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Physiology

2015

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Articles 1 - 30 of 57

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

Alternative Use Of Dna Binding Domains By The Neurospora White Collar Complex Dictates Circadian Regulation And Light Responses, Bin Wang, Xiaoying Zhou, Jennifer J. Loros, Jay C. Dunlap Dec 2015

Alternative Use Of Dna Binding Domains By The Neurospora White Collar Complex Dictates Circadian Regulation And Light Responses, Bin Wang, Xiaoying Zhou, Jennifer J. Loros, Jay C. Dunlap

Open Dartmouth: Faculty Open Access Scholarship

In the Neurospora circadian system, the White Collar complex (WCC) of WC-1 and WC-2 drives transcription of the circadian pacemaker gene frequency (frq), whose gene product, FRQ, as a part of the FRQ-FRH complex (FFC), inhibits its own expression. The WCC is also the principal Neurospora photoreceptor; WCC-mediated light induction of frq resets the clock, and all acute light induction is triggered by WCC binding to promoters of light-induced genes. However, not all acutely light-induced genes are also clock regulated, and conversely, not all clock-regulated direct targets of WCC are light induced; the structural determinants governing the shift from WCC ...


Endothelial Protein Kinase Map4k4 Promotes Vascular Inflammation And Atherosclerosis, Rachel J. Roth Flach, Athanasia Skoura, Anouch Matevossian, Laura V. Danai, Wei Zheng, Christian Cortes, Samit K. Bhattacharya, Myriam Aouadi, G. Nana Hagan, Joseph Yawe, Pranitha Vangala, Lorena Garcia Menendez, Marcus P. Cooper, Timothy P. Fitzgibbons, Leonard Buckbinder, Michael P. Czech Dec 2015

Endothelial Protein Kinase Map4k4 Promotes Vascular Inflammation And Atherosclerosis, Rachel J. Roth Flach, Athanasia Skoura, Anouch Matevossian, Laura V. Danai, Wei Zheng, Christian Cortes, Samit K. Bhattacharya, Myriam Aouadi, G. Nana Hagan, Joseph Yawe, Pranitha Vangala, Lorena Garcia Menendez, Marcus P. Cooper, Timothy P. Fitzgibbons, Leonard Buckbinder, Michael P. Czech

Program in Molecular Medicine Publications and Presentations

Signalling pathways that control endothelial cell (EC) permeability, leukocyte adhesion and inflammation are pivotal for atherosclerosis initiation and progression. Here we demonstrate that the Sterile-20-like mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4), which has been implicated in inflammation, is abundantly expressed in ECs and in atherosclerotic plaques from mice and humans. On the basis of endothelial-specific MAP4K4 gene silencing and gene ablation experiments in Apoe(-/-) mice, we show that MAP4K4 in ECs markedly promotes Western diet-induced aortic macrophage accumulation and atherosclerotic plaque development. Treatment of Apoe(-/-) and Ldlr(-/-) mice with a selective small-molecule MAP4K4 inhibitor also markedly reduces atherosclerotic ...


Systematic Dissection Of Roles For Chromatin Regulators In Dynamics Of Transcriptional Response To Stress In Yeast: A Dissertation, Hsiuyi V. Chen Dec 2015

Systematic Dissection Of Roles For Chromatin Regulators In Dynamics Of Transcriptional Response To Stress In Yeast: A Dissertation, Hsiuyi V. Chen

GSBS Dissertations and Theses

The following work demonstrates that chromatin regulators play far more pronounced roles in dynamic gene expression than they do in steady-state. Histone modifications have been associated with transcription activity. However, previous analyses of gene expression in mutants affecting histone modifications show limited alteration. I systematically dissected the effects of 83 histone mutants and 119 gene deletion mutants on gene induction/repression in response to diamide stress in yeast. Importantly, I observed far more changes in gene induction/repression than changes in steady-state gene expression. The extensive dynamic gene expression profile of histone mutants and gene deletion mutants also allowed me ...


Genetic And Acute Cpeb1 Depletion Ameliorate Fragile X Pathophysiology, Tsuyoshi Udagawa, Natalie Farny, Mira Jakovcevski, Hanoch Kaphzan, Juan Alarcon, Shobha Anilkumar, Maria Ivshina, Jessica Hurt, Kentaro Nagaoka, Vijayalaxmi Nalavadi, Lori Lorenz, Gary Bassell, Schahram Akbarian, Sumantra Chattarji, Eric Klann, Joel Richter Dec 2015

Genetic And Acute Cpeb1 Depletion Ameliorate Fragile X Pathophysiology, Tsuyoshi Udagawa, Natalie Farny, Mira Jakovcevski, Hanoch Kaphzan, Juan Alarcon, Shobha Anilkumar, Maria Ivshina, Jessica Hurt, Kentaro Nagaoka, Vijayalaxmi Nalavadi, Lori Lorenz, Gary Bassell, Schahram Akbarian, Sumantra Chattarji, Eric Klann, Joel Richter

Natalie G. Farny

Fragile X syndrome (FXS), the most common cause of inherited mental retardation and autism, is caused by transcriptional silencing of FMR1, which encodes the translational repressor fragile X mental retardation protein (FMRP). FMRP and cytoplasmic polyadenylation element-binding protein (CPEB), an activator of translation, are present in neuronal dendrites, are predicted to bind many of the same mRNAs and may mediate a translational homeostasis that, when imbalanced, results in FXS. Consistent with this possibility, Fmr1(-/y); Cpeb1(-/-) double-knockout mice displayed amelioration of biochemical, morphological, electrophysiological and behavioral phenotypes associated with FXS. Acute depletion of CPEB1 in the hippocampus of adult Fmr1 ...


Autophagy And Its Potential Role In Stress And Feed Efficiency Using Avian Lines, Alissa Laura Piekarski Dec 2015

Autophagy And Its Potential Role In Stress And Feed Efficiency Using Avian Lines, Alissa Laura Piekarski

Theses and Dissertations

Autophagy is a highly conserved cellular mechanism that is responsible for the degradation and recycling of damaged organelles. Recently, autophagy has been involved in critical roles during overall development of the organism and degradation of damaged cellular components. This pathway has witnessed dramatic growth in the last few years and has been extensively studied in yeast and mammals, however, there is a paucity of information in avian (non-mammalian) species. First, we characterized genes involved in the autophagy pathway in male and female Jungle Fowl to determine gender and tissue specific differences. Secondly, tissue and genotype differences in Japanese quail selected ...


A New Method For Shear Wave Speed Estimation In Shear Wave Elastography, Aaron J. Engel, Gregory R. Bashford Dec 2015

A New Method For Shear Wave Speed Estimation In Shear Wave Elastography, Aaron J. Engel, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

Visualization of mechanical properties of tissue can aid in noninvasive pathology diagnosis. Shear wave elastography (SWE) measures the elastic properties of soft tissues by estimation of local shear wave propagation speed. In this paper, a new robust method for estimation of shear wave speed is introduced which has the potential for simplifying continuous filtering and real-time elasticity processing. Shear waves were generated by external mechanical excitation and imaged at a high frame rate. Three homogeneous phantoms of varying elastic moduli and one inclusion phantom were imaged. Waves propagating in separate directions were filtered and shear wave speed was estimated by ...


Homozygous Knockout Of The Piezo1 Gene In The Zebrafish Is Not Associated With Anemia, Boris E. Shmukler, Nicholas C. Huston, Jonathan N. Thon, Chih-Wen Ni, George Kourkoulis, Nathan D. Lawson, Barry H. Paw, Seth L. Alper Dec 2015

Homozygous Knockout Of The Piezo1 Gene In The Zebrafish Is Not Associated With Anemia, Boris E. Shmukler, Nicholas C. Huston, Jonathan N. Thon, Chih-Wen Ni, George Kourkoulis, Nathan D. Lawson, Barry H. Paw, Seth L. Alper

Molecular, Cell and Cancer Biology Publications

We have now examined the erythroid phenotype in this zebrafish strain carrying a ZFN genomic knockout of piezo1. Genotyping was performed as previously described. In contrast to the anemic phenotype observed in zebrafish subjected to morpholino knockdown of piezo, the genomic ZFN knockout of piezo1 did not segregate either with anemia in the 3-dpf embryo or with dysmorphic erythrocyte morphology in the adult fish.


Direct Visualization Of Hiv-1 Replication Intermediates Shows That Capsid And Cpsf6 Modulate Hiv-1 Intra-Nuclear Invasion And Integration, Christopher R. Chin, Jill Perreira, George Savidis, Jocelyn M. Portmann, Aaron M. Aker, Eric M. Feeley, Miles C. Smith, Abraham L. Brass Nov 2015

Direct Visualization Of Hiv-1 Replication Intermediates Shows That Capsid And Cpsf6 Modulate Hiv-1 Intra-Nuclear Invasion And Integration, Christopher R. Chin, Jill Perreira, George Savidis, Jocelyn M. Portmann, Aaron M. Aker, Eric M. Feeley, Miles C. Smith, Abraham L. Brass

Microbiology and Physiological Systems Publications and Presentations

Direct visualization of HIV-1 replication would improve our understanding of the viral life cycle. We adapted established technology and reagents to develop an imaging approach, ViewHIV, which allows evaluation of early HIV-1 replication intermediates, from reverse transcription to integration. These methods permit the simultaneous evaluation of both the capsid protein (CA) and viral DNA genome (vDNA) components of HIV-1 in both the cytosol and nuclei of single cells. ViewHIV is relatively rapid, uses readily available reagents in combination with standard confocal microscopy, and can be done with virtually any HIV-1 strain and permissive cell lines or primary cells. Using ViewHIV ...


Hepatic Nutrient And Hormonal Regulation Of The Pancreatic-Derived Factor (Pander) Promoter, Whitney Ratliff Nov 2015

Hepatic Nutrient And Hormonal Regulation Of The Pancreatic-Derived Factor (Pander) Promoter, Whitney Ratliff

Graduate Theses and Dissertations

PANcreatic-DERived factor (PANDER, FAM3B) has been shown to regulate glycemic levels via interactions with both pancreatic islets and the liver. Although PANDER is predominantly expressed from the endocrine pancreas, recent work has provided sufficient evidence that the liver may also be an additional tissue source of PANDER production. At physiological levels, PANDER is capable of disrupting insulin signaling and promoting increased hepatic glucose production. As shown in some animal models, strong expression of PANDER, induced by viral delivery within the liver, induces hepatic steatosis. However, no studies to date have explicitly characterized the transcriptional regulation of PANDER from the liver ...


Roles Of Protein Arginine Methyltransferase 7 And Jumonji Domain-Containing Protein 6 In Adipocyte Differentiation: A Dissertation, Yu-Jie Hu Oct 2015

Roles Of Protein Arginine Methyltransferase 7 And Jumonji Domain-Containing Protein 6 In Adipocyte Differentiation: A Dissertation, Yu-Jie Hu

GSBS Dissertations and Theses

Regulation of gene expression comprises a wide range of mechanisms that control the abundance of gene products in response to environmental and developmental changes. These biological processes can be modulated by posttranslational modifications including arginine methylation. Among the enzymes that catalyze the methylation, protein arginine methyltransferase 7 (PRMT7) is known to modify histones to repress gene expression. Jumonji domain-containing protein 6 (JMJD6) is a putative arginine demethylase that potentially antagonize PRMT7. However, the biological significance of these enzymes is not well understood. This thesis summarizes the investigation of both PRMT7 and JMJD6 in cell culture models for adipocyte differentiation. The ...


Mcnamara 201412 Nih Scap Innocentive Challenge Solution - T-Bow Rainbow T-Cells And Tumor Cells Spatial Multiplexing Gene Expression Reporter System – Plus Supplement Plus Posters - 20151027 - Please Download "75" Instead, George Mcnamara Oct 2015

Mcnamara 201412 Nih Scap Innocentive Challenge Solution - T-Bow Rainbow T-Cells And Tumor Cells Spatial Multiplexing Gene Expression Reporter System – Plus Supplement Plus Posters - 20151027 - Please Download "75" Instead, George Mcnamara

George McNamara

McNamara 201412 NIH SCAP InnoCentive Challenge Solution - T-Bow Rainbow T-cells and Tumor Cells Spatial Multiplexing Gene Expression Reporter System – plus supplement plus posters - 20151027.

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Please download the current 20151027 (October 27, 2015) Tattletales and T-Bow update from

http://0-works.bepress.com.library.simmons.edu/gmcnamara/75/

The bepress web site is not letting me replace the old pdf here at "65" with the additional 10 pages update.

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The download is my/Cooper lab solution (submission) to the 2014 NIH Single Cell Analysis Program (SCAP) InnoCentive Challenge, "Follow That Cell". I submitted the Solution on 20141215Mon (with 20 minutes to spare). The Challenge web ...


Hcm1 Integrates Signals From Cdk1 And Calcineurin To Control Cell Proliferation, Heather E. Arsenault, Jagoree Roy, Claudine E. Mapa, Martha S. Cyert, Jennifer A. Benanti Oct 2015

Hcm1 Integrates Signals From Cdk1 And Calcineurin To Control Cell Proliferation, Heather E. Arsenault, Jagoree Roy, Claudine E. Mapa, Martha S. Cyert, Jennifer A. Benanti

Molecular, Cell and Cancer Biology Publications

Cyclin-dependent kinase (Cdk1) orchestrates progression through the cell cycle by coordinating the activities of cell-cycle regulators. Although phosphatases that oppose Cdk1 are likely to be necessary to establish dynamic phosphorylation, specific phosphatases that target most Cdk1 substrates have not been identified. In budding yeast, the transcription factor Hcm1 activates expression of genes that regulate chromosome segregation and is critical for maintaining genome stability. Previously we found that Hcm1 activity and degradation are stimulated by Cdk1 phosphorylation of distinct clusters of sites. Here we show that, upon exposure to environmental stress, the phosphatase calcineurin inhibits Hcm1 by specifically removing activating phosphorylations ...


Control Of Stem Cell Self-Renewal And Differentiation By The Heterochronic Genes And The Cellular Asymmetry Machinery In Caenorhabditis Elegans, Omid F. Harandi, Victor Ambros Oct 2015

Control Of Stem Cell Self-Renewal And Differentiation By The Heterochronic Genes And The Cellular Asymmetry Machinery In Caenorhabditis Elegans, Omid F. Harandi, Victor Ambros

Victor R. Ambros

Transitions between asymmetric (self-renewing) and symmetric (proliferative) cell divisions are robustly regulated in the context of normal development and tissue homeostasis. To genetically assess the regulation of these transitions, we used the postembryonic epithelial stem (seam) cell lineages of Caenorhabditis elegans. In these lineages, the timing of these transitions is regulated by the evolutionarily conserved heterochronic pathway, whereas cell division asymmetry is conferred by a pathway consisting of Wnt (Wingless) pathway components, including posterior pharynx defect (POP-1)/TCF, APC related/adenomatosis polyposis coli (APR-1)/APC, and LIT-1/NLK (loss of intestine/Nemo-like kinase). Here we explore the genetic regulatory mechanisms ...


Mir-14 Regulates Autophagy During Developmental Cell Death By Targeting Ip3-Kinase 2, Charles Nelson, Victor Ambros, Eric Baehrecke Oct 2015

Mir-14 Regulates Autophagy During Developmental Cell Death By Targeting Ip3-Kinase 2, Charles Nelson, Victor Ambros, Eric Baehrecke

Victor R. Ambros

Macroautophagy (autophagy) is a lysosome-dependent degradation process that has been implicated in age-associated diseases. Autophagy is involved in both cell survival and cell death, but little is known about the mechanisms that distinguish its use during these distinct cell fates. Here, we identify the microRNA miR-14 as being both necessary and sufficient for autophagy during developmentally regulated cell death in Drosophila. Loss of miR-14 prevented induction of autophagy during salivary gland cell death, but had no effect on starvation-induced autophagy in the fat body. Moreover, misexpression of miR-14 was sufficient to prematurely induce autophagy in salivary glands, but not in ...


Cfap54 Is Required For Proper Ciliary Motility And Assembly Of The Central Pair Apparatus In Mice, Casey W. Mckenzie, Branch Craige, Tiffany V. Kroeger, Rozzy Finn, Todd A. Wyatt, Joseph H. Sisson, Jacqueline A. Pavlik, Lara Strittmatter, Gregory M. Hendricks, George B. Witman, Lance Lee Sep 2015

Cfap54 Is Required For Proper Ciliary Motility And Assembly Of The Central Pair Apparatus In Mice, Casey W. Mckenzie, Branch Craige, Tiffany V. Kroeger, Rozzy Finn, Todd A. Wyatt, Joseph H. Sisson, Jacqueline A. Pavlik, Lara Strittmatter, Gregory M. Hendricks, George B. Witman, Lance Lee

Cell and Developmental Biology Publications

Motile cilia and flagella play critical roles in fluid clearance and cell motility, and dysfunction commonly results in the pediatric syndrome primary ciliary dyskinesia (PCD). CFAP221, also known as PCDP1, is required for ciliary and flagellar function in mice and Chlamydomonas reinhardtii, where it localizes to the C1d projection of the central microtubule apparatus and functions in a complex that regulates flagellar motility in a calcium-dependent manner. We demonstrate that the genes encoding the mouse homologues of the other C. reinhardtii C1d complex members are primarily expressed in motile ciliated tissues, suggesting a conserved function in mammalian motile cilia. The ...


Weekly Treatment Of 2-Hydroxypropyl-Beta-Cyclodextrin Improves Intracellular Cholesterol Levels In Ldl Receptor Knockout Mice, Sofie M.A. Walenbergh, Tom Houben, Tim Hendrikx, Mike L.J. Jeurissen, Patrick J. Van Gorp, Nathalie Vaes, Steven W.M. Olde Damink, Fons Verheyen, Ger H. Koek, Dieter Lutjohann, Alena Grebe, Eicke Latz, Ronit Shiri-Sverdlov Sep 2015

Weekly Treatment Of 2-Hydroxypropyl-Beta-Cyclodextrin Improves Intracellular Cholesterol Levels In Ldl Receptor Knockout Mice, Sofie M.A. Walenbergh, Tom Houben, Tim Hendrikx, Mike L.J. Jeurissen, Patrick J. Van Gorp, Nathalie Vaes, Steven W.M. Olde Damink, Fons Verheyen, Ger H. Koek, Dieter Lutjohann, Alena Grebe, Eicke Latz, Ronit Shiri-Sverdlov

Open Access Articles

Recently, the importance of lysosomes in the context of the metabolic syndrome has received increased attention. Increased lysosomal cholesterol storage and cholesterol crystallization inside macrophages have been linked to several metabolic diseases, such as atherosclerosis and non-alcoholic fatty liver disease (NAFLD). Two-hydroxypropyl-beta-cyclodextrin (HP-B-CD) is able to redirect lysosomal cholesterol to the cytoplasm in Niemann-Pick type C1 disease, a lysosomal storage disorder. We hypothesize that HP-B-CD ameliorates liver cholesterol and intracellular cholesterol levels inside Kupffer cells (KCs). Hyperlipidemic low-density lipoprotein receptor knockout (Ldlr(-/-)) mice were given weekly, subcutaneous injections with HP-B-CD or control PBS. In contrast to control injections, hyperlipidemic mice ...


Determination Of Fatty Acid Oxidation And Lipogenesis In Mouse Primary Hepatocytes, Thomas E. Akie, Marcus P. Cooper Aug 2015

Determination Of Fatty Acid Oxidation And Lipogenesis In Mouse Primary Hepatocytes, Thomas E. Akie, Marcus P. Cooper

GSBS Student Publications

Lipid metabolism in liver is complex. In addition to importing and exporting lipid via lipoproteins, hepatocytes can oxidize lipid via fatty acid oxidation, or alternatively, synthesize new lipid via de novo lipogenesis. The net sum of these pathways is dictated by a number of factors, which in certain disease states leads to fatty liver disease. Excess hepatic lipid accumulation is associated with whole body insulin resistance and coronary heart disease. Tools to study lipid metabolism in hepatocytes are useful to understand the role of hepatic lipid metabolism in certain metabolic disorders. In the liver, hepatocytes regulate the breakdown and synthesis ...


Investigating The Effects Of Mutant Fus On Stress Response In Amyotrophic Lateral Sclerosis: A Thesis, Laura J. Kaushansky Aug 2015

Investigating The Effects Of Mutant Fus On Stress Response In Amyotrophic Lateral Sclerosis: A Thesis, Laura J. Kaushansky

GSBS Dissertations and Theses

During stress, eukaryotes regulate protein synthesis in part through formation of cytoplasmic, non-membrane-bound complexes called stress granules (SGs). SGs transiently store signaling proteins and stalled translational complexes in response to stress stimuli (e.g. oxidative insult, DNA damage, temperature shifts and ER dysfunction). The functional outcome of SGs is proper translational regulation and signaling, allowing cells to overcome stress.

The fatal motor neuron disease Amyotrophic Lateral Sclerosis (ALS) develops in an age-related manner and is marked by progressive neuronal death, with cytoplasmic protein aggregation, excitotoxicity and increased oxidative stress as major hallmarks. Fused in Sarcoma/Translocated in Liposarcoma (FUS) is ...


Gating Mechanisms Of The Canonical Trp Channel Isoform Trpc4, Dhananjay P. Thakur Aug 2015

Gating Mechanisms Of The Canonical Trp Channel Isoform Trpc4, Dhananjay P. Thakur

UT GSBS Dissertations and Theses (Open Access)

Non-selective cation channels formed by Transient Receptor Potential Canonical (TRPC) proteins play important roles in regulatory and pathophysiological processes. These channels are known to be activated downstream from phospholipase C (PLC) signaling. However, the mechanism by which the PLC pathway activates TRPC4/C5 remains unclear. Uniquely, TRPC4 is maximally activated only when two separate G protein pathways, Gq/11 and Gi/o, are co-stimulated, making it a coincidence detector of Gq/11- and Gi/o -coupled receptor activation. Using HEK293 cells co-expressing mouse TRPC4β and selected G protein-coupled receptors, I observed that coincident stimulation of G ...


Hydrophobic Surfactant Proteins Strongly Induce Negative Curvature, Mariya Chavarha, Ryan W. Loney, Shankar B. Rananavare, Stephen B. Hall Jul 2015

Hydrophobic Surfactant Proteins Strongly Induce Negative Curvature, Mariya Chavarha, Ryan W. Loney, Shankar B. Rananavare, Stephen B. Hall

Chemistry Faculty Publications and Presentations

The hydrophobic surfactant proteins SP-B and SP-C greatly accelerate the adsorption of vesicles containing the surfactant lipids to form a film that lowers the surface tension of the air/water interface in the lungs. Pulmonary surfactant enters the interface by a process analogous to the fusion of two vesicles. As with fusion, several factors affect adsorption according to how they alter the curvature of lipid leaflets, suggesting that adsorption proceeds via a rate-limiting structure with negative curvature, in which the hydrophilic face of the phospholipid leaflets is concave. In the studies reported here, we tested whether the surfactant proteins might ...


Inducible Deletion Of Protein Kinase Map4k4 In Obese Mice Improves Insulin Sensitivity In Liver And Adipose Tissues, Laura V. Danai, Rachel J. Roth Flach, Joseph V Virbasius, Lorena Garcia Menendez, Dae Young Jung, Jong Hun Kim, Jason K. Kim, Michael P. Czech Jul 2015

Inducible Deletion Of Protein Kinase Map4k4 In Obese Mice Improves Insulin Sensitivity In Liver And Adipose Tissues, Laura V. Danai, Rachel J. Roth Flach, Joseph V Virbasius, Lorena Garcia Menendez, Dae Young Jung, Jong Hun Kim, Jason K. Kim, Michael P. Czech

Program in Molecular Medicine Publications and Presentations

Studies in vitro suggest that mitogen-activated protein kinase kinase kinase kinase 4 (Map4k4) attenuates insulin signaling, but confirmation in vivo is lacking since Map4k4 knockout is lethal during embryogenesis. We thus generated mice with floxed Map4k4 alleles and a tamoxifen-inducible Cre/ERT2 recombinase under the control of the ubiquitin C promoter to induce whole-body Map4k4 deletion after these animals reached maturity. Tamoxifen administration to these mice induced Map4k4 deletion in all tissues examined, causing decreased fasting blood glucose concentrations and enhanced insulin signaling to AKT in adipose tissue and liver but not in skeletal muscle. Surprisingly, however, mice generated with ...


Drug-Resistant Hiv-1 Protease Regains Functional Dynamics Through Cleavage Site Coevolution, Nevra Ozer, Aysegul Ozen, Celia Schiffer, Turkan Haliloglu May 2015

Drug-Resistant Hiv-1 Protease Regains Functional Dynamics Through Cleavage Site Coevolution, Nevra Ozer, Aysegul Ozen, Celia Schiffer, Turkan Haliloglu

Celia A. Schiffer

Drug resistance is caused by mutations that change the balance of recognition favoring substrate cleavage over inhibitor binding. Here, a structural dynamics perspective of the regained wild-type functioning in mutant HIV-1 proteases with coevolution of the natural substrates is provided. The collective dynamics of mutant structures of the protease bound to p1-p6 and NC-p1 substrates are assessed using the Anisotropic Network Model (ANM). The drug-induced protease mutations perturb the mechanistically crucial hinge axes that involve key sites for substrate binding and dimerization and mainly coordinate the intrinsic dynamics. Yet with substrate coevolution, while the wild-type dynamic behavior is restored in ...


Biological Significance Of Photoreceptor Photocycle Length: Vivid Photocycle Governs The Dynamic Vivid-White Collar Complex Pool Mediating Photo-Adaptation And Response To Changes In Light Intensity, Arko Dasgupta, Chen-Hui Chen, Changhwan Lee, Amy S. Gladfelter, Jay C. Dunlap, Jennifer J. Loros May 2015

Biological Significance Of Photoreceptor Photocycle Length: Vivid Photocycle Governs The Dynamic Vivid-White Collar Complex Pool Mediating Photo-Adaptation And Response To Changes In Light Intensity, Arko Dasgupta, Chen-Hui Chen, Changhwan Lee, Amy S. Gladfelter, Jay C. Dunlap, Jennifer J. Loros

Open Dartmouth: Faculty Open Access Scholarship

Most organisms on earth sense light through the use of chromophore-bearing photoreceptive proteins with distinct and characteristic photocycle lengths, yet the biological significance of this adduct decay length is neither understood nor has been tested. In the filamentous fungus Neurospora crassa VIVID (VVD) is a critical player in the process of photoadaptation, the attenuation of light-induced responses and the ability to maintain photosensitivity in response to changing light intensities. Detailed in vitro analysis of the photochemistry of the blue light sensing, FAD binding, LOV domain of VVD has revealed residues around the site of photo-adduct formation that influence the stability ...


Discovering The Sequence Specificity Of Human Dyrk2 And Dyrk4, Julie Klaric May 2015

Discovering The Sequence Specificity Of Human Dyrk2 And Dyrk4, Julie Klaric

University Scholar Projects

Protein phosphorylation is a post-translational modification (PTM) that is ubiquitous in regulating cellular processes. It is the most common PTM used in signal translation. Protein kinases are the class of enzymes that catalyze the transfer of a phosphate group from ATP to a specific amino acid on a substrate protein. In eukaryotes, kinases generally add a phosphate to serine, threonine, or tyrosine residues. Short linear patterns in the amino acid sequence of the substrate protein help guide the protein kinase to the correct residue to be phosphorylated. However, these patterns, or “motifs,” as well as the complete list of substrates ...


The Characterization Of Amyloid Fibrils And Novel Synthetic Heparin-Binding Peptides Binding To Cell Surfaces, Nicole Marie Hackenbrack May 2015

The Characterization Of Amyloid Fibrils And Novel Synthetic Heparin-Binding Peptides Binding To Cell Surfaces, Nicole Marie Hackenbrack

Chancellor’s Honors Program Projects

No abstract provided.


The Development Of Skeletal Muscle In Young Horses: An Ultrasonography And Satellite Cell Approach, Emma K. Lavigne May 2015

The Development Of Skeletal Muscle In Young Horses: An Ultrasonography And Satellite Cell Approach, Emma K. Lavigne

Honors Scholar Theses

Muscle growth in young horses is characterized by an increase in muscle cross-sectional area, which can be accomplished through the activation and differentiation of satellite cells. Satellite cells can be stimulated or inhibited in response to different cytokines and growth factors and are key mediators of muscle hypertrophy and regeneration. The aim of this study was to investigate the growth of the longissimus dorsi (LD) muscle in horses under 5 years of age and to obtain preliminary data on satellite cell behavior in foals. The area, width, height, and subcutaneous fat were measured using ultrasonography at 6-month increments over the ...


Functional Significance Of Gill Claudin Proteins In Rainbow Trout (Oncorhynchus Mykiss) Osmoregulation, Joanna Katarzyna Bujak May 2015

Functional Significance Of Gill Claudin Proteins In Rainbow Trout (Oncorhynchus Mykiss) Osmoregulation, Joanna Katarzyna Bujak

Theses and Dissertations

Claudin proteins, a key element of tight junction complexes, are known to control paracellular permeability. In euryhaline fish, changes in claudin abundance and localization are critical during salinity acclimation. In seawater, a leaky paracellular pathway that facilitates sodium extrusion is hypothesized to be controlled by claudin proteins. The aim of this study was to evaluate the role of Claudin-10c, -10d -10e and Claudin-30 in gill function in freshwater (FW) and seawater (SW) rainbow trout (Oncorhynchus mykiss). I examined mRNA and protein abundance along with cellular localization. A tissue distribution survey showed that all of the claudins studied were predominantly expressed ...


A Major Role Of Insulin In Promoting Obesity-Associated Adipose Tissue Inflammation, David J. Pedersen, Adilson L Guilherme, Laura V. Danai, Lauren Heyda, Anouch Matevossian, Jessica L. Cohen, Sarah M. Nicoloro, Juerg R. Straubhaar, Hye Lim Noh, Dae Young Jung, Jason K. Kim, Michael P. Czech May 2015

A Major Role Of Insulin In Promoting Obesity-Associated Adipose Tissue Inflammation, David J. Pedersen, Adilson L Guilherme, Laura V. Danai, Lauren Heyda, Anouch Matevossian, Jessica L. Cohen, Sarah M. Nicoloro, Juerg R. Straubhaar, Hye Lim Noh, Dae Young Jung, Jason K. Kim, Michael P. Czech

Open Access Articles

OBJECTIVE: Adipose tissue (AT) inflammation is associated with systemic insulin resistance and hyperinsulinemia in obese rodents and humans. A longstanding concept is that hyperinsulinemia may promote systemic insulin resistance through downregulation of its receptor on target tissues. Here we tested the novel hypothesis that insulin also impairs systemic insulin sensitivity by specifically enhancing adipose inflammation.

METHODS: Circulating insulin levels were reduced by about 50% in diet-induced and genetically obese mice by treatments with diazoxide or streptozotocin, respectively. We then examined AT crown-like structures, macrophage markers and pro-inflammatory cytokine expression in AT. AT lipogenesis and systemic insulin sensitivity was also monitored ...


Role Of Protein Kinase Map4k4 In Energy Metabolism: A Dissertation, Laura V. Danai Apr 2015

Role Of Protein Kinase Map4k4 In Energy Metabolism: A Dissertation, Laura V. Danai

GSBS Dissertations and Theses

Systemic glucose regulation is essential for human survival as low or chronically high glucose levels can be detrimental to the health of an individual. Glucose levels are highly regulated via inter-organ communication networks that alter metabolic function to maintain euglycemia. For example, when nutrient levels are low, pancreatic α-cells secrete glucagon, which signals to the liver to promote glycogen breakdown and glucose production. In times of excess nutrient intake, pancreatic β-cells release insulin. Insulin signals to the liver to suppress hepatic glucose production, and signals to the adipose tissue and the skeletal muscle to take up excess glucose via insulin-regulated ...


Nonenzymatic Glycosylation Of Erythrocyte Membrane Proteins. Relevance To Diabetes, J A. Miller, Ellen M. Gravallese, H F. Bunn Apr 2015

Nonenzymatic Glycosylation Of Erythrocyte Membrane Proteins. Relevance To Diabetes, J A. Miller, Ellen M. Gravallese, H F. Bunn

Ellen M. Gravallese

Nonenzymatic glycosylation of proteins of the erythrocyte membrane was determined by incubating erythrocyte ghosts with [3H]borohydride. The incorporation of tritium into protein provides a reliable assay of ketoamine linkages. The membrane proteins from 18 patients with diabetes incorporated twice as much radioactivity as membrane proteins from normal erythrocytes. After acid hydrolysis, amino acid analysis showed that the majority of radioactivity was localized to glucosyllysine. Autoradiograms showed that all of the major proteins of the erythrocyte membrane, separated by electrophoresis on sodium dodecyl sulfate gels, contained ketoamine linkages. No protein bands in either normal or diabetic erythrocytes showed significant preferential ...