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Full-Text Articles in Life Sciences

A Persistence Detector For Metabolic Network Rewiring In An Animal, Jote T. Bulcha, Gabrielle E. Giese, Zulfikar Ali, Yong-Uk Lee, Melissa D. Walker, Amy D. Holdorf, L. Safak Yilmaz, Robert C. Brewster, Albertha J. M. Walhout Jan 2019

A Persistence Detector For Metabolic Network Rewiring In An Animal, Jote T. Bulcha, Gabrielle E. Giese, Zulfikar Ali, Yong-Uk Lee, Melissa D. Walker, Amy D. Holdorf, L. Safak Yilmaz, Robert C. Brewster, Albertha J. M. Walhout

Open Access Articles

Biological systems must possess mechanisms that prevent inappropriate responses to spurious environmental inputs. Caenorhabditis elegans has two breakdown pathways for the short-chain fatty acid propionate: a canonical, vitamin B12-dependent pathway and a propionate shunt that is used when vitamin B12 levels are low. The shunt pathway is kept off when there is sufficient flux through the canonical pathway, likely to avoid generating shunt-specific toxic intermediates. Here, we discovered a transcriptional regulatory circuit that activates shunt gene expression upon propionate buildup. Nuclear hormone receptor 10 (NHR-10) and NHR-68 function together as a "persistence detector" in a type 1, coherent feed-forward loop ...


The Caenorhabditis Elegans Oxidative Stress Response Requires The Nhr-49 Transcription Factor, Queenie Hu, Dayana R. D'Amora, Lesley T. Macneil, Albertha J. M. Walhout, Terrance J. Kubiseski Dec 2018

The Caenorhabditis Elegans Oxidative Stress Response Requires The Nhr-49 Transcription Factor, Queenie Hu, Dayana R. D'Amora, Lesley T. Macneil, Albertha J. M. Walhout, Terrance J. Kubiseski

Open Access Articles

The overproduction of reactive oxygen species (ROS) in cells can lead to the development of diseases associated with aging. We have previously shown that C. elegans BRAP-2 (Brca1 associated binding protein 2) regulates phase II detoxification genes such as gst-4, by increasing SKN-1 activity. Previously, a transcription factor (TF) RNAi screen was conducted to identify potential activators that are required to induce gst-4 expression in brap-2(ok1492) mutants. The lipid metabolism regulator NHR-49/HNF4 was among 18 TFs identified. Here, we show that knockdown of nhr-49 suppresses the activation of gst-4 caused by brap-2 inactivation and that gain-of-function alleles of ...


A Persistence Detector For Metabolic Network Rewiring In An Animal, Jote T. Bulcha, Gabrielle E. Giese, Zulfikar Ali, Yong-Uk Lee, Melissa D. Walker, Amy D. Holdorf, L. Safak Yilmaz, Robert C. Brewster, Albertha J. M. Walhout Aug 2018

A Persistence Detector For Metabolic Network Rewiring In An Animal, Jote T. Bulcha, Gabrielle E. Giese, Zulfikar Ali, Yong-Uk Lee, Melissa D. Walker, Amy D. Holdorf, L. Safak Yilmaz, Robert C. Brewster, Albertha J. M. Walhout

University of Massachusetts Medical School Faculty Publications

Persistence detection is a mechanism that ensures a physiological output is only executed when the relevant input is sustained. Gene regulatory network circuits known as coherent type 1 feed forward loops (FFLs) with an AND-logic gate have been proposed to generate persistence detection. In such circuits two transcription factors (TFs) are both required to activate target genes and one of the two TFs activates the other. While numerous FFLs have been identified, examples of actual persistence detectors have only been described for bacteria. Here, we discover a transcriptional persistence detector in Caenorhabditis elegans involving the nuclear hormone receptors nhr-10 and ...


Efn-4 Functions In Lad-2-Mediated Axon Guidance In Caenorhabditis Elegans, Alicia A. Schwieterman, Cory J. Donelson, Jonathan L. Mcmurry, Martin L. Hudson Mar 2017

Efn-4 Functions In Lad-2-Mediated Axon Guidance In Caenorhabditis Elegans, Alicia A. Schwieterman, Cory J. Donelson, Jonathan L. Mcmurry, Martin L. Hudson

Jonathan McMurry

During development of the nervous system, growing axons rely on guidance molecules to direct axon pathfinding. A well-characterized family of guidance molecules are the membrane-associated ephrins, which together with their cognate Eph receptors, direct axon navigation in a contact-mediated fashion. InC. elegans, the ephrin-Eph signaling system is conserved and is best characterized for their roles in neuroblast migration during early embryogenesis. This study demonstrates a role for theC. elegansephrin EFN-4 in axon guidance. We provide both genetic and biochemical evidence that is consistent with theC. elegansdivergent L1 cell adhesion molecule LAD-2 acting as a non-canonical ephrin receptor to EFN-4 to ...


Hlh-30/Tfeb-Mediated Autophagy Functions In A Cell-Autonomous Manner For Epithelium Intrinsic Cellular Defense Against Bacterial Pore-Forming Toxin In C. Elegans, Huan-Da Chen, Raffi V. Aroian, Chang-Shi Chen Feb 2017

Hlh-30/Tfeb-Mediated Autophagy Functions In A Cell-Autonomous Manner For Epithelium Intrinsic Cellular Defense Against Bacterial Pore-Forming Toxin In C. Elegans, Huan-Da Chen, Raffi V. Aroian, Chang-Shi Chen

Open Access Articles

Autophagy is an evolutionarily conserved intracellular system that maintains cellular homeostasis by degrading and recycling damaged cellular components. The transcription factor HLH-30/TFEB-mediated autophagy has been reported to regulate tolerance to bacterial infection, but less is known about the bona fide bacterial effector that activates HLH-30 and autophagy. Here, we reveal that bacterial membrane pore-forming toxin (PFT) induces autophagy in an HLH-30-dependent manner in Caenorhabditis elegans. Moreover, autophagy controls the susceptibility of animals to PFT toxicity through xenophagic degradation of PFT and repair of membrane-pore cell-autonomously in the PFT-targeted intestinal cells in C. elegans. These results demonstrate that autophagic pathways ...


A Gene-Centered C. Elegans Protein-Dna Interaction Network Provides A Framework For Functional Predictions, Juan Fuxman Bass, Carles Pons, Lucie Kozlowski, John S. Reece-Hoyes, Shaleen Shrestha, Amy D. Holdorf, Akihiro Mori, Chad L. Myers, Albertha J. M. Walhout Oct 2016

A Gene-Centered C. Elegans Protein-Dna Interaction Network Provides A Framework For Functional Predictions, Juan Fuxman Bass, Carles Pons, Lucie Kozlowski, John S. Reece-Hoyes, Shaleen Shrestha, Amy D. Holdorf, Akihiro Mori, Chad L. Myers, Albertha J. M. Walhout

Open Access Articles

Transcription factors (TFs) play a central role in controlling spatiotemporal gene expression and the response to environmental cues. A comprehensive understanding of gene regulation requires integrating physical protein-DNA interactions (PDIs) with TF regulatory activity, expression patterns, and phenotypic data. Although great progress has been made in mapping PDIs using chromatin immunoprecipitation, these studies have only characterized ~10% of TFs in any metazoan species. The nematode C. elegans has been widely used to study gene regulation due to its compact genome with short regulatory sequences. Here, we delineated the largest gene-centered metazoan PDI network to date by examining interactions between 90 ...


The Thioredoxin Trx-1 Regulates The Major Oxidative Stress Response Transcription Factor, Skn-1, In Caenorhabditis Elegans, Katie C. Mccallum May 2016

The Thioredoxin Trx-1 Regulates The Major Oxidative Stress Response Transcription Factor, Skn-1, In Caenorhabditis Elegans, Katie C. Mccallum

UT GSBS Dissertations and Theses (Open Access)

The ability to respond to hostile environmental conditions is critical for the survival of an organism. Oxidative stress is an adverse state in which reactive oxygen species (ROS) accumulate to a harmful level and, if left unresolved, can lead to cellular dysfunction and organismal disease. Sophisticated detoxification systems, characterized by a battery of enzymatic antioxidants, are utilized to neutralize ROS thereby reducing stress. However, ROS are also purposefully produced by designated cellular enzymes to facilitate the signaling and regulation of critical physiological processes. Therefore, both the production and neutralization of ROS must be tightly controlled. Indeed, the expression of detoxification ...


Efn-4 Functions In Lad-2-Mediated Axon Guidance In Caenorhabditis Elegans, Alicia A. Schwieterman, Cory J. Donelson, Jonathan L. Mcmurry, Martin L. Hudson Feb 2016

Efn-4 Functions In Lad-2-Mediated Axon Guidance In Caenorhabditis Elegans, Alicia A. Schwieterman, Cory J. Donelson, Jonathan L. Mcmurry, Martin L. Hudson

Faculty Publications

During development of the nervous system, growing axons rely on guidance molecules to direct axon pathfinding. A well-characterized family of guidance molecules are the membrane-associated ephrins, which together with their cognate Eph receptors, direct axon navigation in a contact-mediated fashion. InC. elegans, the ephrin-Eph signaling system is conserved and is best characterized for their roles in neuroblast migration during early embryogenesis. This study demonstrates a role for theC. elegansephrin EFN-4 in axon guidance. We provide both genetic and biochemical evidence that is consistent with theC. elegansdivergent L1 cell adhesion molecule LAD-2 acting as a non-canonical ephrin receptor to EFN-4 to ...


Using C. Elegans For Aging Research, Heidi A. Tissenbaum Jan 2015

Using C. Elegans For Aging Research, Heidi A. Tissenbaum

Molecular, Cell and Cancer Biology Publications

Over a century ago, the zoologist Emile Maupas first identified the nematode, Rhabditis elegans, in the soil in Algiers. Subsequent work and phylogenic studies renamed the species Caenorhabditis elegans or more commonly referred to as C. elegans; (Caeno meaning recent; rhabditis meaning rod; elegans meaning nice). However, it was not until 1963, when Sydney Brenner, already successful from his work on DNA, RNA, and the genetic code, suggested the future of biological research lay in model organisms. Brenner believed that biological research required a model system that could grow in vast quantities in the lab, were cheap to maintain and ...


Transcriptional Regulation Of Caenorhabditis Elegans Foxo/Daf-16 Modulates Lifespan, Ankita Bansal, Eun-Soo Kwon, Darryl Conte Jr., Haibo Liu, Michael J. Gilchrist, Lesley T. Macneil, Heidi A. Tissenbaum Apr 2014

Transcriptional Regulation Of Caenorhabditis Elegans Foxo/Daf-16 Modulates Lifespan, Ankita Bansal, Eun-Soo Kwon, Darryl Conte Jr., Haibo Liu, Michael J. Gilchrist, Lesley T. Macneil, Heidi A. Tissenbaum

Program in Gene Function and Expression Publications

BACKGROUND: Insulin/IGF-1 signaling plays a central role in longevity across phylogeny. In C. elegans, the forkhead box O (FOXO) transcription factor, DAF-16, is the primary target of insulin/IGF-1 signaling, and multiple isoforms of DAF-16 (a, b, and d/f) modulate lifespan, metabolism, dauer formation, and stress resistance. Thus far, across phylogeny modulation of mammalian FOXOs and DAF-16 have focused on post-translational regulation with little focus on transcriptional regulation. In C. elegans, we have previously shown that DAF-16d/f cooperates with DAF-16a to promote longevity. In this study, we generated transgenic strains expressing near-endogenous levels of either daf-16a or ...