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Articles 2821 - 2850 of 3278

Full-Text Articles in Cell and Developmental Biology

Yeast Cell Adhesion Molecules Have Functional Amyloid-Forming Sequences, Caleen B. Ramsook, Cho Tan, Melissa C. Garcia, Raymond Fung, Gregory Soybelman, Ryan Henry, Anna Litewka, Shanique O’Meally, Henry N. Otoo, Roy A. Khalaf, Anne M. Dranginis, Nand K. Gaur, Stephen A. Klotz, Jason M. Rauceo, Chong K. Jue, Peter N. Lipke Mar 2010

Yeast Cell Adhesion Molecules Have Functional Amyloid-Forming Sequences, Caleen B. Ramsook, Cho Tan, Melissa C. Garcia, Raymond Fung, Gregory Soybelman, Ryan Henry, Anna Litewka, Shanique O’Meally, Henry N. Otoo, Roy A. Khalaf, Anne M. Dranginis, Nand K. Gaur, Stephen A. Klotz, Jason M. Rauceo, Chong K. Jue, Peter N. Lipke

Publications and Research

The occurrence of highly conserved amyloid-forming sequences in Candida albicans Als proteins (H. N. Otoo et al., Eukaryot. Cell 7:776–782, 2008) led us to search for similar sequences in other adhesins from C. albicans and Saccharomyces cerevisiae. The beta-aggregation predictor TANGO found highly beta-aggregation-prone sequences in almost all yeast adhesins. These sequences had an unusual amino acid composition: 77% of their residues were beta-aggregation aliphatic amino acids Ile, Thr, and Val, which is more than 4-fold greater than their prevalence in the S. cerevisiae proteome. High beta-aggregation potential peptides from S. cerevisiae Flo1p and C. albicans Eap1p rapidly formed insoluble …

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Structure And Function Of Glycosylated Tandem Repeats From Candida Albicans Als Adhesins, Aaron T. Frank, Caleen B. Ramsook, Henry N. Otoo, Cho Tan, Gregory Soybelman, Jason M. Rauceo, Nand K. Gaur, Stephen A. Klotz, Peter N. Lipke Mar 2010

Structure And Function Of Glycosylated Tandem Repeats From Candida Albicans Als Adhesins, Aaron T. Frank, Caleen B. Ramsook, Henry N. Otoo, Cho Tan, Gregory Soybelman, Jason M. Rauceo, Nand K. Gaur, Stephen A. Klotz, Peter N. Lipke

Publications and Research

Tandem repeat (TR) regions are common in yeast adhesins, but their structures are unknown, and their activities are poorly understood. TR regions in Candida albicans Als proteins are conserved glycosylated 36-residue sequences with cell-cell aggregation activity (J. M. Rauceo, R. De Armond, H. Otoo, P. C. Kahn, S. A. Klotz, N. K. Gaur, and P. N. Lipke, Eukaryot. Cell 5:1664–1673, 2006). Ab initio modeling with either Rosetta or LINUS generated consistent structures of three-stranded antiparallel beta-sheet domains, whereas randomly shuffled sequences with the same composition generated various structures with consistently higher energies. O- and N-glycosylation patterns showed that each TR …

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An Analysis Of Phenotypic Marker Presence On Umr-106 Cells Following Acclimation To Media Reduced In Estrogenic Compounds, Levi Castle Feb 2010

An Analysis Of Phenotypic Marker Presence On Umr-106 Cells Following Acclimation To Media Reduced In Estrogenic Compounds, Levi Castle

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Levi Castle on February 12, 2010.

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Mechanisms Of Er Stress-Mediated Mitochondrial Membrane Permeabilization., Sanjeev Gupta, Lorraine Cuffe, Eva Szegezdi, Susan E Logue, Catherine Neary, Sandra Healy, Afshin Samali Feb 2010

Mechanisms Of Er Stress-Mediated Mitochondrial Membrane Permeabilization., Sanjeev Gupta, Lorraine Cuffe, Eva Szegezdi, Susan E Logue, Catherine Neary, Sandra Healy, Afshin Samali

Rowan-Virtua School of Osteopathic Medicine Departmental Research

During apoptosis, the process of mitochondrial outer membrane permeabilization (MOMP) represents a point-of-no-return as it commits the cell to death. Here we have assessed the role of caspases, Bcl-2 family members and the mitochondrial permeability transition pore on ER stress-induced MOMP and subsequent cell death. Induction of ER stress leads to upregulation of several genes such as Grp78, Edem1, Erp72, Atf4, Wars, Herp, p58ipk, and ERdj4 and leads to caspase activation, release of mitochondrial intermembrane proteins and dissipation of mitochondrial transmembrane potential (DeltaPsim). Mouse embryonic fibroblasts (MEFs) from caspase-9, -2 and, -3 knock-out mice were resistant to ER stress-induced apoptosis …

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Real-Time Pcr Method For The Quantification Of Burkholderia Cepacia Complex Attached To Lung Epithelial Cells And Inhibitionn Of That Attachment, Ciara Wight, Gillian Herbert, Ruth Pilkington, Máire Callaghan, Siobhan Mcclean Jan 2010

Real-Time Pcr Method For The Quantification Of Burkholderia Cepacia Complex Attached To Lung Epithelial Cells And Inhibitionn Of That Attachment, Ciara Wight, Gillian Herbert, Ruth Pilkington, Máire Callaghan, Siobhan Mcclean

Articles

To develop a rapid method to quantify the attachment of the cystic fibrosis pathogen, Burkholderia multivorans, to lung epithelial cells (16HBE14o(-)) using real-time PCR with a view to monitoring potential inhibition of lung cell attachment. Mammalian and bacterial DNA were purified from bacteria attached to lung epithelial cells. The relative amount of bacteria attached was determined by amplification of the recA gene relative to the human GAPDH gene, in the presence of SYBR Green. The method was thoroughly validated and shown to correlate well with traditional plating techniques. Inhibition of bacterial attachment with simple sugars was then evaluated by real-time …

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Induction And Regulation Of Autophagy By Novel Prenylation Inhibitors In Sts-26t Malignant Peripheral Nerve Sheath Tumor (Mpnst) Cells, Komal Madhukar Sane Jan 2010

Induction And Regulation Of Autophagy By Novel Prenylation Inhibitors In Sts-26t Malignant Peripheral Nerve Sheath Tumor (Mpnst) Cells, Komal Madhukar Sane

Wayne State University Dissertations

Prenylation pathways have been targeted via several different compounds that inhibit farnesyl transferase (FTase) and/or geranylgeranyl transferase (GGTase) enzymes in many cellular and animal models of cancer. Some of these have also been evaluated in clinical trials with limited success. Multiple mechanisms of action have been elucidated for such compounds, including cell cycle arrest, proteasome inhibition, apoptosis and most recently, autophagy. However, there is still an urgent need of effective agents of this class of anti-tumor therapeutics. In this dissertation, I sought to delve into this issue by characterizing our novel prenylation inhibitors and their potential as anti-tumor agents. Novel …

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Comparing Models Of Evolution For Ordered And Disordered Proteins, Celeste J. Brown, Audra K. Johnson, Gary W. Daughdrill Jan 2010

Comparing Models Of Evolution For Ordered And Disordered Proteins, Celeste J. Brown, Audra K. Johnson, Gary W. Daughdrill

Molecular Biosciences Faculty Publications

Most models of protein evolution are based upon proteins that form relatively rigid 3D structures. A significant fraction of proteins, the so-called disordered proteins, do not form rigid 3D structures and sample a broad conformational ensemble. Disordered proteins do not typically maintain long-range interactions, so the constraints on their evolution should be different than ordered proteins. To test this hypothesis, we developed and compared models of evolution for disordered and ordered proteins. Substitution matrices were constructed using the sequences of putative homologs for sets of experimentally characterized disordered and ordered proteins. Separate matrices, at three levels of sequence similarity ( …

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Animal Models Of Alzheimer's Disease, Gemma Casadesus, Gary Arendash, Frank Laferla, Mike Mcdonald Jan 2010

Animal Models Of Alzheimer's Disease, Gemma Casadesus, Gary Arendash, Frank Laferla, Mike Mcdonald

Molecular Biosciences Faculty Publications

No abstract provided.

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Impaired M3 And Enhanced M2 Muscarinic Receptor Contractile Function In A Streptozotocin Model Of Mouse Diabetic Urinary Bladder, K. J. Pak, Rennolds S. Ostrom, M. Matsui, F. J. Ehlert Jan 2010

Impaired M3 And Enhanced M2 Muscarinic Receptor Contractile Function In A Streptozotocin Model Of Mouse Diabetic Urinary Bladder, K. J. Pak, Rennolds S. Ostrom, M. Matsui, F. J. Ehlert

Pharmacy Faculty Articles and Research

We investigated the contractile roles of M2 and M3 muscarinic receptors in urinary bladder from streptozotocin-treated mice. Wild-type and M2 muscarinic receptor knockout (M2 KO) mice were given a single injection of vehicle or streptozotocin (125 mg kg−1) 2–24 weeks prior to bladder assays. The effect of forskolin on contractions elicited to the muscarinic agonist, oxotremorine-M, was measured in isolated urinary bladder (intact or denuded of urothelium). Denuded urinary bladder from vehicle-treated wild-type and M2 KO mice exhibited similar contractile responses to oxotremorine-M, when contraction was normalized relative to that elicited by KCl (50 mM). Eight to 9 weeks after …

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The Wheat Bzip Factor, Taabf1, Mediates Aba-Induced Gene Expression In Bombarded Barley Aleurone Layers, Benjamin R. Keyser Jan 2010

The Wheat Bzip Factor, Taabf1, Mediates Aba-Induced Gene Expression In Bombarded Barley Aleurone Layers, Benjamin R. Keyser

Honors Theses

The plant hormone Abscisic acid (ABA) plays a central role in maturation and germination in seeds, as well as mediating adaptive responses to abiotic environmental stresses. ABA induces the expression of many genes, including late-embryogenesis-abundant genes such as HVA1. To elucidate the ABA signaling pathway leading to HVA1 expression, we focus on the bZIP factor TaABF1. Analysis of the interplay between ABA and TaABF1 in the aleurone cells of imbibing cereal grains indicated that the two are not additive in their induction of the HVA1 promoter. A synthetic ABA analog, PBI-51, did not specifically inhibit the effect of exogenous ABA …

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Apoptosis Initiation And Angiogenesis Inhibition: Melanoma Targets For Nanosecond Pulsed Electric Fields, Xinhua Chen, Juergen F. Kolb, R. James Swanson, Karl H. Schoenbach, Stephen J. Beebe Jan 2010

Apoptosis Initiation And Angiogenesis Inhibition: Melanoma Targets For Nanosecond Pulsed Electric Fields, Xinhua Chen, Juergen F. Kolb, R. James Swanson, Karl H. Schoenbach, Stephen J. Beebe

Bioelectrics Publications

Many effective anti-cancer strategies target apoptosis and angiogenesis mechanisms. Applications of non-ionizing, nanosecond pulsed electric fields (nsPEFs) induce apoptosis in vitro and eliminate cancer in vivo; however in vivo mechanisms require closer analysis. These studies investigate nsPEF-induced apoptosis and anti-angiogenesis examined by fluorescent microscopy, immunoblots, and morphology. Six hours after treatment with one hundred 300 ns pulses at 40 kV/cm, cells transiently expressed active caspases indicating that caspase-mediated mechanisms. Three hours after treatment transient peaks in Histone 2AX phosphorylation coincided with terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells and pyknotic nuclei, suggesting caspase-independent mechanisms on nuclei/DNA. Large …

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Chapter 26 – Multiple Color Single Molecule Tirf Imaging And Tracking Of Maps And Motors, Jennifer L. Ross, Ram Dixit Jan 2010

Chapter 26 – Multiple Color Single Molecule Tirf Imaging And Tracking Of Maps And Motors, Jennifer L. Ross, Ram Dixit

Biology Faculty Research

Microtubules are part of a complex mechano-chemical network inside cells. In order to understand how the components of these systems work together, careful in vitro experiments must be performed with added complexity. These experiments can ideally image all the interacting species. In order to image these molecules, multiple-color fluorescence imaging can be performed. In this chapter, we describe some methods for performing multiple-color single molecule fluorescence imaging using total internal reflection fluorescence microscopy. We give several specific examples of species of microtubule-associate proteins and motors that can be examined with detailed protocols for labeling, purification, and imaging.

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Chapter 27 – Studying Plus-End Tracking At Single Molecule Resolution Using Tirf Microscopy, Ram Dixit, Jennifer L. Ross Jan 2010

Chapter 27 – Studying Plus-End Tracking At Single Molecule Resolution Using Tirf Microscopy, Ram Dixit, Jennifer L. Ross

Biology Faculty Research

The highly dynamic microtubule plus-ends are key sites of regulation that impact the organization and function of the microtubule cytoskeleton. Much of this regulation is performed by the microtubule plus-end tracking (+TIP) family of proteins. +TIPs are a structurally diverse group of proteins that bind to and track with growing microtubule plus-ends in cells. +TIPs regulate microtubule dynamics as well as mediate interactions between microtubule tips and other cellular structures. Most +TIPs can directly bind to microtubules in vitro; however, the mechanisms for their plus-end specificity are not fully understood. Cellular studies of +TIP activity are complicated by the fact …

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A Chemical Genetics Approach To Elucidate Mechanisms Of The Fission Yeast Polo Kinase In Cell Division, Jennifer Phelan, Dawn Clifford Hart Jan 2010

A Chemical Genetics Approach To Elucidate Mechanisms Of The Fission Yeast Polo Kinase In Cell Division, Jennifer Phelan, Dawn Clifford Hart

Student Summer Scholars Manuscripts

Cell division is a fundamental biological event that underlies the growth and development of all organisms. Because human and fission yeast (Schizosaccharomyces pombe) cells divide symmetrically through constriction of the actomyosin ring, fission yeast provides an ideal model system to reveal conserved cell cycle properties. In fission yeast, an evolutionarily conserved protein, Mid1, plays a critical role in organizing the early steps of contractile ring formation. Mid1 functions as a scaffold to bridge the cell cortex with the contractile ring. Cells lacking mid1 form off-centered, highly disorganized ring structures and exhibit severe cell division defects. Our previous research …

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Phosphorylation Of The Glycine Transporter 1, Javier Vargas Medrano Jan 2010

Phosphorylation Of The Glycine Transporter 1, Javier Vargas Medrano

Open Access Theses & Dissertations

The extracellular levels of the neurotransmitter glycine in the brain are tightly regulated by the high-affinity glycine transporter 1 (GlyT1) and the clearance of glycine depends on its rate of transport and the levels of cell surface GlyT1. Over the past years, it has been shown that PKC activation diminishes the activity and promoted phosphorylation of several neurotransmitter transporters including the dopamine, serotonin and norepinephrine transporters however, its role is unknown for the glycine transporter. To get insights into the role of PKC activation on GlyT1 regulation, we used three N-terminus GlyT1 isoforms stably expressed in porcine aortic endothelial (PAE) …

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Pattern Recognition In Cytopathology For Papanicolaou Screening, Jonathan Blackledge, Dmitriy Dubovitskiy Jan 2010

Pattern Recognition In Cytopathology For Papanicolaou Screening, Jonathan Blackledge, Dmitriy Dubovitskiy

Conference papers

A unique space oriented filer is presented in order to detect and isolate the cell of a nucleus for applications in cytopathology. A classification method for nuclei is then considered based on the application of a set of features which includes certain fractal parameters. Segmentation algorithms are considered in which a self-adjustable sharpening filter is designed to enhance object location. Although the methods discussed and the algorithms developed have a range of applications, in this work we focus the engineering of a system for automating a Papanicolaou screening test using standard optical images

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Regulatory And Functional Aspects Of Foxo3a Transcription Factor And Their Implications In Prostate Cancer, Melissa Elise Dobson Jan 2010

Regulatory And Functional Aspects Of Foxo3a Transcription Factor And Their Implications In Prostate Cancer, Melissa Elise Dobson

Wayne State University Dissertations

The P13K/Akt pathway is a critical mediator of growth factor signaling involving many cellular functions. The deregulation of this pathway has been shown to be involved in the development of various cancers. One of the main targets of this pathway is FoxO3a, a transcription factor whose target genes are involved in important cellular processes such as apoptosis, cell cycle control, and glucose metabolism. FoxO3a is regulated by various post translational modifications including acetylation, ubiquitination and phosphorylation. The transcription factor is directly phosphorylated by Akt on 3 residues: Threonine 32, Serine 253 and Serine 315. Phosphorylation by Akt generates binding sites …

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The Role Of Ledgf/P75 In Transcriptional Regulation, Jeffrey Ryan Kugelman Jan 2010

The Role Of Ledgf/P75 In Transcriptional Regulation, Jeffrey Ryan Kugelman

Open Access Theses & Dissertations

The Lens Epithelial Derived Growth Factor p75 (LEDGF/p75) is a chromatin bound protein whose cellular function is not yet clearly known. A role in transcriptional regulation had been previously proposed based on its interaction with the basal transcriptional machinery and on its effects on the expression of genes involved in the cellular response to environmental stresses. To further elucidate the function of LEDGF/p75, we conducted a global and unbiased evaluation of the role of this protein in gene expression. To that aim, we performed a microarray analysis of cellular gene expression in cells that are severely depleted of LEDGF/p75. To …

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Matriptase/Pdgf D/Beta-Pdgfr Signaling Axis In Human Prostate Cancer: The Role Of Pten In The Regulation Of Pdgf D Expression, M. Katie Conley-Lacomb Jan 2010

Matriptase/Pdgf D/Beta-Pdgfr Signaling Axis In Human Prostate Cancer: The Role Of Pten In The Regulation Of Pdgf D Expression, M. Katie Conley-Lacomb

Wayne State University Dissertations

Platelet Derived Growth Factor (PDGF) is a family of mesenchymal growth factors that regulate cell proliferation, migration, and differentiation. Unlike the classic PDGF ligands A and B, which are secreted as active dimers, PDGF D must undergo extracellular proteolytic processing to remove its N-terminal CUB domain from the C-terminal PDGF growth domain before the ligand is able to stimulate its receptor, PDGF receptor beta (?-PDGFR). Importantly, recent clinical studies have shown that ?-PDGFR is upregulated in primary prostate cancer and bone metastases. However, PDGF B, formerly thought to be the sole ligand for ?-PDGFR, is not expressed in clinical prostate …

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The Lyme Disease Spirochete, Borrelia Burgdorferi, In Tick Species Collected From Raccoons (Procyon Lotor) And Opossums (Didelphis Virginiana) Trapped In The Warren And Barren Counties Of South Central Kentucky, Kristina Tackett Dec 2009

The Lyme Disease Spirochete, Borrelia Burgdorferi, In Tick Species Collected From Raccoons (Procyon Lotor) And Opossums (Didelphis Virginiana) Trapped In The Warren And Barren Counties Of South Central Kentucky, Kristina Tackett

Masters Theses & Specialist Projects

The incidence of tick-borne zoonoses such as Ehrlichiosis, Rocky Mountain Spotted Fever, and Lyme disease has steadily increased in the southeastern United States in recent years. According to the Centers for Disease Control and Prevention (CDC), the southeastern states accounted for 1,200 of the 27,000 total cases of Lyme disease reported in the U.S. in 2007. Although Ixodes scapularis is the most commonly recognized vector for the Lyme disease spirochete Borrelia burgdorferi, Dermacentor variabilis (a common vector for Rocky Mountain Spotted Fever) also has been shown to be a viable host for this pathogen. The purpose of the present …

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Cloning Of "Animal Cryptochrome" Cdna From The Model Organism Chlamydomonas Reinhardtii For Functional Analysis Of Its Protein Product, Shobha Lavanya Silparasetty Dec 2009

Cloning Of "Animal Cryptochrome" Cdna From The Model Organism Chlamydomonas Reinhardtii For Functional Analysis Of Its Protein Product, Shobha Lavanya Silparasetty

Masters Theses & Specialist Projects

reinhardtii, a unicellular green alga, is a model organism to study the circadian clock. Cryptochromes are the blue light photoreceptors that entrain the clock in some organisms. The CPH1 protein of C. reinhardtii resembles the cryptochromes of the plant model Arabidopsis, but whether CPH1 entrains the circadian clock in C. reinhardtii is not yet known. Recent reports have suggested the existence of one more cryptochrome in C. reinhardtii, which resembles the cryptochromes of animals. However, the amino acid sequence of this protein shows even higher sequence similarity with the 6-4 DNA photolyase of Arabidopsis. DNA photolyases …

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Inhibition Of Pi 3-Kinase Signaling Contributes To Metronidazole Resistance In The Protozoan Parasite, Entamoeba Histolytica, Rhonda Powell Dec 2009

Inhibition Of Pi 3-Kinase Signaling Contributes To Metronidazole Resistance In The Protozoan Parasite, Entamoeba Histolytica, Rhonda Powell

All Theses

Amoebiasis is defined as an intestinal infection with the human protozoan parasite, Entamoeba histolytica; approximately 100,000 deaths annually can be attributed to amoebiasis. Disease states range from asymptomatic colonization to invasive amoebiasis, characterized by abdominal pain and dysentery. Dissemination to extraintestinal sites, such as the liver and/or brain, can occur. Vesicle trafficking is critical for parasite virulence, and multiple signaling cascades within the pathogen facilitate these events.
One important regulator of signal transduction is the tightly controlled PI 3-kinase (PI3K), which phosphorylates the lipid, phosphatidylinositol bisphosphate (PIP2), producing phosphatidylinositol trisphosphate (PIP3). Effector proteins, such as Akt, …

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Drosophila Adult Eye Model To Teach Scanning Electron Microscopy In An Undergraduate Cell Biology Laboratory, Meghana Tare, Oorvashi Roy Puli, Sarah M. Oros, Amit Singh Dec 2009

Drosophila Adult Eye Model To Teach Scanning Electron Microscopy In An Undergraduate Cell Biology Laboratory, Meghana Tare, Oorvashi Roy Puli, Sarah M. Oros, Amit Singh

Biology Faculty Publications

We have devised an undergraduate laboratory exercise to study tissue morphology using fruit fly, Drosophila melanogaster, as the model organism. Drosophila can be reared in a cost effective manner in a short period of time. This experiment was a part of the undergraduate curriculum of the cell biology laboratory course aimed to demonstrate the use of scanning electron microscopy (SEM) technique to study the morphology of adult eye of Drosophila. The adult eye of Drosophila is a compound eye, which comprises of 800 unit eyes, and serves as an excellent model for SEM studies. We used flies that …

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Identification Of A Conserved Cluster In The Rh Domain Of Grk Critical For Activation By Gpcrs, Faiza Baameur Dec 2009

Identification Of A Conserved Cluster In The Rh Domain Of Grk Critical For Activation By Gpcrs, Faiza Baameur

Dissertations and Theses (Open Access)

One of the most critical aspects of G Protein Coupled Receptors (GPCRs) regulation is their rapid and acute desensitization following agonist stimulation. Phosphorylation of these receptors by GPCR kinases (GRK) is a major mechanism of desensitization. Considerable evidence from studies of rhodopsin kinase and GRK2 suggests there is an allosteric docking site for the receptor distinct from the GRK catalytic site. While the agonist-activated GPCR appears crucial for GRK activation, the molecular details of this interaction remain unclear. Recent studies suggested an important role for the N- and C-termini and domains in the small lobe of the kinase domain in …

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The Role Of Multiple Ccaat-Binding Factors In Candida Albicans Gene Expression, Lashall Lynn Bates Dec 2009

The Role Of Multiple Ccaat-Binding Factors In Candida Albicans Gene Expression, Lashall Lynn Bates

Graduate Theses and Dissertations

The CCAAT-binding factor is a heterooligomeric transcription factor that is evolutionarily conserved in eukaryotes. In yeast, the DNA-binding component that interacts with the CCAAT consensus sequence in promoters consists of the subunits termed Hap2p, Hap3p and Hap5p. In yeast and fungi, a fourth subunit, Hap4p, is required for regulating gene expression. The goal of this research is to understand the function of the Candida albicans CCAAT-binding factor and how it relates to virulence and pathogenicity. C. albicans is a human opportunistic pathogen responsible for a variety of mucosal and systemic infections that result in significant morbidity and mortality, particularly in …

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Characterization And Functional Regulation Of Bioactive Peptides In Avian Macrophages And Heterophils, Lakshmi Kannan Dec 2009

Characterization And Functional Regulation Of Bioactive Peptides In Avian Macrophages And Heterophils, Lakshmi Kannan

Graduate Theses and Dissertations

Oligopeptides and low molecular weight polypeptides play central roles as effectors and signal transducers acting as hormones, neurotransmitters, growth factors, toxins, and antimicrobial factors that are important for the survival of the organism. Owing to the ubiquitous involvement of peptides in many key regulatory processes, we have been interested to identify native peptides in different cells and tissues and understand their functions. To conduct our studies, we used avian macrophages and heterophils as models of specialized cells which constitute central components of innate immunity. These studies involved (a) qualitative identification and characterization of the peptides associated with high intensity mass …

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Hexabromocyclododecane Decreases Tumor-Cell-Binding Capacity And Cell-Surface Protein Expression Of Human Natural Killer Cells, Natasha C. Hinkson, Margaret M. Whalen Nov 2009

Hexabromocyclododecane Decreases Tumor-Cell-Binding Capacity And Cell-Surface Protein Expression Of Human Natural Killer Cells, Natasha C. Hinkson, Margaret M. Whalen

Chemistry Faculty Research

Hexabromocyclododecane (HBCD) is a flame retardant that decreases the lytic function of human natural killer (NK) cells. NK cells defend against tumor cells and virally infected cells. Thus, HBCD has the potential to increase cancer incidence and viral infections. NK cells must bind to their targets for lysis to occur. Thus, concentrations of HBCD that decrease lytic function were examined for their ability to alter NK binding to tumor targets. Levels of HBCD that caused a loss of binding function were examined for effects on expression of cell surface proteins needed for binding. NK cells exposed to HBCD for 24 …

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Phylogeography Of The Frog Leptodactylus Validus (Amphibia: Anura): Patterns And Timing Of Colonization Events In The Lesser Antilles, Arley Camargo, W. Ronald Heyer, Rafael O. De Sá Nov 2009

Phylogeography Of The Frog Leptodactylus Validus (Amphibia: Anura): Patterns And Timing Of Colonization Events In The Lesser Antilles, Arley Camargo, W. Ronald Heyer, Rafael O. De Sá

Biology Faculty Publications

The frog Leptodactylus validus occurs in northern South America, Trinidad and Tobago, and the southern Lesser Antilles (Grenada and St. Vincent). Mitochondrial DNA sequences were used to perform a nested clade phylogeographic analysis (NCPA), to date colonization events, and to analyze colonization patterns using on a relaxed molecular clock and coalescent simulations. L. validus originated on the mainland and first colonized Trinidad with subsequent independent colonizations of Tobago and the Lesser Antilles from Trinidad. The NCPA suggests a historical vicariant event between populations in Trinidad and Tobago from those in the Lesser Antilles. The colonization of Trinidad occurred 1 million …

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Integral Membrane Proteins Brr6 And Apq12 Link Assembly Of The Nuclear Pore Complex To Lipid Homeostasis In The Endoplasmic Reticulum, Christine A. Hodge, Vineet Choudhary, Michael J. Wolyniak, John J. Scarcelli, Roger Schneiter, Charles N. Cole Oct 2009

Integral Membrane Proteins Brr6 And Apq12 Link Assembly Of The Nuclear Pore Complex To Lipid Homeostasis In The Endoplasmic Reticulum, Christine A. Hodge, Vineet Choudhary, Michael J. Wolyniak, John J. Scarcelli, Roger Schneiter, Charles N. Cole

Dartmouth Scholarship

Cells of Saccharomyces cerevisiae lacking Apq12, a nuclear envelope (NE)-endoplasmic reticulum (ER) integral membrane protein, are defective in assembly of nuclear pore complexes (NPCs), possibly because of defects in regulating membrane fluidity. We identified BRR6, which encodes an essential integral membrane protein of the NE-ER, as a dosage suppressor of apq12 Delta. Cells carrying the temperature-sensitive brr6-1 allele have been shown to have defects in nucleoporin localization, mRNA metabolism and nuclear transport. Electron microscopy revealed that brr6-1 cells have gross NE abnormalities and proliferation of the ER. brr6-1 cells were hypersensitive to compounds that affect membrane biophysical properties and to …

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Tetrabromobisphenol A Has Immunosuppressive Effects On Human Natural Killer Cells, Esther Caroline Kibakaya, Krishna Stephen, Margaret M. Whalen Oct 2009

Tetrabromobisphenol A Has Immunosuppressive Effects On Human Natural Killer Cells, Esther Caroline Kibakaya, Krishna Stephen, Margaret M. Whalen

Chemistry Faculty Research

Human natural killer (NK) cells are lymphocytes that destroy tumor cells, virally-infected cells, and antibody-coated cells. Tetrabromobisphenol A (TBBPA) is used both as a reactive and as an additive flame retardant in a variety of materials and appears to contaminate the environment. TBBPA has been found in human blood samples and if it interferes with NK cell function, this could increase the risk of tumor development and/or viral infection. The present study examines the effects of exposure to various concentrations of TBBPA for 24 hr, 48 hr, and 6 days on the lytic function, tumor-target-binding function, and ATP levels of …

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