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Articles 1 - 30 of 49

Full-Text Articles in Cell Biology

Arf Gtpases And Their Gefs And Gaps: Concepts And Challenges, Elizabeth Sztul, Pei-Wen Chen, James E. Casanova, Jacqueline Cherfils, Joel B. Dacks, David G. Lambright, Fang-Jen S. Lee, Paul A. Randazzo, Lorraine C. Santy, Annette Schurmann, Ilka Wilhelmi, Marielle E. Yohe, Richard A. Kahn May 2019

Arf Gtpases And Their Gefs And Gaps: Concepts And Challenges, Elizabeth Sztul, Pei-Wen Chen, James E. Casanova, Jacqueline Cherfils, Joel B. Dacks, David G. Lambright, Fang-Jen S. Lee, Paul A. Randazzo, Lorraine C. Santy, Annette Schurmann, Ilka Wilhelmi, Marielle E. Yohe, Richard A. Kahn

Program in Molecular Medicine Publications and Presentations

Detailed structural, biochemical, cell biological, and genetic studies of any gene/protein are required to develop models of its actions in cells. Studying a protein family in the aggregate yields additional information, as one can include analyses of their coevolution, acquisition or loss of functionalities, structural pliability, and the emergence of shared or variations in molecular mechanisms. An even richer understanding of cell biology can be achieved through evaluating functionally linked protein families. In this review, we summarize current knowledge of three protein families: the ARF GTPases, the guanine nucleotide exchange factors (ARF GEFs) that activate them, and the GTPase-activating ...


Manganese Influx And Expression Of Zip8 Is Essential In Primary Myoblasts And Contributes To Activation Of Sod2, Shellaina J. V. Gordon, Daniel E. Fenker, Katherine E. Vest, Teresita Padilla-Benavides Dec 2018

Manganese Influx And Expression Of Zip8 Is Essential In Primary Myoblasts And Contributes To Activation Of Sod2, Shellaina J. V. Gordon, Daniel E. Fenker, Katherine E. Vest, Teresita Padilla-Benavides

University of Massachusetts Medical School Faculty Publications

Trace elements such as copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn) are enzyme cofactors and second messengers in cell signaling. Trace elements are emerging as key regulators of differentiation and development of mammalian tissues including blood, brain, and skeletal muscle. We previously reported an influx of Cu and dynamic expression of various metal transporters during differentiation of skeletal muscle cells. Here, we demonstrate that during differentiation of skeletal myoblasts an increase of additional trace elements such as Mn, Fe and Zn occurs. Interestingly the Mn increase is concomitant with increased Mn-dependent SOD2 levels. To better understand the Mn ...


Basic Cell And Molecular Biology 3e: What We Know And How We Found Out, Gerald Bergtrom Sep 2018

Basic Cell And Molecular Biology 3e: What We Know And How We Found Out, Gerald Bergtrom

Cell and Molecular Biology 3e: What We Know and How We Found Out - All Versions

No abstract provided.


Llc Tumor Cells-Derivated Factors Reduces Adipogenesis In Co-Culture System, Magno Alves Lopes, Felipe Oliveira Franco, Felipe Henriques, Sidney Barnabe Peres, Miguel Luiz Batista Jr. Jul 2018

Llc Tumor Cells-Derivated Factors Reduces Adipogenesis In Co-Culture System, Magno Alves Lopes, Felipe Oliveira Franco, Felipe Henriques, Sidney Barnabe Peres, Miguel Luiz Batista Jr.

Open Access Articles

Cancer cachexia (CC) is a multifactorial syndrome with an unknown etiology. The primary symptom is the progressive reduction of the body weight. Recently, down-regulation of adipogenic and lipogenic genes were demonstrated to be early affected during cachexia progression in adipose tissue (AT), resulting in AT remodeling. Thus, this study aimed to evaluate in a co-culture system the influence of the Lewis Lung Carcinoma (LLC) tumor cells (c/c-LLC) in an established pre-adipocyte cell line 3T3-L1 adipogenic capacity. c/c-LLC in the presence of 3T3-L1 caused a reduction in lipids accumulation, suggesting that secretory tumor cells products may affect adipogenesis. Interestingly ...


Annotated Cell And Molecular Biology 3e: What We Know And How We Found Out, Gerald Bergtrom Jul 2018

Annotated Cell And Molecular Biology 3e: What We Know And How We Found Out, Gerald Bergtrom

Cell and Molecular Biology 3e: What We Know and How We Found Out - All Versions

No abstract provided.


Nuclear Export Through Nuclear Envelope Remodeling In Saccharomyces Cerevisiae, Baojin Ding, Anne M. Mirza, James A. Ashley, Vivian Budnik, Mary Munson Jun 2018

Nuclear Export Through Nuclear Envelope Remodeling In Saccharomyces Cerevisiae, Baojin Ding, Anne M. Mirza, James A. Ashley, Vivian Budnik, Mary Munson

University of Massachusetts Medical School Faculty Publications

In eukaryotes, subsets of exported mRNAs are organized into large ribonucleoprotein (megaRNP) granules. How megaRNPs exit the nucleus is unclear, as their diameters are much larger than the nuclear pore complex (NPC) central channel. We previously identified a non-canonical nuclear export mechanism in Drosophila (Speese et al., Cell 2012) and mammals (Ding et al., in preparation), in which megaRNPs exit the nucleus by budding across nuclear envelope (NE) membranes. Here, we present evidence for a similar pathway in the nucleus of the budding yeast S. cerevisiae, which contain morphologically similar granules bearing mRNAs. Wild-type yeast displayed these granules at very ...


Neuronal Modulation Of Brown Adipose Activity Through Perturbation Of White Adipocyte Lipogenesis, Adilson L. Guilherme, David J. Pedersen, Felipe Henriques, Alexander H. Bedard, Elizabeth Henchey, Mark Kelly, Kamal Rahmouni, Donald A. Morgan, Michael P. Czech May 2018

Neuronal Modulation Of Brown Adipose Activity Through Perturbation Of White Adipocyte Lipogenesis, Adilson L. Guilherme, David J. Pedersen, Felipe Henriques, Alexander H. Bedard, Elizabeth Henchey, Mark Kelly, Kamal Rahmouni, Donald A. Morgan, Michael P. Czech

University of Massachusetts Medical School Faculty Publications

White adipose tissue (WAT) secretes factors to communicate with other metabolic organs to maintain energy homeostasis. We previously reported that perturbation of adipocyte de novo lipogenesis (DNL) by deletion of fatty acid synthase (FASN) causes expansion of sympathetic neurons within white adipose tissue (WAT) and the appearance of beige adipocytes. Here we report evidence that white adipocyte DNL activity is also coupled to neuronal regulation and thermogenesis in brown adipose tissue (BAT). Induced deletion of FASN in all adipocytes in mature mice (iAdFASNKO) enhanced sympathetic innervation and neuronal activity as well as UCP1 expression in both WAT and BAT. In ...


Deconvolution Of Subcellular Protrusion Heterogeneity And The Underlying Actin Regulator Dynamics From Live Cell Imaging, Chuangqi Wang, Hee June Choi, Sung-Jin Kim, Aesha Desai, Namgyu Lee, Dohoon Kim, Yongho Bae, Kwonmoo Lee Jan 2018

Deconvolution Of Subcellular Protrusion Heterogeneity And The Underlying Actin Regulator Dynamics From Live Cell Imaging, Chuangqi Wang, Hee June Choi, Sung-Jin Kim, Aesha Desai, Namgyu Lee, Dohoon Kim, Yongho Bae, Kwonmoo Lee

University of Massachusetts Medical School Faculty Publications

Cell protrusion is morphodynamically heterogeneous at the subcellular level. However, the mechanistic understanding of protrusion activities is usually based on the ensemble average of actin regulator dynamics at the cellular or population levels. Here, we establish a machine learning-based computational framework called HACKS (deconvolution of Heterogeneous Activity Coordination in cytosKeleton at a Subcellular level) to deconvolve the subcellular heterogeneity of lamellipodial protrusion in migrating cells. HACKS quantitatively identifies distinct subcellular protrusion phenotypes from highly heterogeneous protrusion activities and reveals their underlying actin regulator dynamics at the leading edge. Furthermore, it can identify specific subcellular protrusion phenotypes susceptible to pharmacological perturbation ...


Sample Chapter. Cell And Molecular Biology 3e: What We Know And How We Found Out, Gerald Bergtrom Jan 2018

Sample Chapter. Cell And Molecular Biology 3e: What We Know And How We Found Out, Gerald Bergtrom

Cell and Molecular Biology 3e: What We Know and How We Found Out - All Versions

No abstract provided.


The Fission Yeast S-Phase Cyclin Cig2 Can Drive Mitosis, Mira Magner, Daniel L. Keifenheim, Nicholas R. Rhind Nov 2017

The Fission Yeast S-Phase Cyclin Cig2 Can Drive Mitosis, Mira Magner, Daniel L. Keifenheim, Nicholas R. Rhind

University of Massachusetts Medical School Faculty Publications

Commitment to mitosis is regulated by cyclin-dependent kinase (CDK) activity. In the fission yeast Schizosaccharomyces pombe, the major B-type cyclin, Cdc13, is necessary and sufficient to drive mitotic entry. Furthermore, Cdc13 is also sufficient to drive S phase, demonstrating that a single cyclin can regulate alternating rounds of replication and mitosis and providing the foundation of the quantitative model of CDK function. It has been assumed that Cig2, a B-type cyclin expressed only during S-phase and incapable of driving mitosis in wild-type cells, was specialized for S-phase regulation. Here, we show that Cig2 is capable of driving mitosis. Cig2/CDK ...


Crispr-Based Dna Imaging In Living Cells Reveals Cell Cycle-Dependent Chromosome Dynamics, Hanhui Ma, Li-Chun Tu, University Of Central Florida, Yu-Chieh Chung, David Grünwald, Shaojie Zhang, Thoru Pederson Sep 2017

Crispr-Based Dna Imaging In Living Cells Reveals Cell Cycle-Dependent Chromosome Dynamics, Hanhui Ma, Li-Chun Tu, University Of Central Florida, Yu-Chieh Chung, David Grünwald, Shaojie Zhang, Thoru Pederson

University of Massachusetts Medical School Faculty Publications

In contrast to the well-studied condensation and folding of chromosomes during mitosis, their dynamics in interphase are less understood. We developed a sensitive, multicolor system, CRISPR-Sirius, allowing the real-time tracking of the dynamics of chromosomal loci. We tracked loci kilobases to megabases apart and found significant variation in the inter-locus distances of each pair, indicating differing degrees of DNA contortion. We resolved two distinct modes of dynamics of loci: saltatory local movements as well as translational movements of the domain. The magnitude of both of these modes of movements increased from early to late G1, whereas the translational movements were ...


Rapid Isolation Of Functionally Intact Nuclei From The Yeast Saccharomyces, Mario Niepel, Julia Farr, Michael P. Rout, Caterina Strambio-De-Castilla Jul 2017

Rapid Isolation Of Functionally Intact Nuclei From The Yeast Saccharomyces, Mario Niepel, Julia Farr, Michael P. Rout, Caterina Strambio-De-Castilla

University of Massachusetts Medical School Faculty Publications

Most available methods for nuclear isolation entail lengthy procedures that are difficult to master and generally emphasize yield and enrichment over nuclear preservation, thus limiting their utility for further studies. Here we demonstrate a novel and robust method to rapidly isolate well-preserved yeast nuclei. The method can be easily adapted to multiple preparation scales depending on experimental need and it can readily be performed on multiple samples by a single researcher in one day. We show that the nuclei fraction is strongly enriched and that the resulting nuclei are free from contaminating endoplasmic reticulum and other cell debris. EM studies ...


Single-Molecule Fish In Drosophila Muscle Reveals Location Dependent Mrna Composition Of Megarnps, Akiko Noma, Carlas Smith, Maximiliaan Huisman, Robert M. Martin, Melissa J. Moore, David Grünwald Jun 2017

Single-Molecule Fish In Drosophila Muscle Reveals Location Dependent Mrna Composition Of Megarnps, Akiko Noma, Carlas Smith, Maximiliaan Huisman, Robert M. Martin, Melissa J. Moore, David Grünwald

University of Massachusetts Medical School Faculty Publications

Single-molecule fluorescence in-situ hybridization (smFISH) provides direct access to the spatial relationship between nucleic acids and specific subcellular locations. The ability to precisely localize a messenger RNA can reveal key information about its regulation. Although smFISH is well established in cell culture or thin sections, methods for its accurate application to tissues are lacking. The utility of smFISH in thick tissue sections must overcome several challenges, including probe penetration of fixed tissue, accessibility of target mRNAs for probe hybridization, high fluorescent background, spherical aberration along the optical axis, and image segmentation of organelles. Here we describe how we overcame these ...


Glycolytic Reliance Promotes Anabolism In Photoreceptors, Yashodhan Chinchore, Tedi Begaj, David Wu, Eugene Drokhlyansky, Constance L. Cepko Jun 2017

Glycolytic Reliance Promotes Anabolism In Photoreceptors, Yashodhan Chinchore, Tedi Begaj, David Wu, Eugene Drokhlyansky, Constance L. Cepko

Senior Scholars Program

Vertebrate photoreceptors are among the most metabolically active cells, exhibiting a high rate of ATP consumption. This is coupled with a high anabolic demand, necessitated by the diurnal turnover of a specialized membrane-rich organelle, the outer segment, which is the primary site of phototransduction. How photoreceptors balance their catabolic and anabolic demands is poorly understood. Here, we show that rod photoreceptors in mice rely on glycolysis for their outer segment biogenesis. Genetic perturbations targeting allostery or key regulatory nodes in the glycolytic pathway impacted the size of the outer segments. Fibroblast growth factor signaling was found to regulate glycolysis, with ...


Diverse Stimuli Engage Different Neutrophil Extracellular Trap Pathways, Elaine F. Kenny, Alf Herzig, Renate Krüger, Aaron Muth, Santanu Mondal, Paul R. Thompson, Volker Brinkmann, Horst Von Bernuth, Arturo Zychlinsky Jun 2017

Diverse Stimuli Engage Different Neutrophil Extracellular Trap Pathways, Elaine F. Kenny, Alf Herzig, Renate Krüger, Aaron Muth, Santanu Mondal, Paul R. Thompson, Volker Brinkmann, Horst Von Bernuth, Arturo Zychlinsky

Thompson Lab Publications

Neutrophils release neutrophil extracellular traps (NETs) which ensnare pathogens and have pathogenic functions in diverse diseases. We examined the NETosis pathways induced by five stimuli; PMA, the calcium ionophore A23187, nigericin, Candida albicans and Group B Streptococcus. We studied NET production in neutrophils from healthy donors with inhibitors of molecules crucial to PMA induced NETs including protein kinase C, calcium, reactive oxygen species, the enzymes myeloperoxidase (MPO) and neutrophil elastase. Additionally, neutrophils from chronic granulomatous disease patients, carrying mutations in the NADPH oxidase complex or a MPO-deficient patient were examined. We show that PMA, C. albicans and GBS use a ...


Ift Trains In Different Stages Of Assembly Queue At The Ciliary Base For Consecutive Release Into The Cilium, Jason M. Brown, Tyler Picariello, Deborah A. Cochran, George B. Witman, Karl Lechtreck May 2017

Ift Trains In Different Stages Of Assembly Queue At The Ciliary Base For Consecutive Release Into The Cilium, Jason M. Brown, Tyler Picariello, Deborah A. Cochran, George B. Witman, Karl Lechtreck

Radiology Publications and Presentations

Intraflagellar transport (IFT) trains, multimegadalton assemblies of IFT proteins and motors, traffic proteins in cilia. To study how trains assemble, we employed fluorescence protein-tagged IFT proteins in Chlamydomonas reinhardtii. IFT-A and motor proteins are recruited from the cell body to the basal body pool, assembled into trains, move through the cilium, and disperse back into the cell body. In contrast to this 'open' system, IFT-B proteins from retrograde trains reenter the pool and a portion is reused directly in anterograde trains indicating a 'semi-open' system. Similar IFT systems were also observed in Tetrahymena thermophila and IMCD3 cells. FRAP analysis indicated ...


Super-Resolution Microscopy Reveals That Disruption Of Ciliary Transition Zone Architecture Is A Cause Of Joubert Syndrome, Xiaoyu Shi, Galo Garcia Iii, Julie C. Van De Weghe, University Of California, San Francisco, Gregory J. Pazour, Dan Doherty, Bo Huang, Jeremy F. Reiter May 2017

Super-Resolution Microscopy Reveals That Disruption Of Ciliary Transition Zone Architecture Is A Cause Of Joubert Syndrome, Xiaoyu Shi, Galo Garcia Iii, Julie C. Van De Weghe, University Of California, San Francisco, Gregory J. Pazour, Dan Doherty, Bo Huang, Jeremy F. Reiter

University of Massachusetts Medical School Faculty Publications

Diverse human ciliopathies, including nephronophthisis (NPHP), Meckel syndrome (MKS) and Joubert syndrome (JBTS), can be caused by mutations affecting components of the transition zone, a ciliary domain near its base. The transition zone controls the protein composition of the ciliary membrane, but how it does so is unclear. To better understand the transition zone and its connection to ciliopathies, we defined the arrangement of key proteins in the transition zone using two-color stochastic optical reconstruction microscopy (STORM). This mapping revealed that NPHP and MKS complex components form nested rings comprised of nine-fold doublets. The NPHP complex component RPGRIP1L forms a ...


Melatonin And Its Metabolites Protect Human Melanocytes Against Uvb-Induced Damage: Involvement Of Nrf2-Mediated Pathways, Zorica Janjetovic, Stuart G. Jarrett, Elizabeth F. Lee, Cory Duprey, Russel J. Reiter, Andrzej T. Slominski Apr 2017

Melatonin And Its Metabolites Protect Human Melanocytes Against Uvb-Induced Damage: Involvement Of Nrf2-Mediated Pathways, Zorica Janjetovic, Stuart G. Jarrett, Elizabeth F. Lee, Cory Duprey, Russel J. Reiter, Andrzej T. Slominski

Toxicology and Cancer Biology Faculty Publications

Ultraviolet light (UV) is an inducer of reactive oxygen species (ROS) as well as 6-4-photoproducts and cyclobutane pyrimidine dimers (CPD) in the skin, which further cause damage to the skin cells. Irradiation of cultured human melanocytes with UVB stimulated ROS production, which was reduced in cells treated with melatonin or its metabolites: 6-hydroxymelatonin (6-OHM), N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK), N-acetylserotonin (NAS), and 5-methoxytryptamine (5-MT). Melatonin and its derivatives also stimulated the expression of NRF2 (nuclear factor erythroid 2 [NF-E2]-related factor 2) and its target enzymes and proteins that play an important role in cell protection from different damaging factors including UVB ...


Size-Dependent Expression Of The Mitotic Activator Cdc25 As A Mechanism Of Size Control In Fission Yeast, Daniel L. Keifenheim, Xi-Ming Sun, Edridge D'Souza, Makoto J. Ohira, Mira Magner, Lawrence Livermore National Laboratory, Samuel Marguerat, Nicholas R. Rhind Feb 2017

Size-Dependent Expression Of The Mitotic Activator Cdc25 As A Mechanism Of Size Control In Fission Yeast, Daniel L. Keifenheim, Xi-Ming Sun, Edridge D'Souza, Makoto J. Ohira, Mira Magner, Lawrence Livermore National Laboratory, Samuel Marguerat, Nicholas R. Rhind

University of Massachusetts Medical School Faculty Publications

Proper cell size is essential for cellular function (Hall et al., 2004). Nonetheless, despite more than 100 years of work on the subject, the mechanisms that maintain cell size homeostasis are largely mysterious (Marshall et al., 2012). Cells in growing populations maintain cell size within a narrow range by coordinating growth and division. Bacterial and eukaryotic cells both demonstrate homeostatic size control, which maintains population-level variation in cell size within a certain range, and returns the population average to that range if it is perturbed (Marshall et al., 2012; Turner et al., 2012; Amodeo and Skotheim, 2015). Recent work has ...


An Estradiol-Inducible Promoter Enables Fast, Graduated Control Of Gene Expression In Fission Yeast, Makoto J. Ohira, David G. Hendrickson, R. Scott Mcisaac, Nicholas R. Rhind Feb 2017

An Estradiol-Inducible Promoter Enables Fast, Graduated Control Of Gene Expression In Fission Yeast, Makoto J. Ohira, David G. Hendrickson, R. Scott Mcisaac, Nicholas R. Rhind

University of Massachusetts Medical School Faculty Publications

The fission yeast Schizosaccharomyces pombe lacks a diverse toolkit of inducible promoters for experimental manipulation. Available inducible promoters suffer from slow induction kinetics, limited control of expression levels and/or a requirement for defined growth medium. In particular, no S. pombe inducible promoter systems exhibit a linear dose response, which would allow expression to be tuned to specific levels. We have adapted a fast, orthogonal promoter system with a large dynamic range and a linear dose response, based on β-estradiol-regulated function of the human estrogen receptor, for use in S. pombe. We show that this promoter system, termed Z3 ...


Protein-Nanoparticle Co-Engineering: Self-Assembly, Intracellular Protein Delivery, And Crispr/Cas9-Based Gene Editing, Rubul Mout Jan 2017

Protein-Nanoparticle Co-Engineering: Self-Assembly, Intracellular Protein Delivery, And Crispr/Cas9-Based Gene Editing, Rubul Mout

Doctoral Dissertations

Direct cytoplasmic delivery of gene editing nucleases such CRISPR/Cas9 systems and therapeutic proteins provides enormous opportunities in curing human genetic diseases, and assist research in basic cell biology. One approach to attain such a goal is through engineering nanotechnological tools to mimic naturally existing intra- and extracellular protein delivery/transport systems. Nature builds transport systems for proteins and other biomolecules through evolution-derived sophisticated molecular engineering. Inspired by such natural assemblies, I employed molecular engineering approaches to fabricate self-assembled nanostructures to use as intracellular protein delivery tools. Briefly, proteins and gold nanoparticles were co-engineered to carry complementary electrostatic recognition elements ...


An Alternative Splicing Program Promotes Adipose Tissue Thermogenesis, Santiago Vernia, Yvonne J. K. Edwards, Myoung Souk Han, Julie Cavanagh-Kyros, Tamera Barrett, Jason K. Kim, Roger J. Davis Sep 2016

An Alternative Splicing Program Promotes Adipose Tissue Thermogenesis, Santiago Vernia, Yvonne J. K. Edwards, Myoung Souk Han, Julie Cavanagh-Kyros, Tamera Barrett, Jason K. Kim, Roger J. Davis

University of Massachusetts Medical School Faculty Publications

Alternative pre-mRNA splicing expands the complexity of the transcriptome and controls isoform-specific gene expression. Whether alternative splicing contributes to metabolic regulation is largely unknown. Here we investigated the contribution of alternative splicing to the development of diet-induced obesity. We found that obesity-induced changes in adipocyte gene expression include alternative pre-mRNA splicing. Bioinformatics analysis associated part of this alternative splicing program with sequence specific NOVA splicing factors. This conclusion was confirmed by studies of mice with NOVA deficiency in adipocytes. Phenotypic analysis of the NOVA-deficient mice demonstrated increased adipose tissue thermogenesis and improved glycemia. We show that NOVA proteins mediate a ...


Suppression Of Ischemia In Arterial Occlusive Disease By Jnk-Promoted Native Collateral Artery Development, Kasmir Ramo, Koichi Sugamura, Siobhan M. Craige, John F. Keaney Jr., Roger J. Davis Aug 2016

Suppression Of Ischemia In Arterial Occlusive Disease By Jnk-Promoted Native Collateral Artery Development, Kasmir Ramo, Koichi Sugamura, Siobhan M. Craige, John F. Keaney Jr., Roger J. Davis

Davis Lab Publications

Arterial occlusive diseases are major causes of morbidity and mortality. Blood flow to the affected tissue must be restored quickly if viability and function are to be preserved. We report that disruption of the mixed-lineage protein kinase (MLK) - cJun NH2-terminal kinase (JNK) signaling pathway in endothelial cells causes severe blockade of blood flow and failure to recover in the murine femoral artery ligation model of hindlimb ischemia. We show that the MLK-JNK pathway is required for the formation of native collateral arteries that can restore circulation following arterial occlusion. Disruption of the MLK-JNK pathway causes decreased Dll4/Notch signaling, excessive ...


The Histone H3k9 Demethylase Kdm3a Promotes Anoikis By Transcriptionally Activating Pro-Apoptotic Genes Bnip3 And Bnip3l, Victoria E. Pedanou, Stephane Gobeil, Sebastien Tabaries, Tessa M. Simone, Lihua Julie Zhu, Peter M. Siegel, Michael R. Green Jul 2016

The Histone H3k9 Demethylase Kdm3a Promotes Anoikis By Transcriptionally Activating Pro-Apoptotic Genes Bnip3 And Bnip3l, Victoria E. Pedanou, Stephane Gobeil, Sebastien Tabaries, Tessa M. Simone, Lihua Julie Zhu, Peter M. Siegel, Michael R. Green

Open Access Articles

Epithelial cells that lose attachment to the extracellular matrix undergo a specialized form of apoptosis called anoikis. Here, using large-scale RNA interference (RNAi) screening, we find that KDM3A, a histone H3 lysine 9 (H3K9) mono- and di-demethylase, plays a pivotal role in anoikis induction. In attached breast epithelial cells, KDM3A expression is maintained at low levels by integrin signaling. Following detachment, integrin signaling is decreased resulting in increased KDM3A expression. RNAi-mediated knockdown of KDM3A substantially reduces apoptosis following detachment and, conversely, ectopic expression of KDM3A induces cell death in attached cells. We find that KDM3A promotes anoikis through transcriptional activation ...


Semaphorin3a Increases Focal Adhesion Formation To Shift The Relationship Between Cell Migration And Substratum Concentration Through A Rock-Dependent Mechanism, Frances V. Compere, Scott Gehler Jun 2016

Semaphorin3a Increases Focal Adhesion Formation To Shift The Relationship Between Cell Migration And Substratum Concentration Through A Rock-Dependent Mechanism, Frances V. Compere, Scott Gehler

Celebration of Learning

Cell migration is essential for many life processes, including wound healing, embryonic development and cancer metastasis. Cells move across a surface by interacting and forming adhesions with the molecules in their environment, specifically the extracellular matrix. Past studies have shown that there is an optimal level of cell-substratum adhesive strength that allows for the most cell migration and spreading (DiMilla et al., 1993; Gaudet et al., 2003). The mechanism by which this works is not well understood, however. Semaphorin 3A (Sema3A) has been shown to increase the expression of integrin receptors, which help mediate the formation of the adhesions between ...


No Current Evidence For Widespread Dosage Compensation In S. Cerevisiae, Eduardo M. Torres, Michael Springer, Angelika Amon Mar 2016

No Current Evidence For Widespread Dosage Compensation In S. Cerevisiae, Eduardo M. Torres, Michael Springer, Angelika Amon

UMass Metabolic Network Publications

Previous studies of laboratory strains of budding yeast had shown that when gene copy number is altered experimentally, RNA levels generally scale accordingly. This is true when the copy number of individual genes or entire chromosomes is altered. In a recent study, Hose et al. (2015) reported that this tight correlation between gene copy number and RNA levels is not observed in recently isolated wild Saccharomyces cerevisiae variants. To understand the origins of this proposed difference in gene expression regulation between natural variants and laboratory strains of S. cerevisiae, we evaluated the karyotype and gene expression studies performed by Hose ...


Excitatory Transmission Onto Agrp Neurons Is Regulated By Cjun Nh2-Terminal Kinase 3 In Response To Metabolic Stress, Santiago Vernia, Caroline Morel, Joseph C. Madara, Julie Cavanagh-Kyros, Tamera Barrett, Kathryn O. Chase, Norman J. Kennedy, Dae Young Jung, Jason K. Kim, Neil Aronin, Richard A. Flavell, Bradford B. Lowell, Roger J. Davis Feb 2016

Excitatory Transmission Onto Agrp Neurons Is Regulated By Cjun Nh2-Terminal Kinase 3 In Response To Metabolic Stress, Santiago Vernia, Caroline Morel, Joseph C. Madara, Julie Cavanagh-Kyros, Tamera Barrett, Kathryn O. Chase, Norman J. Kennedy, Dae Young Jung, Jason K. Kim, Neil Aronin, Richard A. Flavell, Bradford B. Lowell, Roger J. Davis

Davis Lab Publications

The cJun NH2-terminal kinase (JNK) signaling pathway is implicated in the response to metabolic stress. Indeed, it is established that the ubiquitously expressed JNK1 and JNK2 isoforms regulate energy expenditure and insulin resistance. However, the role of the neuron-specific isoform JNK3 is unclear. Here we demonstrate that JNK3 deficiency causes hyperphagia selectively in high fat diet (HFD)-fed mice. JNK3 deficiency in neurons that express the leptin receptor LEPRb was sufficient to cause HFD-dependent hyperphagia. Studies of sub-groups of leptin-responsive neurons demonstrated that JNK3 deficiency in AgRP neurons, but not POMC neurons, was sufficient to cause the hyperphagic response. These ...


Ggggcc Microsatellite Rna Is Neuritically Localized, Induces Branching Defects, And Perturbs Transport Granule Function, Alondra Schweizer Burguete, Sandra Almeida, Fen-Biao Gao, Robert Kalb, Michael R. Akins, Nancy M. Bonini Dec 2015

Ggggcc Microsatellite Rna Is Neuritically Localized, Induces Branching Defects, And Perturbs Transport Granule Function, Alondra Schweizer Burguete, Sandra Almeida, Fen-Biao Gao, Robert Kalb, Michael R. Akins, Nancy M. Bonini

Open Access Articles

Microsatellite expansions are the leading cause of numerous neurodegenerative disorders. Here we demonstrate that GGGGCC and CAG microsatellite repeat RNAs associated with C9orf72 in ALS/FTD and with polyglutamine diseases, respectively, localize to neuritic granules that undergo active transport into distal neuritic segments. In cultured mammalian spinal cord neurons, the presence of neuritic GGGGCC repeat RNA correlates with neuronal branching defects and the repeat RNA localizes to granules that label with FMRP, a transport granule component. Using a Drosophila GGGGCC expansion disease model, we characterize dendritic branching defects that are modulated by FMRP and Orb2. The human orthologues of these ...


Near-Infrared Photoactivatable Control Of Ca Signaling And Optogenetic Immunomodulation, Lian He, Yuanwei Zhang, Guolin Ma, Peng Tan, Zhan Jun Li, Shengbing Zhang, Xiang Wu, Ji Jing, Shaohai Fang, Lijuan Zhou, Youjun Wang, Yun Huang, Patrick Hogan, Gang Han, Yubin Zhou Dec 2015

Near-Infrared Photoactivatable Control Of Ca Signaling And Optogenetic Immunomodulation, Lian He, Yuanwei Zhang, Guolin Ma, Peng Tan, Zhan Jun Li, Shengbing Zhang, Xiang Wu, Ji Jing, Shaohai Fang, Lijuan Zhou, Youjun Wang, Yun Huang, Patrick Hogan, Gang Han, Yubin Zhou

Open Access Articles

The application of current channelrhodopsin-based optogenetic tools is limited by the lack of strict ion selectivity and the inability to extend the spectra sensitivity into the near-infrared (NIR) tissue transmissible range. Here we present an NIR-stimulable optogenetic platform (termed "Opto-CRAC") that selectively and remotely controls Ca2+ oscillations and Ca2+-responsive gene expression to regulate the function of non-excitable cells, including T lymphocytes, macrophages and dendritic cells. When coupled to upconversion nanoparticles, the optogenetic operation window is shifted from the visible range to NIR wavelengths to enable wireless photoactivation of Ca2+-dependent signaling and optogenetic modulation of immunoinflammatory responses. In a ...


A Mitochondria-Anchored Isoform Of The Actin-Nucleating Spire Protein Regulates Mitochondrial Division, Uri Manor, Sadie Bartholomew, Gonen Golani, Eric Christenson, Michael Kozlov, Henry Higgs, James Spudich, Jennifer Lippincott-Schwartz Aug 2015

A Mitochondria-Anchored Isoform Of The Actin-Nucleating Spire Protein Regulates Mitochondrial Division, Uri Manor, Sadie Bartholomew, Gonen Golani, Eric Christenson, Michael Kozlov, Henry Higgs, James Spudich, Jennifer Lippincott-Schwartz

Open Dartmouth: Faculty Open Access Scholarship

Mitochondrial division, essential for survival in mammals, is enhanced by an inter-organellar process involving ER tubules encircling and constricting mitochondria. The force for constriction is thought to involve actin polymerization by the ER-anchored isoform of the formin protein inverted formin 2 (INF2). Unknown is the mechanism triggering INF2-mediated actin polymerization at ER-mitochondria intersections. We show that a novel isoform of the formin-binding, actin-nucleating protein Spire, Spire1C, localizes to mitochondria and directly links mitochondria to the actin cytoskeleton and the ER. Spire1C binds INF2 and promotes actin assembly on mitochondrial surfaces. Disrupting either Spire1C actin- or formin-binding activities reduces mitochondrial constriction ...