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Molecular Biology

2009

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Articles 1 - 30 of 62

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Computational Prediction Of The Agregated Structure Of Denatured Lysozyme, Pongsathorn Chotikasemsri Dec 2009

Computational Prediction Of The Agregated Structure Of Denatured Lysozyme, Pongsathorn Chotikasemsri

Masters Theses & Specialist Projects

Mis-folded proteins and their associated aggregates are a contributing factor in some human diseases. In this study we used the protein lysozyme as a model to define aggregation structures under denaturing conditions. Sasahara et al. (2007), Frare et al. (2009, 2006), and Rubin et al. (2008) observed conditions where heat denatured lysozyme formed fibril structures that were observed to be 8-17 nanometers in diameter under the electron microscope. Even though the crystal structure of lysozyme is known, the denatured form of this protein is still unknown. Therefore, we used Rosetta++ protein folding and blind docking software to create in silico ...


Quantifying And Resolving Multiple Vector Transformants In S. Cerevisiae Plasmid Libraries, Thomas C. Scanlon, Elizabeth C. Gray, Karl E. Griswold Nov 2009

Quantifying And Resolving Multiple Vector Transformants In S. Cerevisiae Plasmid Libraries, Thomas C. Scanlon, Elizabeth C. Gray, Karl E. Griswold

Open Dartmouth: Faculty Open Access Scholarship

In addition to providing the molecular machinery for transcription and translation, recombinant microbial expression hosts maintain the critical genotype-phenotype link that is essential for high throughput screening and recovery of proteins encoded by plasmid libraries. It is known that Escherichia coli cells can be simultaneously transformed with multiple unique plasmids and thusly complicate recombinant library screening experiments. As a result of their potential to yield misleading results, bacterial multiple vector transformants have been thoroughly characterized in previous model studies. In contrast to bacterial systems, there is little quantitative information available regarding multiple vector transformants in yeast. Saccharomyces cerevisiae is the ...


The Energy Profiles Of Atomic Conformational Transition Intermediates Of Adenylate Kinase, Yaping Feng, Lei Yang, Andrzej Kloczkowski, Robert L. Jernigan Nov 2009

The Energy Profiles Of Atomic Conformational Transition Intermediates Of Adenylate Kinase, Yaping Feng, Lei Yang, Andrzej Kloczkowski, Robert L. Jernigan

Biochemistry, Biophysics and Molecular Biology Publications

The elastic network interpolation (ENI)1 is a computationally efficient and physically realistic method to generate conformational transition intermediates between two forms of a given protein. However it can be asked whether these calculated conformations provide good representatives for these intermediates. In this study, we use ENI to generate conformational transition intermediates between the open form and the closed forms of adenylate kinase (AK). Based on Cα-only intermediates, we construct atomic intermediates by grafting all the atoms of known AK structures onto the Cα atoms and then perform CHARMM energy minimization to remove steric conflicts and optimize ...


A Feedback Circuit Involving Let-7-Family Mirnas And Daf-12 Integrates Environmental Signals And Developmental Timing In Caenorhabditis Elegans, Christopher M. Hammell, Xantha Karp, Victor R. Ambros Nov 2009

A Feedback Circuit Involving Let-7-Family Mirnas And Daf-12 Integrates Environmental Signals And Developmental Timing In Caenorhabditis Elegans, Christopher M. Hammell, Xantha Karp, Victor R. Ambros

Program in Molecular Medicine Publications and Presentations

Animal development is remarkably robust; cell fates are specified with spatial and temporal precision despite physiological and environmental contingencies. Favorable conditions cause Caenorhabditis elegans to develop rapidly through four larval stages (L1-L4) to the reproductive adult. In unfavorable conditions, L2 larvae can enter the developmentally quiescent, stress-resistant dauer larva stage, enabling them to survive for prolonged periods before completing development. A specific progression of cell division and differentiation events occurs with fidelity during the larval stages, regardless of whether an animal undergoes continuous or dauer-interrupted development. The temporal patterning of developmental events is controlled by the heterochronic genes, whose products ...


Ppar Agonists Down-Regulate The Expression Of Atp10c Mrna During Adipogenesis, A Peretich, Maria Cekanova Ms, Rndr, Phd, S Hurst, Sj Baek, Madhu Dahr Nov 2009

Ppar Agonists Down-Regulate The Expression Of Atp10c Mrna During Adipogenesis, A Peretich, Maria Cekanova Ms, Rndr, Phd, S Hurst, Sj Baek, Madhu Dahr

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

No abstract provided.


Protein Flexibility: Coordinate Uncertainties And Interpretation Of Structural Differences, Alexander A. Rashin, Abraham H. L. Rashin, Robert L. Jernigan Nov 2009

Protein Flexibility: Coordinate Uncertainties And Interpretation Of Structural Differences, Alexander A. Rashin, Abraham H. L. Rashin, Robert L. Jernigan

Biochemistry, Biophysics and Molecular Biology Publications

Valid interpretations of conformational movements in protein structures determined by X-ray crystallography require that the movement magnitudes exceed their uncertainty threshold. Here, it is shown that such thresholds can be obtained from the distance difference matrices (DDMs) of 1014 pairs of independently determined structures of bovine ribonuclease A and sperm whale myoglobin, with no explanations provided for reportedly minor coordinate differences. The smallest magnitudes of reportedly functional motions are just above these thresholds. Uncertainty thresholds can provide objective criteria that distinguish between true conformational changes and apparent `noise', showing that some previous interpretations of protein coordinate changes attributed to external ...


Venn, A Tool For Titrating Sequence Conservation Onto Protein Structures, Jay Vyas, Michael R. Gryk, Martin R. Schiller Oct 2009

Venn, A Tool For Titrating Sequence Conservation Onto Protein Structures, Jay Vyas, Michael R. Gryk, Martin R. Schiller

Life Sciences Faculty Publications

Residue conservation is an important, established method for inferring protein function, modularity and specificity. It is important to recognize that it is the 3D spatial orientation of residues that drives sequence conservation. Considering this, we have built a new computational tool, VENN that allows researchers to interactively and graphically titrate sequence homology onto surface representations of protein structures. Our proposed titration strategies reveal critical details that are not readily identified using other existing tools. Analyses of a bZIP transcription factor and receptor recognition of Fibroblast Growth Factor using VENN revealed key specificity determinants. Weblink: http://sbtools.uchc.edu/venn/.


Self-Assembly And Disassembly Of The Snare Complex: Examined Using Circular Dichroism And Atomic Force Microscopy, Jeremy D. Cook, Won Jin Cho, Timothy L. Stemmler, Bhanu P. Jena Sep 2009

Self-Assembly And Disassembly Of The Snare Complex: Examined Using Circular Dichroism And Atomic Force Microscopy, Jeremy D. Cook, Won Jin Cho, Timothy L. Stemmler, Bhanu P. Jena

Biochemistry and Molecular Biology Faculty Publications

In this study, we report for the first time that both t-SNAREs and v-SNARE and their complexes in buffered suspension, exhibit defined peaks at CD signals of 208 and 222 nm wavelengths, consistent with a higher degree of helical secondary structure. Surprisingly, when incorporated in lipid membrane, both SNAREs and their complexes exhibit reduced folding. In presence of NSF-ATP, the SNARE complex disassembles, as reflected from the CD signals demonstrating elimination of α-helices within the structure.


Immunopurification Of Ago1 Mirnps Selects For A Distinct Class Of Microrna Targets, Xin Hong, Molly Hammell, Victor R. Ambros, Stephen M. Cohen Sep 2009

Immunopurification Of Ago1 Mirnps Selects For A Distinct Class Of Microrna Targets, Xin Hong, Molly Hammell, Victor R. Ambros, Stephen M. Cohen

Program in Molecular Medicine Publications and Presentations

microRNAs comprise a few percent of animal genes and have been recognized as important regulators of a diverse range of biological processes. Understanding the biological functions of miRNAs requires effective means to identify their targets. Combined efforts from computational prediction, miRNA over-expression or depletion, and biochemical purification have identified thousands of potential miRNA-target pairs in cells and organisms. Complementarity to the miRNA seed sequence appears to be a common principle in target recognition. Other features, including miRNA-target duplex stability, binding site accessibility, and local UTR structure might affect target recognition. Yet computational approaches using such contextual features have yielded largely ...


Systematic Analysis Of Dynamic Mirna-Target Interactions During C. Elegans Development, Liang Zhang, Molly Hammell, Brian A. Kudlow, Victor R. Ambros, Min Han Aug 2009

Systematic Analysis Of Dynamic Mirna-Target Interactions During C. Elegans Development, Liang Zhang, Molly Hammell, Brian A. Kudlow, Victor R. Ambros, Min Han

Program in Molecular Medicine Publications and Presentations

Although microRNA (miRNA)-mediated functions have been implicated in many aspects of animal development, the majority of miRNA::mRNA regulatory interactions remain to be characterized experimentally. We used an AIN/GW182 protein immunoprecipitation approach to systematically analyze miRNA::mRNA interactions during C. elegans development. We characterized the composition of miRNAs in functional miRNA-induced silencing complexes (miRISCs) at each developmental stage and identified three sets of miRNAs with distinct stage-specificity of function. We then identified thousands of miRNA targets in each developmental stage, including a significant portion that is subject to differential miRNA regulation during development. By identifying thousands of miRNA ...


Sh2-Dependent Autophosphorylation Within The Tec Family Kinase Itk, Raji E. Joseph, Andrew Severin, Lie Min, D. Bruce Fulton, Amy H. Andreotti Aug 2009

Sh2-Dependent Autophosphorylation Within The Tec Family Kinase Itk, Raji E. Joseph, Andrew Severin, Lie Min, D. Bruce Fulton, Amy H. Andreotti

Biochemistry, Biophysics and Molecular Biology Publications

The Tec family kinase, Itk (interleukin-2 tyrosine kinase), undergoes an in cis autophosphorylation on Y180 within its Src homology 3 (SH3) domain. Autophosphorylation of the Itk SH3 domain by the Itk kinase domain is strictly dependent on the presence of the intervening Src homology 2 (SH2) domain. A direct docking interaction between the Itk kinase and SH2 domains brings the Itk SH3 domain into the active site where Y180 is then phosphorylated. We now identify the residues on the surface of the Itk SH2 domain responsible for substrate docking and show that this SH2 surface mediates autophosphorylation in the full-length ...


Differential Expression Of Collagen Type V And Xi Α-1 In Human Ascending Thoracic Aortic Aneurysms, Julia Thom Oxford Aug 2009

Differential Expression Of Collagen Type V And Xi Α-1 In Human Ascending Thoracic Aortic Aneurysms, Julia Thom Oxford

Biomolecular Research Center Publications and Presentations

Background—The molecular mechanisms leading to ascending thoracic aortic aneurysms (ATAAs) remain unknown. We hypothesized that alterations in expression levels of specific fibrillar collagens occur during the aneurysmal process.

Methods—Surgical samples from ascending aortas from patients with degenerative ATAAs were subdivided by aneurysm diameter: small, 5 to 6 cm; medium, 6 to 7 cm; and large, greater than 7 cm; and compared with nonaneurysmal aortas (mean diameter, 2.3 cm).

Results—Histology, immunofluorescence, and electron microscopy demonstrated greater disorganization of extracellular matrix constituents in ATAAs as compared with control with an increase in collagen α1(XI) within regions of ...


Polytene Chromosome Squash Methods For Studying Transcription And Epigenetic Chromatin Modification In Drosophila Using Antibodies, Kristen M. Johansen, Weili Cai, Huai Deng, Xiaomin Bao, Weiguo Zhang, Jack Girton, Jorgen Johansen Aug 2009

Polytene Chromosome Squash Methods For Studying Transcription And Epigenetic Chromatin Modification In Drosophila Using Antibodies, Kristen M. Johansen, Weili Cai, Huai Deng, Xiaomin Bao, Weiguo Zhang, Jack Girton, Jorgen Johansen

Biochemistry, Biophysics and Molecular Biology Publications

The giant polytene chromosomes from Drosophila third instar larval salivary glands provide an important model system for studying the architectural changes in chromatin morphology associated with the process of transcription initiation and elongation. Especially, analysis of the heat shock response has proved useful in correlating chromatin structure remodeling with transcriptional activity. An important tool for such studies is the labeling of polytene chromosome squash preparations with antibodies to the enzymes, transcription factors, or histone modifications of interest. However, in any immunohistochemical experiment there will be advantages and disadvantages to different methods of fixation and sample preparation, the relative merits of ...


A Proposed Syntax For Minimotif Semantics, Version 1., Jay Vyas, Ronald J. Nowling, Mark W. Maciejewski, Sanguthevar Rajasekaran, Michael R. Gryk, Martin R. Schiller Aug 2009

A Proposed Syntax For Minimotif Semantics, Version 1., Jay Vyas, Ronald J. Nowling, Mark W. Maciejewski, Sanguthevar Rajasekaran, Michael R. Gryk, Martin R. Schiller

Life Sciences Faculty Publications

BACKGROUND:

One of the most important developments in bioinformatics over the past few decades has been the observation that short linear peptide sequences (minimotifs) mediate many classes of cellular functions such as protein-protein interactions, molecular trafficking and post-translational modifications. As both the creators and curators of a database which catalogues minimotifs, Minimotif Miner, the authors have a unique perspective on the commonalities of the many functional roles of minimotifs. There is an obvious usefulness in standardizing functional annotations both in allowing for the facile exchange of data between various bioinformatics resources, as well as the internal clustering of sets of ...


Elucidating The Role Of Staphylococcus Epidermidis Serine-Aspartate Repeat Protein G In Platelet Activation., Marian P. Brennan, A Loughman, Marc Devocelle, S Arasu, Anthony J. Chubb, T J. Foster, Dermot Cox Aug 2009

Elucidating The Role Of Staphylococcus Epidermidis Serine-Aspartate Repeat Protein G In Platelet Activation., Marian P. Brennan, A Loughman, Marc Devocelle, S Arasu, Anthony J. Chubb, T J. Foster, Dermot Cox

Molecular and Cellular Therapeutics Articles

BACKGROUND: Staphylococcus epidermidis is a commensal of the human skin that has been implicated in infective endocarditis and infections involving implanted medical devices. S. epidermidis induces platelet aggregation by an unknown mechanism. The fibrinogen-binding protein serine-aspartate repeat protein G (SdrG) is present in 67-91% of clinical strains.

OBJECTIVES: To determine whether SdrG plays a role in platelet activation, and if so to investigate the role of fibrinogen in this mechanism.

METHODS: SdrG was expressed in a surrogate host, Lactococcus lactis, in order to investigate its role in the absence of other staphylococcal components. Platelet adhesion and platelet aggregation assays were ...


Geometric Build-Up Solutions For Protein Determination Via Distance Geometry, Robert Tucker Davis Aug 2009

Geometric Build-Up Solutions For Protein Determination Via Distance Geometry, Robert Tucker Davis

Masters Theses & Specialist Projects

Proteins carry out an almost innumerable amount of biological processes that are absolutely necessary to life and as a result proteins and their structures are very often the objects of study in research. As such, this thesis will begin with a description of protein function and structure, followed by brief discussions of the two major experimental structure determination methods. Another problem that often arises in molecular modeling is referred to as the Molecular Distance Geometry Problem (MDGP). This problem seeks to find coordinates for the atoms of a protein or molecule when given only a set of pair-wise distances between ...


Identification Of Light-Independent Inhibition Of Human Immunodeficiency Virus-1 Infection Through Bioguided Fractionation Of Hypericum Perforatum, Wendy Maury, Jason P. Price, Melinda A. Brindley, Choonseok Oh, Jeffrey D. Neighbors, David F. Wiemer, Nickolas Wills, Susan L. Carpenter, Catherine C. Hauck, Patricia A. Murphy, Mark P. Widrlechner, Kathleen Delate, Ganesh Kumar, George A. Kraus, Ludmila Rizshsky, Basil J. Nikolau Jul 2009

Identification Of Light-Independent Inhibition Of Human Immunodeficiency Virus-1 Infection Through Bioguided Fractionation Of Hypericum Perforatum, Wendy Maury, Jason P. Price, Melinda A. Brindley, Choonseok Oh, Jeffrey D. Neighbors, David F. Wiemer, Nickolas Wills, Susan L. Carpenter, Catherine C. Hauck, Patricia A. Murphy, Mark P. Widrlechner, Kathleen Delate, Ganesh Kumar, George A. Kraus, Ludmila Rizshsky, Basil J. Nikolau

NCRPIS Publications and Papers

Background
Light-dependent activities against enveloped viruses in St. John's Wort (Hypericum perforatum) extracts have been extensively studied. In contrast, light-independent antiviral activity from this species has not been investigated.

Results
Here, we identify the light-independent inhibition of human immunodeficiency virus-1 (HIV-1) by highly purified fractions of chloroform extracts of H. perforatum. Both cytotoxicity and antiviral activity were evident in initial chloroform extracts, but bioassay-guided fractionation produced fractions that inhibited HIV-1 with little to no cytotoxicity. Separation of these two biological activities has not been reported for constituents responsible for the light-dependent antiviral activities. Antiviral activity was associated with more ...


Comparisons Of Experimental And Computed Protein Anisotropic Temperature Factors, Lei Yang, Guang Song, Robert L. Jernigan Jul 2009

Comparisons Of Experimental And Computed Protein Anisotropic Temperature Factors, Lei Yang, Guang Song, Robert L. Jernigan

Biochemistry, Biophysics and Molecular Biology Publications

Because of its appealing simplicity, the anisotropic network model (ANM) has been widely accepted and applied to study many molecular motion problems: such as ribosome motions, the molecular mechanisms of GroEL-GroES function, allosteric changes in hemoglobin, motor-protein motions, and conformational changes in general. However, the validity of the ANM has not been closely examined. In this work, we use ANM to predict the anisotropic temperature factors of proteins obtained from X-ray and NMR data. The rich, directional anisotropic temperature factor data available for hundreds of proteins in the Protein Data Bank (PDB) are used as validation data to closely test ...


Effect Of Chronic Treatment With A Cyclooxygenase Inhibitor On Reproductive Parameters In Male Rat, Sheikh A Saeed, Naheed Anwar, Khalid M Khan, Noorjehan Sarfraz Jul 2009

Effect Of Chronic Treatment With A Cyclooxygenase Inhibitor On Reproductive Parameters In Male Rat, Sheikh A Saeed, Naheed Anwar, Khalid M Khan, Noorjehan Sarfraz

Department of Biological & Biomedical Sciences

BACKGROUND: Indomethacin is a member of non-steroidal anti-inflammatory drugs (NSAIDs) commonly used for treatment of gout, arthritis, and other inflammatory conditions. It has been shown to inhibit ovarian prostaglandins synthesis in mammals, birds, fish and reptiles. However, the effects of its chronic administration on male reproductive functions remain largely unknown. Using rat as a model, we studied the effect of chronic treatment with indomethacin on the male reproductive system.

METHODS: Testosterone was measured in the serum, testicular tissue, and testicular interstitial fluid by radioimmunoassay. Moreover, we also studied the direct effect of indomethacin in vitro on luteinizing hormone stimulated testosterone ...


Signal Transduction Cross Talk Mediated By Jun N-Terminal Kinase-Interacting Protein And Insulin Receptor Substrate Scaffold Protein Complexes, Claire L. Standen, Norman J. Kennedy, Richard A. Flavell, Roger J. Davis Jul 2009

Signal Transduction Cross Talk Mediated By Jun N-Terminal Kinase-Interacting Protein And Insulin Receptor Substrate Scaffold Protein Complexes, Claire L. Standen, Norman J. Kennedy, Richard A. Flavell, Roger J. Davis

Open Access Articles

Scaffold proteins have been established as important mediators of signal transduction specificity. The insulin receptor substrate (IRS) proteins represent a critical group of scaffold proteins that are required for signal transduction by the insulin receptor, including the activation of phosphatidylinositol 3 kinase. The c-Jun NH(2)-terminal kinase (JNK)-interacting proteins (JIPs) represent a different group of scaffold molecules that are implicated in the regulation of the JNK. These two signaling pathways are functionally linked because JNK can phosphorylate IRS1 on the negative regulatory site Ser-307. Here we demonstrate the physical association of these signaling pathways using a proteomic approach ...


Nuclear Localization Of P38 Mapk In Response To Dna Damage, C. David Wood, Tina Thornton, Guadalupe Sabio, Roger J. Davis, Mercedes Rincon Jun 2009

Nuclear Localization Of P38 Mapk In Response To Dna Damage, C. David Wood, Tina Thornton, Guadalupe Sabio, Roger J. Davis, Mercedes Rincon

Davis Lab Publications

p38 MAP kinase (MAPK) is activated in response to environmental stress, cytokines and DNA damage, and mediates death, cell differentiation and cell cycle checkpoints. The intracellular localization of p38 MAPK upon activation remains unclear, and may depend on the stimulus. We show here that activation of p38 MAPK by stimuli that induce DNA double strand breaks (DSBs), but not other stimuli, leads to its nuclear translocation. In addition, naturally occurring DSBs generated through V(D)J recombination in immature thymocytes also promote nuclear accumulation of p38 MAPK. Nuclear translocation of p38 MAPK does not require its catalytic activity, but is ...


Collective Dynamics Of The Ribosomal Tunnel Revealed By Elastic Network Modeling, Ozge Kurkcuoglu, Zeynep Kurkcuoglu, Pemra Doruker, Robert L. Jernigan Jun 2009

Collective Dynamics Of The Ribosomal Tunnel Revealed By Elastic Network Modeling, Ozge Kurkcuoglu, Zeynep Kurkcuoglu, Pemra Doruker, Robert L. Jernigan

Biochemistry, Biophysics and Molecular Biology Publications

The collective dynamics of the nascent polypeptide exit tunnel are investigated with the computationally efficient elastic network model using normal mode analysis. The calculated normal modes are considered individually and in linear combinations with different coefficients mimicking the phase angles between modes, in order to follow the mechanistic motions of tunnel wall residues. The low frequency fluctuations indicate three distinct regions along the tunnel - the entrance, the neck and the exit – each having distinctly different domain motions. Generally the lining of the entrance region moves in the exit direction, with the exit region having significantly larger motions, but in a ...


Mcl-1 Integrates The Opposing Actions Of Signaling Pathways That Mediate Survival And Apoptosis, Caroline Morel, Scott M. Carlson, Forest M. White, Roger J. Davis May 2009

Mcl-1 Integrates The Opposing Actions Of Signaling Pathways That Mediate Survival And Apoptosis, Caroline Morel, Scott M. Carlson, Forest M. White, Roger J. Davis

Open Access Articles

Mcl-1 is a member of the Bcl2-related protein family that is a critical mediator of cell survival. Exposure of cells to stress causes inhibition of Mcl-1 mRNA translation and rapid destruction of Mcl-1 protein by proteasomal degradation mediated by a phosphodegron created by glycogen synthase kinase 3 (GSK3) phosphorylation of Mcl-1. Here we demonstrate that prior phosphorylation of Mcl-1 by the c-Jun N-terminal protein kinase (JNK) is essential for Mcl-1 phosphorylation by GSK3. Stress-induced Mcl-1 degradation therefore requires the coordinated activity of JNK and GSK3. Together, these data establish that Mcl-1 functions as a site of signal integration between the ...


Effects Of Estrogen On Muscle Damage In Response To An Acute Resistance Exercise Protocol, Megan R. Wolf May 2009

Effects Of Estrogen On Muscle Damage In Response To An Acute Resistance Exercise Protocol, Megan R. Wolf

Honors Scholar Theses

Creatine Kinase (CK) is used as a measure of exercise-induced muscle membrane damage. During acute eccentric (muscle lengthening) exercise, muscle sarcolemma, sarcoplasmic reticulum, and Z-lines are damaged, thus causing muscle proteins and enzymes to leak into the interstitial fluid.

Strenuous eccentric exercise produces an elevation of oxygen free radicals, which further increases muscle damage. Muscle soreness and fatigue can be attributed to this membrane damage. Estradiol, however, may preserve membrane stability post-exercise (Brancaccio, Maffulli, & Limongelli, 2007; Carter, Dobridge, & Hackney, 2001; Tiidus, 2001). Because estradiol has a similar structure to Vitamin E, which is known to have antioxidant properties, and both are known to affect ...


Characterizing The Role Of Phaeobacter In The Mortality Of The Squid, Euprymna Scolopes, Brian Shawn Wong Won May 2009

Characterizing The Role Of Phaeobacter In The Mortality Of The Squid, Euprymna Scolopes, Brian Shawn Wong Won

Honors Scholar Theses

The subject of our study is the Hawaiian bobtail squid, Euprymna scolopes, which is known for its model symbiotic relationship with the bioluminescent bacterium, Vibrio fischeri. The interactions between E. scolopes and V. fischeri provide an exemplary model of the biochemical and molecular dynamics of symbiosis since both members can be cultivated separately and V. fischeri can be genetically modified 1. However, in a laboratory setting, the mortality of embryonic E. scolopes can be a recurrent problem. In many of these fatalities, the egg cases display a pink-hued biofilm, and rosy pigmentation has also been noted in the deaths of ...


Characterization Of A Hypothetical Protein Critical For The Symbiotic Interaction Of Aeromonas Veronii And Hirudo Verbana, Kaitlin Vaughan May 2009

Characterization Of A Hypothetical Protein Critical For The Symbiotic Interaction Of Aeromonas Veronii And Hirudo Verbana, Kaitlin Vaughan

Honors Scholar Theses

The digestive tract symbiosis of the medicinal leech, Hirudo verbana, is a model system for studying the genes required for microbial colonization of digestive tracts, as H. verbana has only two species of bacteria that dominate the crop microbiota, Aeromonas veronii and a Rikenella-like bacterium. Signature-tagged mutagenesis (STM) of the A.

veronii strain, HM21R, revealed genes required for the colonization of the digestive tract. One of these mutants, JG573, has an interrupted gene that is predicted to encode a hypothetical protein. The region flanking the transposon insertion of this mutant was sequenced by primer walking.

Comparison of the flanking DNA ...


Analysis Of The Phosphorylated Forms Of Protein Kinase R, Christine Quartararo May 2009

Analysis Of The Phosphorylated Forms Of Protein Kinase R, Christine Quartararo

Honors Scholar Theses

Protein Kinase R (PKR) is induced by interferon and activated by dsRNA. Subsequent autophosphorylation and phosphorylation of eIF2alpha inhibits viral replication. In the latent state PKR exists as an unphosphorylated monomer. Work in the Cole laboratory has shown two additional states, a phosphorylated monomeric state (pPKRm) and a phosphorylated dimeric state (pPKRd). RNA serves as a scaffold bringing two PKRs together allowing dimerization and autophosphorylation to occur. The contribution of each state to the function of PKR remains unclear. Western blots were performed to examine the phosphorylation states of the essential residues,

T446 and T451. Activity assays have shown activation ...


Contribution Of The Novel C-Terminal Domain To The Ribosome Binding Activities Of Virulence Regulator Bipa, Heeren Makanji May 2009

Contribution Of The Novel C-Terminal Domain To The Ribosome Binding Activities Of Virulence Regulator Bipa, Heeren Makanji

Honors Scholar Theses

Bacterial GTPases regulate many cell functions, including the stress response, signal recognition, protein synthesis, and cell differentiation, through a molecular switch that is activated and deactivated depending on their nucleotide bound state (1). A member of the translational family of bacterial GTPases along with LepA and EF-G, BipA is a 67 kD protein that is essential for virulence and the stress response. Crystal structures from the Robinson lab have shown a unique C-terminal domain on BipA that has been implicated in ribosome binding. Using N-terminal deletion constructs, we have shown that the C-terminal domain is necessary, but not sufficient, to ...


The Role Of Raf Kinase Inhibitor Protein In Cell Motility, Kathryn Grive May 2009

The Role Of Raf Kinase Inhibitor Protein In Cell Motility, Kathryn Grive

Honors Scholar Theses

Raf Kinase Inhibitor Protein (RKIP) has been identified as a phosphatidylethanolamine-binding protein capable of inhibiting Raf-1 kinase, an enzyme significant in cell proliferation and cancer development. When properly functioning, RKIP can mediate the expression of Raf-1 kinase and help prevent uncontrolled cell division. RKIP also has suggested, but unclear, roles in spindle fiber formation during mitosis, regulation of apoptosis, and cell motility. The Fenteany laboratory in the Chemistry Department identified a new small molecule, named Locostatin, as a cell migration inhibitor in mammalian cells, with RKIP as its primary molecular target.

Dictyostelium discoideum possess two RKIP proteins, RKIP-A and RKIP-B ...


Knockdown Of Kiaa0319 Reduces Dendritic Spine Density, Daniel Young Kim May 2009

Knockdown Of Kiaa0319 Reduces Dendritic Spine Density, Daniel Young Kim

Honors Scholar Theses

Developmental Dyslexia is a reading disorder that affects individuals that possess otherwise normal intelligence. Until the four candidate dyslexia susceptibility genes were discovered, the cause of cortical malformations found in post mortem dyslexic brains was unclear. Normal brain development is crucial for the proper wiring of the neural circuitry that allow an individual to perform cognitive tasks like reading. For years, familial and twin studies have suggested that there was a genetic basis to the causation of dyslexia. Kiaa0319 was among the candidate dyslexia susceptibility genes that were ascertained. KIAA0319 is located on Chromosome 6p22.2-22.3 and has been ...