF (cBAF) subunit ARID1A. In contrast …

Mapping Mave Data For Use In Human Genomics Applications, Jeremy A Arbesfeld, Estelle Y Da, James S Stevenson, Kori Kuzma, Anika Paul, Tierra Farris, Benjamin J Capodanno, Sally B Grindstaff, Kevin Riehle, Nuno Saraiva-Agostinho, Jordan F Safer, Jonathan Casper, Maximilian Haeussler, Aleksandar Milosavljevic, Julia Foreman, Helen V Firth, Sarah E Hunt, Sumaiya Iqbal, Melissa S Cline, Alan F Rubin, Alex H Wagner

Faculty, Staff and Students Publications

Background: Experimental data from functional assays have a critical role in interpreting the impact of genetic variants. Assay data must be unambiguously mapped to a reference genome to make it accessible, but it is often reported relative to assay-specific sequences, complicating downstream use and integration of variant data across resources. To make multiplexed assays of variant effect (MAVE) data more broadly available to the research and clinical communities, the Atlas of Variant Effects Alliance mapped MAVE data from the MaveDB community database to human reference sequences, creating an extensive set of machine-readable homology mappings that are incorporated into widely used …

Genomic Balancing Act: Deciphering Dna Rearrangements In The Complex Chromosomal Aberration Involving 5p152, 2q311, And 18q2132, Zain Dardas, Dana Marafi, Ruizhi Duan, Jawid M Fatih, Omnia F El-Rashidy, Christopher M Grochowski, Claudia M B Carvalho, Shalini N Jhangiani, Weimin Bi, Haowei Du, Richard A Gibbs, Jennifer E Posey, Daniel G Calame, Maha S Zaki, James R Lupski

Faculty, Staff and Students Publications

Despite extensive research into the genetic underpinnings of neurodevelopmental disorders (NDD), many clinical cases remain unresolved. We studied a female proband with a NDD, mildly dysmorphic facial features, and brain stem hypoplasia on neuroimaging. Comprehensive genomic analyses revealed a terminal 5p loss and a terminal 18q gain in the proband while a diploid copy number for chromosomes 5 and 18 in both parents. Genomic investigations in the proband identified an unbalanced translocation t(5;18) with additional genetic material from chromosome 2 (2q31.3) inserted at the breakpoint, pointing to a complex chromosomal rearrangement (CCR) involving 5p15.2, 2q31.3, and 18q21.32. Breakpoint junction analyses …

Characterizing Features Affecting Local Ancestry Inference Performance In Admixed Populations, Jessica Honorato-Mauer, Nirav N Shah, Adam X Maihofer, Clement C Zai, Sintia Belangero, Caroline M Nievergelt, Marcos Santoro, Elizabeth G Atkinson

Faculty, Staff and Students Publications

In recent years, significant efforts have been made to improve methods for genomic studies of admixed populations using local ancestry inference (LAI). Accurate LAI is crucial to ensure that downstream analyses accurately reflect the genetic ancestry of research participants. Here, we test analytic strategies for LAI to provide guidelines for optimal accuracy, focusing on admixed populations reflective of Latin America's primary continental ancestries-African (AFR), Amerindigenous (AMR), and European (EUR). Simulating linkage-disequilibrium-informed admixed haplotypes under a variety of 2- and 3-way admixture models, we implemented a standard LAI pipeline, testing the impact of reference panel composition, DNA data type, demography, and …

Whole Exome Sequencing As A Screening Tool In Dogs: A Pilot Study, Fréderique Boeykens, Evelien Bogaerts, Liesbeth Vossaert, Luc Peelman, Filip Van Nieuwerburgh, Jimmy H Saunders, Bart J G Broeckx

Faculty, Staff and Students Publications

Background: Whole-exome sequencing (WES) is used to selectively sequence all exons of protein-coding genes. WES is considered as a cost-effective and direct approach for identifying phenotype-associated variants in protein-coding regions and is as such situated between the traditional Sanger sequencing and whole genome sequencing (WGS). While WES is already widely used as a clinical tool in human and medical genetics, its use in veterinary medicine is currently restricted to research purposes. In this article, we aimed to provide baseline performance characteristics of a WES design to assess its suitability with future applications in veterinary clinical genetics in mind.

Methods: To …

Cocaine-Induced Dna-Dependent Protein Kinase Relieves Rnap Ii Pausing By Promoting Trim28 Phosphorylation And Rnap Ii Hyperphosphorylation To Enhance Hiv Transcription, Adhikarimayum Lakhikumar Sharma, Priya Tyagi, Meenata Khumallambam, Mudit Tyagi

Center for Translational Medicine Faculty Papers

Drug abuse continues to pose a significant challenge in HIV control efforts. In our investigation, we discovered that cocaine not only upregulates the expression of the DNA-dependent protein kinase (DNA-PK) but also augments DNA-PK activation by enhancing its phosphorylation at S2056. Moreover, DNA-PK phosphorylation triggers the higher localization of the DNA-PK into the nucleus. The finding that cocaine increases the nuclear localization of the DNA-PK provides further support to our observation of enhanced DNA-PK recruitment at the HIV long terminal repeat (LTR) following cocaine exposure. By activating and facilitating the nuclear localization of the DNA-PK, cocaine effectively orchestrates multiple stages …

Characterization And Visualization Of Tandem Repeats At Genome Scale, Egor Dolzhenko, Adam English, Harriet Dashnow, Guilherme De Sena Brandine, Tom Mokveld, William J Rowell, Caitlin Karniski, Zev Kronenberg, Matt C Danzi, Warren A Cheung, Chengpeng Bi, Emily Farrow, Aaron Wenger, Khi Pin Chua, Verónica Martínez-Cerdeño, Trevor D Bartley, Peng Jin, David L Nelson, Stephan Zuchner, Tomi Pastinen, Aaron R Quinlan, Fritz J Sedlazeck, Michael A Eberle

Faculty, Staff and Students Publications

Tandem repeat (TR) variation is associated with gene expression changes and numerous rare monogenic diseases. Although long-read sequencing provides accurate full-length sequences and methylation of TRs, there is still a need for computational methods to profile TRs across the genome. Here we introduce the Tandem Repeat Genotyping Tool (TRGT) and an accompanying TR database. TRGT determines the consensus sequences and methylation levels of specified TRs from PacBio HiFi sequencing data. It also reports reads that support each repeat allele. These reads can be subsequently visualized with a companion TR visualization tool. Assessing 937,122 TRs, TRGT showed a Mendelian concordance of …

Histone Serotonylation Regulates Ependymoma Tumorigenesis, Hsiao-Chi Chen, Peihao He, Malcolm Mcdonald, Michael R Williamson, Srinidhi Varadharajan, Brittney Lozzi, Junsung Woo, Dong-Joo Choi, Debosmita Sardar, Emmet Huang-Hobbs, Hua Sun, Siri M Ippagunta, Antrix Jain, Ganesh Rao, Thomas E Merchant, David W Ellison, Jeffrey L Noebels, Kelsey C Bertrand, Stephen C Mack, Benjamin Deneen

Faculty, Staff and Students Publications

Bidirectional communication between tumors and neurons has emerged as a key facet of the tumor microenvironment that drives malignancy1,2. Another hallmark feature of cancer is epigenomic dysregulation, where alterations in gene expression influences cell states and interactions with the tumor microenvironment3. Ependymoma (EPN) is a pediatric brain tumor that relies on epigenomic remodeling to engender malignancy4,5; how these epigenetic mechanisms intersect with extrinsic neuronal signaling during EPN tumor progression is unknown. Here we show that activity of serotonergic neurons regulates EPN tumorigenesis, while serotonin itself also serves as an activating …

Genomic Signatures Of Strawberry Domestication And Diversification, Zhen Fan, Vance M Whitaker

Faculty, Staff and Student Publications

Cultivated strawberry (Fragaria × ananassa) has a brief history of less than 300 yr, beginning with the hybridization of octoploids Fragaria chiloensis and Fragaria virginiana. Here we explored the genomic signatures of early domestication and subsequent diversification for different climates using whole-genome sequences of 289 wild, heirloom, and modern varieties from two major breeding programs in the United States. Four nonadmixed wild octoploid populations were identified, with recurrent introgression among the sympatric populations. The proportion of F. virginiana ancestry increased by 20% in modern varieties over initial hybrids, and the proportion of F. chiloensis subsp. pacifica rose from 0% to …

Histone Proteoform Analysis Reveals Epigenetic Changes In Adult Mouse Brown Adipose Tissue In Response To Cold Stress, Bethany C Taylor, Loic H Steinthal, Michelle Dias, Hari Krishna Yalamanchili, Scott A Ochsner, Gladys E Zapata, Nitesh R Mehta, Neil J Mckenna, Nicolas L Young, Alli M Nuotio-Antar

Faculty, Staff and Students Publications

BACKGROUND: Regulation of the thermogenic response by brown adipose tissue (BAT) is an important component of energy homeostasis with implications for the treatment of obesity and diabetes. Our preliminary analyses of RNA-Seq data uncovered many nodes representing epigenetic modifiers that are altered in BAT in response to chronic thermogenic activation. Thus, we hypothesized that chronic thermogenic activation broadly alters epigenetic modifications of DNA and histones in BAT.

RESULTS: Motivated to understand how BAT function is regulated epigenetically, we developed a novel method for the first-ever unbiased top-down proteomic quantitation of histone modifications in BAT and validated our results with a …

The Role Of Epigenetic Mechanisms In The Long-Term Effects Of Early-Life Adversity And Mother-Infant Relationship On Physiology And Behavior Of Offspring In Laboratory Rats And Mice, Olga V Burenkova, Elena L Grigorenko

Faculty, Staff and Students Publications

Maternal care during the early postnatal period of altricial mammals is a key factor in the survival and adaptation of offspring to environmental conditions. Natural variations in maternal care and experimental manipulations with maternal-child relationships modeling early-life adversity (ELA) in laboratory rats and mice have a strong long-term influence on the physiology and behavior of offspring in rats and mice. This literature review is devoted to the latest research on the role of epigenetic mechanisms in these effects of ELA and mother-infant relationship, with a focus on the regulation of hypothalamic-pituitary-adrenal axis and brain-derived neurotrophic factor. An important part of …

Fusionneoantigen: : A Resource Of Fusion Gene-Specific Neoantigens, Himansu Kumar, Ruihan Luo, Jianguo Wen, Chengyuan Yang, Xiaobo Zhou, Pora Kim

Faculty, Staff and Student Publications

Among the diverse sources of neoantigens (i.e. single-nucleotide variants (SNVs), insertions or deletions (Indels) and fusion genes), fusion gene-derived neoantigens are generally more immunogenic, have multiple targets per mutation and are more widely distributed across various cancer types. Therefore, fusion gene-derived neoantigens are a potential source of highly immunogenic neoantigens and hold great promise for cancer immunotherapy. However, the lack of fusion protein sequence resources and knowledge prevents this application. We introduce 'FusionNeoAntigen', a dedicated resource for fusion-specific neoantigens, accessible at https://compbio.uth.edu/FusionNeoAntigen. In this resource, we provide fusion gene breakpoint crossing neoantigens focused on ∼43K fusion proteins of ∼16K in-frame …

Cov2var, A Function Annotation Database Of Sars-Cov-2 Genetic Variation, Yuzhou Feng, Jiahao Yi, Lin Yang, Yanfei Wang, Jianguo Wen, Weiling Zhao, Pora Kim, Xiaobo Zhou

Faculty, Staff and Student Publications

The COVID-19 pandemic, caused by the coronavirus SARS-CoV-2, has resulted in the loss of millions of lives and severe global economic consequences. Every time SARS-CoV-2 replicates, the viruses acquire new mutations in their genomes. Mutations in SARS-CoV-2 genomes led to increased transmissibility, severe disease outcomes, evasion of the immune response, changes in clinical manifestations and reducing the efficacy of vaccines or treatments. To date, the multiple resources provide lists of detected mutations without key functional annotations. There is a lack of research examining the relationship between mutations and various factors such as disease severity, pathogenicity, patient age, patient gender, cross-species …

Fam20a: A Potential Diagnostic Biomarker For Lung Squamous Cell Carcinoma, Yalin Zhang, Qin Sun, Yangbo Liang, Xian Yang, Hailian Wang, Siyuan Song, Yi Wang, Yong Feng

Faculty, Staff and Students Publications

Background: Lung squamous cell carcinoma (LUSC) ranks among the carcinomas with the highest incidence and dismal survival rates, suffering from a lack of effective therapeutic strategies. Consequently, biomarkers facilitating early diagnosis of LUSC could significantly enhance patient survival. This study aims to identify novel biomarkers for LUSC.

Methods: Utilizing the TCGA, GTEx, and CGGA databases, we focused on the gene encoding Family with Sequence Similarity 20, Member A (FAM20A) across various cancers. We then corroborated these bioinformatic predictions with clinical samples. A range of analytical tools, including Kaplan-Meier, MethSurv database, Wilcoxon rank-sum, Kruskal-Wallis tests, Gene Set Enrichment Analysis, …

Fast Inference Of Genetic Recombination Rates In Biobank Scale Data, Ardalan Naseri, William Yue, Shaojie Zhang, Degui Zhi

Faculty, Staff and Student Publications

Although rates of recombination events across the genome (genetic maps) are fundamental to genetic research, the majority of current studies only use one standard map. There is evidence suggesting population differences in genetic maps, and thus estimating population-specific maps, are of interest. Although the recent availability of biobank-scale data offers such opportunities, current methods are not efficient at leveraging very large sample sizes. The most accurate methods are still linkage disequilibrium (LD)-based methods that are only tractable for a few hundred samples. In this work, we propose a fast and memory-efficient method for estimating genetic maps from population genotyping data. …

Methylation Of Nonessential Genes In Cutaneous Melanoma – Rule Out Hypothesis, Ivan P Gorlov, Kathleen Conway, Sharon N Edmiston, Eloise A Parrish, Honglin Hao, Christopher I Amos, Spiridon Tsavachidis, Olga Y Gorlova, Colin Begg, Eva Hernando, Chao Cheng, Ronglai Shen, Irene Orlow, Li Luo, Marc S Ernstoff, Pei Fen Kuan, David W Ollila, Yihsuan S Tsai, Marianne Berwick, Nancy E Thomas

Faculty, Staff and Students Publications

Differential methylation plays an important role in melanoma development and is associated with survival, progression and response to treatment. However, the mechanisms by which methylation promotes melanoma development are poorly understood. The traditional explanation of selective advantage provided by differential methylation postulates that hypermethylation of regulatory 5'-cytosine-phosphate-guanine-3' dinucleotides (CpGs) downregulates the expression of tumor suppressor genes and therefore promotes tumorigenesis. We believe that other (not necessarily alternative) explanations of the selective advantages of methylation are also possible. Here, we hypothesize that melanoma cells use methylation to shut down transcription of nonessential genes - those not required for cell survival and …

Mechanism Of Rare Variant In Acta2, P.Arg149cys, Driving Diverse Vascular Disease, Kaveeta Kaw

Dissertations and Theses (Open Access)

Heterozygous variants in ACTA2 (smooth muscle (SM) α-actin) predispose to thoracic aortic aneurysms and dissections (TAAD) and early-onset coronary artery disease (CAD). The most common ACTA2 mutation is a genetic alteration of arginine 149 to a cysteine, ACTA2 p.Arg149Cys, which accounts for disease in 24% of all ACTA2 mutation carriers.(1) ACTA2 p.Arg149Cys mutation carriers present with either TAAD or CAD but rarely have both diseases. To identify the molecular mechanisms dictating whether an individual with ACTA2 p.Arg149Cys develops TAAD or CAD, CRISPR/Cas9 technology was used to generate the mutant mouse, Acta2^R149C/+, in a C57BL6 background. Acta2^R149C/+ mice …

Supercoiling And Looping Promote Dna Base Accessibility And Coordination Among Distant Sites, Jonathan M Fogg, Allison K Judge, Erik Stricker, Hilda L Chan, Lynn Zechiedrich

Faculty, Staff and Students Publications

DNA in cells is supercoiled and constrained into loops and this supercoiling and looping influence every aspect of DNA activity. We show here that negative supercoiling transmits mechanical stress along the DNA backbone to disrupt base pairing at specific distant sites. Cooperativity among distant sites localizes certain sequences to superhelical apices. Base pair disruption allows sharp bending at superhelical apices, which facilitates DNA writhing to relieve torsional strain. The coupling of these processes may help prevent extensive denaturation associated with genomic instability. Our results provide a model for how DNA can form short loops, which are required for many essential …

Discovery Of Potent Bet Bromodomain 1 Stereoselective Inhibitors Using Dna-Encoded Chemical Library Selections, Rajesh Sharma, Kyoung-Jae Choi, My Diem Quan, Sonum Sharma, Banumathi Sankaran, Hyekyung Park, Anel Lagrone, Jean J Kim, Kevin R Mackenzie, Allan Chris M Ferreon, Choel Kim, Josephine C Ferreon

Faculty, Staff and Students Publications

Expression of a few master transcription factors can reprogram the epigenetic landscape and three-dimensional chromatin topology of differentiated cells and achieve pluripotency. During reprogramming, thousands of long-range chromatin contacts are altered, and changes in promoter association with enhancers dramatically influence transcription. Molecular participants at these sites have been identified, but how this re-organization might be orchestrated is not known. Biomolecular condensation is implicated in subcellular organization, including the recruitment of RNA polymerase in transcriptional activation. Here, we show that reprogramming factor KLF4 undergoes biomolecular condensation even in the absence of its intrinsically disordered region. Liquid-liquid condensation of the isolated KLF4 …

Evidence For Craniofacial Enhancer Variation Underlying Nonsyndromic Cleft Lip And Palate, Vershanna E Morris, S Shahrukh Hashmi, Lisha Zhu, Lorena Maili, Christian Urbina, Steven Blackwell, Matthew R Greives, Edward P Buchanan, John B Mulliken, Susan H Blanton, W Jim Zheng, Jacqueline T Hecht, Ariadne Letra

Faculty, Staff and Student Publications

Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common birth defect for which only ~ 20% of the underlying genetic variation has been identified. Variants in noncoding regions have been increasingly suggested to contribute to the missing heritability. In this study, we investigated whether variation in craniofacial enhancers contributes to NSCLP. Candidate enhancers were identified using VISTA Enhancer Browser and previous publications. Prioritization was based on patterning defects in knockout mice, deletion/duplication of craniofacial genes in animal models and results of whole exome/whole genome sequencing studies. This resulted in 20 craniofacial enhancers to be investigated. Custom amplicon-based …

The Ubiquitin Ligase Cullin-1 Associates With Chromatin And Regulates Transcription Of Specific C-Myc Target Genes, Melanie A Sweeney, Polina Iakova, Laure Maneix, Fu-Yuan Shih, Hannah E Cho, Ergun Sahin, Andre Catic

Faculty, Staff and Students Publications

Transcription is regulated through a dynamic interplay of DNA-associated proteins, and the composition of gene-regulatory complexes is subject to continuous adjustments. Protein alterations include post-translational modifications and elimination of individual polypeptides. Spatially and temporally controlled protein removal is, therefore, essential for gene regulation and accounts for the short half-life of many transcription factors. The ubiquitin-proteasome system is responsible for site- and target-specific ubiquitination and protein degradation. Specificity of ubiquitination is conferred by ubiquitin ligases. Cullin-RING complexes, the largest family of ligases, require multi-unit assembly around one of seven cullin proteins. To investigate the direct role of cullins in ubiquitination of …

Integrating Mouse And Human Genetic Data To Move Beyond Gwas And Identify Causal Genes In Cholesterol Metabolism, Zhonggang Li, James A Votava, Gregory J M Zajac, Jenny N Nguyen, Fernanda B Leyva Jaimes, Sophia M Ly, Jacqueline A Brinkman, Marco De Giorgi, Sushma Kaul, Cara L Green, Samantha L St Clair, Sabrina L Belisle, Julia M Rios, David W Nelson, Mary G Sorci-Thomas, William R Lagor, Dudley W Lamming, Chi-Liang Eric Yen, Brian W Parks

Faculty, Staff and Students Publications

Identifying the causal gene(s) that connects genetic variation to a phenotype is a challenging problem in genome-wide association studies (GWASs). Here, we develop a systematic approach that integrates mouse liver co-expression networks with human lipid GWAS data to identify regulators of cholesterol and lipid metabolism. Through our approach, we identified 48 genes showing replication in mice and associated with plasma lipid traits in humans and six genes on the X chromosome. Among these 54 genes, 25 have no previously identified role in lipid metabolism. Based on functional studies and integration with additional human lipid GWAS datasets, we pinpoint Sestrin1 as …

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 …

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 Departmental Research

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 …

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 Departmental Research

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. …

Cohort Of Birth Modifies The Association Between Fto Genotype And Bmi, James Niels Rosenquist, Steven F. Lehrer, A. James O'Malley, Alan M. Zaslavsky, Jordan W. Smoller, Nicholas A. Christakis

Dartmouth Scholarship

A substantial body of research has explored the relative roles of genetic and environmental factors on phenotype expression in humans. Recent research has also sought to identify gene-environment (or g-by-e) interactions, with mixed success. One potential reason for these mixed results may relate to the fact that genetic effects might be modified by changes in the environment over time. For example, the noted rise of obesity in the United States in the latter part of the 20th century might reflect an interaction between genetic variation and changing environmental conditions that together affect the penetrance of genetic influences. To evaluate this …