Medicine and Health Sciences Commons^™

Lysosome-Related Organelles Contain An Expansion Compartment That Mediates Delivery Of Zinc Transporters To Promote Homeostasis, Adelita D Mendoza, Nicholas Dietrich, Chieh-Hsiang Tan, Daniel Herrera, Jennysue Kasiah, Zachary Payne, Ciro Cubillas, Daniel L Schneider, Kerry Kornfeld

2020-Current year OA Pubs

Zinc is an essential nutrient-it is stored during periods of excess to promote detoxification and released during periods of deficiency to sustain function. Lysosome-related organelles (LROs) are an evolutionarily conserved site of zinc storage, but mechanisms that control the directional zinc flow necessary for homeostasis are not well understood. In

Fused In Sarcoma Regulates Glutamate Signaling And Oxidative Stress Response, Chiong-Hee Wong, Abu Rahat, Howard C Chang

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Mutations in fused in sarcoma (fust-1) are linked to ALS. However, how these ALS causative mutations alter physiological processes and lead to the onset of ALS remains largely unknown. By obtaining humanized fust-1 ALS mutations via CRISPR-CAS9, we generated a C. elegans ALS model. Homozygous fust-1 ALS mutant and fust-1 deletion animals are viable in C. elegans. This allows us to better characterize the molecular mechanisms of fust-1-dependent responses. We found FUST-1 plays a role in regulating superoxide dismutase, glutamate signaling, and oxidative stress. FUST-1 suppresses SOD-1 and VGLUT/EAT-4 in the nervous system. FUST-1 also regulates synaptic AMPA-type glutamate receptor …

Dominant Negative Variants In Kif5b Cause Osteogenesis Imperfecta Via Down Regulation Of Mtor Signaling, Ronit Marom, Anika Lindsey, Jacob Lesinski, Michael L. Nonet, Jian Chen, Dustin Baldridge, Gary A. Silverman, Stephen C. Pak, Et Al.

2020-Current year OA Pubs

BACKGROUND: Kinesin motor proteins transport intracellular cargo, including mRNA, proteins, and organelles. Pathogenic variants in kinesin-related genes have been implicated in neurodevelopmental disorders and skeletal dysplasias. We identified de novo, heterozygous variants in KIF5B, encoding a kinesin-1 subunit, in four individuals with osteogenesis imperfecta. The variants cluster within the highly conserved kinesin motor domain and are predicted to interfere with nucleotide binding, although the mechanistic consequences on cell signaling and function are unknown.

METHODS: To understand the in vivo genetic mechanism of KIF5B variants, we modeled the p.Thr87Ile variant that was found in two patients in the C. elegans ortholog, …

Macrocephaly And Developmental Delay Caused By Missense Variants In Rab5c, Klaas Koop, Weimin Yuan, Bo Zhang, Zachary D Dawson, Anika Lindsey, Huiyan Huang, Dustin Baldridge, Gary A Silverman, Stephen C Pak, Tim Schedl, Et Al.

2020-Current year OA Pubs

Rab GTPases are important regulators of intracellular vesicular trafficking. RAB5C is a member of the Rab GTPase family that plays an important role in the endocytic pathway, membrane protein recycling and signaling. Here we report on 12 individuals with nine different heterozygous de novo variants in RAB5C. All but one patient with missense variants (n = 9) exhibited macrocephaly, combined with mild-to-moderate developmental delay. Patients with loss of function variants (n = 2) had an apparently more severe clinical phenotype with refractory epilepsy and intellectual disability but a normal head circumference. Four missense variants were investigated experimentally. In vitro biochemical …

18s Rrna Methyltransferases Dimt1 And Bud23 Drive Intergenerational Hormesis, Noa Liberman, Eric Lieberman Greer, Et Al.

2020-Current year OA Pubs

Heritable non-genetic information can regulate a variety of complex phenotypes. However, what specific non-genetic cues are transmitted from parents to their descendants are poorly understood. Here, we perform metabolic methyl-labeling experiments to track the heritable transmission of methylation from ancestors to their descendants in the nematode Caenorhabditis elegans (C. elegans). We find heritable methylation in DNA, RNA, proteins, and lipids. We find that parental starvation elicits reduced fertility, increased heat stress resistance, and extended longevity in fed, naïve progeny. This intergenerational hormesis is accompanied by a heritable increase in N6'-dimethyl adenosine (m

Invited Review: Adrenocortical Function In Avian And Non-Avian Reptiles: Insights From Dispersed Adrenocortical Cells., Rocco V. Carsia, Patrick J. Mcilroy, Henry B John-Alder

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Herein we review our work involving dispersed adrenocortical cells from several lizard species: the Eastern Fence Lizard (Sceloporus undulatus), Yarrow's Spiny Lizard (Sceloporus jarrovii), Striped Plateau Lizard (Sceloporus virgatus) and the Yucatán Banded Gecko (Coleonyx elegans). Early work demonstrated changes in steroidogenic function of adrenocortical cells derived from adult S. undulatus associated with seasonal interactions with sex. However, new information suggests that both sexes operate within the same steroidogenic budget over season. The observed sex effect was further explored in orchiectomized and ovariectomized lizards, some supported with exogenous testosterone. Overall, a suppressive effect of testosterone was evident, especially in cells …

G Protein-Coupled Receptor Kinase-2 (Grk-2) Controls Exploration Through Neuropeptide Signaling In Caenorhabditis Elegans, Kristen Davis, Christo Mitchell, Olivia Weissenfels, Jihong Bai, David M. Raizen, Michael Ailion, Irini Topalidou

Department of Neuroscience Faculty Papers

Animals alter their behavior in manners that depend on environmental conditions as well as their developmental and metabolic states. For example, C. elegans is quiescent during larval molts or during conditions of satiety. By contrast, worms enter an exploration state when removed from food. Sensory perception influences movement quiescence (defined as a lack of body movement), as well as the expression of additional locomotor states in C. elegans that are associated with increased or reduced locomotion activity, such as roaming (exploration behavior) and dwelling (local search). Here we find that movement quiescence is enhanced, and exploration behavior is reduced in …

Trim-Nhl Protein, Nhl-2, Modulates Cell Fate Choices In The C. Elegans Germ Line, John L. Brenner, Erin M. Jyo, Ariz Mohammad, Paul Fox, Vovanti Jones, Elaine Mardis, Tim Schedl, Eleanor M. Maine

2020-Current year OA Pubs

Many tissues contain multipotent stem cells that are critical for maintaining tissue function. In Caenorhabditis elegans, germline stem cells allow gamete production to continue in adulthood. In the gonad, GLP-1/Notch signaling from the distal tip cell niche to neighboring germ cells activates a complex regulatory network to maintain a stem cell population. GLP-1/Notch signaling positively regulates production of LST-1 and SYGL-1 proteins that, in turn, interact with a set of PUF/FBF proteins to positively regulate the stem cell fate. We previously described sog (suppressor of glp-1 loss of function) and teg (tumorous enhancer of glp-1 gain of function) genes that …

Innexin Function Dictates The Spatial Relationship Between Distal Somatic Cells In The Caenorhabditis Elegans Gonad Without Impacting The Germline Stem Cell Pool, Theadora Tolkin, Ariz Mohammad, Todd A Starich, Ken C Q Nguyen, David H Hall, Tim Schedl, E Jane Albert Hubbard, David Greenstein

2020-Current year OA Pubs

Gap-junctional signaling mediates myriad cellular interactions in metazoans. Yet, how gap junctions control the positioning of cells in organs is not well understood. Innexins compose gap junctions in invertebrates and affect organ architecture. Here, we investigate the roles of gap-junctions in controlling distal somatic gonad architecture and its relationship to underlying germline stem cells in

Dual Mechanisms Implemented By Lin-28 For Positive Regulation Of Hbl-1 Are Necessary For Proper Development Of Distinct Tissues In Caenorhabditis Elegans, Madeleine Minutillo

Graduate School of Biomedical Sciences Theses and Dissertations

In Caenorhabditis elegans, the heterochronic pathway is comprised of a hierarchy of genes that control the proper timing of developmental events. hbl-1 (Hunchback Like-1) encodes an Ikaros family zinc-finger transcription factor that promotes the L2 stage cell fate events of the hypodermis. The downregulation ofhbl-1 is a crucial step for the transition from the L2 to the L3 stage. There are two known processes through which negative regulation of hbl-1 occurs: suppression of hbl-1 expression by 3 let-7 miRNAs through the hbl-1 3’UTR and inhibition of HBL-1 activity by LIN-46. The mechanisms by which hbl-1 is positively regulated have not …

Conservation And Divergence In The Heterochronic Pathway Of C. Elegans And C. Briggsae, Maria Ivanova, Eric G. Moss

Rowan-Virtua Research Day

The heterochronic pathway of Caenorhabditis elegans is exemplary as a mechanism of developmental timing: mutations in genes of this pathway alter the relative timing of diverse developmental events independent of spatial or cell type specific regulation. It is the most thoroughly characterized developmental timing pathway known. Most of the heterochronic genes are conserved across great evolutionary time, and a few homologs seem to have developmental timing roles in certain contexts. The degree to which other organisms have explicit developmental timing mechanisms, and what factors comprise those mechanisms, isn’t generally known.

Developmental pathways evolve even if the resulting morphology remains the …

Functional Analysis Of A Novel De Novo Variant In Ppp5c Associated With Microcephaly, Seizures, And Developmental Delay, Sara M Fielder, Jill A Rosenfeld, Lindsay C Burrage, Lisa Emrick, Seema Lalani, Ruben Attali, Joshua N Bembenek, Hieu Hoang, Dustin Baldridge, Gary A Silverman, Undiagnosed Diseases Network, Tim Schedl, Stephen C Pak

2020-Current year OA Pubs

We describe a proband evaluated through the Undiagnosed Diseases Network (UDN) who presented with microcephaly, developmental delay, and refractory epilepsy with a de novo p.Ala47Thr missense variant in the protein phosphatase gene, PPP5C. This gene has not previously been associated with a Mendelian disease, and based on the population database, gnomAD, the gene has a low tolerance for loss-of-function variants (pLI = 1, o/e = 0.07). We functionally evaluated the PPP5C variant in C. elegans by knocking the variant into the orthologous gene, pph-5, at the corresponding residue, Ala48Thr. We employed assays in three different biological processes where pph-5 was …

Harmonizing Model Organism Data In The Alliance Of Genome Resources., Alliance Of Genome Resources Consortium, Anna V. Anagnostopoulos, Susan M. Bello, Judith A. Blake, Olin Blodgett, Carol J. Bult, Karen R. Christie, Mary E. Dolan, Paul Hale, James A. Kadin, Monica S. Mcandrews, Howie Motenko, David R. Shaw, Constance M. Smith, Cynthia L. Smith, Monika Tomczuk, Laurens G. Wilming

Faculty Research 2022

The Alliance of Genome Resources (the Alliance) is a combined effort of 7 knowledgebase projects: Saccharomyces Genome Database, WormBase, FlyBase, Mouse Genome Database, the Zebrafish Information Network, Rat Genome Database, and the Gene Ontology Resource. The Alliance seeks to provide several benefits: better service to the various communities served by these projects; a harmonized view of data for all biomedical researchers, bioinformaticians, clinicians, and students; and a more sustainable infrastructure. The Alliance has harmonized cross-organism data to provide useful comparative views of gene function, gene expression, and human disease relevance. The basis of the comparative views is shared calls of …

High-Throughput Methodology To Identify Crispr-Generated Danio Rerio Mutants Using Fragment Analysis With Unmodified Pcr Products, Sarah Colijn, Ying Yin, Amber N Stratman

2020-Current year OA Pubs

Targeted mutagenesis in zebrafish, fruit flies, and C. elegans has been significantly improved over the years through CRISPR technology. CRISPR enables researchers to efficiently examine cellular pathways by inducing small, targeted mutations in vivo. Though these mutations are commonly random insertions or deletions (indels), they often result in functionally disrupted alleles of a target gene if the CRISPR components are appropriately designed. However, current protocols used to identify the presence of CRISPR-generated indels are often labor intensive, time-consuming, or expensive. Here, we describe a straightforward, high-throughput method for identifying the presence of mutations by using a fragment analyzer platform which …

Ascaris Suum Informs Extrasynaptic Volume Transmission In Nematodes, Louise E Atkinson, Yang Liu, Fiona Mckay, Elke Vandewyer, Charles Viau, Allister Irvine, Bruce A Rosa, Zihui Li, Qingxiao Liang, Nikki J Marks, Aaron G Maule, Makedonka Mitreva, Isabel Beets, Lingjun Li, Angela Mousley

2020-Current year OA Pubs

Neural circuit synaptic connectivities (the connectome) provide the anatomical foundation for our understanding of nematode nervous system function. However, other nonsynaptic routes of communication are known in invertebrates including extrasynaptic volume transmission (EVT), which enables short- and/or long-range communication in the absence of synaptic connections. Although EVT has been highlighted as a facet of

Vitamin B12 Deficiency Does Not Stimulate Amyloid-Beta Toxicity In A Ceanorhabditis Elegans Model Of Alzheimer’S Disease, Opeyemi F. Showemimo

Electronic Theses and Dissertations

Alzheimer’s disease (AD) is symptomized by amyloid-beta plaques in the brain and accounts for more than 65 percent of dementia cases. Vitamin B12 (cobalamin) deficiency can result in similar cognitive impairment and roughly 15% of the elderly are vitamin B12 deficient. Vitamin B12 deficiency results in the accumulation of toxic methylmalonic acid and homocysteine. Hyperhomocysteinemia is a strong risk factor for AD. To test if vitamin B12 deficiency stimulates amyloid-beta toxicity, Caenorhabditis elegans expressing amyloid-beta in muscle were fed either vitamin B12-deficient OP50-1 or vitamin B12-rich HT115(DE3) E. coli bacteria. Increased amyloid-beta toxicity was found in worms fed the …

The Gene Ontology Resource: Enriching A Gold Mine., Gene Ontology Consortium, Judith A. Blake, Mary E. Dolan, Harold J. Drabkin, David P. Hill

Faculty Research 2021

The Gene Ontology Consortium (GOC) provides the most comprehensive resource currently available for computable knowledge regarding the functions of genes and gene products. Here, we report the advances of the consortium over the past two years. The new GO-CAM annotation framework was notably improved, and we formalized the model with a computational schema to check and validate the rapidly increasing repository of 2838 GO-CAMs. In addition, we describe the impacts of several collaborations to refine GO and report a 10% increase in the number of GO annotations, a 25% increase in annotated gene products, and over 9,400 new scientific articles …

Exploring The Mechanism Of Cleavage And Secretion Of The Major Sperm Protein (Msp) Domain Of The Vapb/Vpr-1 Protein, Hala Zein-Sabatto

All ETDs from UAB

VAPB is one of three mammalian VAP proteins. It is a type-II ER transmembrane protein whose N-terminal major sperm protein domain (MSPd) is cleaved and secreted. Since the MSPd faces the cytosol, rather than the ER lumen, how it is cleaved and secreted is not yet known. In humans, P56S is a substitution mutation within the VAPB protein that segregates with cases of familial Amyotrophic Lateral Sclerosis (ALS) and prevents the secretion of VAPB MSPd. The work described in this thesis uses C. elegans to study how the N-terminal MSPd of VAPB is proteolytically processed, secreted, and regulated. C. elegans …

Behavioral Responses To Gold Nanoparticle Exposure And H2o2-Induced Oxidative Stress In Caenorhabditis Elegans, Rachel Pride, Ashley Wagner

DePaul Discoveries

Gold nanoparticles (AuNPs) have been utilized in many biomedical disciplines, most notably cancer therapy and drug delivery. Recent research suggests that with specific peptide manipulation, AuNPs can deliver drugs across the blood-brain barrier (BBB), allowing for treatment of neurodegeneration and other neurological afflictions. Neurodegeneration has been shown to be caused by oxidative stress. The present experiment aimed to assess the effects of AuNPs on C. elegans behavior that had undergone H₂O₂-induced oxidative stress. It was predicted that worms exposed to both H₂O₂ and AuNPs would have higher survival, mechanosensation, and thrashing rates than …

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 …

A Role Of Vitamin B2 In Reducing Amyloid-Beta Toxicity In A Caenorhabditis Elegans Alzheimer’S Disease Model, Muhammad Tukur Ameen

Electronic Theses and Dissertations

Alzheimer’s disease (AD) is associated with amyloid-beta peptide deposition and loss of mitochondrial function. Using a transgenic C. elegans AD worm model expressing amyloid-beta in body wall muscle, we determined that supplementation with either of the forms of vitamin B₂, flavin mononucleotide (FMN) or flavin adenine dinucleotide (FAD) protected against amyloid-beta mediated paralysis. FMN and FAD were then assayed to determine effects on ATP, oxygen consumption, and reactive oxygen species (ROS) with these compounds not significantly improving any of these mitochondrial bioenergetic functions. Knockdown of the daf-16/FOXO transcriptional regulator or the FAD synthase enzyme completely abrogated the …

Cerium Oxide Nanoparticle Aggregates Affect Stress Response And Function In Caenorhabditis Elegans, Steven Rogers, Kevin M. Rice, Nandini Manne, Tolou Shokuhfar, Kun He, Vellaisamy Selvaraj, Eric Blough

Eric Blough

Objective: The continual increase in production and disposal of nanomaterials raises concerns regarding the safety of nanoparticles on the environmental and human health. Recent studies suggest that cerium oxide (CeO2) nanoparticles may possess both harmful and beneficial effects on biological processes. The primary objective of this study is to evaluate how exposure to different concentrations (0.17–17.21 µg/mL) of aggregated CeO2 nanoparticles affects indices of whole animal stress and survivability in Caenorhabditis elegans.

Methods: Caenorhabditis elegans were exposed to different concentrations of CeO2 nanoparticles and evaluated.

Results: Our findings demonstrate that chronic exposure of CeO2 nanoparticle aggregates is …

Cerium Oxide Nanoparticle Aggregates Affect Stress Response And Function In Caenorhabditis Elegans, Steven Rogers, Kevin M. Rice, Nandini Manne, Tolou Shokuhfar, Kun He, Vellaisamy Selvaraj, Eric Blough

Nandini Manne

Objective: The continual increase in production and disposal of nanomaterials raises concerns regarding the safety of nanoparticles on the environmental and human health. Recent studies suggest that cerium oxide (CeO2) nanoparticles may possess both harmful and beneficial effects on biological processes. The primary objective of this study is to evaluate how exposure to different concentrations (0.17–17.21 µg/mL) of aggregated CeO2 nanoparticles affects indices of whole animal stress and survivability in Caenorhabditis elegans.

Methods: Caenorhabditis elegans were exposed to different concentrations of CeO2 nanoparticles and evaluated.

Results: Our findings demonstrate that chronic exposure of CeO2 nanoparticle aggregates is …

Cerium Oxide Nanoparticle Aggregates Affect Stress Response And Function In Caenorhabditis Elegans, Steven Rogers, Kevin M. Rice, Nandini Manne, Tolou Shokuhfar, Kun He, Vellaisamy Selvaraj, Eric Blough

Kevin M Rice

Objective: The continual increase in production and disposal of nanomaterials raises concerns regarding the safety of nanoparticles on the environmental and human health. Recent studies suggest that cerium oxide (CeO2) nanoparticles may possess both harmful and beneficial effects on biological processes. The primary objective of this study is to evaluate how exposure to different concentrations (0.17–17.21 µg/mL) of aggregated CeO2 nanoparticles affects indices of whole animal stress and survivability in Caenorhabditis elegans.

Methods: Caenorhabditis elegans were exposed to different concentrations of CeO2 nanoparticles and evaluated.

Results: Our findings demonstrate that chronic exposure of CeO2 nanoparticle aggregates is …

Caenorhabditis Elegans Dbl-1/Bmp Regulates Lipid Accumulation Via Interaction With Insulin Signaling, James F. Clark, Michael Meade, Gehan Ranepura, David H. Hall, Cathy Savage-Dunn

Publications and Research

Metabolic homeostasis is coordinately controlled by diverse inputs. Understanding these regulatory networks is vital to combating metabolic disorders. The nematode Caenorhabditis elegans has emerged as a powerful, genetically tractable model system for the discovery of lipid regulatory mechanisms. Here we introduce DBL-1, the C. elegans homolog of bone morphogenetic protein 2/4 (BMP2/4), as a significant regulator of lipid homeostasis. We used neutral lipid staining and a lipid droplet marker to demonstrate that both increases and decreases in DBL-1/BMP signaling result in reduced lipid stores and lipid droplet count. We find that lipid droplet size, however, correlates positively with the level …

Systems Biology Approach To Late-Onset Alzheimer's Disease Genome-Wide Association Study Identifies Novel Candidate Genes Validated Using Brain Expression Data And Caenorhabditis Elegans Experiments, Shubhabrata Mukherjee, Joshua C. Russell, Daniel T. Carr, Jeremy D. Burgess, Mariet Allen, Daniel J. Serie, Kevin L. Boehme, John S. K. Kauwe, Adam C. Naj, David W. Fardo, Dennis W. Dickson, Thomas J. Montine, Nilufer Ertekin-Taner, Matt R. Kaeberlein, Paul K. Crane

Biostatistics Faculty Publications

Introduction—We sought to determine whether a systems biology approach may identify novel late-onset Alzheimer's disease (LOAD) loci.

Methods—We performed gene-wide association analyses and integrated results with human protein-protein interaction data using network analyses. We performed functional validation on novel genes using a transgenic Caenorhabditis elegans Aβ proteotoxicity model and evaluated novel genes using brain expression data from people with LOAD and other neurodegenerative conditions.

Results—We identified 13 novel candidate LOAD genes outside chromosome 19. Of those, RNA interference knockdowns of the C. elegans orthologs of UBC, NDUFS3, EGR1, and ATP5H were associated with Aβ …

Investigating The Role Of The Host Multidrug Resistance Associated Protein Transporter Family In Burkholderia Cepacia Complex Pathogenicity Using A Caenorhabditis Elegans Infection Model, Pietro Tedesco, Marco Visone, Ermenegilda Parrilli, Maria Luisa Tutino, Elena Perrin, Isabel Maida, Renato Fani, Francesco Ballestriero, Radleigh Santos, Clemencia Pinilla, Elia Di Schiavi, George Tegos, Donatella De Pascale

Mathematics Faculty Articles

This study investigated the relationship between host efflux system of the non-vertebrate nematode Caenorhabditis elegans and Burkholderia cepacia complex (Bcc) strain virulence. This is the first comprehensive effort to profile host-transporters within the context of Bcc infection. With this aim, two different toxicity tests were performed: a slow killing assay that monitors mortality of the host by intestinal colonization and a fast killing assay that assesses production of toxins. A Virulence Ranking scheme was defined, that expressed the toxicity of the Bcc panel members, based on the percentage of surviving worms. According to this ranking the 18 Bcc strains were …

Genome-Scale Spatiotemporal Analysis Of Caenorhabditis Elegans Microrna Promoter Activity, Natalia Julia Martinez, Maria C. Ow, John S. Reece-Hoyes, M. Inmaculada Barrasa, Victor R. Ambros, Albertha J. M. Walhout

Victor R. Ambros

The Caenorhabditis elegans genome encodes more than 100 microRNAs (miRNAs). Genetic analyses of miRNA deletion mutants have only provided limited insights into miRNA function. To gain insight into the function of miRNAs, it is important to determine their spatiotemporal expression pattern. Here, we use miRNA promoters driving the expression of GFP as a proxy for miRNA expression. We describe a set of 73 transgenic C. elegans strains, each expressing GFP under the control of a miRNA promoter. Together, these promoters control the expression of 89 miRNAs (66% of all predicted miRNAs). We find that miRNA promoters drive GFP expression in …

Nhl-2 Modulates Microrna Activity In Caenorhabditis Elegans, Christopher Hammell, Isabella Lubin, Peter Boag, T. Keith Blackwell, Victor Ambros

Victor R. Ambros

TRIM-NHL proteins represent a large class of metazoan proteins implicated in development and disease. We demonstrate that a C. elegans TRIM-NHL protein, NHL-2, functions as a cofactor for the microRNA-induced silencing complex (miRISC) and thereby enhances the posttranscriptional repression of several genetically verified microRNA targets, including hbl-1 and let-60/Ras (by the let-7 family of microRNAs) and cog-1 (by the lsy-6 microRNA). NHL-2 is localized to cytoplasmic P-bodies and physically associates with the P-body protein CGH-1 and the core miRISC components ALG-1/2 and AIN-1. nhl-2 and cgh-1 mutations compromise the repression of microRNA targets in vivo but do not affect microRNA …

The Flywch Transcription Factors Flh-1, Flh-2, And Flh-3 Repress Embryonic Expression Of Microrna Genes In C. Elegans, Maria C. Ow, Natalia Julia Martinez, Philip H. Olsen, Howard S. Silverman, M. Inmaculada Barrasa, Barbara Conradt, Albertha J. M. Walhout, Victor R. Ambros

Victor R. Ambros

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression post-transcriptionally via antisense base-pairing. Although miRNAs are involved in a variety of important biological functions, little is known about their transcriptional regulation. Using yeast one-hybrid assays, we identified transcription factors with a FLYWCH Zn-finger DNA-binding domain that bind to the promoters of several Caenorhabditis elegans miRNA genes. The products of the flh-1 and flh-2 genes function redundantly to repress embryonic expression of lin-4, mir-48, and mir-241, miRNA genes that are normally expressed only post-embryonically. Although single mutations in either flh-1 or flh-2 genes result in a viable phenotype, double mutation …