Digital Commons Network^™

Dna Fork Remodeling Proteins, Zranb3 And Smarcal1, Are Uniquely Essential For Aging Hematopoiesis, Saul Kushinsky, Matthew V. Puccetti, Clare M. Adams, Irina Shkundina, Nikkole James, Brittany M. Mahon, Peter Michener, Christine M. Eischen

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Over a lifetime, hematopoietic stem and progenitor cells (HSPCs) are forced to repeatedly proliferate to maintain hematopoiesis, increasing their susceptibility to DNA damaging replication stress. However, the proteins that mitigate this stress, protect HSPC replication, and prevent aging-driven dysregulation are unknown. We report two evolutionarily conserved, ubiquitously expressed chromatin remodeling enzymes with similar DNA replication fork reversal biochemical functions, Zranb3 and Smarcal1, have surprisingly specialized roles in distinct HSPC populations. While both proteins actively mitigate replication stress and prevent DNA damage and breaks during lifelong hematopoiesis, the loss of either resulted in distinct biochemical and biological consequences. Notably, defective long-term …

Onecut2 Acts As A Lineage Plasticity Driver In Adenocarcinoma As Well As Neuroendocrine Variants Of Prostate Cancer, Chen Qian, Qian Yang, Mirja Rotinen, Rongrong Huang, Hyoyoung Kim, Brad Gallent, Yiwu Yan, Radu M Cadaneanu, Baohui Zhang, Salma Kaochar, Stephen J Freedland, Edwin M Posadas, Leigh Ellis, Dolores Di Vizio, Colm Morrissey, Peter S Nelson, Lauren Brady, Ramachandran Murali, Moray J Campbell, Wei Yang, Beatrice S Knudsen, Elahe A Mostaghel, Huihui Ye, Isla P Garraway, Sungyong You, Michael R Freeman

Faculty, Staff and Students Publications

Androgen receptor- (AR-) indifference is a mechanism of resistance to hormonal therapy in prostate cancer (PC). Here we demonstrate that ONECUT2 (OC2) activates resistance through multiple drivers associated with adenocarcinoma, stem-like and neuroendocrine (NE) variants. Direct OC2 gene targets include the glucocorticoid receptor (GR; NR3C1) and the NE splicing factor SRRM4, which are key drivers of lineage plasticity. Thus, OC2, despite its previously described NEPC driver function, can indirectly activate a portion of the AR cistrome through epigenetic activation of GR. Mechanisms by which OC2 regulates gene expression include promoter binding, enhancement of genome-wide chromatin accessibility, and super-enhancer reprogramming. Pharmacologic …

Senescent Cancer-Associated Fibroblasts In Pancreatic Adenocarcinoma Restrict Cd8+ T Cell Activation And Limit Responsiveness To Immunotherapy In Mice, Benjamin Assouline, Sheila A Stewart, Et Al.

2020-Current year OA Pubs

Senescent cells within tumors and their stroma exert complex pro- and anti-tumorigenic functions. However, the identities and traits of these cells, and the potential for improving cancer therapy through their targeting, remain poorly characterized. Here, we identify a senescent subset within previously-defined cancer-associated fibroblasts (CAFs) in pancreatic ductal adenocarcinomas (PDAC) and in premalignant lesions in mice and humans. Senescent CAFs isolated from mouse and humans expressed elevated levels of immune-regulatory genes. Depletion of senescent CAFs, either genetically or using the Bcl-2 inhibitor ABT-199 (venetoclax), increased the proportion of activated CD8

Targeted Degradation Of Extracellular Mitochondrial Aspartyl-Trna Synthetase Modulates Immune Responses, Benjamin S Johnson, Janet S Lee, Et Al.

2020-Current year OA Pubs

The severity of bacterial pneumonia can be worsened by impaired innate immunity resulting in ineffective pathogen clearance. We describe a mitochondrial protein, aspartyl-tRNA synthetase (DARS2), which is released in circulation during bacterial pneumonia in humans and displays intrinsic innate immune properties and cellular repair properties. DARS2 interacts with a bacterial-induced ubiquitin E3 ligase subunit, FBXO24, which targets the synthetase for ubiquitylation and degradation, a process that is inhibited by DARS2 acetylation. During experimental pneumonia, Fbxo24 knockout mice exhibit elevated DARS2 levels with an increase in pulmonary cellular and cytokine levels. In silico modeling identified an FBXO24 inhibitory compound with immunostimulatory …

Genomic Reference Resource For African Cattle: Genome Sequences And High-Density Array Variants., Abdulfatai Tijjani, Sumaya Kambal, Endashaw Terefe, Regina Njeru, Moses Ogugo, Gideon Ndambuki, Ayao Missohou, Amadou Traore, Bashir Salim, Chukwunonso Ezeasor, Claire D'Andre H, Emmanuel T Obishakin, Boubacar Diallo, Essodina Talaki, Issaka Y Abdoukarim, Oyekanmi Nash, Richard Osei-Amponsah, Simeone Ravaorimanana, Youssouf Issa, Tsadkan Zegeye, Christopher Mukasa, Christian Tiambo, James G D Prendergast, Stephen J Kemp, Jianlin Han, Karen Marshall, Olivier Hanotte

Faculty Research 2024

The diversity in genome resources is fundamental to designing genomic strategies for local breed improvement and utilisation. These resources also support gene discovery and enhance our understanding of the mechanisms of resilience with applications beyond local breeds. Here, we report the genome sequences of 555 cattle (208 of which comprise new data) and high-density (HD) array genotyping of 1,082 samples (537 new samples) from indigenous African cattle populations. The new sequences have an average genome coverage of ~30X, three times higher than the average (~10X) of the over 300 sequences already in the public domain. Following variant quality checks, we …

Novel Mutation Leading To Splice Donor Loss In A Conserved Site Of Dmd Gene Causes Duchenne Muscular Dystrophy With Cryptorchidism, Jianhai Chen, Yangying Jia, Jie Zhong, Kun Zhang, Hongzheng Dai, Guanglin He, Fuping Li, Li Zeng, Chuanzhu Fan, Huayan Xu

Faculty, Staff and Students Publications

Background: As one of the most common congenital abnormalities in male births, cryptorchidism has been found to have a polygenic aetiology according to previous studies of common variants. However, little is known about genetic predisposition of rare variants for cryptorchidism, since rare variants have larger effective size on diseases than common variants.

Methods: In this study, a cohort of 115 Chinese probands with cryptorchidism was analysed using whole-genome sequencing, alongside 19 parental controls and 2136 unaffected men. Additionally, CRISPR-Cas9 editing of a conserved variant was performed in a mouse model, with MRI screening used to observe the phenotype.

Results: In …

Membrane Vectorial Lipidomic Features Of Coral Host Cells’ Plasma Membrane And Lipid Profiles Of Their Endosymbionts Cladocopium, Tatyana V Sikorskaya, Ekaterina V Ermolenko, Taliya T Ginanova, Andrey V Boroda, Kseniya V Efimova, Mikhail Bogdanov

Faculty, Staff and Student Publications

The symbiotic relationships between coral animal host and autotrophic dinoflagellates are based on the mutual exchange and tight control of nutritional inputs supporting successful growth. The corals Sinularia heterospiculata and Acropora aspera were cultivated using a flow-through circulation system supplying seawater during cold and warm seasons of the year, then sorted into host cells and symbionts and subjected to phylogenetic, morphological, and advanced lipid analyses. Here we show, that the lipidomes of the dinoflagellates Cladocopium C1/C3 and acroporide-specific Cladocopium hosted by the corals, are determined by lipidomic features of different thermosensitivity and unique betaine- and phospholipid molecular species. Phosphatidylserines and …

Investigating Gene Functions And Single-Cell Expression Profiles Of De Novo Variants In Orofacial Clefts, Toshiyuki Itai, Fangfang Yan, Andi Liu, Yulin Dai, Chihiro Iwaya, Sarah W Curtis, Elizabeth J Leslie, Lukas M Simon, Peilin Jia, Xiangning Chen, Junichi Iwata, Zhongming Zhao

Faculty, Staff and Student Publications

Orofacial clefts (OFCs) are common congenital birth defects with various etiologies, including genetic variants. Online Mendelian Inheritance in Man (OMIM) annotated several hundred genes involving OFCs. Furthermore, several hundreds of de novo variants (DNVs) have been identified from individuals with OFCs. Some DNVs are related to known OFC genes or pathways, but there are still many DNVs whose relevance to OFC development is unknown. To explore novel gene functions and their cellular expression profiles, we focused on DNVs in genes that were not listed in OMIM. We collected 960 DNVs in 853 genes from published studies and curated these genes, …

Involvement Of The Choroid Plexus In Alzheimer's Disease Pathophysiology: Findings From Mouse And Human Proteomic Studies, Aurore Delvenne, Suzanne E Schindler, Et Al.

2020-Current year OA Pubs

BACKGROUND: Structural and functional changes of the choroid plexus (ChP) have been reported in Alzheimer's disease (AD). Nonetheless, the role of the ChP in the pathogenesis of AD remains largely unknown. We aim to unravel the relation between ChP functioning and core AD pathogenesis using a unique proteomic approach in mice and humans.

METHODS: We used an APP knock-in mouse model, APP

RESULTS: ChP tissue proteome was dysregulated in APP

CONCLUSIONS: Together, our findings support the hypothesis of ChP dysfunction in AD. These ChP changes were related to amyloid pathology. Therefore, the ChP could become a novel promising therapeutic target …

Crispr-Cas9 And Cas12a Target Site Richness Reflects Genomic Diversity In Natural Populations Of Anopheles Gambiae And Aedes Aegypti Mosquitoes, Travis C Collier, Yoosook Lee, Derrick K Mathias, Víctor López Del Amo

Faculty, Staff and Student Publications

Due to limitations in conventional disease vector control strategies including the rise of insecticide resistance in natural populations of mosquitoes, genetic control strategies using CRISPR gene drive systems have been under serious consideration. The identification of CRISPR target sites in mosquito populations is a key aspect for developing efficient genetic vector control strategies. While genome-wide Cas9 target sites have been explored in mosquitoes, a precise evaluation of target sites focused on coding sequence (CDS) is lacking. Additionally, target site polymorphisms have not been characterized for other nucleases such as Cas12a, which require a different DNA recognition site (PAM) and would …

Cellular Endosomal Potassium Ion Flux Regulates Arenavirus Uncoating During Virus Entry, Amelia B Shaw, Hiu Nam Tse, Owen Byford, Grace Plahe, Alex Moon-Walker, Samantha E Hover, Erica Ollmann Saphire, Sean P J Whelan, Jamel Mankouri, Juan Fontana, John N Barr

2020-Current year OA Pubs

Lymphocytic choriomeningitis virus (LCMV) is an enveloped and segmented negative-sense RNA virus classified within the

Brilacidin, A Novel Antifungal Agent Against Cryptococcus Neoformans, Camila Diehl, Dong-Gyu Kim, Tamara L Doering, Et Al.

2020-Current year OA Pubs

UNLABELLED:

IMPORTANCE: Invasive fungal infections have a high mortality rate causing more deaths annually than tuberculosis or malaria. Cryptococcosis, one of the most prevalent fungal diseases, is generally characterized by meningitis and is mainly caused by two closely related species of basidiomycetous yeasts,

A Reinterpretation Of The Relationship Between Persistent And Resurgent Sodium Currents, Samuel P Brown, Ryan J Lawson, Jonathan D Moreno, Joseph L Ransdell

2020-Current year OA Pubs

The resurgent sodium current (I

Chimeric Antigen Receptor-Induced Antigen Loss Protects Cd5cart Cells From Fratricide Without Compromising On-Target Cytotoxicity, Royce Ma, Mae Woods, Phillip Burkhardt, Noah Crooks, Dayenne G Van Leeuwen, Daniil Shmidt, Jacob Couturier, Alexandre Chaumette, Divya Popat, Laquisa C Hill, Rayne H Rouce, Sachin Thakkar, Aaron F Orozco, Alexandre F Carisey, Malcolm K Brenner, Maksim Mamonkin

Center for Medical Ethics and Health Policy Staff Publications

Chimeric antigen receptor T cells (CART) targeting lymphocyte antigens can induce T cell fratricide and require additional engineering to mitigate self-damage. We demonstrate that the expression of a chimeric antigen receptor (CAR) targeting CD5, a prominent pan-T cell antigen, induces rapid internalization and complete loss of the CD5 protein on T cells, protecting them from self-targeting. Notably, exposure of healthy and malignant T cells to CD5.CART cells induces similar internalization of CD5 on target cells, transiently shielding them from cytotoxicity. However, this protection is short-lived, as sustained activity of CD5.CART cells in patients with T cell malignancies results in full …

Mutant Androgen Receptor Induces Neurite Loss And Senescence Independently Of Are Binding In A Neuronal Model Of Sbma, Jordyn Karliner, Y Liu, Diane Merry

Department of Biochemistry and Molecular Biology Faculty Papers

Spinal and bulbar muscular atrophy (SBMA) is a slowly progressing neuromuscular disease caused by a polyglutamine (polyQ)-encoding CAG trinucleotide repeat expansion in the androgen receptor (AR) gene, leading to AR aggregation, lower motor neuron death, and muscle atrophy. AR is a ligand-activated transcription factor that regulates neuronal architecture and promotes axon regeneration; however, whether AR transcriptional functions contribute to disease pathogenesis is not fully understood. Using a differentiated PC12 cell model of SBMA, we identified dysfunction of polyQ-expanded AR in its regulation of neurite growth and maintenance. Specifically, we found that in the presence of androgens, polyQ-expanded AR inhibited neurite …

Biophysics Of Protein-Lipid Interactions, Paula A Bender, Vasanthi Jayaraman

Faculty, Staff and Student Publications

The biological phenomenon of protein-lipid interactions in cell membranes underlies the diversity of peripheral membrane protein function and physical properties of the membrane. To summarize novel findings in the field, this research highlight focuses on recent publications in Biophysical Journal.

Chimeric Viruses Enable Study Of Antibody Responses To Human Rotaviruses In Mice, Sarah Woodyear, Tawny L Chandler, Takahiro Kawagishi, Tom M Lonergan, Vanshika A Patel, Caitlin A Williams, Sallie R Permar, Siyuan Ding, Sarah L Caddy

2020-Current year OA Pubs

The leading cause of gastroenteritis in children under the age of five is rotavirus infection, accounting for 37% of diarrhoeal deaths in infants and young children globally. Oral rotavirus vaccines have been widely incorporated into national immunisation programs, but whilst these vaccines have excellent efficacy in high-income countries, they protect less than 50% of vaccinated individuals in low- and middle-income countries. In order to facilitate the development of improved vaccine strategies, a greater understanding of the immune response to existing vaccines is urgently needed. However, the use of mouse models to study immune responses to human rotavirus strains is currently …

Exploring Lipin1 As A Promising Therapeutic Target For The Treatment Of Duchenne Muscular Dystrophy, Abdulrahman Jama, Abdullah A Alshudukhi, Steve Burke, Lixin Dong, John Karanja Kamau, Brooklyn Morris, Ibrahim A Alkhomsi, Brian N Finck, Andrew Alvin Voss, Hongmei Ren

2020-Current year OA Pubs

BACKGROUND: Duchenne muscular dystrophy (DMD) is a progressive and devastating muscle disease, resulting from the absence of dystrophin. This leads to cell membrane instability, susceptibility to contraction-induced muscle damage, subsequent muscle degeneration, and eventually disability and early death of patients. Currently, there is no cure for DMD. Our recent studies identified that lipin1 plays a critical role in maintaining myofiber stability and integrity. However, lipin1 gene expression levels are dramatically reduced in the skeletal muscles of DMD patients and mdx mice.

METHODS: To identify whether increased lipin1 expression could prevent dystrophic pathology, we employed unique muscle-specific mdx:lipin1 transgenic (mdx:lipin1

RESULTS: …

Mapping The Contribution Of The C-Linker Domain To Gating Polarity In Cnbd Channels, Jenna L Lin, Yongchang Chang, Debanjan Tewari, John Cowgill, Baron Chanda

2020-Current year OA Pubs

Ion channels of the cyclic nucleotide-binding domain (CNBD) family play a crucial role in the regulation of key biological processes, such as photoreception and pacemaking activity in the heart. These channels exhibit high sequence and structural similarity but differ greatly in their functional responses to membrane potential. The CNBD family includes hyperpolarization-activated ion channels and depolarization-activated ether-à-go-go channels. Structural and functional studies show that the differences in the coupling interface between these two subfamilies' voltage-sensing domain and pore domain may underlie their differential response to membrane polarity. However, other structural components may also contribute to defining the polarity differences in …

Development Of A Hydrogen Peroxide-Inactivated Vaccine That Protects Against Viscerotropic Yellow Fever In A Non-Human Primate Model, Ian J Amanna, Archana Thomas, Flora Engelmann, Erika Hammarlund, Hans-Peter Raué, Adam L Bailey, Elizabeth A Poore, Benjamin K Quintel, Anne D Lewis, Michael K Axthelm, Amanda L Johnson, Lois M A Colgin, Michael S Diamond, Ilhem Messaoudi, Mark K Slifka

2020-Current year OA Pubs

Yellow fever virus (YFV) is endemic in >40 countries and causes viscerotropic disease with up to 20%-60% mortality. Successful live-attenuated yellow fever (YF) vaccines were developed in the mid-1930s, but their use is restricted or formally contraindicated in vulnerable populations including infants, the elderly, and people with compromised immune systems. In these studies, we describe the development of a next-generation hydrogen peroxide-inactivated YF vaccine and determine immune correlates of protection based on log neutralizing index (LNI) and neutralizing titer-50% (NT

Systemic Interindividual Dna Methylation Variants In Cattle Share Major Hallmarks With Those In Humans, Wen-Jou Chang, Maria S Baker, Eleonora Laritsky, Chathura J Gunasekara, Uditha Maduranga, Justine C Galliou, Joseph W Mcfadden, Jessica R Waltemyer, Bruce Berggren-Thomas, Brianna N Tate, Hanxue Zhang, Benjamin D Rosen, Curtis P Van Tassell, George E Liu, Cristian Coarfa, Yi Athena Ren, Robert A Waterland

Faculty, Staff and Students Publications

BACKGROUND: We recently identified ~ 10,000 correlated regions of systemic interindividual epigenetic variation (CoRSIVs) in the human genome. These methylation variants are amenable to population studies, as DNA methylation measurements in blood provide information on epigenetic regulation throughout the body. Moreover, establishment of DNA methylation at human CoRSIVs is labile to periconceptional influences such as nutrition. Here, we analyze publicly available whole-genome bisulfite sequencing data on multiple tissues of each of two Holstein cows to determine whether CoRSIVs exist in cattle.

RESULTS: Focusing on genomic blocks with ≥ 5 CpGs and a systemic interindividual variation index of at least 20, …

The Potential Anti-Arrhythmic Effect Of Sglt2 Inhibitors, Hong-Yi Duan, Hector Barajas-Martinez, Charles Antzelevitch, Dan Hu

Department of Medicine Faculty Papers

Sodium-glucose cotransporter type 2 inhibitors (SGLT2i) were initially recommended as oral anti-diabetic drugs to treat type 2 diabetes (T2D), by inhibiting SGLT2 in proximal tubule and reduce renal reabsorption of sodium and glucose. While many clinical trials demonstrated the tremendous potential of SGLT2i for cardiovascular diseases. 2022 AHA/ACC/HFSA guideline first emphasized that SGLT2i were the only drug class that can cover the entire management of heart failure (HF) from prevention to treatment. Subsequently, the antiarrhythmic properties of SGLT2i have also attracted attention. Although there are currently no prospective studies specifically on the anti-arrhythmic effects of SGLT2i. We provide clues from …

Setd3 Is A Mechanosensitive Enzyme That Methylates Actin On His73 To Regulate Mitochondrial Dynamics And Function, Vaibhav Deshmukh, James F Martin

Faculty, Staff and Students Publications

Mitochondria, which act as sensors of metabolic homeostasis and metabolite signaling, form a dynamic intracellular network that continuously changes shape, size and localization to respond to localized cellular energy demands. Mitochondrial dynamics and function depend on interactions with the F-actin cytoskeleton that are poorly understood. Here, we show that SET domain protein 3 (SETD3), a recently described actin histidine methyltransferase, directly methylates actin at histidine-73 and enhances F-actin polymerization on mitochondria. SETD3 is a mechano-sensitive enzyme that is localized on the outer mitochondrial membrane and promotes actin polymerization around mitochondria. SETD3 loss of function leads to diminished F-actin around mitochondria …

Learning To Express Reward Prediction Error-Like Dopaminergic Activity Requires Plastic Representations Of Time, Ian Cone, Claudia Clopath, Harel Z Shouval

Faculty, Staff and Student Publications

The dominant theoretical framework to account for reinforcement learning in the brain is temporal difference learning (TD) learning, whereby certain units signal reward prediction errors (RPE). The TD algorithm has been traditionally mapped onto the dopaminergic system, as firing properties of dopamine neurons can resemble RPEs. However, certain predictions of TD learning are inconsistent with experimental results, and previous implementations of the algorithm have made unscalable assumptions regarding stimulus-specific fixed temporal bases. We propose an alternate framework to describe dopamine signaling in the brain, FLEX (Flexibly Learned Errors in Expected Reward). In FLEX, dopamine release is similar, but not identical …

Pulmonary Osteoclast-Like Cells In Silica Induced Pulmonary Fibrosis, Yoshihiro Hasegawa, Steven L Teitelbaum, Et Al.

2020-Current year OA Pubs

The pathophysiology of silicosis is poorly understood, limiting development of therapies for those who have been exposed to the respirable particle. We explored mechanisms of silica-induced pulmonary fibrosis in human lung samples collected from patients with occupational exposure to silica and in a longitudinal mouse model of silicosis using multiple modalities including whole-lung single-cell RNA sequencing and histological, biochemical, and physiologic assessments. In addition to pulmonary inflammation and fibrosis, intratracheal silica challenge induced osteoclast-like differentiation of alveolar macrophages and recruited monocytes, driven by induction of the osteoclastogenic cytokine, receptor activator of nuclear factor κΒ ligand (RANKL) in pulmonary lymphocytes, and …

27-Hydroxycholesterol Acts On Estrogen Receptor Α Expressed By Pomc Neurons In The Arcuate Nucleus To Modulate Feeding Behavior, Hui Ye, Xiaohua Yang, Bing Feng, Pei Luo, Valeria C Torres Irizarry, Leslie Carrillo-Sáenz, Meng Yu, Yongjie Yang, Benjamin P Eappen, Marcos David Munoz, Nirali Patel, Sarah Schaul, Lucas Ibrahimi, Penghua Lai, Xinyue Qi, Yuliang Zhou, Maya Kota, Devin Dixit, Madeline Mun, Chong Wee Liew, Yuwei Jiang, Chunmei Wang, Yanlin He, Pingwen Xu

Faculty, Staff and Students Publications

Oxysterols are metabolites of cholesterol that regulate cholesterol homeostasis. Among these, the most abundant oxysterol is 27-hydroxycholesterol (27HC), which can cross the blood-brain barrier. Because 27HC functions as an endogenous selective estrogen receptor modulator, we hypothesize that 27HC binds to the estrogen receptor α (ERα) in the brain to regulate energy balance. Supporting this view, we found that delivering 27HC to the brain reduced food intake and activated proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (POMCARH) in an ERα-dependent manner. In addition, we observed that inhibiting brain ERα, deleting ERα in POMC neurons, or chemogenetic inhibition of …

Monoallelic De Novo Ajap1 Loss-Of-Function Variants Disrupt Trans-Synaptic Control Of Neurotransmitter Release, Simon Früh, Sami Boudkkazi, Peter Koppensteiner, Vita Sereikaite, Li-Yuan Chen, Diego Fernandez-Fernandez, Pascal D Rem, Daniel Ulrich, Jochen Schwenk, Ziyang Chen, Elodie Le Monnier, Thorsten Fritzius, Sabrina M Innocenti, Valérie Besseyrias, Luca Trovò, Michal Stawarski, Emanuela Argilli, Elliott H Sherr, Bregje Van Bon, Erik-Jan Kamsteeg, Maria Iascone, Alba Pilotta, Maria R Cutrì, Mahshid S Azamian, Andrés Hernández-García, Seema R Lalani, Jill A Rosenfeld, Xiaonan Zhao, Tiphanie P Vogel, Herda Ona, Daryl A Scott, Peter Scheiffele, Kristian Strømgaard, Mehdi Tafti, Martin Gassmann, Bernd Fakler, Ryuichi Shigemoto, Bernhard Bettler

Faculty, Staff and Students Publications

Adherens junction–associated protein 1 (AJAP1) has been implicated in brain diseases; however, a pathogenic mechanism has not been identified. AJAP1 is widely expressed in neurons and binds to γ-aminobutyric acid type B receptors (GBRs), which inhibit neurotransmitter release at most synapses in the brain. Here, we show that AJAP1 is selectively expressed in dendrites and trans-synaptically recruits GBRs to presynaptic sites of neurons expressing AJAP1. We have identified several monoallelic AJAP1 variants in individuals with epilepsy and/or neurodevelopmental disorders. Specifically, we show that the variant p.(W183C) lacks binding to GBRs, resulting in the inability to recruit them. Ultrastructural analysis revealed …

Clonal Hematopoiesis Driven By Mutated Dnmt3a Promotes Inflammatory Bone Loss, Hui Wang, Kimon Divaris, Bohu Pan, Xiaofei Li, Jong-Hyung Lim, Gundappa Saha, Marko Barovic, Danai Giannakou, Jonathan M Korostoff, Yu Bing, Souvik Sen, Kevin Moss, Di Wu, James D Beck, Christie M Ballantyne, Pradeep Natarajan, Kari E North, Mihai G Netea, Triantafyllos Chavakis, George Hajishengallis

Faculty, Staff and Student Publications

Clonal hematopoiesis of indeterminate potential (CHIP) arises from aging-associated acquired mutations in hematopoietic progenitors, which display clonal expansion and produce phenotypically altered leukocytes. We associated CHIP-DNMT3A mutations with a higher prevalence of periodontitis and gingival inflammation among 4,946 community-dwelling adults. To model DNMT3A-driven CHIP, we used mice with the heterozygous loss-of-function mutation R878H, equivalent to the human hotspot mutation R882H. Partial transplantation with Dnmt3a

Parg Is Essential For Polθ-Mediated Dna End-Joining By Removing Repressive Poly-Adp-Ribose Marks, Umeshkumar Vekariya, Leonid Minakhin, Gurushankar Chandramouly, Mrityunjay Tyagi, Tatiana Kent, Katherine Sullivan-Reed, Jessica Atkins, Douglas Ralph, Margaret Nieborowska-Skorska, Anna-Mariya Kukuyan, Hsin-Yao Tang, Richard T. Pomerantz, Tomasz Skorski

Department of Biochemistry and Molecular Biology Faculty Papers

DNA polymerase theta (Polθ)-mediated end-joining (TMEJ) repairs DNA double-strand breaks and confers resistance to genotoxic agents. How Polθ is regulated at the molecular level to exert TMEJ remains poorly characterized. We find that Polθ interacts with and is PARylated by PARP1 in a HPF1- independent manner. PARP1 recruits Polθ to the vicinity of DNA damage via PARylation dependent liquid demixing, however, PARylated Polθ cannot perform TMEJ due to its inability to bind DNA. PARG-mediated de-PARylation of Polθ reactivates its DNA binding and end-joining activities. Consistent with this, PARG is essential for TMEJ and the temporal recruitment of PARG to DNA …

Emergent Emm4 Group A Streptococcus Evidences A Survival Strategy During Interaction With Immune Effector Cells, Chioma M Odo, Luis A Vega, Piyali Mukherjee, Sruti Debroy, Anthony R Flores, Samuel A Shelburne

Faculty, Staff and Student Publications

The major gram-positive pathogen group A Streptococcus (GAS) is a model organism for studying microbial epidemics as it causes waves of infections. Since 1980, several GAS epidemics have been ascribed to the emergence of clones producing increased amounts of key virulence factors such as streptolysin O (SLO). Herein, we sought to identify mechanisms underlying our recently identified temporal clonal emergence among emm4 GAS, given that emergent strains did not produce augmented levels of virulence factors relative to historic isolates. By creating and analyzing isoallelic strains, we determined that a conserved mutation in a previously undescribed gene encoding a putative carbonic …