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Articles 1 - 9 of 9

Full-Text Articles in Cell Biology

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 ...


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 ...


Nanosecond Pulsed Electric Field Effects On Cell Cycle And Apoptosis, Emily H. Hall Apr 2006

Nanosecond Pulsed Electric Field Effects On Cell Cycle And Apoptosis, Emily H. Hall

Theses and Dissertations in Biomedical Sciences

Apoptosis, programmed cell death, is a highly regulated and complex pathway essential for embryonic development, immune-system function and maintenance of tissue homeostasis where cells induce their own cell death. Cells undergoing apoptosis exhibit a distinctive phenotype characterized by maintenance of membrane integrity, cell shrinkage, phosphatidylserine (PS) externalization at the plasma membrane, caspase protease activation, DNA fragmentation, release of cytochrome c from the mitochondrion, and membrane blebbing. An important regulatory protein in the apoptotic pathway is p53. The p53 protein functions to modulate the cell cycle by arresting cells in the G1 and G 2 phases to repair DNA damage, and ...


Modulation Of Tgfβ-Induced Pai -1 Expression By Changes In Actin Polymerization In Human Mesangial Cells, Keyur Patel Apr 2006

Modulation Of Tgfβ-Induced Pai -1 Expression By Changes In Actin Polymerization In Human Mesangial Cells, Keyur Patel

Theses and Dissertations in Biomedical Sciences

Chronic renal diseases show increased deposition of extracellular matrix (ECM) in the glomerulus (glomerulosclerosis). Glomerulosclerosis is associated with activation of normally quiescent glomerular mesangial cells into myofibroblast-like cells. The overall objective of this study is to delineate cellular mechanism/s of myofibroblast-differentiation in disease states. In cultured mesangial cells certain characteristics of myofibroblast differentiation (α-smooth muscle actin (α-SMA) and hypertrophy) are associated with an increase in polymeric actin microfilaments (stress fibers). It is likely that other genes are also regulated in an actin cytoskeleton-dependent manner during myofibroblast differentiation. In these studies, we therefore examined the hypothesis that changes in the ...


The Study Of Nitric Oxide Synthase Expression, Function, And Regulation In The Renal Vasculature During Postnatal Renal Development, Brian Blake Ratliff Apr 2006

The Study Of Nitric Oxide Synthase Expression, Function, And Regulation In The Renal Vasculature During Postnatal Renal Development, Brian Blake Ratliff

Theses and Dissertations in Biomedical Sciences

The newborn kidney is vulnerable to vasomotor acute renal failure (ARF) from adverse perinatal events or complications of prematurity. Nitric oxide (NO) vasodilation is vitally protective in this type of ARF, but its relationship with other vasoactive factors, such as angiotensin II (AII) has not been examined. In the immature kidney, nitric oxide synthase (NOS) isoforms, specifically eNOS and nNOS, are developmentally regulated, but their specific role and regulation are unknown.

The enhanced vasodilatory role of NO in the immature kidney was hypothesized to be attributed to regulatory, expressional, and functional differences in eNOS and nNOS isoforms from the adult ...


Pathways Of Skeletal Muscle Atrophy: Hiv As A Model System?, Chelsea Bueter, Michelle Mckinzey, Chloe Salzmann, Michael Zorniak Jan 2006

Pathways Of Skeletal Muscle Atrophy: Hiv As A Model System?, Chelsea Bueter, Michelle Mckinzey, Chloe Salzmann, Michael Zorniak

Eukaryon

Skeletal Muscle Atrophy (SMA) is a phenomenon found in many diseases and disorders. SMA is characterized by protein degradation induced by various pathways. Ten years ago, little was known about the mechanisms that lead from these disorders to protein degradation. Current research focuses on the mechanisms thought to induce SMA. It is now known that many of these pathways involve ubiquitin conjugate accumulation and increased proteasome activity resulting in rapid protein degradation and decreased synthesis. HIV associated proteins, such as Vpr, cause overexpression of atrogin-1 which promotes atrophy. Cachexia operates mainly through the IKK/NF¨ºB pathway and MuRF-1 Ub-ligase ...


Isolation And Functional Mapping Of Human T-Cell Leukemia Virus Type 1 Tax Oncoprotein Dna-Damage Complexes, Sarah Saionz Durkin Jan 2006

Isolation And Functional Mapping Of Human T-Cell Leukemia Virus Type 1 Tax Oncoprotein Dna-Damage Complexes, Sarah Saionz Durkin

Theses and Dissertations in Biomedical Sciences

Human T-cell Leukemia Virus Type 1 (HTLV-1) is a transforming retrovirus which causes Adult T-cell Leukemia (ATL) and HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP). Cellular transformation can be caused by a single viral trans-activating protein, Tax. Tax may contribute to transformation through interaction with components of the DNA damage response pathway, promoting cellular genomic instability. We examined cellular Tax complexes in an effort to elucidate potential protein-protein interactions that can model the Tax-induced molecular events.

We also investigated the role of post-translational modification in regulating Tax function. We employed a direct physical analysis of Tax complexes isolated ...


Never Let Me Clone? Countering An Ethical Argument Against The Reproductive Cloning Of Humans, Yvette Pearson Jan 2006

Never Let Me Clone? Countering An Ethical Argument Against The Reproductive Cloning Of Humans, Yvette Pearson

Philosophy Faculty Publications

In the March 2006 issue of EMBO reports, Christof Tannert, a bioethicist at the Max Delbrück Research Centre in Berlin, Germany, presented a moral argument against human reproductive cloning on the basis of Immanuel Kant’s categorical imperative (Tannert, 2006). In this article, I address some problems with Tannert’s views and show that our concerns about this prospective procedure should prompt us to scrutinize carefully the conventional procreative practices and attitudes. Indeed, if we set aside objections that are grounded in genetic determinism, many of the offensive features of human cloning are identical to problems with procreation by more ...


Linking Ligand-Induced Alterations In Androgen Receptor Structure To Differential Gene Expression: A First Step In The Rational Design Of Selective Androgen Receptor Modulators, Dmitri Kazmin, Tatiana Prytkova, C. Edgar Cook, Russell Wolfinger, Tzu-Ming Chu, David Beratan, J. D. Norris, Ching-Yi Chang, Donald P. Mcdonnell Jan 2006

Linking Ligand-Induced Alterations In Androgen Receptor Structure To Differential Gene Expression: A First Step In The Rational Design Of Selective Androgen Receptor Modulators, Dmitri Kazmin, Tatiana Prytkova, C. Edgar Cook, Russell Wolfinger, Tzu-Ming Chu, David Beratan, J. D. Norris, Ching-Yi Chang, Donald P. Mcdonnell

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We have previously identified a family of novel androgen receptor (AR) ligands that, upon binding, enable AR to adopt structures distinct from that observed in the presence of canonical agonists. In this report, we describe the use of these compounds to establish a relationship between AR structure and biological activity with a view to defining a rational approach with which to identify useful selective AR modulators. To this end, we used combinatorial peptide phage display coupled with molecular dynamic structure analysis to identify the surfaces on AR that are exposed specifically in the presence of selected AR ligands. Subsequently, we ...