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Cell and Developmental Biology

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Articles 1261 - 1290 of 1533

Full-Text Articles in Biology

Na/K-Atpase Mimetic Pnaktide Peptide Inhibits The Growth Of Human Cancer Cells, Zhichuan Li, Zhongbing Zhang, Joe X. Xie, Xin Li, Jiang Tian, Ting Cai, Hongaun Cui, Hanfei Ding, Joseph I. Shapiro Md, Zijian Xie Jul 2011

Na/K-Atpase Mimetic Pnaktide Peptide Inhibits The Growth Of Human Cancer Cells, Zhichuan Li, Zhongbing Zhang, Joe X. Xie, Xin Li, Jiang Tian, Ting Cai, Hongaun Cui, Hanfei Ding, Joseph I. Shapiro Md, Zijian Xie

Biochemistry and Microbiology

Cells contain a large pool of non-pumping Na/K-ATPase that participates in signal transduction. Here, we show that the expression of α1 Na/K-ATPase is significantly reduced in human prostate carcinoma as well as in several human cancer cell lines. This down-regulation impairs the ability of Na/K-ATPase to regulate Src-related signaling processes. Supplement of pNaKtide, a peptide derived from α1 Na/K-ATPase, reduces activities of Src and Src effectors. Consequently, these treatments stimulate apoptosis and inhibit growth in cultures of human cancer cells. Moreover, administration of pNaKtide inhibits angiogenesis and growth of tumor xenograft. Thus, the new findings demonstrate the in vivo effectiveness …


Mechanical Test Methods For Assessing Porcine Carotid And Uterine Artery Burst Pressure Following Ex Vivo Ultrasonic Ligature Seal And Transection, Carissa M. Krane, Margaret Pinnell, Courtney Gardner, Mercedes Thompson, James Coleman, Robert Wilkens Jul 2011

Mechanical Test Methods For Assessing Porcine Carotid And Uterine Artery Burst Pressure Following Ex Vivo Ultrasonic Ligature Seal And Transection, Carissa M. Krane, Margaret Pinnell, Courtney Gardner, Mercedes Thompson, James Coleman, Robert Wilkens

Biology Faculty Publications

A test method was developed to identify those variables important for assessing the performance of ultrasonic surgical devices in ex vivo ligature sealing of porcine carotid and uterine arteries. Ruggedness testing using a small sample size in pilot experiments was conducted using a newly developed test method in an effort to assess the usefulness of this methodology and to identify test variables that might warrant further testing. The development of this test method included the use of a custom-designed prototypic tension device for load-controlled ex vivo vessel stretching during saline perfusion and subsequent seal and transection of porcine arteries with …


Homoplastic Microinversions And The Avian Tree Of Life, E. L. Braun, R T. Kimball, K. L. Han, N. R. Luhasz-Velez, A. J. Bonilla, Jena L. Chojnowski, J. V. Smith, R. C. Bowie, M. J. Braun, S. J. Hackett, J. Harshman, C. J. Huddleston, B. D. Marks, W. S. Moore, S. Reddy, F. H. Sheldon, C. C. Witt, T. Yuri May 2011

Homoplastic Microinversions And The Avian Tree Of Life, E. L. Braun, R T. Kimball, K. L. Han, N. R. Luhasz-Velez, A. J. Bonilla, Jena L. Chojnowski, J. V. Smith, R. C. Bowie, M. J. Braun, S. J. Hackett, J. Harshman, C. J. Huddleston, B. D. Marks, W. S. Moore, S. Reddy, F. H. Sheldon, C. C. Witt, T. Yuri

Natural Sciences Faculty Publications

BACKGROUND:

Microinversions are cytologically undetectable inversions of DNA sequences that accumulate slowly in genomes. Like many other rare genomic changes (RGCs), microinversions are thought to be virtually homoplasy-free evolutionary characters, suggesting that they may be very useful for difficult phylogenetic problems such as the avian tree of life. However, few detailed surveys of these genomic rearrangements have been conducted, making it difficult to assess this hypothesis or understand the impact of microinversions upon genome evolution.

RESULTS:

We surveyed non-coding sequence data from a recent avian phylogenetic study and found substantially more microinversions than expected based upon prior information about vertebrate …


Septin Filaments Exhibit A Dynamic, Paired Organization That Is Conserved From Yeast To Mammals, Bradley S. Demay, Xiaobo Bai, Louisa Howard, Patricia Occhipinti, Rebecca A. Meseroll, Elias T. Spiliotis, Rudolf Oldenbourg, Amy S. Gladfelter May 2011

Septin Filaments Exhibit A Dynamic, Paired Organization That Is Conserved From Yeast To Mammals, Bradley S. Demay, Xiaobo Bai, Louisa Howard, Patricia Occhipinti, Rebecca A. Meseroll, Elias T. Spiliotis, Rudolf Oldenbourg, Amy S. Gladfelter

Dartmouth Scholarship

The septins are conserved, GTP-binding proteins important for cytokinesis, membrane compartmentalization, and exocytosis. However, it is unknown how septins are arranged within higher-order structures in cells. To determine the organization of septins in live cells, we developed a polarized fluorescence microscopy system to monitor the orientation of GFP dipole moments with high spatial and temporal resolution. When GFP was fused to septins, the arrangement of GFP dipoles reflected the underlying septin organization. We demonstrated in a filamentous fungus, a budding yeast, and a mammalian epithelial cell line that septin proteins were organized in an identical highly ordered fashion. Fluorescence anisotropy …


The Cell Biology Of Multi-Nucleated Giant Cell Formation, Johnathan L. Bartee May 2011

The Cell Biology Of Multi-Nucleated Giant Cell Formation, Johnathan L. Bartee

Theses

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The Role Of Phosphoinositide Signaling In Breast Cancer Metastasis Suppressor 1-Mediated Metastasis Suppression Of Human Breast Carcinoma Cells, Sitaram Harihar May 2011

The Role Of Phosphoinositide Signaling In Breast Cancer Metastasis Suppressor 1-Mediated Metastasis Suppression Of Human Breast Carcinoma Cells, Sitaram Harihar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Breast cancer is the most common non-skin cancer in women and the second most common cause of cancer-related death in U.S. women. Despite numerous advances in treatment strategies against breast cancer, the presence of undetected distant metastasis of the primary tumor remains the main cause of mortality. Current screening and detection methods such as mammograms are simply not sensitive enough to detect formation of metastasis. Further, currently available therapies against metastatic breast cancer do not provide a complete cure for the disease. Thus, understanding the biology and molecular factors involved in cancer metastasis will help aid in preventing the onset …


Design Of A Factorial Experiment With Randomization Restrictions To Assess Medical Device Performance On Vascular Tissue, Wiebke Diestelkamp, Carissa M. Krane, Margaret Pinnell May 2011

Design Of A Factorial Experiment With Randomization Restrictions To Assess Medical Device Performance On Vascular Tissue, Wiebke Diestelkamp, Carissa M. Krane, Margaret Pinnell

Biology Faculty Publications

Background: Energy-based surgical scalpels are designed to efficiently transect and seal blood vessels using thermal energy to promote protein denaturation and coagulation. Assessment and design improvement of ultrasonic scalpel performance relies on both in vivo and ex vivo testing. The objective of this work was to design and implement a robust, experimental test matrix with randomization restrictions and predictive statistical power, which allowed for identification of those experimental variables that may affect the quality of the seal obtained ex vivo.

Methods: The design of the experiment included three factors: temperature (two levels); the type of solution used to perfuse the …


Endo-Porter–Mediated Delivery Of Phosphorodiamidate Morpholino Oligos (Pmos) In Erythrocyte Suspension Cultures From Cope's Gray Treefrog Hyla Chrysoscelis, Venkateshwar Mutyam, Matthew V. Puccetti, James Frisbie, David L. Goldstein, Carissa M. Krane May 2011

Endo-Porter–Mediated Delivery Of Phosphorodiamidate Morpholino Oligos (Pmos) In Erythrocyte Suspension Cultures From Cope's Gray Treefrog Hyla Chrysoscelis, Venkateshwar Mutyam, Matthew V. Puccetti, James Frisbie, David L. Goldstein, Carissa M. Krane

Biology Faculty Publications

Cope's gray treefrog, Hyla chrysoscelis, is a freeze-tolerant anuran that accumulates cryoprotective glycerol during cold acclimation. H. chrysoscelis erythrocytes express the aquaglyceroporin HC-3, which facilitates transmembrane glycerol and water movement. Aquaglyceroporins have no pharmacological inhibitors, and no genetic knockout tools currently exist for H. chrysoscelis. A phosphorodiamidate morpholino oligo (PMO)–mediated expression knockdown approach was therefore pursued to provide a model for testing the role of HC-3. We describe a novel procedure optimized for specific, efficient knockdown of HC-3 expression in amphibian erythrocyte suspensions cultured at nonmammalian physiological temperatures using Endo-Porter. Our protocol includes three critical components: pre-incubation at 37°C, …


Cop 9 Signalosome Subunit 6 Stabilizes Cop1, A Novel E3 Ubiquitin Ligase For 14-3-3Σ, Hyun Ho Choi May 2011

Cop 9 Signalosome Subunit 6 Stabilizes Cop1, A Novel E3 Ubiquitin Ligase For 14-3-3Σ, Hyun Ho Choi

Dissertations and Theses (Open Access)

14-3-3σ, a gene upregulated by p53 in response to DNA damage, exists as part of a positive-feedback loop which activates p53 and is a human cancer epithelial marker downregulated in various cancer types. 14-3-3σ levels are critical for maintaining p53 activity in response to DNA damage and regulating signal mediator such as Akt. Here, we identify Mammalian Constitutive Photomorphogenic 1 (COP1) as a novel E3 ubiquitin ligase for targeting 14-3-3σ through proteasome degradation. We show for the first time that COP9 signalosome subunit 6 (CSN6) associates with COP1 and is involved in 14-3-3σ ubiquitin-mediated degradation. Mechanistic studies show that CSN6 …


Investigating The Effects Of Silencing Epha2 In Metastatic Breast Cancer Cells, Stephanie Erzinger May 2011

Investigating The Effects Of Silencing Epha2 In Metastatic Breast Cancer Cells, Stephanie Erzinger

Dissertations and Theses (Open Access)

EphA2, also known as ECK (epithelial cell kinase), is a transmembrane receptor tyrosine kinase that is commonly over-expressed in cancers such as those of the prostate, colon, lung, and breast. For breast cancers, EphA2 overexpression is most prominent in the ER-negative subtype, and is associated with a higher rate of lung metastasis. Studies conducted to demonstrate the role of EphA2 in a non-cancerous environment have shown that it is very important in developmental processes, but not in normal adult tissues. These results make EphA2 a prospective therapeutic target since new therapies are needed for the more aggressive ER-negative breast cancers. …


The Immunophenotypic And Cytokine Characterization Of The Osteoarthritic Human Patellar Fat Pad: Comparison To Subcutaneous Adipose Tissue, Katie Marie Hamel Apr 2011

The Immunophenotypic And Cytokine Characterization Of The Osteoarthritic Human Patellar Fat Pad: Comparison To Subcutaneous Adipose Tissue, Katie Marie Hamel

Honors Capstones

No abstract provided.


Stem Cell Biology And Strategies For Therapeutic Development In Degenerative Diseases And Cancer, Angel A. Alvarez '98 Apr 2011

Stem Cell Biology And Strategies For Therapeutic Development In Degenerative Diseases And Cancer, Angel A. Alvarez '98

Doctoral Dissertations

Stem cell biology is an exciting field that will lead to significant advancements in science and medicine. We hypothesize that inducing the expression of stem cell genes, using the embryonic stem cell gene nanog, will reprogram cells and dedifferentiate human mesenchymal stem cells into pluripotent stem cells capable of neural differentiation. The aims of initial studies are as follows:

Aim 1: Demonstrate that forced expression of the embryonic stem cell gene nanog induces changes in human mesenchymal stem cells to an embryonic stem cell-like phenotype.

Aim 2: Demonstrate that induced expression of nanog up-regulates the expression of multiple embryonic stem …


Modulation Of Glutamate-Mediated Neuronal Cell Death By Neurosteroids, Benjamin J. Phelps Apr 2011

Modulation Of Glutamate-Mediated Neuronal Cell Death By Neurosteroids, Benjamin J. Phelps

Undergraduate Theses and Capstone Projects

Traumatic brain injury (TBI) is a major cause of death and permanent disability in the United States. Approximately 1.7 million cases of TBI are reported annually. After an injury to the head, excessive glutamate, an excitatory neurotransmitter, is released into the extracellular fluid resulting in the excitotoxic death of neuronal tissue. Recent studies have suggested neurosteroids, may serve as an effective means by which to modulate excitotoxicity via the excitatory neurotransmitter alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). Using mixed astrocyte-neuronal cell cultures (14-16 DIV) exposed to increasing concentrations of AMPA as the model for TBI, the experiments examined the effect of the neurosteroids, …


Angiostatin Like Peptides In Milk: Potential Development For Dairy Products Capable Of Cancer Prevention, Erin Stefanutti Mar 2011

Angiostatin Like Peptides In Milk: Potential Development For Dairy Products Capable Of Cancer Prevention, Erin Stefanutti

Master's Theses

For the past 40 years, antiangiogenic approaches have been of major interest in the development of methods to cure and prevent cancer. Angiogenesis, the development of blood vessels from pre-existing vascularization, is essential for cancer growth and spread of metastasis through the delivery of nutrients and oxygen essential to sustain the metabolic activity of these malignant cells. Blocking access to blood will cause cancerous cells to assume a dormant state creating inactive micro-tumors innocuous to the host. Angiostatin, the internal fragment of the fibrinolytic zymogen plasminogen, has shown great potential in reducing cancer size and number of metastatic colonies in …


Stress-Induced Proteolysis Of Fkbp10: Mutational Analysis And Functional Implications, Lindsey A. Murphy Jan 2011

Stress-Induced Proteolysis Of Fkbp10: Mutational Analysis And Functional Implications, Lindsey A. Murphy

Featured Research

Cellular signaling is a complex system of communication that regulates cell function through a variety of molecular messengers. When cell survival is threatened by changes in environment or by malfunction of internal regulatory pathways, signals are initiated to restore homeostasis. Deficient protein processing within the endoplasmic reticulum (ER) causes an accumulation of misfolded proteins and stress signaling. The resulting stress signaling includes both adaptive signals (unfolded protein response) and in cases of severe ER stress apoptotic signals induced via the mitochondria. FKBP10 is a key ER luminal peptidy-prolyl isomerase (rotamase) that mediates protein folding. The production of chaperone proteins and …


Analysis Of Biological Features Associated With Meiotic Recombination Hot And Cold Spots In Saccharomyces Cerevisiae, Loren Hansen, Nak-Kyeong Kim, Leonardo Mariño-Ramírez, David Landsman Jan 2011

Analysis Of Biological Features Associated With Meiotic Recombination Hot And Cold Spots In Saccharomyces Cerevisiae, Loren Hansen, Nak-Kyeong Kim, Leonardo Mariño-Ramírez, David Landsman

Mathematics & Statistics Faculty Publications

Meiotic recombination is not distributed uniformly throughout the genome. There are regions of high and low recombination rates called hot and cold spots, respectively. The recombination rate parallels the frequency of DNA double-strand breaks (DSBs) that initiate meiotic recombination. The aim is to identify biological features associated with DSB frequency. We constructed vectors representing various chromatin and sequence-based features for 1179 DSB hot spots and 1028 DSB cold spots. Using a feature selection approach, we have identified five features that distinguish hot from cold spots in Saccharomyces cerevisiae with high accuracy, namely the histone marks H3K4me3, H3K14ac, H3K36me3, and H3K79me3; …


The Impact Of Tricaine Methanesulfonate, 2-Phenoxyethanol, And Carvone-Methyl Salicylate On The Innate Immune Response Of Zebrafish (Danio Rerio), Charles R. Wulff Jan 2011

The Impact Of Tricaine Methanesulfonate, 2-Phenoxyethanol, And Carvone-Methyl Salicylate On The Innate Immune Response Of Zebrafish (Danio Rerio), Charles R. Wulff

Honors Theses

Anesthesia plays a vital role in the maintenance of aquaculture species, where it is used to minimize stress during complex handling tasks such as transport, assessment, and harvesting. However, anesthetics have been shown to suppress the innate immune response, which could impact immunity and increase risk of infection. Tricaine methanesulfonate (MS-222) and 2-Phenoxyethanol (2-PE) represent two of the most commonly used anesthetics in aquaculture, with R-(+)-carvone, in the form of carvone-methyl salicylate (CMS) has recently been proposed as an alternative anesthetic for food fish. These three anesthetics were used to assess the influence of anesthetics on the immune system of …


Rho Kinase Regulates Basement Membrane Dynamics To Coordinate Salivary Gland Branching Morphogenesis And Tissue Organization, William Patrick Daley Jan 2011

Rho Kinase Regulates Basement Membrane Dynamics To Coordinate Salivary Gland Branching Morphogenesis And Tissue Organization, William Patrick Daley

Legacy Theses & Dissertations (2009 - 2024)

Branching morphogenesis is a developmental mechanism utilized by many organs, including the salivary gland, lung, kidney, and mammary gland, to increase the epithelial surface area for secretion or absorption. The embryonic submandibular salivary gland (SMG) is a classic model for studying tissue morphogenesis in three dimensions ex vivo. Salivary gland development requires distinct but overlapping processes: morphogenesis, the actual physical rearrangement of cells into complex three dimensional structures, and cytodifferentiation, the process by which these cells begin to take on their own specialized function. Polarization, or the organization of cells into a cohesive tissue structure, also occurs concurrently during organ …


Examination Of The Mitochondrial Health Of The Basigin Null Mouse Retina, Kristine Anne V. Pablo Jan 2011

Examination Of The Mitochondrial Health Of The Basigin Null Mouse Retina, Kristine Anne V. Pablo

UNF Graduate Theses and Dissertations

Basigin gene products are cell adhesion molecules that are expressed by photoreceptor cells, Müller cells and endothelial cells of the mammalian retina. Previous studies have suggested that a lactate shuttle exists between the photoreceptor cells and the Müller cells, with Basigin being an essential component in this shuttle. Deletion of the Basigin gene in mice results in blindness with an eventual retinal degeneration. It was hypothesized that the lactate shuttle between photoreceptors and Müller cells does not form in Basigin null mice and that the blindness is attributed to faulty photoreceptor metabolism. Therefore, the purpose of this study was to …


The Characterization Of Genes Involved In Response To The Phenol Derivative And Xenoestrogen Bisphenol-A In Saccharomyces Cerevisiae, Sasha N. Farina Jan 2011

The Characterization Of Genes Involved In Response To The Phenol Derivative And Xenoestrogen Bisphenol-A In Saccharomyces Cerevisiae, Sasha N. Farina

CMC Senior Theses

Bisphenol A is an estrogenic compound that is found in polycarbonate plastics and epoxy resins; humans are continuously exposed to the compound and it is believed to possess the same carcinogenic effects as estrogen (Iso, 2006). In this study, I used Saccharomyces cerevisiae as a model organism to identify mechanisms by which BPA acts based on the genomic profiling of kinase genes from a Mat-α haploid deletion library. Kinases regulate many other proteins, so the identification of a single mutant could identify an entire affected pathway of genes. I conducted a systematic screen of these mutants using the phenotype of …


Variation, Systematics, And Relationships Of The Leptodactylus Bolivianus Complex (Amphibia: Anura: Leptodactylidae), W. Ronald Heyer, Rafael O. De Sá Jan 2011

Variation, Systematics, And Relationships Of The Leptodactylus Bolivianus Complex (Amphibia: Anura: Leptodactylidae), W. Ronald Heyer, Rafael O. De Sá

Biology Faculty Publications

Heyer, W. Ronald, and Rafael O. de Sá. Variation, Systematics, and Relationships of the Leptodactylus bolivianus Complex (Amphibia: Anura: Leptodactylidae). Smithsonian Contributions to Zoology, number 635, viii + 58 pages, 21 figures, 20 tables, 2011.—The Leptodactylus bolivianuscomplex has been considered to consist of one or two species, L. bolivianus alone or L. bolivianus and L. insularum. Detailed morphological analyses were undertaken to evaluate variation in the complex, which ranges from Costa Rica through Panama, across northern South America in the river valleys draining to the Caribbean, and throughout much of the Amazon basin with southern limits in Bolivia. Members of …


Mechanical Forces And Tumor Cells: Insight Into The Biophysical Aspects Of Cancer Progression, Indrajyoti Indra Jan 2011

Mechanical Forces And Tumor Cells: Insight Into The Biophysical Aspects Of Cancer Progression, Indrajyoti Indra

Wayne State University Dissertations

Mechanical forces play an important role in the regulation of cellular behavior and physiological processes including adhesion, migration, proliferation, tissue repair, embryogenesis and development. In addition, a number of diseases including cancer, have been linked to changes in cellular and extracellular mechanical properties. However, whether a correlation exists between the progression of cancer towards metastasis and mechanical factors has not been clearly defined. Additionally, how a cell responds to changes in extracellular mechanical cues as it gains metastatic abilities is poorly understood. To address these questions, we have utilized a panel of murine breast cancer cell lines with progressive metastatic. …


Β3-Adrenergic Agonists Mimic Eustress Response And Reduce Leptin-Mediated Proliferation In A Gbm Cell Line , Johnathan Lawrence, Nicholas J. Cook, Richard A. Rovin, Robert J. Winn Jan 2011

Β3-Adrenergic Agonists Mimic Eustress Response And Reduce Leptin-Mediated Proliferation In A Gbm Cell Line , Johnathan Lawrence, Nicholas J. Cook, Richard A. Rovin, Robert J. Winn

Journal Articles

A great deal of mental stress, depression, and anxiety often overwhelm cancer patients; those diagnosed with glioblastoma multiforme (GBM) are no exception. Different types of stress invariably impact what has been termed “the brain-adipocyte BDNF/leptin axis” (Dr. Cao and colleagues of the Comprehensive Cancer Center at The Ohio State University). For example, eustress (good stress) and distress (bad stress) both lead to increased sympathetic activity and adrenal gland stimulation, yet eustress reduces leptin levels and attenuates tumor growth while distress increases leptin levels and augments tumor growth. Complicating matters in GBM is that leptin and its receptor are expressed at …


Glioblastoma Derived Exosomes Contribute To Tumor Immune Evasion , Keith Z. Sabin, Danny Lebert, Vanessa Thibado, Richard A. Rovin, Johnathan Lawrence, Robert J. Winn Jan 2011

Glioblastoma Derived Exosomes Contribute To Tumor Immune Evasion , Keith Z. Sabin, Danny Lebert, Vanessa Thibado, Richard A. Rovin, Johnathan Lawrence, Robert J. Winn

Journal Articles

Glioblastoma multiforme (GBM) is the most frequent and lethal primary brain tumor in adults. Despite intense biomedical research, the median survival after diagnosis is 15 months. One factor contributing to this poor prognosis is the immune protection afforded by the tumor microenvironment. Tumors have a diverse repertoire of immune-evasive techniques. One method of evasion not well explored is the release of tumor-derived exosomes. Exosomes are tiny membrane-bound vesicles of endocytic origin that contain viable mRNA and functional proteins that can affect the physiology of recipient cells. Exosome release has been reported for numerous cancer types, including GBM. Exosomes from colon …


Escherichia Coli Fpg Glycosylase Is Nonrendundant And Required For The Rapid Global Repair Of Oxidized Purine And Pyrimidine Damage In Vivo, Brandy J. Schalow, Charmain T. Courcelle, Justin Courcelle Jan 2011

Escherichia Coli Fpg Glycosylase Is Nonrendundant And Required For The Rapid Global Repair Of Oxidized Purine And Pyrimidine Damage In Vivo, Brandy J. Schalow, Charmain T. Courcelle, Justin Courcelle

Biology Faculty Publications and Presentations

Endonuclease (Endo) III and formamidopyrimidine-N-glycosylase (Fpg) are two of the predominant DNA glycosylases in Escherichia coli that remove oxidative base damage. In cell extracts and purified form, Endo III is generally more active toward oxidized pyrimidines, while Fpg is more active towards oxidized purines. However, the substrate specificities of these enzymes partially overlap in vitro. Less is known about the relative contribution of these enzymes in restoring the genomic template following oxidative damage. In this study, we examined how efficiently Endo III and Fpg repair their oxidative substrates in vivo following treatment with hydrogen peroxide. We found …


Quantifying Agonist Activity At G Protein-Coupled Receptors, Frederick J. Ehlert, Hinako Suga, Michael T. Griffin Jan 2011

Quantifying Agonist Activity At G Protein-Coupled Receptors, Frederick J. Ehlert, Hinako Suga, Michael T. Griffin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

When an agonist activates a population of G protein-coupled receptors (GPCRs), it elicits a signaling pathway that culminates in the response of the cell or tissue. This process can be analyzed at the level of a single receptor, a population of receptors, or a downstream response. Here we describe how to analyze the downstream response to obtain an estimate of the agonist affinity constant for the active state of single receptors.

Receptors behave as quantal switches that alternate between active and inactive states (Figure 1). The active state interacts with specific G proteins or other signaling partners. In the absence …


Biphasic Targeting And Cleavage Furrow Ingression Directed By The Tail Of A Myosin Ii, X. Fang, J. Y. Luo, R. Nishihama, C. Wloka, C. Dravis, M. Travaglia, M. Iwase, Elizabeth Ann Vallen, E. Bi Dec 2010

Biphasic Targeting And Cleavage Furrow Ingression Directed By The Tail Of A Myosin Ii, X. Fang, J. Y. Luo, R. Nishihama, C. Wloka, C. Dravis, M. Travaglia, M. Iwase, Elizabeth Ann Vallen, E. Bi

Biology Faculty Works

Cytokinesis in animal and fungal cells utilizes a contractile actomyosin ring (AMR). However, how myosin II is targeted to the division site and promotes AMR assembly, and how the AMR coordinates with membrane trafficking during cytokinesis, remains poorly understood. Here we show that Myo1 is a two-headed myosin II in Saccharomyces cerevisiae, and that Myo1 localizes to the division site via two distinct targeting signals in its tail that act sequentially during the cell cycle. Before cytokinesis, Myo1 localization depends on the septin-binding protein Bni5. During cytokinesis, Myo1 localization depends on the IQGAP Iqg1. We also show that the Myo1 …


The Roles Of Elevated Bcl-2 In Ovarian Cancer, Nicole Shree Anderson Dec 2010

The Roles Of Elevated Bcl-2 In Ovarian Cancer, Nicole Shree Anderson

USF Tampa Graduate Theses and Dissertations

Ovarian cancer (OC) is the second most common gynecologic cancer; however it is responsible for the most gynecologic cancer-related deaths. Apoptosis evasion is an important mechanism in OC tumorigenesis, and the prototypic anti-apoptotic protein, B-cell lymphoma 2 (Bcl-2), is often overexpressed in OC tumors. Gaining a better understanding of the mechanism(s) behind Bcl-2 overexpression and potential extra-anti-apoptotic functions of Bcl-2 could elucidate the importance of elevated Bcl-2 in OC. In the current study, I show through immunohistochemical analysis of normal, benign, and OC tissue sections, that both epithelial and stromal Bcl-2 expression decreases with OC progression. However, the number of …


Identification Of An Archaeal Presenilin-Like Intramembrane Protease, Celia Torres-Arancivia, Carolyn M. Ross, Jose Chavez, Zahra Assur, Georgia Dolios, Filippo Mancia, Iban Ubarretxena-Belandia Sep 2010

Identification Of An Archaeal Presenilin-Like Intramembrane Protease, Celia Torres-Arancivia, Carolyn M. Ross, Jose Chavez, Zahra Assur, Georgia Dolios, Filippo Mancia, Iban Ubarretxena-Belandia

Publications and Research

Background: The GXGD-type diaspartyl intramembrane protease, presenilin, constitutes the catalytic core of the c-secretase multi-protein complex responsible for activating critical signaling cascades during development and for the production of b-amyloid peptides (Ab) implicated in Alzheimer’s disease. The only other known GXGD-type diaspartyl intramembrane proteases are the eukaryotic signal peptide peptidases (SPPs). The presence of presenilin-like enzymes outside eukaryots has not been demonstrated. Here we report the existence of presenilin-like GXGD-type diaspartyl intramembrane proteases in archaea.

Methodology and Principal Findings: We have employed in vitro activity assays to show that MCMJR1, a polytopic membrane protein from the archaeon Methanoculleus marisnigri JR1, …


Repression Of Wnt Signaling By A Fer-Type Nonreceptor Tyrosine Kinase, Aaron P. Putzke Sep 2010

Repression Of Wnt Signaling By A Fer-Type Nonreceptor Tyrosine Kinase, Aaron P. Putzke

Biology Faculty Scholarship

The Wnt signaling pathway must be properly modulated to ensure an appropriate output: pathological conditions result from either insufficient or excessive levels of Wnt signal. For example, hyperactivation of the Wnt pathway is associated with various cancers and subnormal Wnt signaling can lead to increased invasiveness of tumor cells. We found that the Caenorhabditis elegans ortholog of the Fer nonreceptor tyrosine kinase, FRK-1, limits Wnt signaling by preventing the adhesion complex-associated β-catenin, HMP-2, from participating in Wnt-dependent specification of the endoderm during embryogenesis. Removal of FRK-1 function results in relocalization of HMP-2 to the nucleus of epidermal cells, and allows …