Life Sciences Commons^™

Consumption Of High Ω-3 Fatty Acid Diet Suppressed Prostate Tumorigenesis In C3(1) Tag Mice, Juliana Akinsete, Gabriela Ion, Theodore Witte, W. Hardman

Gabriela Ion

Prostate cancer incidence and mortality are high in the Western world and high ω-6/ω-3 PUFA in the Western diet may be a contributing factor. We investigated whether changing from a diet that approximates ω-6 fat content of the Western diet to a high ω-3 fat diet at adulthood might reduce prostate cancer risk. Female SV 129 mice that had consumed a high ω-6 diet containing corn oil for 2 weeks were bred with homozygous C3(1)Tag transgenic male mice. All male offspring were weaned to the corn oil diet (CO) until postpuberty when half of the male offspring were transferred to …

Characterization Of The Monomer-Dimer Equilibrium Of Recombinant Histo-Aspartic Protease From Plasmodium Falciparum, Huogen Xiao, Lee-Ann Briere, Stanley Dunn, Rickey Yada

Stanley D Dunn

Histo-aspartic protease (HAP) from Plasmodium falciparum is an intriguing aspartic protease due to its unique structure. Our previous study reported the first recombinant expression of soluble HAP, in its truncated form (lys77p-Leu328) (p denotes prosegment), as a thioredoxin (Trx) fusion protein Trx-tHAP. The present study found that the recombinant Trx-tHAP fusion protein aggregated during purification which could be prevented through the addition of 0.2% CHAPS. Trx-tHAP fusion protein was processed into a mature form of tHAP (mtHAP) by both autoactivation, and activation with either enterokinase or plasmepsin II. Using gel filtration chromatography as well as sedimentation velocity and equilibrium ultracentrifugation, …

The B Subunits In The Peripheral Stalk Of F1f0 Atp Synthase Preferentially Adopt An Offset Relationship, Shane Claggett, Mac O'Neil Plancher, Stanley Dunn, Brian Cain

Stanley D Dunn

The peripheral stalk of F1F0 ATP synthase is essential for the binding of F1 to FO and for proper transfer of energy between the two sectors of the enzyme. The peripheral stalk of Escherichia coli is composed of a dimer of identical b subunits. In contrast, photosynthetic organisms express two b-like genes that form a heterodimeric peripheral stalk. Previously we generated chimeric peripheral stalks in which a portion of the tether and dimerization domains of the E. coli b subunits were replaced with homologous sequences from the b and b' subunits of Thermosynechococcus elongatus (Claggett, S. B., Grabar, T. B., …

Functionally Compensating Coevolving Positions Are Neither Homoplasic Nor Conserved In Clades, Gregory Gloor, Gaurav Tyagi, Dana Abrassart, Andrew Kingston, Andrew Fernandes, Stanley Dunn, Christopher Brandl

Stanley D Dunn

We demonstrated that a pair of positions in phosphoglycerate kinase that score highly by three nonparametric covariation measures are important for function even though the positions can be occupied by aliphatic, aromatic, or charged residues. Examination of these pairs suggested that the majority of the covariation scores could be explained by within-clade conservation. However, an analysis of diversity showed that the conservation within clades of covarying pairs was indistinguishable from pairs of positions that do not covary, thus ruling out both clade conservation and extensive homoplasy as means to identify covarying positions. Mutagenesis showed that the residues in the covarying …

36 Degrees Step Size Of Proton-Driven C-Ring Rotation In Fof1-Atp Synthase, Monika Düser, Nawid Zarrabi, Daniel Cipriano, Stefan Ernst, Gary Glick, Stanley Dunn, Michael Börsch

Stanley D Dunn

Synthesis of adenosine triphosphate ATP, the 'biological energy currency', is accomplished by F(o)F(1)-ATP synthase. In the plasma membrane of Escherichia coli, proton-driven rotation of a ring of 10 c subunits in the F(o) motor powers catalysis in the F(1) motor. Although F(1) uses 120 degrees stepping during ATP synthesis, models of F(o) predict either an incremental rotation of c subunits in 36 degrees steps or larger step sizes comprising several fast substeps. Using single-molecule fluorescence resonance energy transfer, we provide the first experimental determination of a 36 degrees sequential stepping mode of the c-ring during ATP synthesis.

Re-Introduction Of Transmembrane Serine Residues Reduce The Minimum Pore Diameter Of Channelrhodopsin-2, Robert Dempski, Ryan Richards

Robert E. Dempski

Channelrhodopsin-2 (ChR2) is a microbial-type rhodopsin found in the green algae Chlamydomonas reinhardtii. Under physiological conditions, ChR2 is an inwardly rectifying cation channel that permeates a wide range of mono- and divalent cations. Although this protein shares a high sequence homology with other microbial-type rhodopsins, which are ion pumps, ChR2 is an ion channel. A sequence alignment of ChR2 with bacteriorhodopsin, a proton pump, reveals that ChR2 lacks specific motifs and residues, such as serine and threonine, known to contribute to non-covalent interactions within transmembrane domains. We hypothesized that reintroduction of the eight transmembrane serine residues present in bacteriorhodopsin, but …

Purification And Characterization Of Novel Nucleases From A Thermophilic Fungus, Kyle Landry

Kyle S Landry

A thermophilic fungus was isolated from composted horse manure. The organism was as a Chaetomium sp. by sequencing the highly conserved ITS region of the fungus and comparing to known regions in a genomic database and was referred to as TM-417. TM-417 was found to have an optimal growth temperature of 45 ^oC and an optimal pH of 7.0. An extracellular DNase and RNase was found to be produced by the isolate and were purified 145.58-fold and 127.6-fold respectively using a combination of size exclusion chromatography and a novel affinity membrane purification system. The extent of purification was determined …

Non-Helicobacter Pylori Related Duodenal Ulcer Disease In Children, Yoram Elitsur, Zandra Lawrence

Yoram Elitsur

Background. In spite of the worldwide distribution of Helicobacter pylori infection, recent data have reported an increased rate of non-H. pylori, non-NSAIDs-duodenal ulcer disease in adults. The estimated rate of these ulcers in children is unknown. We aimed to investigate the prevalence of non-H. pylori, non-NSAIDs-peptic ulcer disease in our pediatric patients who undergo upper endoscopic procedures. Methods. A retrospective analysis of 622 upper endoscopic reports was performed. Reports that documented mucosal ulcerations were included in our study. The demographic, clinical, endoscopic, and histological data were retrieved. The H. pylori-negative, duodenal/gastric ulcer-positive patients were compared with H. pylori-positive, duodenal/gastric ulcer-positive …

Is Sudden Infant Death Syndrome Associated With Helicobacter Pylori Infection In Children?, Yoram Elitsur, William Btriest, Zia Sabet, Cheryl Neace, Chuancang Jiang, Eapen Thomas

Yoram Elitsur

Helicobacter pylori infection has recently been implicated in the pathogenesis of sudden infant death syndrome (SIDS). We investigated this association. Twenty-five pairs of gastric and tracheal tissue specimens obtained from autopsies of 25 children with previous diagnoses of SIDS were available for this study. The presence of H. pylori organisms was evaluated by three different methods: histology (hematoxylin-eosin or Giemsa staining), immunohistochemistry, and nested polymerase chain reaction technique. We were unable to confirm the presence of H. pylori organisms by the first two methods. H. pylori DNA was identified by nested polymerase chain reaction in six different tissue specimens (stomach, …

Global Analysis Of Gene Expression Changes During Retinoic Acid-Induced Growth Arrest And Differentiation Of Melanoma: Comparison To Differentially Expressed Genes In Melanocytes Vs Melanoma, Mary Estler, Goran Boskovic, James Denvir, Sarah Miles, Donald Primerano, Richard Niles

James Denvir

BACKGROUND: The incidence of malignant melanoma has significantly increased over the last decade. Some of these malignancies are susceptible to the growth inhibitory and pro-differentiating effects of all-trans-retinoic acid (RA). The molecular changes responsible for the biological activity of RA in melanoma are not well understood. RESULTS: In an analysis of sequential global gene expression changes during a 4-48 h RA treatment of B16 mouse melanoma cells, we found that RA increased the expression of 757 genes and decreased the expression of 737 genes. We also compared the gene expression profile (no RA treatment) between non-malignant melan-a mouse melanocytes and …

A High Omega-3 Fatty Acid Diet Has Different Effects On Early And Late Stage Myeloid Progenitors, Melinda Varney, James Buchanan, Yulia Dementieva, W. Hardman, Vincent Sollars

Elaine Hardman Ph.D.

The effects of the polyunsaturated omega-3 (n-3) and omega-6 (n-6) fatty acids (FA) on hematopoiesis are complex in that both FA forms are processed into leukotrienes, eicosanoids, and prostaglandins, which can have independent effects. These FA have antagonistic effects in that n-6 FA prostaglandins tend to be pro-proliferative and pro-inflammatory, while the effects of n-3 FA prostaglandins are the opposite. We have previously shown that diets high in n-3 FA reduce the size of the middle to later stage myeloid progenitor compartment in FVB X sv129 F1hybrid mice. To assay the effects of high n-3 FA diets on earlier stages …

Epigenetic Modification As An Enabling Mechanism For Leukemic Transformation, Vincent Sollars

Vincent E Sollars

Cancer is now thought of as a fundamentally genetic disease, in that changes in the genome result in aberrant gene expression of oncogenes and tumor suppressor genes to promote oncogenesis. However, with our increasing knowledge of gene regulation, it is becoming obvious that changes in nucleotide sequence are not the sole mechanism for eliciting changes in transcription. An additional layer of regulation of gene expression, called epigenetics, is now being realized as increasingly important in oncogenesis. Epigenetics is defined as non-sequence based changes in chromatin that elicit changes in gene expression that are propagated through mitosis and/or meiosis. The alleles …

Membrane Fusion Proteins Are Required For Oskar Mrna Localization In The Drosophila Egg Chamber, Douglas Ruden, Vincent Sollars, Xiaoyan Wang, Daisuke Mori, Marina Alterman, Xiangyi Lu

Vincent E Sollars

We used a genetic screen in Drosophila to identify mutations which disrupt the localization of oskar mRNA during oogenesis. Based on the hypothesis that some cytoskeletal components which are required during the mitotic divisions will also be required for oskar mRNA localization during oogenesis, we designed the following genetic screen. We screened for P-element insertions in genes which slow down the blastoderm mitotic divisions. A secondary genetic screen was to generate female germ-line clones of these potential cell division cycle genes and to identify those which cause the mislocalization of oskar mRNA. We identified mutations in ter94 which disrupt the …

Diversity In Secreted Pla2-Iia Activity Among Inbred Mouse Strains That Are Resistant Or Susceptible To Apcmin/+ Tumorigenesis, Marina Markova, Revati Koratkar, Karen Silverman, Vincent Sollars, Melina Macphee-Pellini, Rhonda Walters, Juan Palazzo, Arthur Buchberg, Linda Siracusa, Steven Farber

Vincent E Sollars

The secreted phospholipase A₂ type IIA (Pla2g2a) gene was previously identified as a modifier of intestinal adenoma multiplicity in Apc^Min/+ mice. To determine if intestinal secreted phospholipase A₂ (sPLA₂) activity was also attenuated in susceptible strains, we developed a sensitive assay to directly quantitate sPLA₂ activity in the murine intestinal tract utilizing a fluorescent BODIPY-labeled phospholipid substrate. Here, we report assay conditions that distinguish between secreted and cytosolic PLA₂ enzyme activities in extracts of intestinal tissue. The small intestine exhibited higher activity levels than the large intestine. Consistent with predictions from the sPLA …

A Drosophila Kinesin-Like Protein, Klp38b, Functions During Meiosis, Mitosis, And Segmentation, Douglas Ruden, Wei Cui, Vincent Sollars, Marina Alterman

Vincent E Sollars

We show that klp38B, isolated as a mutation that dominantly prolongs blastoderm mitotic cycles in Drosophila, encodes a Drosophila kinesin-like protein. Further genetic analyses show that Klp38B not only functions during mitosis, but is also required for meiosis and abdominal segmentation. Sequence comparisons suggest that Klp38B encodes an aminoterminal microtubule motor domain, a central a-helical coiled-coil domain, and a C-terminal globular domain. Evidence that Klp38B is required during meiosis is that flies transheterozygous for mutations in both klp38B and nod have a high frequency of 4th chromosome meiotic nondisjunction. Nod is a chromokinesin, a chromosome binding kinesin, that is believed …

17-N-Allylamino-17-Demethoxygeldanamycin Induces A Diverse Response In Human Acute Myelogenous Cells, Jennifer Napper, Vincent Sollars

Vincent E Sollars

The goal of this study was to ascertain the specific effects of 17-N-Allylamino-17-demethoxygeldanamycin (17-AAG) treatment in human acute myelogenous leukemia (AML). Four human leukemia cell lines were treated with varying doses of 17-AAG followed by analysis of toxicity, apoptosis, proliferation, and cell cycle. Cell cycle analysis revealed that the cells accumulate in G2/M phase within 96 hours of treatment, although the effect was not equivalent among the cell lines. p21, p53 expression and MDR1 activity were among the possible mechanisms uncovered for the differing responses. Exploiting these differences may allow for more effective combinatory treatments in patients with AML.

A High Omega-3 Fatty Acid Diet Has Different Effects On Early And Late Stage Myeloid Progenitors, Melinda Varney, James Buchanan, Yulia Dementieva, W. Hardman, Vincent Sollars

Vincent E Sollars

The effects of the polyunsaturated omega-3 (n-3) and omega-6 (n-6) fatty acids (FA) on hematopoiesis are complex in that both FA forms are processed into leukotrienes, eicosanoids, and prostaglandins, which can have independent effects. These FA have antagonistic effects in that n-6 FA prostaglandins tend to be pro-proliferative and pro-inflammatory, while the effects of n-3 FA prostaglandins are the opposite. We have previously shown that diets high in n-3 FA reduce the size of the middle to later stage myeloid progenitor compartment in FVB X sv129 F1hybrid mice. To assay the effects of high n-3 FA diets on earlier stages …

Guanosine Diphosphatase Is Required For Protein And Sphingolipid Glycosylation In The Golgi Lumen Of Saccharomyces Cerevisiae, Claudia Abeijon, Ken Yanagisawa, Elisabet Mandon, Alex Hausler, Kelley Moremen, Carlos Hirschberg, Phillips Robbins

Elisabet Mandon

Current models for nucleotide sugar use in the Golgi apparatus predict a critical role for the lumenal nucleoside diphosphatase. After transfer of sugars to endogenous macromolecular acceptors, the enzyme converts nucleoside diphosphates to nucleoside monophosphates which in turn exit the Golgi lumen in a coupled antiporter reaction, allowing entry of additional nucleotide sugar from the cytosol. To test this model, we cloned the gene for the S. cerevisiae guanosine diphosphatase and constructed a null mutation. This mutation should reduce the concentrations of GDP-mannose and GMP and increase the concentration of GDP in the Golgi lumen. The alterations should in turn …

Viability Of Lactic Acid Bacteria And Sensory Evaluation In Cinnamomum Verum And Allium Sativum-Bio-Yogurts Made From Camel And Cow Milk, Ahmad Salihin Hj Baba, Shori A. B.

Ahmad Salihin Hj Baba

The present study investigate the effect of herbal water extract prepared from Allium sativum and Cinnamomum verum on the viability of lactic acid bacteria (Lactobacillus spp and Streptococcus thermophilus) in cow- and camel-milk yogurts during 21 day refrigerated storage. The organoleptic properties of fresh-yogurts were evaluated. Lactobacillus spp count for fresh cow milk-yogurts (0 day) in both present and absent of C. verum and A. sativum was ranged from 1.4×0 6 to 2.1×10 6 cfu/mL. These values were not significantly changed throughout the 21 days of refrigerated storage. Lactobacillusspp count in fresh plain camel milk- yogurt was 13.2×10 6 cfu/mL …

Identifying Metalloproteins Through X-Ray Fluorescence Mapping And Mass Spectrometry., José Argüello, Daniel Raimunda, Tripti Khare, Carol Giometti, Stefan Vogt, Lydia Finney

José M. Argüello

Metals are critical and dynamic components of biochemistry. To understand their roles, we greatly need tools to identify the ligands that bind them within the complexity of natural systems. This work describes the development of methods that not only detect and distinguish metals, but also characterize the proteins that bind them. We describe an approach to expose, identify and quantify metalloproteins in complex mixtures by sequential non-denaturing 2D-gel electrophoresis (2D GE)/X-ray Fluorescence (XRF) and tandem mass spectrometry (MS/MS) in the same spot of a sample. We first apply the development of 2D GE/XRF to Shewanella oneidensis MR-1, a well-studied system, …

Evolution And Diversity Of Periplasmic Proteins Involved In Copper Homeostasis In Gamma Proteobacteria., José Argüello, Georgina Hernandez-Montes, Brenda Valderrama

José M. Argüello

Background: Different systems contributing to copper homeostasis in bacteria have been described in recent years involving periplasmic and transport proteins that provide resistance via metal efflux to the extracellular media (CopA/Cue, Cus, Cut, and Pco). The participation of these proteins in the assembly of membrane, periplasmic and secreted cuproproteins has also been postulated. The integration and interrelation of these systems and their apparent redundancies are less clear since they have been studied in alternative systems. Based on the idea that cellular copper is not free but rather it is transferred via protein-protein interactions, we hypothesized that systems would coevolve and …

The Molecular Determinants Of The Zinc Transporter, Hzip4, Robert Dempski, Sagar Antala, Tuong-Vi Nguyen

Robert E. Dempski

Zinc is an essential micronutrient which is required for the function of hundreds of cellular enzymes. In addition, zinc is the second most abundant transition metal found in biological systems (iron is most abundant). However, the concentration of free zinc is nano to picomolar since most zinc is bound to proteins. This makes investigating the mechanism of zinc transport across the plasma membrane a challenge. Our interest has been to elucidate the mechanism of zinc transport mediated by one member of the ZIP family of proteins, hZIP4.

Conformational Equilibrium Of N-Myristoylated Camp-Dependent Protein Kinase A By Molecular Dynamics Simulations, Alessandro Cembran, Larry R. Masterson, Christopher L. Mcclendon, Susan S. Taylor, Jiali Gao, Gianluigi Veglia

Larry Masterson