Genetic Processes Commons^™

Novel Mutations In The Gtpbp3 Gene For Mitochondrial Disease And Characteristics Of Related Phenotypic Spectrum: The First Three Cases From China, Hui-Ming Yan, Zhi-Mei Liu, Bei Cao, Victor Wei Zhang, Yi-Duo He, Zheng-Jun Jia, Hui Xi, Jing Liu, Fang Fang, Hua Wang

Faculty, Staff and Students Publications

Combined Oxidative Phosphorylation Deficiency 23 (COXPD23) caused by mutations in GTPBP3 gene is a rare mitochondrial disease, and this disorder identified from the Chinese population has not been described thus far. Here, we report a case series of three patients with COXPD23 caused by GTPBP3 mutations, from a severe to a mild phenotype. The main clinical features of these patients include lactic acidosis, myocardial damage, and neurologic symptoms. Whole genome sequencing and targeted panels of candidate human mitochondrial genome revealed that patient 1 was a compound heterozygote with novel mutations c.413C > T (p. A138V) and c.509_510del (p. E170Gfs∗42) in GTPBP3 …

Pathway‐Extended Gene Expression Signatures Integrate Novel Biomarkers That Improve Predictions Of Patient Responses To Kinase Inhibitors, Ashis Bagchee‐Clark, Eliseos J. Mucaki, Tyson Whitehead, Peter Rogan

Biochemistry Publications

Cancer chemotherapy responses have been related to multiple pharmacogenetic biomarkers, often for the same drug. This study utilizes machine learning to derive multi‐gene expression signatures that predict individual patient responses to specific tyrosine kinase inhibitors, including erlotinib, gefitinib, sorafenib, sunitinib, lapatinib and imatinib. Support vector machine (SVM) learning was used to train mathematical models that distinguished sensitivity from resistance to these drugs using a novel systems biology‐based approach. This began with expression of genes previously implicated in specific drug responses, then expanded to evaluate genes whose products were related through biochemical pathways and interactions. Optimal pathway‐extended SVMs predicted responses in …

Overcoming Barriers For Sirna Therapeutics: From Bench To Bedside, Muhammad Imran Sajid, Muhammad Moazzam, Shun Kato, Kayley Yeseom Cho, Rakesh Kumar Tiwari

Pharmacy Faculty Articles and Research

The RNA interference (RNAi) pathway possesses immense potential in silencing any gene in human cells. Small interfering RNA (siRNA) can efficiently trigger RNAi silencing of specific genes. FDA Approval of siRNA therapeutics in recent years garnered a new hope in siRNA therapeutics. However, their therapeutic use is limited by several challenges. siRNAs, being negatively charged, are membrane-impermeable and highly unstable in the systemic circulation. In this review, we have comprehensively discussed the extracellular barriers, including enzymatic degradation of siRNAs by serum endonucleases and RNAases, rapid renal clearance, membrane impermeability, and activation of the immune system. Besides, we have thoroughly described …

Versatile Phenotype-Activated Cell Sorting, Jihwan Lee, Zhuohe Liu, Peter H Suzuki, John F Ahrens, Shujuan Lai, Xiaoyu Lu, Sihui Guan, François St-Pierre

Faculty, Staff and Students Publications

Unraveling the genetic and epigenetic determinants of phenotypes is critical for understanding and re-engineering biology and would benefit from improved methods to separate cells based on phenotypes. Here, we report SPOTlight, a versatile high-throughput technique to isolate individual yeast or human cells with unique spatiotemporal profiles from heterogeneous populations. SPOTlight relies on imaging visual phenotypes by microscopy, precise optical tagging of single target cells, and retrieval of tagged cells by fluorescence-activated cell sorting. To illustrate SPOTlight's ability to screen cells based on temporal properties, we chose to develop a photostable yellow fluorescent protein for extended imaging experiments. We screened 3 …

Effects Of Germline And Somatic Events In Candidate Brca-Like Genes On Breast-Tumor Signatures, Weston R. Bodily, Brian H. Shirts, Tom Walsh, Suleyman Gulsuner, Mary-Claire King, Alyssa Parker, Moom Roosan, Stephen R. Piccolo

Pharmacy Faculty Articles and Research

Mutations in BRCA1 and BRCA2 cause deficiencies in homologous recombination repair (HR), resulting in repair of DNA double-strand breaks by the alternative non-homologous end-joining pathway, which is more error prone. HR deficiency of breast tumors is important because it is associated with better responses to platinum salt therapies and PARP inhibitors. Among other consequences of HR deficiency are characteristic somatic-mutation signatures and gene-expression patterns. The term “BRCA-like” (or “BRCAness”) describes tumors that harbor an HR defect but have no detectable germline mutation in BRCA1 or BRCA2. A better understanding of the genes and molecular events associated with tumors being …

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 …

A Substitution In Cgmp-Dependent Protein Kinase 1 Associated With Aortic Disease Induces An Active Conformation In The Absence Of Cgmp, Matthew H Chan, Sahar Aminzai, Tingfei Hu, Amatya Taran, Sheng Li, Choel Kim, Renate B Pilz, Darren E Casteel

Faculty, Staff and Students Publications

Type 1 cGMP-dependent protein kinases (PKGs) play important roles in human cardiovascular physiology, regulating vascular tone and smooth-muscle cell phenotype. A mutation in the human PRKG1 gene encoding cGMP-dependent protein kinase 1 (PKG1) leads to thoracic aortic aneurysms and dissections. The mutation causes an arginine-to-glutamine (RQ) substitution within the first cGMP-binding pocket in PKG1. This substitution disrupts cGMP binding to the pocket, but it also unexpectedly causes PKG1 to have high activity in the absence of cGMP via an unknown mechanism. Here, we identified the molecular mechanism whereby the RQ mutation increases basal kinase activity in the human PKG1α and …

Aav-Crispr Gene Editing Is Negated By Pre-Existing Immunity To Cas9, Ang Li, Mark R Tanner, Ciaran M Lee, Ayrea E Hurley, Marco De Giorgi, Kelsey E Jarrett, Timothy H Davis, Alexandria M Doerfler, Gang Bao, Christine Beeton, William R Lagor

Faculty, Staff and Students Publications

Adeno-associated viral (AAV) vectors are a leading candidate for the delivery of CRISPR-Cas9 for therapeutic genome editing in vivo. However, AAV-based delivery involves persistent expression of the Cas9 nuclease, a bacterial protein. Recent studies indicate a high prevalence of neutralizing antibodies and T cells specific to the commonly used Cas9 orthologs from Streptococcus pyogenes (SpCas9) and Staphylococcus aureus (SaCas9) in humans. We tested in a mouse model whether pre-existing immunity to SaCas9 would pose a barrier to liver genome editing with AAV packaging CRISPR-Cas9. Although efficient genome editing occurred in mouse liver with pre-existing SaCas9 immunity, this was accompanied by …

Determining The Genetic Control Of Neural Tube Malformation Through Genetic Interactions With Idgf3, Elli N. Fox

Honors Projects

Genetic mutations disrupting human neural tube formation can lead to birth defects such as spina bifida and anencephaly. Defects can result in lack of neural tube closure in either the caudal (spina bifida) or cranial (anencephaly) regions. Little is known about the genes that cause these malformations. Researchers have been using the model organism Drosophila melanogaster in an attempt to determine genes responsible for neural tube malformations. Recently, an ortholog of human chitin-like protein, imaginal disc growth factor 3 (Idgf3), has been identified as important in the proper formation of Drosophila egg dorsal appendages. However, the molecular mechanism responsible for …

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 …

Provider Attitudes And Practice Patterns For Direct-Acting Antiviral Therapy For Patients With Hepatocellular Carcinoma, Nicole E Rich, Ju Dong Yang, Ponni V Perumalswami, Naim Alkhouri, Whitney Jackson, Neehar D Parikh, Neil Mehta, Reena Salgia, Andres Duarte-Rojo, Laura Kulik, Mina Rakoski, Adnan Said, Omobonike Oloruntoba, George N Ioannou, Maarouf A Hoteit, Andrew M Moon, Amol S Rangnekar, Sheila L Eswaran, Elizabeth Zheng, Janice H Jou, James Hanje, Anjana Pillai, Ruben Hernaez, Robert Wong, Steven Scaglione, Hrishikesh Samant, Devika Kapuria, Shaun Chandna, Russell Rosenblatt, Veeral Ajmera, Catherine T Frenette, Sanjaya K Satapathy, Parvez Mantry, Prasun Jalal, Binu V John, Oren K Fix, Michael Leise, Christina C Lindenmeyer, Avegail Flores, Nayan Patel, Z Gordon Jiang, Nyan Latt, Renumathy Dhanasekaran, Mobolaji Odewole, Sofia Kagan, Jorge A Marrero, Amit G Singal

Faculty, Staff and Students Publications

BACKGROUND & AIMS: Direct-acting antivirals (DAAs) are effective against hepatitis C virus and sustained virologic response is associated with reduced incidence of hepatocellular carcinoma (HCC). However, there is controversy over the use of DAAs in patients with active or treated HCC and uncertainty about optimal management of these patients. We aimed to characterize attitudes and practice patterns of hepatology practitioners in the United States regarding the use of DAAs in patients with HCC.

METHODS: We conducted a survey of hepatology providers at 47 tertiary care centers in 25 states. Surveys were sent to 476 providers and we received 279 responses …

The Sineb1 Element In The Long Non-Coding Rna Malat1 Is Necessary For Tdp-43 Proteostasis, Tuan M Nguyen, Elena B Kabotyanski, Lucas C Reineke, Jiaofang Shao, Feng Xiong, Joo-Hyung Lee, Julien Dubrulle, Hannah Johnson, Fabio Stossi, Phoebe S Tsoi, Kyoung-Jae Choi, Alexander G Ellis, Na Zhao, Jin Cao, Oluwatoyosi Adewunmi, Josephine C Ferreon, Allan Chris M Ferreon, Joel R Neilson, Michael A Mancini, Xi Chen, Jongchan Kim, Li Ma, Wenbo Li, Jeffrey M Rosen

Faculty, Staff and Students Publications

Transposable elements (TEs) comprise a large proportion of long non-coding RNAs (lncRNAs). Here, we employed CRISPR to delete a short interspersed nuclear element (SINE) in Malat1, a cancer-associated lncRNA, to investigate its significance in cellular physiology. We show that Malat1 with a SINE deletion forms diffuse nuclear speckles and is frequently translocated to the cytoplasm. SINE-deleted cells exhibit an activated unfolded protein response and PKR and markedly increased DNA damage and apoptosis caused by dysregulation of TDP-43 localization and formation of cytotoxic inclusions. TDP-43 binds stronger to Malat1 without the SINE and is likely 'hijacked' by cytoplasmic Malat1 to the …

Using Active Learning To Build A Foundation For Bioinformatics Training., Stacey E. Wahl Ph.D., Amy L. Olex Ms

Transforming Libraries for Graduate Students

As Health Sciences Libraries evolve, the support they offer graduate students has evolved to incorporate many aspects of the research life cycle. At Tompkins-McCaw Library for the Health Sciences, we have partnered with the Wright Center for Clinical and Translational Research to offer training workshops for graduate students who are interested in using bioinformatics to plan, analyze, or execute scientific experiments. We offer two series: 1) an 8-week, 1-hour per week seminar series providing a general overview of available techniques and 2) a week-long intensive, two hours per session, series on utilizing free databases from the National Center for Biotechnology …

A "Choose-Your-Own" Classroom-Based Activity That Promotes Scientific Inquiry About Rna Interference, Jeremy L. Hsu

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

RNA interference (RNAi), the process that results in the degradation of a target gene’s mRNA, is a fundamental part of eukaryotic gene regulation and is also an important molecular technique that allows for experimental manipulation of gene expression without altering DNA sequences. Despite the importance of RNAi, there have been relatively few lecture-based activities designed to teach about the consequences of this process and counter common misconceptions. I present here an inquiry-based activity that is centered around a “choose your own experiment” design where students generate hypotheses and critically evaluate their ideas by choosing several simulated experiments. The activity presents …

Single-Nuclei Rna-Seq On Human Retinal Tissue Provides Improved Transcriptome Profiling, Qingnan Liang, Rachayata Dharmat, Leah Owen, Akbar Shakoor, Yumei Li, Sangbae Kim, Albert Vitale, Ivana Kim, Denise Morgan, Shaoheng Liang, Nathaniel Wu, Ken Chen, Margaret M Deangelis, Rui Chen

Faculty, Staff and Students Publications

Single-cell RNA-seq is a powerful tool in decoding the heterogeneity in complex tissues by generating transcriptomic profiles of the individual cell. Here, we report a single-nuclei RNA-seq (snRNA-seq) transcriptomic study on human retinal tissue, which is composed of multiple cell types with distinct functions. Six samples from three healthy donors are profiled and high-quality RNA-seq data is obtained for 5873 single nuclei. All major retinal cell types are observed and marker genes for each cell type are identified. The gene expression of the macular and peripheral retina is compared to each other at cell-type level. Furthermore, our dataset shows an …

A Systematic Comparison Of Lipopolymers For Sirna Delivery To Multiple Breast Cancer Cell Lines: In Vitro Studies, Hamidreza Montazeri Aliabadi, Remant Bahadur Kc, Emira Bousoik, Ashley Barbarino, Bindu Thapa, Melissa Coyle, Parvin Mahdipoor, Hasan Uludağ

Pharmacy Faculty Articles and Research

Small interfering RNA (siRNA) therapy is a promising approach for treatment of a wide range of cancers, including breast cancers that display variable phenotypic features. To explore the general utility of siRNA therapy to control aberrant expression of genes in breast cancer, we conducted a detailed analysis of siRNA delivery and silencing response in vitro in 6 separate breast cancer cell models (MDA-MB-231, MDA-MB-231-KRas-CRM, MCF-7, AU565, MDA-MB-435 and MDA-MB-468 cells). Using lipopolymers for siRNA complexation and delivery, we found a large variation in siRNA delivery efficiency depending on the specific lipopolymer used for siRNA complexation and delivery. Some lipopolymers were …

Integration Of Random Forest Classifiers And Deep Convolutional Neural Networks For Classification And Biomolecular Modeling Of Cancer Driver Mutations, Steve Agajanian, Odeyemi Oluyemi, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Development of machine learning solutions for prediction of functional and clinical significance of cancer driver genes and mutations are paramount in modern biomedical research and have gained a significant momentum in a recent decade. In this work, we integrate different machine learning approaches, including tree based methods, random forest and gradient boosted tree (GBT) classifiers along with deep convolutional neural networks (CNN) for prediction of cancer driver mutations in the genomic datasets. The feasibility of CNN in using raw nucleotide sequences for classification of cancer driver mutations was initially explored by employing label encoding, one hot encoding, and embedding to …

Female Family Members Lack Understanding Of Indeterminate Negative Brca1/2 Test Results Shared By Probands, Deborah Himes, Deborah K. Gibbons, Wendy C. Birmingham, Renea L. Beckstrand, Amanda Gammon, Anita Y. Kinney, Margaret F. Clayton

Faculty Publications

Genetic test results have important implications for close family members. Indeterminate negative results are the most common outcome of BRCA1/2 mutation testing. Little is known about family members’ understanding of indeterminate negative BRCA1/2 test results. The purpose of this mixed-methods study was to investigate how daughters and sisters received and understood genetic test results as shared by their mothers or sisters. Participants included 81 women aged 40-74 with mothers or sisters previously diagnosed with breast cancer and who received indeterminate negative BRCA1/2 test results. Participants had never been diagnosed with breast cancer nor received their own genetic testing or counseling. …

Yeast Mitochondrial Protein Pet111p Binds Directly To Two Distinct Targets In Cox2 Mrna, Suggesting A Mechanism Of Translational Activation, Julia L Jones, Katharina B Hofmann, Andrew T Cowan, Dmitry Temiakov, Patrick Cramer, Michael Anikin

Rowan-Virtua School of Osteopathic Medicine Departmental Research

The genes in mitochondrial DNA code for essential subunits of the respiratory chain complexes. In yeast, expression of mitochondrial genes is controlled by a group of gene-specific translational activators encoded in the nucleus. These factors appear to be part of a regulatory system that enables concerted expression of the necessary genes from both nuclear and mitochondrial genomes to produce functional respiratory complexes. Many of the translational activators are believed to act on the 5'-untranslated regions of target mRNAs, but the molecular mechanisms involved in this regulation remain obscure. In this study, we used a combination of in vivo and in …

Transcriptional Influence Of Retinoic Acid And Its Effects On Angiogenesis Of Murine Salivary Glands., Isaac Feinn

College of Arts & Sciences Senior Theses

Salivary gland hypofunction is a major disorder of salivary glands, and can arise either from diseases such as xerostomia, or from defective epithelial morphogenesis during embryogenesis. Hundreds of thousands of individuals suffer from dry mouth, and there is currently no restorative therapy for these patients. Investigation of salivary gland developmental biology will inform regenerative therapies. Currently it is known that retinoic acid (RA), the biologically active form of Vitamin A, is required for proper development of the salivary gland, but little is known about its cellular mechanism regulating organogenesis. This study sought to analyze salivary gland development in Rdh10 knock …

Dna Double Strand Breaks: To Repair, Or Not To Repair, Susiyan Jiang

NYMC Student Theses and Dissertations

DNA damages that cause double-strand breaks (DSBs) to the chromosome are most harmful. Subsequent choices have critical consequences for cell fate. Without repair, cells will face certain death. Low-fidelity repair will introduce mutations that could transform the cells, leading to carcinogenesis.

How cells make the decision is not well-understood. A single DSB can lead to apoptosis for some cells, whereas others can repair up to 25 DSBs and survive. It has been postulated that decision to repair DSBs is a stochastic process.

In the nucleus, DSBs elicit a cascade of signaling events that require the recognition, protection, processing, and subsequent …

Does Family Communication Matter? Exploring Knowledge Of Breast Cancer Genetics In Cancer Families, Deborah Himes, Sarah H. Davis, Jane Lassetter Phd, Rn, Neil E. Peterson, Margaret F. Clayton, Wendy C. Birmingham, Anita Y. Kinney

Faculty Publications

Purpose: Knowledge of breast cancer genetics is critical for those at increased hereditary risk who must make decisions about breast cancer screening options. This descriptive study explored theory-based relationships among cognitive and emotional variables related to knowledge of breast cancer genetics in cancer families. Methods: Participants included first-degree relatives of women with breast cancer who had received genetic counseling and testing. Study participants themselves did not have breast cancer and had not received genetic counseling or testing. Data were collected by telephone interviews and surveys. Variables analyzed included numeracy, health literacy, cancer-related distress, age, education, and the reported amount of …

Supervised Dimension Reduction For Large-Scale "Omics" Data With Censored Survival Outcomes Under Possible Non-Proportional Hazards, Lauren Spirko-Burns, Karthik Devarajan

COBRA Preprint Series

The past two decades have witnessed significant advances in high-throughput ``omics" technologies such as genomics, proteomics, metabolomics, transcriptomics and radiomics. These technologies have enabled simultaneous measurement of the expression levels of tens of thousands of features from individual patient samples and have generated enormous amounts of data that require analysis and interpretation. One specific area of interest has been in studying the relationship between these features and patient outcomes, such as overall and recurrence-free survival, with the goal of developing a predictive ``omics" profile. Large-scale studies often suffer from the presence of a large fraction of censored observations and potential …

Cyclin C: The Story Of A Non-Cycling Cyclin, Jan Jezek, Daniel G J Smethurst, David C Stieg, Z A C Kiss, Sara E Hanley, Vidyaramanan Ganesan, Kai-Ti Chang, Katrina F Cooper, Randy Strich

Rowan-Virtua School of Osteopathic Medicine Departmental Research

The class I cyclin family is a well-studied group of structurally conserved proteins that interact with their associated cyclin-dependent kinases (Cdks) to regulate different stages of cell cycle progression depending on their oscillating expression levels. However, the role of class II cyclins, which primarily act as transcription factors and whose expression remains constant throughout the cell cycle, is less well understood. As a classic example of a transcriptional cyclin, cyclin C forms a regulatory sub-complex with its partner kinase Cdk8 and two accessory subunits Med12 and Med13 called the Cdk8-dependent kinase module (CKM). The CKM reversibly associates with the multi-subunit …

Mechanisms Of Trinucleotide Repeat Instability During Dna Synthesis, Kara Y. Chan

Theses and Dissertations--Toxicology and Cancer Biology

Genomic instability, in the form of gene mutations, insertions/deletions, and gene amplifications, is one of the hallmarks in many types of cancers and other inheritable genetic disorders. Trinucleotide repeat (TNR) disorders, such as Huntington’s disease (HD) and Myotonic dystrophy (DM) can be inherited and repeats may be extended through subsequent generations. However, it is not clear how the CAG repeats expand through generations in HD. Two possible repeat expansion mechanisms include: 1) polymerase mediated repeat extension; 2) persistent TNR hairpin structure formation persisting in the genome resulting in expansion after subsequent cell division. Recent in vitro studies suggested that a …

Iron-Dependent Cleavage Of Ribosomal Rna During Oxidative Stress In The Yeast Saccharomyces Cerevisiae, Jessica A Zinskie, Arnab Ghosh, Brandon M Trainor, Daniel Shedlovskiy, Dimitri G Pestov, Natalia Shcherbik

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Stress-induced strand breaks in rRNA have been observed in many organisms, but the mechanisms by which they originate are not well-understood. Here we show that a chemical rather than an enzymatic mechanism initiates rRNA cleavages during oxidative stress in yeast (Saccharomyces cerevisiae). We used cells lacking the mitochondrial glutaredoxin Grx5 to demonstrate that oxidant-induced cleavage formation in 25S rRNA correlates with intracellular iron levels. Sequestering free iron by chemical or genetic means decreased the extent of rRNA degradation and relieved the hypersensitivity of grx5Δ cells to the oxidants. Importantly, subjecting purified ribosomes to an in vitro iron/ascorbate …

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 …

Snf1 Cooperates With The Cwi Mapk Pathway To Mediate The Degradation Of Med13 Following Oxidative Stress, Stephen D Willis, David C Stieg, Kai Li Ong, Ravina Shah, Alexandra K. Strich, Julianne H Grose, Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Eukaryotic cells, when faced with unfavorable environmental conditions, mount either pro-survival or pro-death programs. The conserved cyclin C-Cdk8 kinase plays a key role in this decision. Both are members of the Cdk8 kinase module that, along with Med12 and Med13, associate with the core Mediator complex of RNA polymerase II. In Saccharomyces cerevisiae, oxidative stress triggers Med13 destruction, which releases cyclin C into the cytoplasm to promote mitochondrial fission and programmed cell death. The SCFGrr1 ubiquitin ligase mediates Med13 degradation dependent on the cell wall integrity pathway, MAPK Slt2. Here we show that the AMP kinase Snf1 activates a second …

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 …

Acetic Acid Induces Sch9p-Dependent Translocation Of Isc1p From The Endoplasmic Reticulum Into Mitochondria, António Rego, Katrina F Cooper, Justin Snider, Yusuf A Hannun, Vítor Costa, Manuela Côrte-Real, Susana R Chaves

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Changes in sphingolipid metabolism have been linked to modulation of cell fate in both yeast and mammalian cells. We previously assessed the role of sphingolipids in cell death regulation using a well characterized yeast model of acetic acid-induced regulated cell death, finding that Isc1p, inositol phosphosphingolipid phospholipase C, plays a pro-death role in this process. Indeed, isc1∆ mutants exhibited a higher resistance to acetic acid associated with reduced mitochondrial alterations. Here, we show that Isc1p is regulated by Sch9p under acetic acid stress, since both single and double mutants lacking Isc1p or/and Sch9p have the same resistant phenotype, and SCH9 …