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Molecular Biology

2000

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Articles 1 - 30 of 39

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

Skeletor, A Novel Chromosomal Protein That Redistributes During Mitosis Provides Evidence For The Formation Of A Spindle Matrix, Diana L. Walker, Dong Wang, Ye Jin, Uttama Rath, Yanming Wang, Jorgen Johansen, Kristen M. Johansen Dec 2000

Skeletor, A Novel Chromosomal Protein That Redistributes During Mitosis Provides Evidence For The Formation Of A Spindle Matrix, Diana L. Walker, Dong Wang, Ye Jin, Uttama Rath, Yanming Wang, Jorgen Johansen, Kristen M. Johansen

Zoology and Genetics Publications

A spindle matrix has been proposed to help organize and stabilize the microtubule spindle during mitosis, though molecular evidence corroborating its existence has been elusive. In Drosophila, we have cloned and characterized a novel nuclear protein, skeletor, that we propose is part of a macromolecular complex forming such a spindle matrix. Skeletor antibody staining shows that skeletor is associated with the chromosomes at interphase, but redistributes into a true fusiform spindle structure at prophase, which precedes microtubule spindle formation. During metaphase, the spindle, defined by skeletor antibody labeling, and the microtubule spindles are coaligned. We find that the skeletor-defined spindle ...


Height Referencing Biochemical Cassette, Marc D. Porter, Vivian W. Jones, Curtis L. Mosher, Eric Henderson Nov 2000

Height Referencing Biochemical Cassette, Marc D. Porter, Vivian W. Jones, Curtis L. Mosher, Eric Henderson

Iowa State University Patents

A height referencing biochemical cassette comprising of a surface suitable to act as a coupling agent, a height referencing indicator, and molecules bonded to the surface. This cassette is a capable of use to test for bonding to these molecules through measuring the height difference between the indicator and the surface. This invention provides an efficient means to quickly and easily test for bonding of molecules to other molecules.


The Peroxisome Proliferator-Activated Receptor Alpha (Ppar ) Regulates Bile Acid Biosynthesis., Mary Hunt, Yi-Zeng Yang, Gosta Eggertsen, Claes Carneheim, Mats Gafvels, Curt Einarsson, Stefan Alexson Sep 2000

The Peroxisome Proliferator-Activated Receptor Alpha (Ppar ) Regulates Bile Acid Biosynthesis., Mary Hunt, Yi-Zeng Yang, Gosta Eggertsen, Claes Carneheim, Mats Gafvels, Curt Einarsson, Stefan Alexson

Articles

Fibrates are a group of hypolipidemic agents which efficiently lower serum triglyceride levels by affecting the expression of many genes involved in lipid metabolism. These effects are exerted via the peroxisome proliferator-activated receptor alpha (PPARa). In addition, fibrates also lower serum cholesterol levels, suggesting a possible link between the PPARa and cholesterol metabolism. Bile acid formation represents an important pathway for elimination of cholesterol, and the sterol 12a-hydroxylase is a branch-point enzyme in the bile acid biosynthetic pathway, which determines the ratio of cholic acid to chenodeoxycholic acid. Treatment of mice for one week with the peroxisome proliferator WY-14,643 ...


Mutations In The Hinge Of A Dynamic Loop Broadly Influence Functional Properties Of Fructose-1,6-Bisphosphatase, Scott W. Nelson, Jun-Yong Choe, Richard B. Honzatko, Herbert J. Fromm Sep 2000

Mutations In The Hinge Of A Dynamic Loop Broadly Influence Functional Properties Of Fructose-1,6-Bisphosphatase, Scott W. Nelson, Jun-Yong Choe, Richard B. Honzatko, Herbert J. Fromm

Biochemistry, Biophysics and Molecular Biology Publications

Loop 52–72 of porcine fructose-1,6-bisphosphatase may play a central role in the mechanism of catalysis and allosteric inhibition by AMP. The loop pivots between different conformational states about a hinge located at residues 50 and 51. The insertion of proline separately at positions 50 and 51 reduces k cat by up to 3-fold, with no effect on the K m for fructose 1,6-bisphosphate. TheK a for Mg2+ in the Lys50→ Pro mutant increases ∼15-fold, whereas that for the Ala51 → Pro mutant is unchanged. Although these mutants retain wild-type binding affinity for AMP and ...


Tryptophan Fluorescence Reveals The Conformational State Of A Dynamic Loop In Recombinant Porcine Fructose-1,6-Bisphosphatase, Scott W. Nelson, Cristina Valeria Iancu, Jun-Yong Choe, Richard B. Honzatko, Herbert J. Fromm Sep 2000

Tryptophan Fluorescence Reveals The Conformational State Of A Dynamic Loop In Recombinant Porcine Fructose-1,6-Bisphosphatase, Scott W. Nelson, Cristina Valeria Iancu, Jun-Yong Choe, Richard B. Honzatko, Herbert J. Fromm

Biochemistry, Biophysics and Molecular Biology Publications

Wild-type porcine fructose-1,6-bisphosphatase (FBPase) has no tryptophan residues. Hence, the mutation of Try57 to tryptophan places a unique fluorescent probe in the structural element (loop 52−72) putatively responsible for allosteric regulation of catalysis. On the basis of steady-state kinetics, circular dichroism spectroscopy, and X-ray crystallography, the mutation has little effect on the functional and structural properties of the enzyme. Fluorescence intensity from the Trp57 mutant is maximal in the presence of divalent cations, fructose 6-phosphate and orthophosphate, which together stabilize an R-state conformation in which loop 52−72 is engaged with the active site. The level of fluorescence ...


Crystallization And Structure Determination Of The Catalytic Trimer Of Methanococcus Jannaschii Aspartate Transcarbamoylase, Jacqueline Vitali, Tatyana Vorobyova, Gordon Websterb, Evan R. Kantrowitza Aug 2000

Crystallization And Structure Determination Of The Catalytic Trimer Of Methanococcus Jannaschii Aspartate Transcarbamoylase, Jacqueline Vitali, Tatyana Vorobyova, Gordon Websterb, Evan R. Kantrowitza

Physics Faculty Publications

Aspartate transcarbamoylase (ATCase) catalyzes the first step in the pyrimidine biosynthetic pathway, the reaction between carbamoyl phosphate and L-aspartate to form N-carbamoyl-L-aspartate and phosphate. The structural analysis of the ATCase catalytic trimer from Methanococcus jannaschii, a unicellular thermophilic archaeabacterium, has been undertaken in order to gain insight into the structural features that are responsible for the thermostability of the enzyme. As a first step, the catalytic trimer was crystallized in space group R32, with unit-cell parameters a = b = 265.3, c = 195.5 Å and two trimers in the asymmetric unit. Its structure was determined using molecular replacement ...


The Role Of Pyruvate Dehydrogenase And Acetyl-Coenzyme A Synthetase In Fatty Acid Synthesis In Developing Arabidopsis Seeds, Jinshan Ke, Robert H. Behal, Stephanie L. Back, Basil J. Nikolau, Eve S. Wurtele, David J. Oliver Jun 2000

The Role Of Pyruvate Dehydrogenase And Acetyl-Coenzyme A Synthetase In Fatty Acid Synthesis In Developing Arabidopsis Seeds, Jinshan Ke, Robert H. Behal, Stephanie L. Back, Basil J. Nikolau, Eve S. Wurtele, David J. Oliver

Botany Publication and Papers

Acetyl-coenzyme A (acetyl-CoA) formed within the plastid is the precursor for the biosynthesis of fatty acids and, through them, a range of important biomolecules. The source of acetyl-CoA in the plastid is not known, but two enzymes are thought to be involved: acetyl-CoA synthetase and plastidic pyruvate dehydrogenase. To determine the importance of these two enzymes in synthesizing acetyl-CoA during lipid accumulation in developing Arabidopsis seeds, we isolated cDNA clones for acetyl-CoA synthetase and for the ptE1α- and ptE1β-subunits of plastidic pyruvate dehydrogenase. To our knowledge, this is the first reported acetyl-CoA synthetase sequence from a plant source. The Arabidopsis ...


Intracellular Transport, Assembly, And Degradation Of Wild-Type And Disease-Linked Mutant Gap Junction Proteins, Judy K. Vanslyke, Suzanne M. Deschênes, Linda S. Musil Jun 2000

Intracellular Transport, Assembly, And Degradation Of Wild-Type And Disease-Linked Mutant Gap Junction Proteins, Judy K. Vanslyke, Suzanne M. Deschênes, Linda S. Musil

Biology Faculty Publications

More than 130 different mutations in the gap junction integral plasma membrane protein connexin32 (Cx32) have been linked to the human peripheral neuropathy X-linked Charcot–Marie–Tooth disease (CMTX). How these various mutants are processed by the cell and the mechanism(s) by which they cause CMTX are unknown. To address these issues, we have studied the intracellular transport, assembly, and degradation of three CMTX-linked Cx32 mutants stably expressed in PC12 cells. Each mutant had a distinct fate: E208K Cx32 appeared to be retained in the endoplasmic reticulum (ER), whereas both the E186K and R142W mutants were transported to perinuclear ...


Electrically Mediated Plasmid Dna Delivery To Hepatocellular Carcinomas In Vivo, L. Heller, M. J. Jaroszeski, D. Coppola, C. Pottinger, R. Gilbert, Richard Heller May 2000

Electrically Mediated Plasmid Dna Delivery To Hepatocellular Carcinomas In Vivo, L. Heller, M. J. Jaroszeski, D. Coppola, C. Pottinger, R. Gilbert, Richard Heller

Bioelectrics Publications

Gene therapy by direct delivery of plasmid DNA has several advantages over viral gene transfer, but plasmid delivery is less efficient. In vivo electroporation has been used to enhance delivery of chemotherapeutic agents to tumors in both animal and human studies. Recently, this delivery technique has been extended to large molecules such as plasmid DNA. Here, the successful delivery of plasmids encoding reporter genes to rat hepatocellular carcinomas by in vivo electroporation is demonstrated.


Test Of Intron Predictions Reveals Novel Splice Sites, Alternatively Spliced Mrnas And New Introns In Meiotically Regulated Genes Of Yeast, Carrie A. Davis, Leslie Grate, Marc Spingola, Manuel Ares Apr 2000

Test Of Intron Predictions Reveals Novel Splice Sites, Alternatively Spliced Mrnas And New Introns In Meiotically Regulated Genes Of Yeast, Carrie A. Davis, Leslie Grate, Marc Spingola, Manuel Ares

Marc Spingola

Correct identification of all introns is necessary to discern the protein-coding potential of a eukaryotic genome. The existence of most of the spliceosomal introns predicted in the genome of Saccharomyces cerevisiae remains unsupported by molecular evidence. We tested the intron predictions for 87 introns predicted to be present in non-ribosomal protein genes, more than a third of all known or suspected introns in the yeast genome. Evidence supporting 61 of these predictions was obtained, 20 predicted intron sequences were not spliced and six predictions identified an intron-containing region but failed to specify the correct splice sites, yielding a successful prediction ...


Molecular Evolution Of Insecticidal Spore-Forming Bacteria, John Pool Apr 2000

Molecular Evolution Of Insecticidal Spore-Forming Bacteria, John Pool

Honors Theses

Molecular methods are increasingly being used to determine the phylogeny of microorganisms. This research was intended to determine phylogenetic relationships for bacteria of the species Bacillus thuringiensis and other members of the Bacillus cereus group. Each strain was analyzed by its sasp-B gene sequence to determine its species classification and relation to other strains studied. Results of this study indicated that according to the sasp-B gene tree, the species Bacillus thuringiensis is a paraphyletic with respect to both Bacillus cereus and Bacillus anthracis. Some unexpected results and implications for species designations are also discussed.


Characterization Of Human T-Cell Leukemia Virus 1 Reverse Transcriptase, Pinky Gundayao Agbuya Apr 2000

Characterization Of Human T-Cell Leukemia Virus 1 Reverse Transcriptase, Pinky Gundayao Agbuya

Theses and Dissertations in Biomedical Sciences

Human T-cell leukemia virus 1 (HTLV-1) is a type C human retrovirus which has been the causative agent of Adult T-cell leukemia. Replication of the retrovirus; requires a reverse transcriptase which converts the retroviral RNA into DNA which is later incorporated into the host's genome. Very little is known about the reverse transcriptase of HTLV-1. Researchers have attempted to purify HTLV-1 RT by isolating the enzyme from human cell lines. Because large amounts of protein could not be produced by this isolation method, the reverse transcriptase cannot be fully characterized. In this research, a recombinant protein expressed in E ...


Xenopus Laevis Gelatinase B (Xmmp-9): Development, Regeneration, And Wound Healing, Brian Walter, Maria Carinato, Jonathan Henry Mar 2000

Xenopus Laevis Gelatinase B (Xmmp-9): Development, Regeneration, And Wound Healing, Brian Walter, Maria Carinato, Jonathan Henry

Brian Walter

It has been argued that matrix metalloproteinases play important roles in cellular differentiation and regeneration in certain systems. While studying changes in gene expression associated with the phenomena of cornea/lens transdifferentiation ("lens regeneration"), which takes place in the larva of Xenopus laevis, we identified the Xenopus gelatinase B gene. The open reading frame is homologous to other gelatinase B genes identified in other species and encodes all of the domains characteristic of this protein. Xenopus gelatinase B (Xmmp-9) is first expressed during early tail-bud stages in a subset of mesodermal cells scattered throughout the body. Expression is also seen ...


Rnai: Double-Stranded Rna Directs The Atp-Dependent Cleavage Of Mrna At 21 To 23 Nucleotide Intervals, Phillip D. Zamore, Thomas Tuschl, Phillip A. Sharp, David P. Bartel Mar 2000

Rnai: Double-Stranded Rna Directs The Atp-Dependent Cleavage Of Mrna At 21 To 23 Nucleotide Intervals, Phillip D. Zamore, Thomas Tuschl, Phillip A. Sharp, David P. Bartel

University of Massachusetts Medical School Faculty Publications

Double-stranded RNA (dsRNA) directs the sequence-specific degradation of mRNA through a process known as RNA interference (RNAi). Using a recently developed Drosophila in vitro system, we examined the molecular mechanism underlying RNAi. We find that RNAi is ATP dependent yet uncoupled from mRNA translation. During the RNAi reaction, both strands of the dsRNA are processed to RNA segments 21-23 nucleotides in length. Processing of the dsRNA to the small RNA fragments does not require the targeted mRNA. The mRNA is cleaved only within the region of identity with the dsRNA. Cleavage occurs at sites 21-23 nucleotides apart, the same interval ...


Multi-Pass Reflectron Time-Of-Flight Mass Spectrometer, Curtiss D. Hanson Jan 2000

Multi-Pass Reflectron Time-Of-Flight Mass Spectrometer, Curtiss D. Hanson

Patents (University of Northern Iowa)

A novel design for a time-of-flight mass spectrometer capable of tandem mass spectrometry measurements with high resolution and high sensitivity using two variable reflectrons in a co-linear geometry. Variably switched reflectrons are oriented coaxially on opposing ends of the ion flight region allowing multiple passes of the ions along the flight region permitting high resolution, tandem mass spectrometry experiments to be performed. An electrostatic particle guide is incorporated to ensure high ion transmission efficiency in a multi-pass system. In addition to permitting the high transmission efficiency of ions, the EPG can be used in a bipolar pulsed mode to isolate ...


Melanocortin-1-Receptor (Mcr-1) Gene Polymorphisms Associated With The Chicken E Locus Alleles, Andrew Ellett Jan 2000

Melanocortin-1-Receptor (Mcr-1) Gene Polymorphisms Associated With The Chicken E Locus Alleles, Andrew Ellett

Inquiry: The University of Arkansas Undergraduate Research Journal

The melanocortin 1-receptor (MCl-R) gene has been associated with E locus phenotypes in chickens. Variant alleles of the E locus are important for accurate down color sexing and also for the inhibition of unwanted tissue pigmentation in broilers. PCR (polymerase chain reaction) based tests for various replacement substitutions found in the published E allele sequences gave unexpected results when tested against known alleles of the E locus. To resolve these issues and gain a better understanding of how replacement substitutions in the MCl-R gene are affecting E locus phenotypes, a number of accessions of the e+, eb, wheaten ( ewh and ...


Molecular Characterization Of The Non-Biotin-Containing Subunit Of 3-Methylcrotonyl-Coa Carboxylase, Angela L. Mckean, Jinshan Ke, Jianping Song, Ping Che, Sara Achenbach, Basil J. Nikolau, Eve S. Wurtele Jan 2000

Molecular Characterization Of The Non-Biotin-Containing Subunit Of 3-Methylcrotonyl-Coa Carboxylase, Angela L. Mckean, Jinshan Ke, Jianping Song, Ping Che, Sara Achenbach, Basil J. Nikolau, Eve S. Wurtele

Botany Publication and Papers

The biotin enzyme, 3-methylcrotonyl-CoA carboxylase (MCCase) (3-methylcrotonyl-CoA:carbon-dioxide ligase (ADP-forming), EC 6.4.1.4), catalyzes a pivotal reaction required for both leucine catabolism and isoprenoid metabolism. MCCase is a heteromeric enzyme composed of biotin-containing (MCC-A) and non-biotin-containing (MCC-B) subunits. Although the sequence of the MCC-A subunit was previously determined, the primary structure of the MCC-B subunit is unknown. Based upon sequences of biotin enzymes that use substrates structurally related to 3-methylcrotonyl-CoA, we isolated the MCC-B cDNA and gene ofArabidopsis. Antibodies directed against the bacterially produced recombinant protein encoded by the MCC-B cDNA react solely with the MCC-B subunit ...


Carbohydrate Regulation Of Leaf Development: Investigating The Role Of Source Strength, Carbon Partitioning And Hexokinase Signaling In Regulating Leaf Senescence , Adam Christopher Miller Jan 2000

Carbohydrate Regulation Of Leaf Development: Investigating The Role Of Source Strength, Carbon Partitioning And Hexokinase Signaling In Regulating Leaf Senescence , Adam Christopher Miller

Retrospective Theses and Dissertations

For many plants, growth in elevated CO2 leads to reduced rates of photosynthesis. To examine the role leaf ontogeny plays in acclimation; we monitored photosynthesis and some related parameters throughout the development of tobacco leaves under ambient and high CO2 conditions. The pattern of photosynthetic rate over time was consistent with the expected pattern for a typical dicot leaf for both. However, the photosynthesis pattern in high-CO2-grown tobacco was shifted temporally to an earlier maximum and subsequent senescent decline. Rubisco activity appeared to be the main factor regulating photosynthetic rates in both treatments. Therefore, we propose a new model for ...


Mechanisms Of Negative Regulation Of Protein Prenylation: Investigation Of Murine Guanylate-Binding Protein 1 , John Thomas Stickney Jan 2000

Mechanisms Of Negative Regulation Of Protein Prenylation: Investigation Of Murine Guanylate-Binding Protein 1 , John Thomas Stickney

Retrospective Theses and Dissertations

Covalent attachment of isoprenoid lipids to proteins is a post-translational modification that occurs on approximately 2% of all cellular proteins. Proteins that contain a CaaX motif as their final four amino acids are presumed to be targets for the addition of C15 or C20 isoprenoids by farnesyl transferase (FTase) or geranylgeranyl transferase I (GGTase I) respectively. This modification is generally believed to occur stoichiometrically, and irreversibly, in vivo. Thus, if prenylation is to be regulated, this control must occur prior to lipid addition. At the moment, there is little evidence that the enzymatic activity of prenyl transferases can be modulated ...


Genetic Variation And Evolution Of Equine Infectious Anemia Virus Rev Quasispecies During Long Term Persistent Infection , Prasith Baccam Jan 2000

Genetic Variation And Evolution Of Equine Infectious Anemia Virus Rev Quasispecies During Long Term Persistent Infection , Prasith Baccam

Retrospective Theses and Dissertations

Genetic variation has been observed in many viruses. Viruses that carry their genetic information in the form of RNA exhibit high mutation rates because the viral polymerase lacks proof-reading mechanisms commonly found in DNA polymerase complexes. The combination of high mutation rates, small genome size, and high replication rates results in a population of closely related viral genotypes, which are commonly referred to as a quasispecies. A consequence of the genetic variation in viruses is possible variation in viral phenotype of the quasispecies population. Furthermore, changes in viral phenotype may be a biologically important factor in progression of disease. Here ...


Characterization Of [Alpha]-Adrenoceptor-Mediated Contractile Responses In The Isolated Bovine Tail Artery And Vein And An Investigation Of Nerve-Mediated Contraction In The Bovine Tail Artery In Response To Electrical Field Stimulation , Marina Val Ioudina Jan 2000

Characterization Of [Alpha]-Adrenoceptor-Mediated Contractile Responses In The Isolated Bovine Tail Artery And Vein And An Investigation Of Nerve-Mediated Contraction In The Bovine Tail Artery In Response To Electrical Field Stimulation , Marina Val Ioudina

Retrospective Theses and Dissertations

The purpose of this study was to identify alpha-adrenoreceptor types and subtypes mediating contractile responses to adrenergic agonists in the bovine tail artery and vein and to investigate nerve-mediated contraction in the bovine tail artery in response to electrical field stimulation. Isolated tissue bath methods were used to study isometric contractile responses in vessel rings. Electrical field stimulation, under constant current conditions, was used to study vessel contraction as a result of neurotransmitter(s) release from sympathetic nerve terminals;Evidence was obtained for the presence of functional alpha1A- and alpha1D-adrenoceptors in the tail artery. Whether functional alpha 1B-adrenoceptors are present ...


Tissue Specific Expression And Regulation Of The Mitogen Regulated Protein Genes , John Tollen Fassett Jan 2000

Tissue Specific Expression And Regulation Of The Mitogen Regulated Protein Genes , John Tollen Fassett

Retrospective Theses and Dissertations

Mitogen Regulated Protein (MRP; also called Proliferin; or MRP/PLF) is a member of the Prolactin/Growth Hormone gene family. There is evidence that MRP/PLF is a uterine growth factor and an angiogenesis factor. Between four and six highly homologous MRP/PLF genes (mrp/plf ) exist in the mouse, but the significance of multiple genes has not been determined. MRP/Plf is produced at high levels during mid-gestation by the placenta, where expression is restricted to the trophoblastic giant cells. To better understand the regulation of the mrp/ plf genes in vivo, we have developed an assay to analyze ...


Bacteriophage Therapy: A Novel Method Of Lytic Phage Delivery , Ratree Platt Jan 2000

Bacteriophage Therapy: A Novel Method Of Lytic Phage Delivery , Ratree Platt

Retrospective Theses and Dissertations

The widespread emergence of multi-antibiotic resistant bacteria has increased the need for alternatives to conventional antibiotic therapy. Accordingly, a significant amount of effort has been made to investigate the potential use of bacteriophages as prophylactic and therapeutic agents for bacterial infections. In this study, molecular biological techniques were applied to construct a lysogen of lytic bacteriophage lambda in an attempt to combat with multi-antibiotic resistant bacteria by a novel method of lytic phage delivery;To accomplish this goal, two plasmid-based site-specific recombination (SSR) systems for integration and recovery of DNA constructs from Escherichia coli and Salmonella typhimurium chromosomes were developed ...


Biochemical And Molecular Genetic Studies Of The Metabolic Role Of Methylcrotonyl-Coa Carboxylase , Ping Che Jan 2000

Biochemical And Molecular Genetic Studies Of The Metabolic Role Of Methylcrotonyl-Coa Carboxylase , Ping Che

Retrospective Theses and Dissertations

The physiological metabolic roles of methylcrotonyl-CoA carboxylase (MCCase) have been investigated. Radiotracer metabolic studies using extracts from isolated mitochondria and incubated with [U-14C]leucine and NaH14CO3, demonstrate that plant mitochondria can catabolize leucine via the following scheme: leucine ⇒ alpha-ketoisocaproate ⇒ isovaleryl-CoA ⇒ 3-methylcrotonyl-CoA ⇒ 3-methylglutaconyl-CoA ⇒ 3-hydroxy-3-methylglutaryl-CoA ⇒ acetoacetate + acetyl-CoA. These findings demonstrate for the first time that the enzymes responsible for leucine catabolism are present in plant mitochondria. We conclude that one of the primary metabolic roles of MCCase in plants is the catabolism of leucine;A single-copy gene encoding the Arabidopsis MCC-A subunit was isolated and characterized. It contains 15 exons separated by ...


Structure And Function Of A Novel Cap-Independent Translation Element In The 3' Untranslated Region Of A Viral Rna , Liang Guo Jan 2000

Structure And Function Of A Novel Cap-Independent Translation Element In The 3' Untranslated Region Of A Viral Rna , Liang Guo

Retrospective Theses and Dissertations

This research focuses on a cap-independent translation element (TE) we identified in the RNA of barley yellow dwarf virus (BYDV). Assisted by the TE, all messenger RNAs of BYDV, which include BYDV genomic RNA and subgenomic RNAs, are translated cap-independently. This allows uncapped, nonpolyadenylated BYDV RNAs to compete with capped and polyadenylated host mRNAs for the translation machinery. The core of the TE is a 105 nt sequence (TE105) located in the 3' UTR of BYDV genomic RNA. Due to its 3' position, at least two functions are necessary for TE105: 3 '--5' communication, and recruitment of translation machinery. TE105 ...


Characterization Of Intracellular Survival Of Mycobacterium Avium Subspecies Paratuberculosis In J774 Murine Macrophages , Jesse Michael Hostetter Jan 2000

Characterization Of Intracellular Survival Of Mycobacterium Avium Subspecies Paratuberculosis In J774 Murine Macrophages , Jesse Michael Hostetter

Retrospective Theses and Dissertations

Mycobacterium avium subspecies paratuberculosis (M. a. ptb) is the causative agent of Johne's disease, a progressive diarrheal disease of wild and domestic ruminants. Like other pathogenic species of mycobacteria, M. a. ptb is an intracellular pathogen of monocytes and monocyte-derived macrophages. In this dissertation we tested the hypothesis that M. a. ptb survives within macrophages by inhibition of acidification and maturation of the phagosomal compartment in which it resides;Chapter 1 consists of a general introduction and a literature review of recent reports concerning normal phagosomal maturation and maturation of the mycobacterial phagosome. Chapter 2 characterizes acidification of the ...


Expression Of Bovine Mammary Gland Ca2+Atpases , Siriwan Prapong Jan 2000

Expression Of Bovine Mammary Gland Ca2+Atpases , Siriwan Prapong

Retrospective Theses and Dissertations

Control of transcellular Ca2+ fluxes associated with lactation are critical to mammary function and Ca2+ homeostasis. Mammary Ca2+ transport and storage may contribute to the pathological hypocalcemia seen in dairy cows at parturition. RT-PCR and Western Blotting were used to identify which Ca2+ ATPases are present in the bovine mammary gland and in milk fat globule membranes (MFGM). PMCA1, PMCA2 and PMCA4 are plasma membrane Ca2+ ATPases expressed in the bovine mammary gland. A putative Golgi Ca2+ ATPase (bSPCA) is also found in significant amounts in the mammary gland. The expression of Ca2+ ATPases in the bovine mammary gland is ...


Characterization Of Skeletor: A Novel Nuclear Protein Implicated In Mitotic Spindle Assembly , Diana Lee Walker Jan 2000

Characterization Of Skeletor: A Novel Nuclear Protein Implicated In Mitotic Spindle Assembly , Diana Lee Walker

Retrospective Theses and Dissertations

The mAb 2A labels Drosophila embryos in a novel, dynamic staining pattern that identifies a nuclear meshwork during interphase, which is remodeled to form a spindle structure at metaphase. This intriguing pattern made the antigens recognized by mAb 2A interesting targets for cloning and analysis, Skeletor was found to be encoded by a complex locus. Two alternatively spliced transcripts from the Skeletor locus were identified, Orf1b/Orf2 and Orf1a. Orf1b/Orf2 has an unusual structure, containing two overlapping open reading frames with coding potentials of 87 kD and 81 kD respectively. Analysis of Orf2 amino acid content reveals overall high ...


Two Dimensional Models Of Tumor Angiogenesis , Serdal Pamuk Jan 2000

Two Dimensional Models Of Tumor Angiogenesis , Serdal Pamuk

Retrospective Theses and Dissertations

Angiogenesis, the formation of new capillaries from pre-existing vessels, is essential for tumor progression. It is critical for the growth of primary cancers. In this thesis we present a new approach to angiogenesis, based on the theory of reinforced random walks, coupled with a Michaelis-Menten type mechanism. This views the endothelial cell receptors as the catalyst for transforming angiogenic factor into proteolytic enzyme in order to model the first stage. In our model we use a curvature-induced proliferation term for the endothelial cell equation. Our numerical results indicate that the proliferation of endothelial cells is high at the tip. Also ...


Absence Of Insect Juvenile Hormones In The American Dog Tick, Dermacentor Veriabilis (Say) (Acari: Ixodidae), And In Ornithodoros Parkeri Cooley (Acari: Argasidae), P. A. Neese, Daniel E. Sonenshine, V. L. Kallapur, C. S. Apperson, R. M. Roe Jan 2000

Absence Of Insect Juvenile Hormones In The American Dog Tick, Dermacentor Veriabilis (Say) (Acari: Ixodidae), And In Ornithodoros Parkeri Cooley (Acari: Argasidae), P. A. Neese, Daniel E. Sonenshine, V. L. Kallapur, C. S. Apperson, R. M. Roe

Biological Sciences Faculty Publications

Synganglia, salivary gland, midgut, ovary, fat body and muscle alone and in combination from the ixodid tick, Dermacentor variabilis (Say), or the argasid tick, Ornithodoros parkeri Cooley, were incubated in vitro in separate experiments with L-[methyl-3H]methionine and farnesoic acid or with [1-14C]acetate. Life stages examined in D. variabilis were 3 and 72 h old (after ecdysis) unfed nymphs, partially fed nymphs (18 and 72 h after attachment to the host), fully engorged nymphs (2 d after detachment from host), 3 and 72 h old (after eclosion) unfed females, partially fed unmated females (12 ...