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2008

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Articles 1 - 30 of 74

Full-Text Articles in Cell Biology

A Genetically Encoded Fluorescent Sensor Of Erk Activity, Christopher D. Harvey, Anka G. Ehrhardt, Cristina Arrigo Cellurale, Haining Zhong, Ryohei Yasuda, Roger J. Davis, Karel Svoboda Dec 2008

A Genetically Encoded Fluorescent Sensor Of Erk Activity, Christopher D. Harvey, Anka G. Ehrhardt, Cristina Arrigo Cellurale, Haining Zhong, Ryohei Yasuda, Roger J. Davis, Karel Svoboda

Davis Lab Publications

The activity of the ERK has complex spatial and temporal dynamics that are important for the specificity of downstream effects. However, current biochemical techniques do not allow for the measurement of ERK signaling with fine spatiotemporal resolution. We developed a genetically encoded, FRET-based sensor of ERK activity (the extracellular signal-regulated kinase activity reporter, EKAR), optimized for signal-to-noise ratio and fluorescence lifetime imaging. EKAR selectively and reversibly reported ERK activation in HEK293 cells after epidermal growth factor stimulation. EKAR signals were correlated with ERK phosphorylation, required ERK activity, and did not report the activities of JNK or p38. EKAR reported ERK ...


A Cell Biology Laboratory Exercise To Study Sub-Cellular Organelles In Drosophila, Meghana Tare, Amit Singh Dec 2008

A Cell Biology Laboratory Exercise To Study Sub-Cellular Organelles In Drosophila, Meghana Tare, Amit Singh

Biology Faculty Publications

The fast-changing scenario of undergraduate education puts emphasis on introducing students to hands-on techniques as part of their laboratory courses. In order to cater to large numbers of students and the time constraints involved with undergraduate level laboratory courses, there is a need for development of experiments that are cost effective and can be completed in a defined time frame. We have devised a laboratory exercise for teaching cell biology using the Drosophila melanogaster model. Drosophila can be reared in a short period of time in a cost effective manner. We used Drosophila tissue to study the sub-cellular organization of ...


The Development And Analysis Of A Closed System Of Vitrification For Mammalian Embryos, Jennifer Graves-Herring Dec 2008

The Development And Analysis Of A Closed System Of Vitrification For Mammalian Embryos, Jennifer Graves-Herring

All Dissertations

Embryo cryopreservation is an integral part of assisted reproduction because it allows for future use of these embryos. Cryopreservation occurs when there are supernumerary embryos or when an embryo transfer cannot be performed.
There are two main methods to cryopreserve embryos. The most recent is vitrification, which uses high concentrations of cryoprotectants, a short time to cool and avoids ice crystals. The 'gold standard' is the slow-cool method, which uses low concentrations of cryoprotectants, a long time to cool embryos and produces extracellular ice crystals.
Prior to introducing vitrification as part of the human cryopreservation regime, it is important that ...


The Leukemogenic T(8;21) Fusion Protein Aml1-Eto Controls Rrna Genes And Associates With Nucleolar-Organizing Regions At Mitotic Chromosomes, Rachit Bakshi, Sayyed K. Zaidi, Sandhya Pande, Mohammad Q. Hassan, Daniel W. Young, Martin A. Montecino, Jane B. Lian, Andre J. Van Wijnen, Janet L. Stein, Gary S. Stein Nov 2008

The Leukemogenic T(8;21) Fusion Protein Aml1-Eto Controls Rrna Genes And Associates With Nucleolar-Organizing Regions At Mitotic Chromosomes, Rachit Bakshi, Sayyed K. Zaidi, Sandhya Pande, Mohammad Q. Hassan, Daniel W. Young, Martin A. Montecino, Jane B. Lian, Andre J. Van Wijnen, Janet L. Stein, Gary S. Stein

Cell and Developmental Biology Publications

RUNX1/AML1 is required for definitive hematopoiesis and is frequently targeted by chromosomal translocations in acute myeloid leukemia (AML). The t(8;21)-related AML1-ETO fusion protein blocks differentiation of myeloid progenitors. Here, we show by immunofluorescence microscopy that during interphase, endogenous AML1-ETO localizes to nuclear microenvironments distinct from those containing native RUNX1/AML1 protein. At mitosis, we clearly detect binding of AML1-ETO to nucleolar-organizing regions in AML-derived Kasumi-1 cells and binding of RUNX1/AML1 to the same regions in Jurkat cells. Both RUNX1/AML1 and AML1-ETO occupy ribosomal DNA repeats during interphase, as well as interact with the endogenous ...


Autonomy And Robustness Of Translocation Through The Nuclear Pore Complex: A Single-Molecule Study, Thomas Dange, David Grunwald, Antje Grunwald, Reiner Peters, Ulrich Kubitscheck Oct 2008

Autonomy And Robustness Of Translocation Through The Nuclear Pore Complex: A Single-Molecule Study, Thomas Dange, David Grunwald, Antje Grunwald, Reiner Peters, Ulrich Kubitscheck

Biochemistry and Molecular Pharmacology Publications and Presentations

All molecular traffic between nucleus and cytoplasm occurs via the nuclear pore complex (NPC) within the nuclear envelope. In this study we analyzed the interactions of the nuclear transport receptors kapalpha2, kapbeta1, kapbeta1DeltaN44, and kapbeta2, and the model transport substrate, BSA-NLS, with NPCs to determine binding sites and kinetics using single-molecule microscopy in living cells. Recombinant transport receptors and BSA-NLS were fluorescently labeled by AlexaFluor 488, and microinjected into the cytoplasm of living HeLa cells expressing POM121-GFP as a nuclear pore marker. After bleaching the dominant GFP fluorescence the interactions of the microinjected molecules could be studied using video microscopy ...


Transient High Glucose Causes Persistent Epigenetic Changes And Altered Gene Expression During Subsequent Normoglycemia, Assam El-Osta, Daniella Brasacchio, Dachun Yao, Alessandro Pocai, Peter L. Jones, Robert G. Roeder, Mark E. Cooper, Michael Brownlee Sep 2008

Transient High Glucose Causes Persistent Epigenetic Changes And Altered Gene Expression During Subsequent Normoglycemia, Assam El-Osta, Daniella Brasacchio, Dachun Yao, Alessandro Pocai, Peter L. Jones, Robert G. Roeder, Mark E. Cooper, Michael Brownlee

Peter Jones Lab Publications

The current goal of diabetes therapy is to reduce time-averaged mean levels of glycemia, measured as HbA1c, to prevent diabetic complications. However, HbA1c only explains <25% of the variation in risk of developing complications. Because HbA1c does not correlate with glycemic variability when adjusted for mean blood glucose, we hypothesized that transient spikes of hyperglycemia may be an HbA1c-independent risk factor for diabetic complications. We show that transient hyperglycemia induces long-lasting activating epigenetic changes in the promoter of the nuclear factor kappaB (NF-kappaB) subunit p65 in aortic endothelial cells both in vitro and in nondiabetic mice, which cause increased p65 gene expression. Both the epigenetic changes and the gene expression changes persist for at least 6 d of subsequent normal glycemia, as do NF-kappaB-induced increases in monocyte chemoattractant protein 1 and vascular cell adhesion molecule 1 expression. Hyperglycemia-induced epigenetic changes and increased p65 expression are prevented by reducing mitochondrial superoxide production or superoxide-induced alpha-oxoaldehydes. These results highlight the dramatic and long-lasting effects that short-term hyperglycemic spikes can have on vascular cells and suggest that transient spikes of hyperglycemia may be an HbA1c-independent risk factor for diabetic complications.


Gene Associations: True Romance Or Chance Meeting In A Nuclear Neighborhood, Jeanne B. Lawrence, Christine Moulton Clemson Sep 2008

Gene Associations: True Romance Or Chance Meeting In A Nuclear Neighborhood, Jeanne B. Lawrence, Christine Moulton Clemson

GSBS Student Publications

Many recent studies have raised interest in the nuclear associations of coregulated genes from different chromosomes, often evoking interpretations of gene-gene interactions, communication, and even "romance." However, in some cases, the associations may be indirect and infrequent and may reflect the segregation of active and inactive genes into different nuclear compartments. The study by Brown et al. (see p. 1083 of this issue) reports that the apparent association of erythroid genes is not a direct interaction nor colocalization to one tiny transcription factory but arises as a result of the known clustering of many active genes with larger splicing factor-rich ...


Gfp Tagging Of Sieve Element Occlusion (Seo) Proteins Results In Green Fluorescent Forisomes, Hélène Pélissier, Winfried Peters, Ray Collier, Aart Van Bel, Michael Knoblauch Sep 2008

Gfp Tagging Of Sieve Element Occlusion (Seo) Proteins Results In Green Fluorescent Forisomes, Hélène Pélissier, Winfried Peters, Ray Collier, Aart Van Bel, Michael Knoblauch

Winfried S. Peters

Forisomes are Ca2+-driven, ATP-independent contractile protein bodies that reversibly occlude sieve elements in faboid legumes. They apparently consist of at least three proteins; potential candidates have been described previously as ‘FOR’ proteins. We isolated three genes from Medicago truncatula that correspond to the putative forisome proteins and expressed their green fluorescent protein (GFP) fusion products in Vicia faba and Glycine max using the composite plant methodology. In both species, expression of any of the constructs resulted in homogenously fluorescent forisomes that formed sieve tube plugs upon stimulation; no GFP fluorescence occurred elsewhere. Isolated fluorescent forisomes reacted to Ca2+ and ...


Biological Signatures Of Vaccine Responses, Lorena Nunez Aug 2008

Biological Signatures Of Vaccine Responses, Lorena Nunez

Honors Scholar Theses

The set of host- and pathogen-specific molecular features of a disease comprise its “signature”. We hypothesize that biological signatures enables distinctions between vaccinated vs. infected individuals. In our research, using porcine samples, protocols were developed that could also be used to identify biological signatures of human disease. Different classes of molecular features will be tested during this project, including indicators of basic immune capacity, which are being studied at this instance.

These indicators of basic immune response such as porcine cytokines and antibodies were validated using Enzyme-linked immunosorbent assay (ELISA). This is an established method that detects antigens by their ...


Characterization Of Phosphatidylinositol (3,4,5)-Trisphosphate Subcellular Localization During Endocytosis In Entamoeba Histolytica, Yevgeniya Byekova Jul 2008

Characterization Of Phosphatidylinositol (3,4,5)-Trisphosphate Subcellular Localization During Endocytosis In Entamoeba Histolytica, Yevgeniya Byekova

All Theses

Entamoeba histolytica is a protozoan parasite that causes amoebic dysentery and liver abscess. Currently, the World Health Organization estimates that amoebic dysentery results in 40,000-100,000 deaths annually worldwide, which places amoebiasis second only to malaria as a leading cause of death due to parasitic infection. The pathogenesis of invasive amoebiasis depends on the parasite's ability to carry out endocytosis in the host's bowel lumen enabling it to colonize the digestive tract. The pathogen is contracted by the ingestion of its multinucleate cysts. Upon excystation in the small intestine, motile trophozoites are released into the bowel lumen ...


Association Of Blood Lead Levels With Onset Of Puberty In Russian Boys, Russ Hauser, Oleg Sergeyev, Susan Korrick, Mary M. Lee, Boris Revich, Elana Gitin, Jane S. Burns, Paige L. Williams Jul 2008

Association Of Blood Lead Levels With Onset Of Puberty In Russian Boys, Russ Hauser, Oleg Sergeyev, Susan Korrick, Mary M. Lee, Boris Revich, Elana Gitin, Jane S. Burns, Paige L. Williams

Lee Lab Publications

BACKGROUND: Epidemiologic studies suggest a temporal trend of earlier onset and longer duration of puberty, raising concerns regarding the potential impact of environmental factors on pubertal development. Lead exposure has been associated with delayed pubertal onset in girls; however, epidemiologic data in boys are limited.

METHODS: We used multivariable logistic regression models to explore the cross-sectional association of blood lead levels with growth and pubertal onset based on physician-assessed testicular volume (TV) and pubertal staging in 489 boys 8-9 years of age from Chapaevsk, Russia. We used multivariable linear regression models to assess associations of blood lead levels with somatic ...


Loss Of Mirna Biogenesis Induces P19arf-P53 Signaling And Senescence In Primary Cells, Rajini R. Mudhasani, Zhiqing Zhu, Gyorgy Hutvagner, Christine M. Eischen, Stephen Lyle, Lisa L. Hall, Jeanne B. Lawrence, Anthony N. Imbalzano, Stephen N. Jones Jul 2008

Loss Of Mirna Biogenesis Induces P19arf-P53 Signaling And Senescence In Primary Cells, Rajini R. Mudhasani, Zhiqing Zhu, Gyorgy Hutvagner, Christine M. Eischen, Stephen Lyle, Lisa L. Hall, Jeanne B. Lawrence, Anthony N. Imbalzano, Stephen N. Jones

Open Access Articles

Dicer, an enzyme involved in microRNA (miRNA) maturation, is required for proper cell differentiation and embryogenesis in mammals. Recent evidence indicates that Dicer and miRNA may also regulate tumorigenesis. To better characterize the role of miRNA in primary cell growth, we generated Dicer-conditional mice. Ablation of Dicer and loss of mature miRNAs in embryonic fibroblasts up-regulated p19(Arf) and p53 levels, inhibited cell proliferation, and induced a premature senescence phenotype that was also observed in vivo after Dicer ablation in the developing limb and in adult skin. Furthermore, deletion of the Ink4a/Arf or p53 locus could rescue fibroblasts from ...


Thymic Selection Determines Γδ T Cell Effector Fate: Antigen-Naive Cells Make Interleukin-17 And Antigen-Experienced Cells Make Interferon Γ, Kirk D. C Jensen, Xiaoqin Su, Sunny Shin, Luke Li, Sawsan Youssef, Sho Yamasaki, Lawrence Steinman, Takashi Saito, Richard M. Locksley, Mark M. Davis, Nicole Baumgarth, Yueh-Hsiu Chien Jul 2008

Thymic Selection Determines Γδ T Cell Effector Fate: Antigen-Naive Cells Make Interleukin-17 And Antigen-Experienced Cells Make Interferon Γ, Kirk D. C Jensen, Xiaoqin Su, Sunny Shin, Luke Li, Sawsan Youssef, Sho Yamasaki, Lawrence Steinman, Takashi Saito, Richard M. Locksley, Mark M. Davis, Nicole Baumgarth, Yueh-Hsiu Chien

Department of Microbiology Papers

γδ T cells contribute uniquely to host immune competence, but how they do so remain unclear. Here, by analyzing T10/T22-specific γδ T cells in mice with different T10/T22 expression patterns, we find that encountering antigen in the thymus is neither required nor inhibitory for the development of these cells. Instead, ligand recognition determines which of two distinct functional subsets γδ T cells will become. When triggered through the TCR, lymphoid-γδ T cells that encounter ligand during development produce IFNγ, while those that develop in the absence of ligand make IL-17, a major inducer of granulopoiesis during inflammation. Indeed ...


An Autonomous Cdr3Δ Is Sufficient For Γδ T Cell Recognition Of The Nonclassical Mhc-I T10/T22, Erin J. Adams, Pavel Strop, Sunny Shin, Yueh-Hsiu Chien, K. Christopher Garcia Jul 2008

An Autonomous Cdr3Δ Is Sufficient For Γδ T Cell Recognition Of The Nonclassical Mhc-I T10/T22, Erin J. Adams, Pavel Strop, Sunny Shin, Yueh-Hsiu Chien, K. Christopher Garcia

Department of Microbiology Papers

It remains unclear whether γδ T cell receptors (TCRs) detect antigens in a manner similar to antibodies or αβ TCRs. Here we show that reactivity between G8 and KN6 γδ TCRs and the MHC class Ib molecule T22 can be transplanted, with retention of wild-type ligand affinity, after en bloc grafting of G8 and KN6 CDR3δ loops in place onto the CDR3α loop of an αβ TCR. We also find that a shared sequence motif within CDR3δ loops of all T22-reactive γδ TCRs binds T22 in energetically distinct fashions, and that T10d, which binds G8 with weak affinity, is converted ...


Nanosecond Pulsed Electric Fields Induce A Mitochondria-Independent Apoptosis In B16f10 Melanoma Cells In Vitro, Wentia Elissa Ford Jul 2008

Nanosecond Pulsed Electric Fields Induce A Mitochondria-Independent Apoptosis In B16f10 Melanoma Cells In Vitro, Wentia Elissa Ford

Theses and Dissertations in Biomedical Sciences

Nanosecond pulsed electric fields (nsPEFs) are ultra-short pulses that induce direct electric field and biological effects that initiate apoptosis. Here the application of ten 300ns pulses ranging in electric fields from 12kV/cm-60kV/cm was administered to determine the effects on B16F10 melanoma cells evaluated by in vitro studies. Initial application of nsPEFs demonstrated apoptosis induction in an electric field- and pulse number-dependent manner measured by caspase activation that correlated with decrease in cell viability 24hr post pulse. In addition caspase activity was shown to be independent of calcium mobilization though ions may play a part in other aspects of ...


The Intermediate Filament Network In Cultured Human Keratinocytes Is Remarkably Extensible And Resilient, Douglas S. Fudge, David Russell, Daniel R. Beriault, Whitney Moore, E. Birgitte Lane, A. Wayne Vogl Jun 2008

The Intermediate Filament Network In Cultured Human Keratinocytes Is Remarkably Extensible And Resilient, Douglas S. Fudge, David Russell, Daniel R. Beriault, Whitney Moore, E. Birgitte Lane, A. Wayne Vogl

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The prevailing model of the mechanical function of intermediate filaments in cells assumes that these 10 nm diameter filaments make up networks that behave as entropic gels, with individual intermediate filaments never experiencing direct loading in tension. However, recent work has shown that single intermediate filaments and bundles are remarkably extensible and elastic in vitro, and therefore well-suited to bearing tensional loads. Here we tested the hypothesis that the intermediate filament network in keratinocytes is extensible and elastic as predicted by the available in vitro data. To do this, we monitored the morphology of fluorescently-tagged intermediate filament networks in cultured ...


The Gonadotropin-Releasing Hormone (Gnrh) Neuronal Population Is Normal In Size And Distribution In Gnrh-Deficient And Gnrh Receptor-Mutant Hypogonadal Mice, John C. Gill, Brandon Wadas, Peilin Chen, Wendy Portillo, Andrea Reyna, Elisa Jorgensen, Shaila Mani, Gerald A. Schwarting, Suzanne M. Moenter, Stuart A. Tobet, Ursula B. Kaiser May 2008

The Gonadotropin-Releasing Hormone (Gnrh) Neuronal Population Is Normal In Size And Distribution In Gnrh-Deficient And Gnrh Receptor-Mutant Hypogonadal Mice, John C. Gill, Brandon Wadas, Peilin Chen, Wendy Portillo, Andrea Reyna, Elisa Jorgensen, Shaila Mani, Gerald A. Schwarting, Suzanne M. Moenter, Stuart A. Tobet, Ursula B. Kaiser

Schwarting Lab Publications

Hypothalamic GnRH neurons are essential for initiation and regulation of reproductive function. In addition to pituitary gonadotrope stimulation, activity of GnRH through its receptor (GnRHR) has been suggested to include autocrine regulation of the GnRH neuron. Two hypogonadal mouse strains, the Gnrh1 mutant (hpg) mice and Gnrhr mutant mice were used to investigate the potential role of GnRH signaling in the proper development and maintenance of GnRH neurons. Immunocytochemical analysis of heterozygous hpg mice revealed a GnRH neuron population that was normal in size and distribution, indicating no effect from reduced Gnrh1 gene dosage on the neurons themselves. To visualize ...


Comparative In Silico Analysis Identifies Bona Fide Myod Binding Sites Within The Myocyte Stress 1 Gene Promoter, Samir Ounzain, Caroline S. Dacwag, Nilesh J. Samani, Anthony N. Imbalzano, Nelson W. Chong May 2008

Comparative In Silico Analysis Identifies Bona Fide Myod Binding Sites Within The Myocyte Stress 1 Gene Promoter, Samir Ounzain, Caroline S. Dacwag, Nilesh J. Samani, Anthony N. Imbalzano, Nelson W. Chong

Imbalzano Lab Publications

BACKGROUND: Myocyte stress 1 (MS1) is a striated muscle actin binding protein required for the muscle specific activity of the evolutionary ancient myocardin related transcription factor (MRTF)/serum response factor (SRF) transcriptional pathway. To date, little is known about the molecular mechanisms that govern skeletal muscle specific expression of MS1. Such mechanisms are likely to play a major role in modulating SRF activity and therefore muscle determination, differentiation and regeneration. In this study we employed a comparative in silico analysis coupled with an experimental promoter characterisation to delineate these mechanisms.

RESULTS: Analysis of MS1 expression in differentiating C2C12 muscle cells ...


Functional Analysis Of Ing1 And Ing4 In Cell Growth And Tumorigenesis: A Dissertation, Andrew H. Coles May 2008

Functional Analysis Of Ing1 And Ing4 In Cell Growth And Tumorigenesis: A Dissertation, Andrew H. Coles

GSBS Dissertations and Theses

The five member Inhibitor of Growth (ING) gene family has been proposed to participate in the regulation of cell growth, DNA repair, inflammation, chromatin remodeling, and tumor suppression. All ING proteins contain a PHD motif implicated in binding to methylated histones and are components of large chromatin remodeling complexes containing histone acetyltransferase (HAT) and histone deacetylase (HDAC) enzymes, suggesting a role for ING proteins in regulating gene transcription. Additionally, forced overexpression studies performed in vitro have indicated that several ING proteins can interact with the p53 tumor suppressor protein and/or the NF-кB protein complex. Since these two proteins play ...


Investigating The Affects Of Cucurbitacin-I On Cellular Motility, Rebecca Lafleur May 2008

Investigating The Affects Of Cucurbitacin-I On Cellular Motility, Rebecca Lafleur

Honors Scholar Theses

Cellular migration is an integral component of many biological processes including immune function, wound healing and cancer cell metastasis. A complete model illustrating the mechanism by which cells accomplish movement is still lacking. Exploring the affects of various drugs on cell motility may be instrumental in discovering new proteins which mediate cell movement. This project aims ultimately to characterize the molecular target of the drug Cucurbitacin-I, a natural plant product. This drug has been shown to inhibit migration of epithelial sheets and may have anti-tumor activity.

In this paper, we show that Cucurbitacin-I inhibits the migration of MDCK and B16F1 ...


Tendon And Ligament Repair: Regeneration And Maturation, Jing Zhao May 2008

Tendon And Ligament Repair: Regeneration And Maturation, Jing Zhao

All Theses

The thesis constitutes the studies about the two aspects of tendon and ligament tissue engineering: regeneration and maturation. Injuries to tendon and ligament are among the most common injuries to the body, particularly in the young and physically active population. Associated with the problems of incomplete healing and recurrent injury, these injuries are not only responsible for large health care cost, but also result in lost work time and individual morbidity. Tissue engineering holds promise in treating these conditions by replacing the injured tissue with engineered tissue exhibited similar mechanical and functional characteristics. Collagen plays a central role in tendon ...


Expression Analysis Of Plant Defense Responses During The Establishment Of Biotrophy And Role Of Abiotic Stress In The Infection Of Dyer’S Woad (Isatis Tinctoria) By Puccinia Thlaspeos., Elizabeth Thomas May 2008

Expression Analysis Of Plant Defense Responses During The Establishment Of Biotrophy And Role Of Abiotic Stress In The Infection Of Dyer’S Woad (Isatis Tinctoria) By Puccinia Thlaspeos., Elizabeth Thomas

All Graduate Theses and Dissertations

The kinetics and amplitude of the salicylic acid-responsive pathogenesis-related (PR) genes and the cytochrome P450 gene ItCYP79B2 in the compatible interaction between Puccinia thlaspeos and dyer’s woad (Isatis tinctoria) during the first 72 hours of inoculation were examined. Immediately following penetration of the host by the rust pathogen, there was a modest up-regulation of PR genes but a significant down-regulation of ItCYP79B2 expression. During haustoria formation, a significant pathogen-mediated suppression of PR genes was observed with a corresponding up-regulation of ItCYP79B2. This potentially facilitates haustoria formation by P. thlaspeos. After haustoria formation, a more significant up-regulation of PR genes ...


Gene Expression In Nuclear Microenvironments For Biological Control And Cancer, Gary S. Stein Apr 2008

Gene Expression In Nuclear Microenvironments For Biological Control And Cancer, Gary S. Stein

Stein, Stein, Lian, vanWijnen Lab Publications

No abstract provided.


Binding Of Atp To Uap56 Is Necessary For Mrna Export, Krishna P. Kota, Stefan R. Wagner, Elvira Huerta, Jean. M. Underwood, Jeffrey A. Nickerson Apr 2008

Binding Of Atp To Uap56 Is Necessary For Mrna Export, Krishna P. Kota, Stefan R. Wagner, Elvira Huerta, Jean. M. Underwood, Jeffrey A. Nickerson

Open Access Articles

The major-histocompatibility-complex protein UAP56 (BAT1) is a DEAD-box helicase that is deposited on mRNA during splicing. UAP56 is retained on spliced mRNA in an exon junction complex (EJC) or, alternatively, with the TREX complex at the 5' end, where it might facilitate the export of the spliced mRNA to the cytoplasm. Using confocal microscopy, UAP56 was found to be concentrated in RNA-splicing speckled domains of nuclei but was also enriched in adjacent nuclear regions, sites at which most mRNA transcription and splicing occur. At speckled domains, UAP56 was in complexes with the RNA-splicing and -export protein SRm160, and, as measured ...


Store-Operated Calcium Entry In Glomerular Mesangial Cells, Sherry Sours-Brothers B.S., M.S. Apr 2008

Store-Operated Calcium Entry In Glomerular Mesangial Cells, Sherry Sours-Brothers B.S., M.S.

Theses and Dissertations

Sours-Brothers, Sherry. Store-operated Calcium Entry in Glomerular Mesangial Cells. Doctor of Philosophy (Integrative Physiology, Molecular Cardiovascular Science Track), April, 2008, 181 pp; 1 table, 25 figures, bibliography, 241 titles. Mesangial cells (MCs) are found within the glomerulus, where they contribute to the regulation of glomerular filtration (GFR). Their contractile function is similar to that of vascular smooth muscle cells, regulated by a number of different Ca2+ release and entry mechanisms in response to vasoactive substances. Among these are store-operated channels (SOC), which have been identified in MC, but whose molecular components are unknown. Deficiency of store-operated Ca2+ entry (SOCE) has ...


Nociceptive Polycationic Peptides Are Chemorepellents In Tetrahymena Thermophila, Alicia E. Schaffner, Heather G. Kuruvilla Apr 2008

Nociceptive Polycationic Peptides Are Chemorepellents In Tetrahymena Thermophila, Alicia E. Schaffner, Heather G. Kuruvilla

Science and Mathematics Faculty Presentations

Chemorepellents are compounds which cause a cell to move away from the source of the repellent, or down a concentration gradient of the compound. In ciliates such as Tetrahymena thermophila and Paramecium tetraurelia, this reorientation is accomplished by ciliary reversal, resulting in jerky or backward swimming which is known as an “avoidance reaction”. This reaction can easily be seen under a simple dissection microscope, allowing for easy characterization of ciliate behavior in different compounds.

A number of compounds are known chemorepellents in Tetrahymena thermophila, including ATP and GTP which have a negative overall charge, and polycations such as lysozyme and ...


Jun N-Terminal Kinase 1 Regulates Epithelial-To-Mesenchymal Transition Induced By Tgf-Beta1, John F. Alcorn, Amy S. Guala, Jos Van Der Velden, Brian Mcelhinney, Charles G. Irvin, Roger J. Davis, Yvonne M.W. Janssen-Heininger Apr 2008

Jun N-Terminal Kinase 1 Regulates Epithelial-To-Mesenchymal Transition Induced By Tgf-Beta1, John F. Alcorn, Amy S. Guala, Jos Van Der Velden, Brian Mcelhinney, Charles G. Irvin, Roger J. Davis, Yvonne M.W. Janssen-Heininger

Davis Lab Publications

Transforming growth factor beta1 (TGF-beta1) is a cardinal cytokine in the pathogenesis of airway remodeling, and promotes epithelial-to-mesenchymal transition (EMT). As a molecular interaction between TGF-beta1 and Jun N-terminal kinase (JNK) has been demonstrated, the goal of this study was to elucidate whether JNK plays a role in TGF-beta1-induced EMT. Primary cultures of mouse tracheal epithelial cells (MTEC) from wild-type, JNK1-/- or JNK2-/- mice were comparatively evaluated for their ability to undergo EMT in response to TGF-beta1. Wild-type MTEC exposed to TGF-beta1 demonstrated a prominent induction of mesenchymal mediators and a loss of epithelial markers, in conjunction with a loss ...


Dictyostelium Discoideum Plasma Membranes Contain An Actin-Nucleating Activity That Requires Ponticulin, An Integral Membrane Glycoprotein, A. Shariff, Elizabeth J. Luna Mar 2008

Dictyostelium Discoideum Plasma Membranes Contain An Actin-Nucleating Activity That Requires Ponticulin, An Integral Membrane Glycoprotein, A. Shariff, Elizabeth J. Luna

Elizabeth J. Luna

In previous equilibrium binding studies, Dictyostelium discoideum plasma membranes have been shown to bind actin and to recruit actin into filaments at the membrane surface. However, little is known about the kinetic pathway(s) through which actin assembles at these, or other, membranes. We have used actin fluorescently labeled with N-(1-pyrenyl)iodoacetamide to examine the kinetics of actin assembly in the presence of D. discoideum plasma membranes. We find that these membranes increase the rate of actin polymerization. The rate of membrane-mediated actin polymerization is linearly dependent on membrane protein concentrations up to 20 micrograms/ml. Nucleation (the association ...


Ponticulin Plays A Role In The Positional Stabilization Of Pseudopods, D. C. Shutt, D. Wessels, K. Wagenknecht, A. Chandrasekhar, Anne L. Hitt, Elizabeth J. Luna, D. R. Soll Mar 2008

Ponticulin Plays A Role In The Positional Stabilization Of Pseudopods, D. C. Shutt, D. Wessels, K. Wagenknecht, A. Chandrasekhar, Anne L. Hitt, Elizabeth J. Luna, D. R. Soll

Elizabeth J. Luna

Ponticulin is a 17-kD glycoprotein that represents a major high affinity link between the plasma membrane and the cortical actin network of Dictyostelium. To assess the role of ponticulin in pseudopod extension and retraction, the motile behavior of two independently generated mutants lacking ponticulin was analyzed using computer-assisted two- and three-dimensional motion analysis systems. More than half of the lateral pseudopods formed off the substratum by ponticulin-minus cells slipped relative to the substratum during extension and retraction. In contrast, all pseudopods formed off the substratum by wild-type cells were positionally fixed in relation to the substratum. Ponticulin-minus cells also formed ...


Mutant Rac1b Expression In Dictyostelium: Effects On Morphology, Growth, Endocytosis, Development, And The Actin Cytoskeleton, S. Palmieri, Thomas Nebl, Robert Pope, D. Seastone, E. Lee, E. Hinchcliffe, Greenfield Sluder, D. Knecht, J. Cardelli, Elizabeth Luna Mar 2008

Mutant Rac1b Expression In Dictyostelium: Effects On Morphology, Growth, Endocytosis, Development, And The Actin Cytoskeleton, S. Palmieri, Thomas Nebl, Robert Pope, D. Seastone, E. Lee, E. Hinchcliffe, Greenfield Sluder, D. Knecht, J. Cardelli, Elizabeth Luna

Elizabeth J. Luna

Rac1 is a small G-protein in the Ras superfamily that has been implicated in the control of cell growth, adhesion, and the actin-based cytoskeleton. To investigate the role of Rac1 during motile processes, we have established Dictyostelium cell lines that conditionally overexpress epitope-tagged Dictyostelium discoideum wild-type Rac1B (DdRac1B) or a mutant DdRac1B protein. Expression of endogenous levels of myc- or GFP-tagged wild-type DdRac1B had minimal effect on cellular morphologies and behaviors. By contrast, expression of a constitutively active mutant (G12-->V or Q61-->L) or a dominant negative mutant (T17-->N) generated amoebae with characteristic cellular defects. The morphological appearance ...