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2006

Cell and Developmental Biology

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Articles 1 - 30 of 122

Full-Text Articles in Life Sciences

Calpain Inhibitor Mdl28170 Modulates Abeta Formation By Inhibiting The Formation Of Intermediate Abeta46 And Protecting Abeta From Degradation, Y Dong, J Tan, Mei-Zhen Cui, G Zhao, G Mao, N Singh, Xuemin Xu Jun 2013

Calpain Inhibitor Mdl28170 Modulates Abeta Formation By Inhibiting The Formation Of Intermediate Abeta46 And Protecting Abeta From Degradation, Y Dong, J Tan, Mei-Zhen Cui, G Zhao, G Mao, N Singh, Xuemin Xu

Mei-Zhen Cui

The observations that three major cleavages within the transmembrane domain of APP, namely, the gamma-cleavage, -cleavage, and the newly identified zeta-cleavage, are involved in the generation of secreted Abeta40 and Abeta42 prompted us to determine how the calpain inhibitor III MDL 28170 influences these three cleavages and Abeta formation. With the use of a cell culture system, our data demonstrate that 1) at either high concentrations, or at a low range of concentrations, at early time points, MDL 28170 inhibits the formation of secreted Abeta40 and Abeta42. However, this effect is due to inhibition of the intermediate Abeta46 generation by ...


Pulmonary Fibroblasts Stimulate The Proliferation Of Cell Lines From Human Lung Adenocarcinomas, Maria Cekanova, T Masi, Howard Plummer, M Majidi, P Fedorocko, Hildegard Schuller Aug 2011

Pulmonary Fibroblasts Stimulate The Proliferation Of Cell Lines From Human Lung Adenocarcinomas, Maria Cekanova, T Masi, Howard Plummer, M Majidi, P Fedorocko, Hildegard Schuller

Howard K. Plummer III

Human lung cancer cell lines are widely used to test anticancer drugs. These in-vitro tests, however, preclude the detection of responses to paracrine factors from surrounding stroma. We have cocultured pulmonary fibroblasts CCD-19Lu, from a healthy donor, or HLF-A, from a patient with epidermoid carcinoma of the lung, with two human pulmonary adenocarcinoma cell lines to test the hypothesis that the fibroblasts stimulate the growth of the tumor cells. Both fibroblast cell lines significantly increased the proliferation of the pulmonary adenocarcinoma cell lines in 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide assays, with HLF-A fibroblasts yielding the most pronounced responses ...


Activated Checkpoint Kinase 2 Provides A Survival Signal For Tumor Cells, Jagadish C. Ghosh, Takehiko Dohi, Christopher M. Raskett, Timothy F. Kowalik, Dario C. Altieri Dec 2006

Activated Checkpoint Kinase 2 Provides A Survival Signal For Tumor Cells, Jagadish C. Ghosh, Takehiko Dohi, Christopher M. Raskett, Timothy F. Kowalik, Dario C. Altieri

Open Access Articles

Tumor cells often become resistant to DNA damage-based therapy; however, the underlying mechanisms are not yet understood. Here, we show that tumor cells exposed to DNA damage counteract cell death by releasing the antiapoptotic protein, survivin, from mitochondria. This is independent of p53, and requires activated checkpoint kinase 2 (Chk2), a putative tumor suppressor. Molecular or genetic targeting of Chk2 prevents the release of survivin from mitochondria, enhances DNA damage-induced tumor cell apoptosis, and inhibits the growth of resistant in vivo tumors. Therefore, activated Chk2 circumvents its own tumor-suppressive functions by promoting tumor cell survival. Inhibiting Chk2 in combination with ...


Expression And Function Of Alpha3 And Beta2 Neuronal Nicotinic Acetylcholine Receptor Subunits In Hek-293 Cells, Nathan W. Steinhafel Dec 2006

Expression And Function Of Alpha3 And Beta2 Neuronal Nicotinic Acetylcholine Receptor Subunits In Hek-293 Cells, Nathan W. Steinhafel

Theses and Dissertations

Single-cell real-time quantitative RT-PCR was used to characterize the mRNA expression of rat neuronal nicotinic acetylcholine receptor (nAChR) subunits α3 and β2 in CA1 hippocampus stratum radiatum and stratum oriens interneurons. α3β2 co-expression was detected in 43% of interneurons analyzed. The nAChR subtype α3β2 was transiently expressed in cells derived from the human embryonic kidney cell line 293 at mRNA levels found in the CA1. The functional properties of α3β2 in HEK-293 cells were characterized by whole-cell patch clamping using acetylcholine (ACh) as an agonist. The kinetics of α3β2 channels were further analyzed by altering the level of α3 DNA ...


Brca1 Foci In Normal S-Phase Nuclei Are Linked To Interphase Centromeres And Replication Of Pericentric Heterochromatin, Gayle Jeannette Pageau, Jeanne B. Lawrence Dec 2006

Brca1 Foci In Normal S-Phase Nuclei Are Linked To Interphase Centromeres And Replication Of Pericentric Heterochromatin, Gayle Jeannette Pageau, Jeanne B. Lawrence

Open Access Articles

Breast cancer-associated protein 1 (BRCA1) forms foci at sites of induced DNA damage, but any significance of these normal S-phase foci is unknown. BRCA1 distribution does not simply mirror or overlap that of replicating DNA; however, BRCA1 foci frequently abut sites of BrdU incorporation, mostly at mid-to-late S phase. Although BRCA1 does not overlap XIST RNA across the inactive X chromosome, BRCA1 foci position overwhelmingly in heterochromatic regions, particularly the nucleolar periphery where many centromeres reside. In humans and mice, including early embryonic cells, BRCA1 commonly associates with interphase centromere-kinetochore complexes, including pericentric heterochromatin. Proliferating cell nuclear antigen or BrdU ...


Inhibition Of Bach1 (Fancj) Helicase By Backbone Discontinuity Is Overcome By Increased Motor Atpase Or Length Of Loading Strand, Rigu Gupta, Sudha Sharma, Kevin M. Doherty, Joshua A. Sommers, Sharon B. Cantor, Robert M. Brosh Dec 2006

Inhibition Of Bach1 (Fancj) Helicase By Backbone Discontinuity Is Overcome By Increased Motor Atpase Or Length Of Loading Strand, Rigu Gupta, Sudha Sharma, Kevin M. Doherty, Joshua A. Sommers, Sharon B. Cantor, Robert M. Brosh

Cancer Biology Publications and Presentations

The BRCA1 associated C-terminal helicase (BACH1) associated with breast cancer has been implicated in double strand break (DSB) repair. More recently, BACH1 (FANCJ) has been genetically linked to the chromosomal instability disorder Fanconi Anemia (FA). Understanding the roles of BACH1 in cellular DNA metabolism and how BACH1 dysfunction leads to tumorigenesis requires a comprehensive investigation of its catalytic mechanism and molecular functions in DNA repair. In this study, we have determined that BACH1 helicase contacts with both the translocating and the non-translocating strands of the duplex are critical for its ability to track along the sugar phosphate backbone and unwind ...


Characterizing The Polycation Receptor Of Paramecium, Eric D. Robinette, Heather G. Kuruvilla Dec 2006

Characterizing The Polycation Receptor Of Paramecium, Eric D. Robinette, Heather G. Kuruvilla

Science and Mathematics Faculty Presentations

Unicellular eukaryotes are complex systems, performing all the tasks needed for survival within the context of a single cell. Protozoans, such as Tetrahymena and Paramecium, use chemosensory systems to detect food and to avoid predation.

Both Tetrahymena and Paramecium have been used as models for studying chemorepellents. Lysozyme, ATP, and GTP have been found to have chemorepellent activity in both ciliates. In Tetrahymena, several PACAP isoforms have been shown to bind to the same receptor as lysozyme, indicating that this receptor may be a more general “polycation receptor” (Keedy et al., 2003). The polycation receptor in Tetrahymena appears to be ...


Intranuclear Binding Kinetics And Mobility Of Single Native U1 Snrnp Particles In Living Cells, David Grunwald, Beatrice Spottke, Volker Buschmann, Ulrich Kubitscheck Dec 2006

Intranuclear Binding Kinetics And Mobility Of Single Native U1 Snrnp Particles In Living Cells, David Grunwald, Beatrice Spottke, Volker Buschmann, Ulrich Kubitscheck

Biochemistry and Molecular Pharmacology Publications and Presentations

Uridine-rich small nuclear ribonucleoproteins (U snRNPs) are splicing factors, which are diffusely distributed in the nucleoplasm and also concentrated in nuclear speckles. Fluorescently labeled, native U1 snRNPs were microinjected into the cytoplasm of living HeLa cells. After nuclear import single U1 snRNPs could be visualized and tracked at a spatial precision of 30 nm at a frame rate of 200 Hz employing a custom-built microscope with single-molecule sensitivity. The single-particle tracks revealed that most U1 snRNPs were bound to specific intranuclear sites, many of those presumably representing pre-mRNA splicing sites. The dissociation kinetics from these sites showed a multiexponential decay ...


The Influence Of Membrane Lipid Order On Cell Shape And Microvesiculation In Human Erythrocytes, Laurie Jackson Gonzalez Nov 2006

The Influence Of Membrane Lipid Order On Cell Shape And Microvesiculation In Human Erythrocytes, Laurie Jackson Gonzalez

Theses and Dissertations

Exposure of human erythrocytes to elevated intracellular calcium causes alterations in cell shape and stimulates shedding of the cell membrane in the form of microvesicles. We hypothesized that both the shape transition and microvesiculation are influenced by microscopic membrane physical properties such as lipid order. To test this hypothesis, membrane properties were manipulated by varying the experimental temperature, membrane cholesterol content, and the internal ionic environment. Changes in membrane order were assessed using steady-state fluorescence spectroscopy with an environment-sensitive probe, laurdan. Our observations led us to the following conclusions: 1) the modest temperature dependence of membrane structure observed with laurdan ...


Fgf4 And Wnt5a/Pcp Signaling Promote Limb Outgrowth By Polarizing Limb Mesenchyme, Keri Lynn Low Nov 2006

Fgf4 And Wnt5a/Pcp Signaling Promote Limb Outgrowth By Polarizing Limb Mesenchyme, Keri Lynn Low

Theses and Dissertations

The focus of this study was to elucidate the molecular and cellular mechanisms whereby fibroblast growth factors (FGFs) mediate outgrowth of the limb. Specifically, we examined the epistatic relationship between FGF and Wnt/Planar cell polarity (PCP) signaling in establishing cell polarity as a mechanism for outgrowth. By implanting beads into embryonic limbs and lateral plate mesoderm, we established that FGF activates Wnt5a in a gradient fashion. Once it was established that Wnt5a was expressed at the right time and place to turn on PCP signaling, we investigated the ability of Wnt5a to influence cell migration and/or cell polarity ...


Limited Functional Redundancy And Oscillation Of Cyclins In Multinucleated Ashbya Gossypii Fungal Cells, A. Katrin Hungerbuehler, Peter Philippsen, Amy S. Gladfelter Nov 2006

Limited Functional Redundancy And Oscillation Of Cyclins In Multinucleated Ashbya Gossypii Fungal Cells, A. Katrin Hungerbuehler, Peter Philippsen, Amy S. Gladfelter

Open Dartmouth: Faculty Open Access Scholarship

Cyclin protein behavior has not been systematically investigated in multinucleated cells with asynchronous mitoses. Cyclins are canonical oscillating cell cycle proteins, but it is unclear how fluctuating protein gradients can be established in multinucleated cells where nuclei in different stages of the division cycle share the cytoplasm. Previous work in A. gossypii, a filamentous fungus in which nuclei divide asynchronously in a common cytoplasm, demonstrated that one G1 and one B-type cyclin do not fluctuate in abundance across the division cycle. We have undertaken a comprehensive analysis of all G1 and B-type cyclins in A. gossypii to determine whether any ...


The Fat Cadherin Acts Through The Hippo Tumor-Suppressor Pathway To Regulate Tissue Size, Maria Willecke, Fisun Hamaratoglu, Madhuri Kango-Singh, Ryan Udan, Chiao-Lin Chen, Chunyao Tao, Xinwei Zhang, Georg Halder Nov 2006

The Fat Cadherin Acts Through The Hippo Tumor-Suppressor Pathway To Regulate Tissue Size, Maria Willecke, Fisun Hamaratoglu, Madhuri Kango-Singh, Ryan Udan, Chiao-Lin Chen, Chunyao Tao, Xinwei Zhang, Georg Halder

Biology Faculty Publications

Background: The Hippo tumor-suppressor pathway has emerged as a key signaling pathway that controls tissue size in Drosophila. Merlin, the Drosophila homolog of the human Neurofibromatosis type-2 (NF2) tumor-suppressor gene, and the related protein Expanded are the most upstream components of the Hippo pathway identified so far. However, components acting upstream of Expanded and Merlin, such as transmembrane receptors, have not yet been identified.

Results: Here, we report that the protocadherin Fat acts as an upstream component in the Hippo pathway. Fat is a known tumor-suppressor gene in Drosophila, and fat mutants have severely overgrown imaginal discs. We found that ...


Lobe And Serrate Are Required For Cell Survival During Early Eye Development In Drosophila, Amit Singh, Xiao Shi, Kwang-Wook Choi Nov 2006

Lobe And Serrate Are Required For Cell Survival During Early Eye Development In Drosophila, Amit Singh, Xiao Shi, Kwang-Wook Choi

Biology Faculty Publications

Organogenesis involves an initial surge of cell proliferation, leading to differentiation. This is followed by cell death in order to remove extra cells. During early development, there is little or no cell death. However, there is a lack of information concerning the genes required for survival during the early cell-proliferation phase. Here, we show that Lobe (L) and the Notch (N) ligand Serrate (Ser), which are both involved in ventral eye growth, are required for cell survival in the early eye disc. We observed that the loss-of-ventral-eye phenotype in L or Ser mutants is due to the induction of cell ...


The Allantois And Chorion, When Isolated Before Circulation Or Chorio-Allantoic Fusion, Have Hematopoietic Potential, Brandon M. Zeigler, Daisuke Sugiyama, Michael Chen, Yalin Guo, K. M. Downs, N. A. Speck Nov 2006

The Allantois And Chorion, When Isolated Before Circulation Or Chorio-Allantoic Fusion, Have Hematopoietic Potential, Brandon M. Zeigler, Daisuke Sugiyama, Michael Chen, Yalin Guo, K. M. Downs, N. A. Speck

Open Dartmouth: Faculty Open Access Scholarship

The chorio-allantoic placenta forms through the fusion of the allantois (progenitor tissue of the umbilical cord), with the chorionic plate. The murine placenta contains high levels of hematopoietic stem cells, and is therefore a stem cell niche. However, it is not known whether the placenta is a site of hematopoietic cell emergence, or whether hematopoietic cells originate from other sites in the conceptus and then colonize the placenta. Here, we show that the allantois and chorion, isolated prior to the establishment of circulation, have the potential to give rise to myeloid and definitive erythroid cells following explant culture. We further ...


Dictyostelium Myosin-Ie Is A Fast Molecular Motor Involved In Phagocytosis, Ulrike Durrwang, Setsuko Fujita-Becker, Muriel Erent, F. Jon Kull Oct 2006

Dictyostelium Myosin-Ie Is A Fast Molecular Motor Involved In Phagocytosis, Ulrike Durrwang, Setsuko Fujita-Becker, Muriel Erent, F. Jon Kull

Open Dartmouth: Faculty Open Access Scholarship

Class I myosins are single-headed motor proteins, implicated in various motile processes including organelle translocation, ion-channel gating, and cytoskeleton reorganization. Here we describe the cellular localization of myosin-IE and its role in the phagocytic uptake of solid particles and cells. A complete analysis of the kinetic and motor properties of Dictyostelium discoideum myosin-IE was achieved by the use of motor domain constructs with artificial lever arms. Class I myosins belonging to subclass IC like myosin-IE are thought to be tuned for tension maintenance or stress sensing. In contrast to this prediction, our results show myosin-IE to be a fast motor ...


Transposition Of Reversed Ac Element Ends Generates Novel Chimeric Genes In Maize, Jianbo Zhang, Feng Zhang, Thomas Peterson Oct 2006

Transposition Of Reversed Ac Element Ends Generates Novel Chimeric Genes In Maize, Jianbo Zhang, Feng Zhang, Thomas Peterson

Genetics, Development and Cell Biology Publications

The maize Activator/Dissociation (Ac/Ds) elements are members of the hAT (hobo, Ac, and Tam3) superfamily of type II (DNA) transposons that transpose through a “cut-and-paste” mechanism. Previously, we reported that a pair of Ac ends in reversed orientation is capable of undergoing alternative transposition reactions that can generate large-scale chromosomal rearrangements, including deletions and inversions. We show here that rearrangements induced by reversed Ac ends transposition can join the coding and regulatory sequences of two linked paralogous genes to generate a series of chimeric genes, some of which are functional. To our knowledge, this is the first report ...


Nnk Activates Erk1/2 And Creb/Atf-1 Via Beta-1-Ar And Egfr Signaling In Human Lung Adenocarcinoma And Small Airway Epithelial Cells, E Laag, M Majidi, Maria Cekanova, T Masi, T Takahashi, Hildegard Schuller Sep 2006

Nnk Activates Erk1/2 And Creb/Atf-1 Via Beta-1-Ar And Egfr Signaling In Human Lung Adenocarcinoma And Small Airway Epithelial Cells, E Laag, M Majidi, Maria Cekanova, T Masi, T Takahashi, Hildegard Schuller

Maria Cekanova MS, RNDr, PhD

We have shown that the tobacco nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is an agonist for -adrenergic receptors (beta-ARs) and increased DNA synthesis of human lung adenocarcinoma cells with features of bronchiolar Clara cells by binding to these receptors. Using a cell line derived from a human pulmonary adenocarcinoma with Clara cell phenotype (PACC) and immortalized human small airway epithelial cells (HPLD1), the putative cells of origin of this cancer type, our current studies have analyzed signaling initiated by binding of NNK to the beta 1-AR. NNK upregulated ERK1/2 and CREB/ATF-1 phosphorylation in a PKA-dependent manner in ...


The Transcriptome Of Human Oocytes, Jose Cibelli, Arif Kocabas, Javier Crosby, Pablo Ross, Hasan Otu, Zeki Beyhan, Zandan Can, Wau-Leong Tam, Guilherme Rosa, Robert Halgren, Bing Lim, Emilio Fernandez Sep 2006

The Transcriptome Of Human Oocytes, Jose Cibelli, Arif Kocabas, Javier Crosby, Pablo Ross, Hasan Otu, Zeki Beyhan, Zandan Can, Wau-Leong Tam, Guilherme Rosa, Robert Halgren, Bing Lim, Emilio Fernandez

Jose Cibelli

The identification of genes and deduced pathways from the mature human oocyte can help us better understand oogenesis, folliculogenesis, fertilization, and embryonic development. Human metaphase II oocytes were used within minutes after removal from the ovary, and its transcriptome was compared with a reference sample consisting of a mixture of total RNA from 10 different normal human tissues not including the ovary. RNA amplification was performed by using a unique protocol. Affymetrix Human Genome U133 Plus 2.0 GeneChip arrays were used for hybridizations. Compared with reference samples, there were 5,331 transcripts significantly up-regulated and 7,074 transcripts significantly ...


Notch1 Contributes To Mouse T-Cell Leukemia By Directly Inducing The Expression Of C-Myc, Vishva Mitra Sharma, Jennifer Ann Calvo, Kyle M. Draheim, Leslie A. Cunningham, Nicole M. Hermance, Levi J. Beverly, Veena Krishnamoorthy, Manoj Bhasin, Anthony J. Capobianco, Michelle A. Kelliher Sep 2006

Notch1 Contributes To Mouse T-Cell Leukemia By Directly Inducing The Expression Of C-Myc, Vishva Mitra Sharma, Jennifer Ann Calvo, Kyle M. Draheim, Leslie A. Cunningham, Nicole M. Hermance, Levi J. Beverly, Veena Krishnamoorthy, Manoj Bhasin, Anthony J. Capobianco, Michelle A. Kelliher

GSBS Student Publications

Recent work with mouse models and human leukemic samples has shown that gain-of-function mutation(s) in Notch1 is a common genetic event in T-cell acute lymphoblastic leukemia (T-ALL). The Notch1 receptor signals through a gamma-secretase-dependent process that releases intracellular Notch1 from the membrane to the nucleus, where it forms part of a transcriptional activator complex. To identify Notch1 target genes in leukemia, we developed mouse T-cell leukemic lines that express intracellular Notch1 in a doxycycline-dependent manner. Using gene expression profiling and chromatin immunoprecipitation, we identified c-myc as a novel, direct, and critical Notch1 target gene in T-cell leukemia. c-myc mRNA ...


In Vivo Mature Immunological Synapses Forming Smacs Mediate Clearance Of Virally Infected Astrocytes From The Brain, Carlos Barcia, Clare Thomas, James Curtin, Gwendalyn King, Kolja Wawrowsky, Marianela Candolfi, Weidong Xiong, Chunyan Liu, Kurt Kroeger, Olivier Boyer, Jerzy Kupiec-Weglinski, David Klatzmann, Maria Castro, Pedro Lowenstein Sep 2006

In Vivo Mature Immunological Synapses Forming Smacs Mediate Clearance Of Virally Infected Astrocytes From The Brain, Carlos Barcia, Clare Thomas, James Curtin, Gwendalyn King, Kolja Wawrowsky, Marianela Candolfi, Weidong Xiong, Chunyan Liu, Kurt Kroeger, Olivier Boyer, Jerzy Kupiec-Weglinski, David Klatzmann, Maria Castro, Pedro Lowenstein

Articles

The microanatomy of immune clearance of infected brain cells remains poorly understood. Immunological synapses are essential anatomical structures that channel information exchanges between T cell–antigen-presenting cells (APC) during the priming and effector phases of T cells' function, and during natural killer–target cell interactions. The hallmark of immunological synapses established by T cells is the formation of the supramolecular activation clusters (SMACs), in which adhesion molecules such as leukocyte function-associated antigen 1 segregate to the peripheral domain of the immunological synapse (p-SMAC), which surrounds the T cell receptor–rich or central SMAC (c-SMAC). The inability so far to detect ...


Expression Of The Primary Carbohydrate Component Of The Bordetella Bronchiseptica Biofilm Matrix Is Dependent On Growth Phase But Independent Of Bvg Regulation, Yasuhiko Irie, Andrew Preston, Ming H. Yuk Sep 2006

Expression Of The Primary Carbohydrate Component Of The Bordetella Bronchiseptica Biofilm Matrix Is Dependent On Growth Phase But Independent Of Bvg Regulation, Yasuhiko Irie, Andrew Preston, Ming H. Yuk

Biology Faculty Publications

We previously showed that the Bvg virulence control system regulates biofilm formation in Bordetella bronchiseptica (Y. Irie, S. Mattoo, and M. H. Yuk, J. Bacteriol. 186:5692-5698, 2004). Analyses of the extracellular components of B. bronchiseptica biofilm matrix revealed that the major sugar component in the matrix was xylose, and linkage analysis indicated a majority of it to be in a 4-linked polymeric form. The production of xylose was independent of Bvg regulation but instead was dependent on bacterial growth phase. In addition, N-acetyl-glucosamine in the matrix was found to be important for the initial development of the biofilm ...


The Localized Dynamics Of A Ca2+Channel (30-Minute Talk), Borbala Mazzag, Christoper Tignanelli, Gregory D. Smith Aug 2006

The Localized Dynamics Of A Ca2+Channel (30-Minute Talk), Borbala Mazzag, Christoper Tignanelli, Gregory D. Smith

Borbala Mazzag

No abstract provided.


Construction Of A Col11a1 Transgene Vector, Cameron Mckell Beck Aug 2006

Construction Of A Col11a1 Transgene Vector, Cameron Mckell Beck

Theses and Dissertations

Background: Cartilage disorders affect millions of people in the United States alone, with effects ranging from poor skeletal development and joint pain to shortened lifespan and perinatal lethality. Many of these disorders have their root in defects of collagen, type XI collagen being among the most important. A mouse model of such a type XI collagen defect is the chondrodysplasia (cho) mutant. Mice homozygous for this null mutation in the Col11a1 gene do not express the α1 chain of type XI collagen. This results in a functional knockout of type XI collagen, leading to insufficient skeletal development and perinatal lethality ...


Functional Interaction Of The Retinoblastoma And Ini1/Snf5 Tumor Suppressors In Cell Growth And Pituitary Tumorigenesis, Cynthia J. Guidi, Rajini R. Mudhasani, Kathleen Hoover, Andrew Koff, Irwin Leav, Anthony N. Imbalzano, Stephen N. Jones Aug 2006

Functional Interaction Of The Retinoblastoma And Ini1/Snf5 Tumor Suppressors In Cell Growth And Pituitary Tumorigenesis, Cynthia J. Guidi, Rajini R. Mudhasani, Kathleen Hoover, Andrew Koff, Irwin Leav, Anthony N. Imbalzano, Stephen N. Jones

Open Access Articles

The Ini1 subunit of the SWI/SNF chromatin remodeling complex suppresses formation of malignant rhabdoid tumors in humans and mice. Transduction of Ini1 into Ini1-deficient tumor-derived cell lines has indicated that Ini1 arrests cell growth, controls chromosomal ploidy, and suppresses tumorigenesis by regulating components of the retinoblastoma (Rb) signaling pathway. Furthermore, conditional inactivation of Ini1 in mouse fibroblasts alters the expression of various Rb-E2F-regulated genes, indicating that endogenous Ini1 levels may control Rb signaling in cells. We have reported previously that loss of one allele of Ini1 in mouse fibroblasts results only in a 15% to 20% reduction in total ...


Supervillin Modulation Of Focal Adhesions Involving Trip6/Zrp-1, Norio Takizawa, Tara C. Smith, Thomas Nebl, Jessica Lynn Crowley, Stephen J. Palmieri, Lawrence M. Lifshitz, Anka G. Ehrhardt, Laura M. Hoffman, Mary C. Beckerle, Elizabeth J. Luna Aug 2006

Supervillin Modulation Of Focal Adhesions Involving Trip6/Zrp-1, Norio Takizawa, Tara C. Smith, Thomas Nebl, Jessica Lynn Crowley, Stephen J. Palmieri, Lawrence M. Lifshitz, Anka G. Ehrhardt, Laura M. Hoffman, Mary C. Beckerle, Elizabeth J. Luna

Women’s Health Research Faculty Publications

Cell-substrate contacts, called focal adhesions (FAs), are dynamic in rapidly moving cells. We show that supervillin (SV)--a peripheral membrane protein that binds myosin II and F-actin in such cells--negatively regulates stress fibers, FAs, and cell-substrate adhesion. The major FA regulatory sequence within SV (SV342-571) binds to the LIM domains of two proteins in the zyxin family, thyroid receptor-interacting protein 6 (TRIP6) and lipoma-preferred partner (LPP), but not to zyxin itself. SV and TRIP6 colocalize within large FAs, where TRIP6 may help recruit SV. RNAi-mediated decreases in either protein increase cell adhesion to fibronectin. TRIP6 partially rescues SV effects on ...


Myod Synergizes With The E-Protein Heb Beta To Induce Myogenic Differentiation, Maura H. Parker, Robert L.S. Perry, Melanie C. Fauteux, Charlotte A. Berkes, Michael A. Rudnicki Aug 2006

Myod Synergizes With The E-Protein Heb Beta To Induce Myogenic Differentiation, Maura H. Parker, Robert L.S. Perry, Melanie C. Fauteux, Charlotte A. Berkes, Michael A. Rudnicki

Biology Faculty Publications

The MyoD family of basic helix-loop-helix transcription factors function as heterodimers with members of the E-protein family to induce myogenic gene activation. The E-protein HEB is alternatively spliced to generate alpha and beta isoforms. While the function of these molecules has been studied in other cell types, questions persist regarding the molecular functions of HEB proteins in skeletal muscle. Our data demonstrate that HEB alpha expression remains unchanged in both myoblasts and myotubes, whereas HEB beta is upregulated during the early phases of terminal differentiation. Upon induction of differentiation, a MyoD-HEB beta complex bound the E1 E-box of the myogenin ...


Cell Edge Features Affected By Microtubule Inhibitor Combinations, Sonal Uppal, Nancy Boudreau, Elizabeth Wendt, Carol Heckman Aug 2006

Cell Edge Features Affected By Microtubule Inhibitor Combinations, Sonal Uppal, Nancy Boudreau, Elizabeth Wendt, Carol Heckman

Applied Statistics and Operations Research Faculty Publications

The tumor promoter, phorbol 12-myristate 13-acetate (PMA), enhances tumor yield through an epigenetic mechanism. PMA, like another promoter, phosphatase inhibitor okadaic acid, works by maintaining proteins in a phosphorylated state. In order to identify chemicals with promoter and antipromoter effects, this laboratory has developed a standard curve of morphogenetic changes using data from precancerous cell lines that eventually became neoplastic. Using the curve as a basis of comparison, we defined the “signature” phenotype as that adopted when a cell line became neoplastic. The results of solving for signature type disclosed that the microtubule-depolymerizing compound, colchicine, had a promoter-like effect [2 ...


Unequal Sister Chromatid And Homolog Recombination At A Tandem Duplication Of The A1 Locus In Maize, Marna D. Yandeau-Nelson, Yiji Xia, Jin Li, M. Gerald Neuffer, Patrick S. Schnable Aug 2006

Unequal Sister Chromatid And Homolog Recombination At A Tandem Duplication Of The A1 Locus In Maize, Marna D. Yandeau-Nelson, Yiji Xia, Jin Li, M. Gerald Neuffer, Patrick S. Schnable

Genetics, Development and Cell Biology Publications

Tandemly arrayed duplicate genes are prevalent. The maize A1-b haplotype is a tandem duplication that consists of the components, a and b. The rate of meiotic unequal recombination at A1-b is ninefold higher when a homolog is present than when it is absent (i.e., hemizygote). When a sequence heterologous homolog is available, 94% of recombinants (264/281) are generated via recombination with the homolog rather than with the sister chromatid. In addition, 83% (220/264) of homolog recombination events involved a rather than b. These results indicate that: (1) the homolog is the preferred template for unequal recombination and ...


Scanning Microarrays At Multiple Intensities Enhances Discovery Of Differentially Expressed Genes, David S. Skibbe, Xiujuan Wang, Xuefeng Zhao, Lisa A. Borsuk, Dan Nettleton, Patrick S. Schnable Aug 2006

Scanning Microarrays At Multiple Intensities Enhances Discovery Of Differentially Expressed Genes, David S. Skibbe, Xiujuan Wang, Xuefeng Zhao, Lisa A. Borsuk, Dan Nettleton, Patrick S. Schnable

Statistics Publications

Motivation: Scanning parameters are often overlooked when optimizing microarray experiments. A scanning approach that extends the dynamic data range by acquiring multiple scans of different intensities has been developed.

Results: Data from each of three scan intensities (low, medium, high) were analyzed separately using multiple scan and linear regression approaches to identify and compare the sets of genes that exhibit statistically significant differential expression. In the multiple scan approach only one-third of the differentially expressed genes were shared among the three intensities, and each scan intensity identified unique sets of differentially expressed genes. The set of differentially expressed genes from ...


Characterization Of Membrane Potentials In Vascular Smooth Muscle Of Hagfish, Lamprey And Trout, Prentiss Jones Jr. Aug 2006

Characterization Of Membrane Potentials In Vascular Smooth Muscle Of Hagfish, Lamprey And Trout, Prentiss Jones Jr.

Dissertations

The objective of this study was to characterize membrane potentials in systemic arteries of Pacific hagfish, Eptatretus stouti, Rainbow trout, Onchorhyncus mykiss, and Sea lamprey Petromyzon marinus. Previous studies have characterized membrane potentials in piscine tissue. However, these studies utilized non-vascular tissues such as cardiac muscle and skeletal muscle (69, 161). Characterization of membrane potentials in fish vasculature is without precedent in the literature. The hypothesis of this study was that membrane potentials in fish vascular smooth muscle differ little between species when comparable vasculature is evaluated.