Cell Biology Commons^™

The Yeast Nuclear Pore Complex Functionally Interacts With Components Of The Spindle Assembly Checkpoint, Tatiana Louk, Oliver Kerscher, Robert J. Scott, Munira A. Basrai, Richard W. Wozniak

Arts & Sciences Articles

Aphysical and functional link between the nuclear pore complex (NPC) and the spindle checkpoint machinery has been established in the yeast Saccharomyces cerevisiae. We show that two proteins required for the execution of the spindle checkpoint, Mad1p and Mad2p, reside predominantly at the NPC throughout the cell cycle. There they are associated with a subcomplex of nucleoporins containing Nup53p, Nup170p, and Nup157p. The association of the Mad1p–Mad2p complex with the NPC requires Mad1p and is mediated in part by Nup53p. On activation of the spindle checkpoint, we detect changes in the interactions between these proteins, including the release of …

Shar-Pei Mediates Cell Proliferation Arrest During Imaginal Disc Growth In Drosophila, Madhuri Kango-Singh, Riitta Nolo, Chunyao Tao, Patrik Verstreken, P. Robin Hiesinger, Hugo J. Bellen, Georg Halder

Biology Faculty Publications

During animal development, organ size is determined primarily by the amount of cell proliferation, which must be tightly regulated to ensure the generation of properly proportioned organs. However, little is known about the molecular pathways that direct cells to stop proliferating when an organ has attained its proper size. We have identified mutations in a novel gene, shar-pei, that is required for proper termination of cell proliferation during Drosophila imaginal disc development. Clones of shar-pei mutant cells in imaginal discs produce enlarged tissues containing more cells of normal size. We show that this phenotype is the result of both …

The Tadpole Of Proceratophrys Avelinoi (Anura: Leptodactylidae), Rafael O. De Sá, José A. Langone

Biology Faculty Publications

The genus Proceratoprhrys is poorly known. It consists of 14 currently recognized species (Frost, 2000) of medium-sized frogs distributed from northeastern Argentina and Paraguay to southeast Amazonia (Rondonia State), eastern and southern Brazil. Proceratophrys avelinoi was described from Misiones, Argentina (Mercadal de Barrio and Barrio, 1993). The larval stage of this species is unknown. Herein, we describe the tadpole and the characteristics of the internal oral anatomy of P avelinoi using scanning electron micros- copy (SEM).

Eye Suppression, A Novel Function Of Teashirt, Requires Wingless Signaling, Amit Singh, Madhuri Kango-Singh, Y. Henry Sun

Biology Faculty Publications

Teashirt (tsh) encodes a Drosophila zinc-finger protein. Misexpression of tsh has been shown to induce ectopic eye formation in the antenna. We report that tsh can suppress eye development. This novel function of tsh is due to the induction of homothorax (hth), a known repressor of eye development, and requires Wingless (WG) signaling. Interestingly, tsh has different functions in the dorsal and ventral eye, suppressing eye development close to the ventral margin, while promoting eye development near the dorsal margin. It affects both growth of eye disc and retinal cell differentiation.

Involvement Of Platelet-Derived Growth Factor, Pdgf Receptor Signaling, Focal Adhesion Kinase And Src In Pressure-Induced Vascular Smooth Muscle Hypertrophy, Darian Clark Rice

Theses and Dissertations in Biomedical Sciences

Elevated blood pressure is associated with varying degrees of arterial remodeling. The mechanisms by which extracellular mechanical stress is converted into intracellular alterations in signal transduction and gene expression have yet to be fully elucidated. Our goal was to investigate the early events in the vascular smooth muscle response to acute hypertension and to identify mediators involved in long-term hypertensive remodeling.

In the acute phase of hypertension we targeted cell surface integrin and growth factor receptors thought to be mechanically sensitive. The signaling molecules FAK, Src and ERK-MAPK are known to be triggered by integrin engagement and growth factor receptor …

Terminal Deoxynucleotidyl Transferase Generation Of Sequence Diversity On Plasmids, Qingbei Zhang

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 Qingbei Zhang on June 19, 2002.

The Effect Of Butyrate Feeding On Skeletal Muscle And Adipose Tissue Glucose Uptake, Sean Eric Thatcher

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 in Biology by Sean Eric Thatcher on May 31, 2002.

The Role Of The Arabidopsis Phosphatidylinositol 3-Kinase In Vacuolar Protein Transport, Christopher A. Jones

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In all eukaryotic organisms vesicle-mediated protein transport is crucial for maintaining cellular homeostasis. Over the past decade significant strides have been made in elucidating the molecular mechanisms governing this complex process. Both genetic and biochemical studies have demonstrated the unequivocal involvement of class III phospatidylinositol 3-kinases (PtdIns 3-kinases) in regulating vesicle transport. While PtdIns 3-kinases have been well studied in both yeast and mammalian systems, the role of these enzymes in plants is poorly understood. In the present study, we demonstrate that the Arabidopsis Ptdlns 3-kinase is localized to the cytoplasm, and perhaps the Golgi apparatus. Moreover, we show that …

The Biophysics Of Leaf Growth In Salt-Stressed Barley. A Study At The Cell Level., Wieland Fricke, Winfried Peters

Winfried S. Peters

A Cycle Of Vam7p Release From And Ptdins 3-P–Dependent Rebinding To The Yeast Vacuole Is Required For Homotypic Vacuole Fusion, Christine Boeddinghaus, Alexey J. Merz, Rico Laage, Christian Ungermann

Dartmouth Scholarship

Vacuole fusion requires a coordinated cascade of priming, docking, and fusion. SNARE proteins have been implicated in the fusion itself, although their precise role in the cascade remains unclear. We now report that the vacuolar SNAP-23 homologue Vam7p is a mobile element of the SNARE complex, which moves from an initial association with the cis-SNARE complex via a soluble intermediate to the docking site. Soluble Vam7p is specifically recruited to vacuoles and can rescue a fusion reaction poisoned with antibodies to Vam7p. Both the recombinant Vam7p PX domain and a FYVE domain construct of human Hrs block the recruitment of …

Prostate Specific Membrane Antigen (Psma): Immunoassay Development And Characterization Of Transcriptional Regulation, Zhen Xiao

Theses and Dissertations in Biomedical Sciences

Prostate cancer (PCA) is the most common cancer and the second leading cause of death among American men. The high mortality is greatly attributed to the lack of early detection tools and effective treatment for metastasis and relapses. Biomarkers that can discriminate benign from malignant tumor and signal the development of androgen independent and metastatic tumor are needed. A biomarker designated prostate specific membrane antigen (PSMA) has the potential to fulfill this need. The objective of this study is to develop a clinically useful immunoassay for quantitation of serum PSMA and to study the molecular mechanism underlying the upregulation of …

Determination Of Nuclear Factor-Kappa B Activation In Cultured Renal Epithelial Cells And Cardiac Myocytes Exposed To Cocaine And Morphine, David Angeles Tiangco

Biological Sciences Theses & Dissertations

Nuclear factor-kappa B (NF-kB) is an important transcription factor that participates in the genetic regulation of inflammation in many tissues. Cocaine and heroin are drugs of abuse associated with renal and cardiac pathology. The purpose of this study was to test the hypothesis that exposure to cocaine or morphine (a metabolite of heroin) would activate NF-kB in renal epithelial cells (COS-7) and cardiac myocytes (H9c2) grown in culture. COS-7 and H9c2 cells were co-transfected with an experimental reporter specific for NF-kB activation and a control reporter with constitutive activity. A dual-luciferase assay was used to determine levels of NF-kB activation …

Spiroplasmas: Evolution, Adaptation And Diversity, Gail E. Gasparich

Gail Gasparich

Variability Of Placental Expression Of Cyclin E Low Molecular Weight Variants, A Bukovsky, Maria Cekanova Ms, Rndr, Phd, Mr Caudle, J Wimalasena, Js Foster, Ja Keenan, Rf Elder

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

No abstract provided.

Actin Dynamics Regulate Myosin Assembly In Muscle Cells, John Dylan Cook

Inquiry: The University of Arkansas Undergraduate Research Journal

During muscle cell (i.e. myocyte )development, organization of actin and myosin into the contractile unit (i.e. sarcomere) is required for proper muscle contraction. By disrupting the processes of muscle cell development, I am able to see which steps play important roles in proper maturation of myocytes. Elucidation of the key pathways in muscle development could lead to a better understanding of human cardiac hypertrophies and muscle myopathies. Since actin filament formation precedes myosin organization, I am using actin assembly inhibitors to determine if actin filaments are a necessary prerequisite for myosin organization. It is hypothesized that disruption of actin will …

Variability Of Placental Expression Of Cyclin E Low Molecular Weight Variants, A Bukovsky, Maria Cekanova Ms, Rndr, Phd, Mr Caudle, J Wimalasena, Js Foster, Ja Keenan, Rf Elder

Maria Cekanova MS, RNDr, PhD

No abstract provided.

Actin And Myosin Remodeling In The A7r5 Smooth Muscle Cell, Michael E. Fultz

Theses, Dissertations and Capstones

Active remodeling of the cytoskeleton has been proposed to contribute to the low energy cost and maintenance of the sustained contraction in smooth muscle. Using confocal microscopy and standard immunohistochemical techniques, direct observation of actin remodeling was studied in the contracting A7r5 cell in response to the diacylglycerol (DAG) analog phorbol 12, 13 dibutyrate (PDBu). -actin was shown to exist in the resting cell as parallel stress cables that extend across the cell. Stimulation by PDBu resulted in a sustained contraction that occurred in approximately eighty-five percent of the A7r5 cells. The initial contraction was not uniform, but primarily occurred …

Functional Requirement Of Aquaporin-5 In Plasma Membranes Of Sweat Glands, Lene N. Nejsum, Tae-Hwan Kwon, Uffe B. Jensen, Ornella Fumagalli, Jørgen Frøkiaer, Carissa M. Krane, Anil G. Menon, Landon S. King, Peter C. Agre, Søren Nielsen

Biology Faculty Publications

The distribution and function of aquaporins (AQPs) have not previously been defined in sweat glands. In this study, AQP1, AQP3, and AQP5 mRNA were demonstrated in rat paw by reverse transcription (RT)–PCR, but AQP2 and AQP4 were not. AQP1, AQP3, and AQP5 protein were confirmed in these tissues by immunoblotting. AQP1 was identified in capillary endothelial cells by immunohistochemical labeling, but not in sweat glands or epidermis. Abundant AQP3 expression was seen in basal levels of epidermis, but not in sweat glands. AQP2 and AQP4 were not observed in either skin or sweat glands. Immunohistochemical labeling revealed abundant AQP5 in …

A Note On Cascade Climbing Of Migrating Goby And Shrimp Postlarvae In Two Maui Streams, M. Eric Benbow, Leslie Luchar Orzetti, Mollie D. Mcintosh, Albert J. Burky

Biology Faculty Publications

In this study, we documented cascade climbing rates of 133 and 230 postlarvae of Lentipes concolor (O‘opu alamo‘o) and Atyoida bisulcata (Opae kahaole), respectively, from two streams on the island of Maui, Hawaii. Climbing measurements and observations were made of postlarvae at the water-substrate interface in cascade habitats of constricted water flow. Both species were observed to move in short bursts of forward progression within or above the pulsing water-substrate interface. Goby postlarval climbing rates ranged from 0.04 – 1.50 cm s–1 and were slower than shrimp rates which ranged from 0.30 – 3.06 cm s–1. The high variability is …

Analysis Of Protein Localization And Secretory Pathway Function Using The Yeast Saccharomyces Cerevisiae, Elizabeth Ann Vallen

Biology Faculty Works

The isolation and characterization of mutants has been crucial in understanding a number of processes in the field of cell biology. In this exercise, students examine the effects of mutations in the secretory pathway on protein localization. Yeast strains deficient for synthesis of histidinol dehydrogenase are transformed with a plasmid encoding a chimeric protein. The chimera contains a signal sequence fused to histidinol dehydrogenase. A strain with a defect in the translocation of secretory proteins into the endoplasmic reticulum (ER) accumulates sufficient histidinol dehydrogenase in the cytoplasm to grow on media lacking histidine. In contrast, yeast proficient for secretion, or …

Apoptosis Pathways: Presence And Significance In Ejaculated Human Spermatozoa, Steven Lewis Taylor

Theses and Dissertations in Biomedical Sciences

Ejaculated sperm display markers that are indicative of apoptosis in somatic cells. The question remains as to whether sperm have operative apoptosis mechanisms. The aim of this research was to test the hypothesis that apoptosis markers in sperm and somatic cells are different.

Ejaculated human sperm from patients and donors were separated into high and low motility fractions using Percoll™ gradients. Contaminating cells were removed using anti-CD45 conjugated paramagnetic beads. Fractions were divided into groups: staurosporine, anti-Fas antibody, and hydrogen peroxide treated and control. Direct enzymatic measurement of caspase activity, flow cytometric evaluation of phosphatidylserine translocation, immunoblots, and immunocytochemistry were …

Improved Energy Model For Membrane Electroporation In Biological Cells Subjected To Electrical Pulses, R. P. Joshi, Q. Hu, K. H. Schoenbach, H. P. Hjalmarson

Bioelectrics Publications

A self-consistent model analysis of electroporation in biological cells has been carried out based on an improved energy model. The simple energy model used in the literature is somewhat incorrect and unphysical for a variety of reasons. Our model for the pore formation energy E(r) includes a dependence on pore population and density. It also allows for variable surface tension, incorporates the effects of finite conductivity on the electrostatic correction term, and is dynamic in nature. Self-consistent calculations, based on a coupled scheme involving the Smoluchowski equation and the improved energy model, are presented. It is shown that E(r) becomes …

Mechanism For Membrane Electroporation Irreversibility Under High-Intensity, Ultrashort Electrical Pulse Conditions, R. P. Joshi, K. H. Schoenbach

Bioelectrics Publications

An improved electroporation model is used to address membrane irreversibility under ultrashort electric pulse conditions. It is shown that membranes can survive a strong electric pulse and recover provided the pore distribution has a relatively large spread. If, however, the population consists predominantly of larger radii pores, then irreversibility can result. Physically, such a distribution could arise if pores at adjacent sites coalesce. The requirement of close proximity among the pore sites is more easily satisfied in smaller organelles than in outer cell membranes. Model predictions are in keeping with recent observations of cell damage to intracellular organelles (e.g., mitochondria), …

Theoretical Predictions Of Electromechanical Deformation Of Cells Subjected To High Voltages For Membrane Electroporation, R. P. Joshi, Q. Hu, K. H. Schoenbach, H. P. Hjalmarson

Bioelectrics Publications

An electromechanical analysis based on thin-shell theory is presented to analyze cell shape changes in response to external electric fields. This approach can be extended to include osmotic-pressure changes. Our calculations demonstrate that at large fields, the spherical cell geometry can be significantly modified, and even ellipsoidal forms would be inappropriate to account for the deformation. Values of the surface forces obtained from our calculations are in very good agreement with the 1–10 mN/m range for membrane rupture reported in the literature. The results, in keeping with reports in the literature, demonstrate that the final shape depends on membrane thickness. …

Dipyridamole Reduces Oxidative Stress In Human Coronary Artery Endothelial And Hela Cell Models, Matthew E. Giangrante

Seton Hall University Dissertations and Theses (ETDs)

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