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Biochemistry, Biophysics, and Structural Biology

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Articles 11551 - 11580 of 13697

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Biological Functions Of The Novel Lysophosphatidic Acid (Lpa) Receptor, Lpa4/P2y9/Gpr23, Peilun Lee Apr 2008

Biological Functions Of The Novel Lysophosphatidic Acid (Lpa) Receptor, Lpa4/P2y9/Gpr23, Peilun Lee

Theses and Dissertations

Lysophosphatidic acid (LPA), a naturally occurring phospholipid present in serum and malignant effusions, elicits diverse biological functions through binding and activating specific cell surface G-protein coupled receptors. In addition to the conventional LPA1/Edg2, LPA2/Edg4 and LPA3/Edg7 receptors of the endothelial differentiation gene (Edg) family, LPA4/p2y9/GPR23 of the purinergic receptor family and the related LPA5/GPR92 and LPA6/p2y5 have been identified as novel LPA receptors. These newly identified LPA receptors are structurally distant from the Edg LPA1-3 receptors and couple to Gq, G12/13 and probably Gs subunits. However, the roles of the LPA4-6 receptors in LPA signal transduction and physiology are poorly …

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Susceptibility Of Chlamydia Trachomatis To The Excipient Hydroxy-Ethylcellulose: Ph And Concentration Dependence Of Antimicrobial Activity, Ali A. Abdul-Sater, David M. Ojcius, M. P. Meyer Apr 2008

Susceptibility Of Chlamydia Trachomatis To The Excipient Hydroxy-Ethylcellulose: Ph And Concentration Dependence Of Antimicrobial Activity, Ali A. Abdul-Sater, David M. Ojcius, M. P. Meyer

All Dugoni School of Dentistry Faculty Articles

Hydroxyethyl cellulose (HEC) is used as a neutral excipient in microbicides used against sexually transmitted pathogens. However, HEC inhibits the infection of cervical epithelial cells by Chlamydia trachomatis at pH 5 in a concentration-dependent manner. At pH 7, infection is inversely dependent on the concentration of HEC, possibly due to pH-dependent calcium sequestration.

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Progress Toward Cariporide Analogs For Sodium-Proton Exchange Inhibition, Jessica Moore, Mark Graves Ii, Jacob A. Vervynckt, William Harley, Fredric Gorin, Hasan Palandoken Apr 2008

Progress Toward Cariporide Analogs For Sodium-Proton Exchange Inhibition, Jessica Moore, Mark Graves Ii, Jacob A. Vervynckt, William Harley, Fredric Gorin, Hasan Palandoken

Chemistry and Biochemistry

The sodium proton exchanger (NHE) is particularly important in maintaining the intracellular pH in human heart and brain. Under anaerobic conditions (i.e., ischemia), a shift from oxidative to nonoxidative glycolysis occurs. The resultant decrease in the intracellular pH activates NHE, which increases the intracellular sodium, initiating the sequence of physiological events that lead to cell death. Thus, there has been great interest in the development of compounds that inhibit NHE. Indeed, potent NHE inhibitors are available. However, a fundamental impediment to the field is the delivery of these compounds to poorly vascularized tissues during the early phases of ischemia when …

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The Effects Of Pc-Based Laboratories On Student Learning, Lester L. Pesterfield, Stuart Burris, Darwin B. Dahl, Hasan Palandoken, Jacqueline Pope-Tarrence Apr 2008

The Effects Of Pc-Based Laboratories On Student Learning, Lester L. Pesterfield, Stuart Burris, Darwin B. Dahl, Hasan Palandoken, Jacqueline Pope-Tarrence

Chemistry and Biochemistry

The Department of Chemistry at Western Kentucky University recently incorporated a net-worked MeasureNet data acquisition and analysis system into in the second semester General Chemistry laboratories. Our investigation team has conducted a study to evaluate the effects of the MeasureNet system on student learning and performance on a Beer's Law laboratory. We focused on two phenomena: the effect of the MeasureNet system on 1) student learning of specific content material and 2) student interest in chemistry and science in general. The study involved a MeasureNet system group (employing a UV-Vis spectrometer and colorimeters) and a control group (employing traditional Spectronic …

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Molybdoproteomes And Evolution Of Molybdenum Utilization, Yan Zhang, Vadim N. Gladyshev Apr 2008

Molybdoproteomes And Evolution Of Molybdenum Utilization, Yan Zhang, Vadim N. Gladyshev

Vadim Gladyshev Publications

The trace element molybdenum (Mo) is utilized in many life forms, where it is a key component of several enzymes involved in nitrogen, sulfur, and carbon metabolism. With the exception of nitrogenase, Mo is bound in proteins to a pterin, thus forming the molybdenum cofactor (Moco) at the catalytic sites of molybdoenzymes. Although a number of molybdoenzymes are well characterized structurally and functionally, evolutionary analyses of Mo utilization are limited. Here, we carried out comparative genomic and phylogenetic analyses to examine occurrence and evolution of Mo utilization in bacteria, archaea, and eukaryotes at the level of (i) Mo transport and …

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Biomechanical Modeling Of Forelimb Adduction In The Eastern Mole, Scalopusaquaticus, Mark Sandefur Apr 2008

Biomechanical Modeling Of Forelimb Adduction In The Eastern Mole, Scalopusaquaticus, Mark Sandefur

Mahurin Honors College Capstone Experience/Thesis Projects

The hypertrophied musculoskeletal system driving adduction of Sealopus aquatieus's forelimb supports the locomotion of these burrowing subterranean mammals. Due to the excessive bulk of the major muscles contributing to this action, it was thought that this particular species may represent a rare case of a mammalian species with a greatly enhanced force contribution from each muscle, correlating with a reduction in the potential for the forelimb to adduct at a high velocity. By assessing the lever ratios of five significant muscles contributing to forelimb adduction, combined with vector analyses for the angles of these muscles' insertions, a model was established …

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The Influence Of Citrate, Maltolate And Fluoride On The Gastrointestinal Absorption Of Aluminum At A Drinking Water-Relevant Concentration: A 26Al And 14C Study, Yuzhao Zhou, Wesley R. Harris, Robert A. Yokel Apr 2008

The Influence Of Citrate, Maltolate And Fluoride On The Gastrointestinal Absorption Of Aluminum At A Drinking Water-Relevant Concentration: A 26Al And 14C Study, Yuzhao Zhou, Wesley R. Harris, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

The objectives were to test the null hypotheses that (1) citrate, maltolate, and fluoride do not significantly influence oral Al bioavailability, Cmax or Tmax at an Al dose relevant to drinking water exposure; and (2) Al citrate and maltolate are absorbed intact from the gastrointestinal tract. Male Fisher rats were given 1 ml of solution intra-gastrically containing 1 nCi 26Al (65 nmol total Al) as the Al3+ ion, or as complexes with 14C-citrate, 14C-maltolate or fluoride, during concurrent 27Al iv infusion. Blood was repeatedly collected for serum 26Al, total Al and 14 …

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Drug Resistance In Malaria: A Peruvian Research Experience, Ryan Haley Apr 2008

Drug Resistance In Malaria: A Peruvian Research Experience, Ryan Haley

Inquiry Journal 2008

No abstract provided.

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The Regulation Of Endothelial And Neuronal Nitric Oxide Synthase Expression In The Preglomerular Vessels By The Increase In Intracellular Calcium Concentration, Stephanie Thomas Montgomery Apr 2008

The Regulation Of Endothelial And Neuronal Nitric Oxide Synthase Expression In The Preglomerular Vessels By The Increase In Intracellular Calcium Concentration, Stephanie Thomas Montgomery

Chemistry & Biochemistry Theses & Dissertations

This purpose of this study was to examine the regulation of endothelial and neuronal nitric oxide synthase expression in the preglomerular vessels of mature and immature porcine kidneys by the increase in intracellular calcium concentration. Angiotensin II can increase intracellular calcium concentrations in two ways; either through the mobilization of intracellular calcium stores or through the influx of calcium from the extracellular fluid through calcium channels. The aim of this study was to determine the effects of a calcium control, a calcium-free control, L- and T-type voltage-gated calcium channel blockers, an internal calcium store release agent, KCI, and EDTA on …

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Toxic Gene Expression In Escherichia Coli Using Trpl As A Repressor, Ian Primm Apr 2008

Toxic Gene Expression In Escherichia Coli Using Trpl As A Repressor, Ian Primm

Honors Capstones

No abstract provided.

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Treg Depletion Inhibits Efficacy Of Cancer Immunotherapy: Implications For Clinical Trials., James Curtin, Marianela Candolfi, Tamer Fakhouri, Chunyan Liu, Anderson Alden, Matthew Edwards, Pedro Lowenstein, Maria Castro Apr 2008

Treg Depletion Inhibits Efficacy Of Cancer Immunotherapy: Implications For Clinical Trials., James Curtin, Marianela Candolfi, Tamer Fakhouri, Chunyan Liu, Anderson Alden, Matthew Edwards, Pedro Lowenstein, Maria Castro

Articles

BACKGROUND: Regulatory T lymphocytes (Treg) infiltrate human glioblastoma (GBM); are involved in tumor progression and correlate with tumor grade. Transient elimination of Tregs using CD25 depleting antibodies (PC61) has been found to mediate GBM regression in preclinical models of brain tumors. Clinical trials that combine Treg depletion with tumor vaccination are underway to determine whether transient Treg depletion can enhance anti-tumor immune responses and improve long term survival in cancer patients. FINDINGS: Using a syngeneic intracrabial glioblastoma (GBM) mouse model we show that systemic depletion of Tregs 15 days after tumor implantation using PC61 resulted in a decrease in Tregs …

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Comment On “Contact Conditions For The Charge In The Theory Of The Electrical Double Layer”, Douglas Henderson, L. B. Bhuiyan Mar 2008

Comment On “Contact Conditions For The Charge In The Theory Of The Electrical Double Layer”, Douglas Henderson, L. B. Bhuiyan

Faculty Publications

Exact results in any field, including statistical mechanics, are both aesthetically pleasing and very valuable in assessing theoretical approximations.

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Crystal Structures Of The Streptomyces Coelicolor Tetr-Like Protein Actr Alone And In Complex With Actinorhodin Or The Actinorhodin Biosynthetic Precursor (S)-Dnpa., A R Willems, K Tahlan, T Taguchi, K Zhang, Z Z Lee, K Ichinose, M S Junop, J R Nodwell Mar 2008

Crystal Structures Of The Streptomyces Coelicolor Tetr-Like Protein Actr Alone And In Complex With Actinorhodin Or The Actinorhodin Biosynthetic Precursor (S)-Dnpa., A R Willems, K Tahlan, T Taguchi, K Zhang, Z Z Lee, K Ichinose, M S Junop, J R Nodwell

Biochemistry Publications

Actinorhodin, an antibiotic produced by Streptomyces coelicolor, is exported from the cell by the ActA efflux pump. actA is divergently transcribed from actR, which encodes a TetR-like transcriptional repressor. We showed previously that ActR represses transcription by binding to an operator from the actA/actR intergenic region. Importantly, actinorhodin itself or various actinorhodin biosynthetic intermediates can cause ActR to dissociate from its operator, leading to derepression. This suggests that ActR may mediate timely self-resistance to an endogenously produced antibiotic by responding to one of its biosynthetic precursors. Here, we report the structural basis for this precursor-mediated derepression with crystal structures of …

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4-Hydroxyphenylretinamide (4hpr) Derivatives Regulate Aromatase Activity And Expression In Breast Cancer Cells, Bin Su, Serena M. Mershon, Laura A. Stonerock, Robert W. Curley Jr., Robert W. Brueggemeier Mar 2008

4-Hydroxyphenylretinamide (4hpr) Derivatives Regulate Aromatase Activity And Expression In Breast Cancer Cells, Bin Su, Serena M. Mershon, Laura A. Stonerock, Robert W. Curley Jr., Robert W. Brueggemeier

Chemistry Faculty Publications

Recent studies exhibit that 4-hydroxyphenylretinamide (4HPR) decreases aromatase activity in breast and placental cells. The effect of synthetic 4HPR analogs on aromatase and expression was examined in three breast cancer cell lines. Most derivatives did not decrease cellular aromatase activity. Two of the analogs even stimulated aromatase activity at the transcriptional level. Only one derivative significantly decreased aromatase in all three breast cancer cell lines and also suppressed CYP19 gene expression in one of the cell line. Placental microsomal aromatase assay rule out the possibility that this compound directly inhibits the aromatase enzyme. A non-genomic mechanism in suppression of cellular …

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Turning The Gene Tap Off; Implications Of Regulating Gene Expression For Cancer Therapeutics, James Curtin, Marianela Candolfi, Weidong Xiong, Pedro Lowenstein, Maria Castro Mar 2008

Turning The Gene Tap Off; Implications Of Regulating Gene Expression For Cancer Therapeutics, James Curtin, Marianela Candolfi, Weidong Xiong, Pedro Lowenstein, Maria Castro

Articles

Cancer poses a tremendous therapeutic challenge worldwide, highlighting the critical need for developing novel therapeutics. A promising cancer treatment modality is gene therapy, which is a form of molecular medicine designed to introduce into target cells genetic material with therapeutic intent. Anticancer gene therapy strategies currently used in preclinical models, and in some cases in the clinic, include proapoptotic genes, oncolytic/replicative vectors, conditional cytotoxic approaches, inhibition of angiogenesis, inhibition of growth factor signaling, inactivation of oncogenes, inhibition of tumor invasion and stimulation of the immune system. The translation of these novel therapeutic modalities from the preclinical setting to the clinic …

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Land Use Influences The Spatiotemporal Controls On Nitrification And Denitrification In Headwater Streams, Clay P. Arango, J. L. Tank Mar 2008

Land Use Influences The Spatiotemporal Controls On Nitrification And Denitrification In Headwater Streams, Clay P. Arango, J. L. Tank

All Faculty Scholarship for the College of the Sciences

N and C cycles in headwater streams are coupled, and land use can modify these cycles by increasing N availability and removing riparian vegetation. To increase our understanding of how land use modifies the controls on N cycling, we quantified rates of 2 microbial N transformations in a total of 18 agricultural and urban streams (with and without riparian buffers) for 3 y to examine how riparian vegetation and land use influence sediment nitrification and denitrification. Nitrification rates were highest in agricultural streams in late spring. Nitrification was not related to streamwater NH4+ concentrations but was positively related …

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Structure And Catalytic Mechanism Of Eukaryotic Selenocysteine Synthase, Oleg M. Ganichkin, Xue-Ming Xu, Bradley A. Carlson, Heiko Mix, Dolph L. Hatfield, Vadim N. Gladyshev, Markus C. Wahl Feb 2008

Structure And Catalytic Mechanism Of Eukaryotic Selenocysteine Synthase, Oleg M. Ganichkin, Xue-Ming Xu, Bradley A. Carlson, Heiko Mix, Dolph L. Hatfield, Vadim N. Gladyshev, Markus C. Wahl

Vadim Gladyshev Publications

In eukaryotes and Archaea, selenocysteine synthase (SecS) converts O-phospho-L-seryl-tRNA[Ser]Sec into selenocysteyltRNA[Ser]Sec using selenophosphate as the selenium donor compound. The molecular mechanisms underlying SecS activity are presently unknown. We have delineated a 450-residue core of mouse SecS, which retained full selenocysteyl-tRNA[Ser]Sec synthesis activity, and determined its crystal structure at 1.65Å resolution. SecS exhibits three domains that place it in the fold type I family of pyridoxal phosphate (PLP)-dependent enzymes. Two SecS monomers interact intimately and together build up two identical active sites around PLP in a Schiff-base linkage with lysine 284. Two SecS dimers further …

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The Pyruvate, Orthophosphate Dikinase Regulatory Proteins Of Arabidopsis Possess A Novel, Unprecedented Ser/Thr Protein Kinase Primary Structure, Chris J. Chastain, Wenxin Xu, Kate Parsley, Gautam Sarath, Jullian Hebberd, Raymond Chollet Feb 2008

The Pyruvate, Orthophosphate Dikinase Regulatory Proteins Of Arabidopsis Possess A Novel, Unprecedented Ser/Thr Protein Kinase Primary Structure, Chris J. Chastain, Wenxin Xu, Kate Parsley, Gautam Sarath, Jullian Hebberd, Raymond Chollet

Department of Biochemistry: Faculty Publications

Pyruvate, orthophosphate dikinase (PPDK) is a ubiquitous, low-abundance metabolic enzyme of undetermined function in C3 plants. Its activity in C3 chloroplasts is light-regulated via reversible phosphorylation of an active-site Thr residue by the PPDK regulatory protein (RP), a most unusual bifunctional protein kinase (PK)/ protein phosphatase (PP). In this paper we document the molecular cloning and functional analysis of the two unique C3 RPs in Arabidopsis thaliana. The first of these, AtRP1, encodes a typical chloroplast-targeted, bifunctional C4-like RP. The second RP gene, AtRP2, encodes a monofunctional polypeptide that possesses in vitro RP-like PK activity but lacks PP activity, …

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4-(4-Chlorophenyl)-5-[1-(4-Chlorophenyl)-2-Methyl-2-Nitropropyl]-1,2,3-Selenadiazole, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam Rath Feb 2008

4-(4-Chlorophenyl)-5-[1-(4-Chlorophenyl)-2-Methyl-2-Nitropropyl]-1,2,3-Selenadiazole, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam Rath

Chemistry & Biochemistry Faculty Works

In the title compound, C18H15Cl2N3O2Se, the selenadiazole ring makes dihedral angles of 49.87 (3) and 55.70 (3)° with the two benzene rings. The dihedral angle between the two benzene rings is 11.90 (5)°. In the crystal structure, intra­molecular C-H...O and C-H...Se inter­actions and inter­molecular C-H...O, C-H...Cl and C-H...N inter­actions are observed.

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Recycling Of Dolichyl Monophosphate To The Cytoplasmic Leaflet Of The Endoplasmic Reticulum After The Cleavage Of Dolichyl Pyrophosphate On The Lumenal Monolayer., Jeffrey S Rush, Ningguo Gao, Mark A Lehrman, Charles J Waechter Feb 2008

Recycling Of Dolichyl Monophosphate To The Cytoplasmic Leaflet Of The Endoplasmic Reticulum After The Cleavage Of Dolichyl Pyrophosphate On The Lumenal Monolayer., Jeffrey S Rush, Ningguo Gao, Mark A Lehrman, Charles J Waechter

Molecular and Cellular Biochemistry Faculty Publications

During protein N-glycosylation, dolichyl pyrophosphate (Dol-P-P) is discharged in the lumenal monolayer of the endoplasmic reticulum (ER). Dol-P-P is then cleaved to Dol-P by Dol-P-P phosphatase (DPPase). Studies with the yeast mutant cwh8Delta, lacking DPPase activity, indicate that recycling of Dol-P produced by DPPase contributes significantly to the pool of Dol-P utilized for lipid intermediate biosynthesis on the cytoplasmic leaflet. Whether Dol-P formed in the lumen diffuses directly back to the cytoplasmic leaflet or is first dephosphorylated to dolichol has not been determined. Incubation of sealed ER vesicles from calf brain with acetyl-Asn-Tyr-Thr-NH(2), an N-glycosylatable peptide, to generate Dol-P-P in …

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Retinoic Acid Decreases Atf-2 Phosphorylation And Sensitizes Melanoma Cells To Taxol-Mediated Growth Inhibition, Ying Huang, Jennifer Minigh, Sarah Miles, Richard N. Niles Feb 2008

Retinoic Acid Decreases Atf-2 Phosphorylation And Sensitizes Melanoma Cells To Taxol-Mediated Growth Inhibition, Ying Huang, Jennifer Minigh, Sarah Miles, Richard N. Niles

Biochemistry and Microbiology

Cutaneous melanoma is often resistant to chemo- and radiotherapy. This resistance has recently been demonstrated to be due, at least in part, to high activating transcription factor 2 (ATF-2) activity in these tumors. In concordance with these reports, we found that B16 mouse melanoma cells had higher levels of ATF-2 than immortalized, but non-malignant mouse melanocytes. In addition, the melanoma cells had a much higher amount of phosphorylated (active) ATF-2 than the immortalized melanocytes. In the course of determining how retinoic acid (RA) stimulates activating protein-1 (AP-1) activity in B16 melanoma, we discovered that this retinoid decreased the phosphorylation of …

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Emergent Decision-Making In Biological Signal Transduction Networks, Tomáš Helikar, John Konvalina, Jack Heidel, Jim A. Rogers Feb 2008

Emergent Decision-Making In Biological Signal Transduction Networks, Tomáš Helikar, John Konvalina, Jack Heidel, Jim A. Rogers

Department of Biochemistry: Faculty Publications

The complexity of biochemical intracellular signal transduction networks has led to speculation that the high degree of interconnectivity that exists in these networks transforms them into an information processing network. To test this hypothesis directly, a large scale model was created with the logical mechanism of each node described completely to allow simulation and dynamical analysis. Exposing the network to tens of thousands of random combinations of inputs and analyzing the combined dynamics of multiple outputs revealed a robust system capable of clustering widely varying input combinations into equivalence classes of biologically relevant cellular responses. This capability was nontrivial in …

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Quenching Of Highly Vibrationally Excited Pyrimidine By Collisions With Co4, Jeremy A. Johnson, Andrew M. Duffin, Brian J. Hom, Karl E. Jackson, Eric T. Sevy Feb 2008

Quenching Of Highly Vibrationally Excited Pyrimidine By Collisions With Co4, Jeremy A. Johnson, Andrew M. Duffin, Brian J. Hom, Karl E. Jackson, Eric T. Sevy

Faculty Publications

Relaxation of highly vibrationally excited pyrimidine (C4N2H4) by collisions with carbon dioxide has been investigated using diode laser transient absorption spectroscopy. Vibrationally hot pyrimidine (E'=40,635 cm^-1) was prepared by 248-nm excimer laser excitation, followed by rapid radiationless relaxation to the ground electronic state. The nascent rotational population distribution (J=58–80) of the 0000 ground state of CO2 resulting from collisions with hot pyrimidine was probed at short times following the excimer laser pulse. Doppler spectroscopy was used to measure the CO2 recoil velocity distribution for J=58–80 of the 0000 state. Rate constants and probabilities for collisions populating these CO2 rotational states …

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Ozone Exposure In A Mouse Model Induces Airway Hyperreactivity That Requires The Presence Of Natural Killer T Cells And Il-17, Paul B. Savage, Muriel Pichavant, Sho Goya, Everett H. Meyer, Richard A. Johnston, Hye Y. Kim, Ponpan Matangkasombut, Ming Zhu, Yoichiro Iwakura, Rosemarie H. Dekruyff, Stephanie A. Shore, Dale T. Umetsu Feb 2008

Ozone Exposure In A Mouse Model Induces Airway Hyperreactivity That Requires The Presence Of Natural Killer T Cells And Il-17, Paul B. Savage, Muriel Pichavant, Sho Goya, Everett H. Meyer, Richard A. Johnston, Hye Y. Kim, Ponpan Matangkasombut, Ming Zhu, Yoichiro Iwakura, Rosemarie H. Dekruyff, Stephanie A. Shore, Dale T. Umetsu

Faculty Publications

Exposure to ozone, which is a major component of air pollution, induces a form of asthma that occurs in the absence of adaptive immunity. Although ozone-induced asthma is characterized by airway neutrophilia, and not eosinophilia, it is nevertheless associated with airway hyperreactivity (AHR), which is a cardinal feature of asthma. Because AHR induced by allergens requires the presence of natural killer T (NKT) cells, we asked whether ozone-induced AHR had similar requirements. We found that repeated exposure of wild-type (WT) mice to ozone induced severe AHR associated with an increase in airway NKT cells, neutrophils, and macrophages. Surprisingly, NKT cell-deficient …

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Novel Role Of Antioxidant-1 (Atox1) As A Copper-Dependent Transcription Factor Involved In Cell Proliferation, S. Itoh, H. W. Kim, O. Nakagawa, K. Ozumi, Susan M. Lessner, H. Aoki, K. Akram, R. D. Mckinney, M. Ushio-Fukai, T. Fukai Feb 2008

Novel Role Of Antioxidant-1 (Atox1) As A Copper-Dependent Transcription Factor Involved In Cell Proliferation, S. Itoh, H. W. Kim, O. Nakagawa, K. Ozumi, Susan M. Lessner, H. Aoki, K. Akram, R. D. Mckinney, M. Ushio-Fukai, T. Fukai

Faculty Publications

Copper plays a fundamental role in regulating cell growth. Many types of human cancer tissues have higher copper levels than normal tissues. Copper can also induce gene expression. However, transcription factors that mediate copper-induced cell proliferation have not been identified in mammals. Here we show that antioxidant-1 (Atox1), previously appreciated as a copper chaperone, represents a novel copper-dependent transcription factor that mediates copper-induced cell proliferation. Stimulation of mouse embryonic fibroblasts (MEFs) with copper markedly increased cell proliferation, cyclin D1 expression, and entry into S phase, which were completely abolished in Atox1-/- MEFs. Promoter analysis and EMSA revealed that copper …

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Monitoring Lys-TrnaLys Phosphatidylglycerol Transferase Activity, Michael Ibba Jan 2008

Monitoring Lys-TrnaLys Phosphatidylglycerol Transferase Activity, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

In some bacteria Lys-tRNALys is used both in translation and for the specific addition of Lys to phosphatidylglycerol in the cytoplasmic membrane. This reaction is catalyzed by the membrane protein MprF, and the lysyl-phosphatidylglycerol formed contributes to the resistance of these bacteria to various cationic antibacterial molecules. Obtaining proteins and reconstituting an in vitro system mimicking membrane conditions is a major challenge to studying the function of membrane proteins, especially when labile substrates such as Lys-tRNALys are required. Here we report methods to obtain a stable enriched membrane fraction containing MprF, and the techniques necessary to quantitatively monitor …

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Comparative Analysis Of Selenocysteine Machinery And Selenoproteome Gene Expression In Mouse Brain Identifies Neurons As Key Functional Sites Of Selenium In Mammals, Yan Zhang, You Zhou, Ulrich Schweizer, Nicolai E. Savaskan, Deame Hua, Jonathan Kipnis, Dolph L. Hatfield, Vadim N. Gladyshev Jan 2008

Comparative Analysis Of Selenocysteine Machinery And Selenoproteome Gene Expression In Mouse Brain Identifies Neurons As Key Functional Sites Of Selenium In Mammals, Yan Zhang, You Zhou, Ulrich Schweizer, Nicolai E. Savaskan, Deame Hua, Jonathan Kipnis, Dolph L. Hatfield, Vadim N. Gladyshev

Vadim Gladyshev Publications

Although dietary selenium (Se) deficiency results in phenotypes associated with selenoprotein depletion in various organs, the brain is protected from Se loss. To address the basis for the critical role of Se in brain function, we carried out comparative gene expression analyses for the complete selenoproteome and associated biosynthetic factors. Using the Allen Brain Atlas, we evaluated 159 regions of adult mouse brain and provided experimental analyses of selected selenoproteins. All 24 selenoprotein mRNAs were expressed in the mouse brain. Most strikingly, neurons in olfactory bulb, hippocampus, cerebral cortex, and cerebellar cortex were exceptionally rich in selenoprotein gene expression, in …

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Examining The Link Between Chromosomal Instability And Aneuploidy In Human Cells, Sarah L. Thompson, Duane A. Compton Jan 2008

Examining The Link Between Chromosomal Instability And Aneuploidy In Human Cells, Sarah L. Thompson, Duane A. Compton

Dartmouth Scholarship

Solid tumors can be highly aneuploid and many display high rates of chromosome missegregation in a phenomenon called chromosomal instability (CIN). In principle, aneuploidy is the consequence of CIN, but the relationship between CIN and aneuploidy has not been clearly defined. In this study, we use live cell imaging and clonal cell analyses to evaluate the fidelity of chromosome segregation in chromosomally stable and unstable human cells. We show that improper microtubule–chromosome attachment (merotely) is a cause of chromosome missegregation in unstable cells and that increasing chromosome missegregation rates by elevating merotely during consecutive mitoses generates CIN in otherwise stable, …

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The Stator Complex Of The A1a0-Atp Synthase--Structural Characterization Of The E And H Subunits., Erik Kish-Trier, Lee-Ann K Briere, Stanley D Dunn, Stephan Wilkens Jan 2008

The Stator Complex Of The A1a0-Atp Synthase--Structural Characterization Of The E And H Subunits., Erik Kish-Trier, Lee-Ann K Briere, Stanley D Dunn, Stephan Wilkens

Biochemistry Publications

Archaeal ATP synthase (A-ATPase) is the functional homolog to the ATP synthase found in bacteria, mitochondria and chloroplasts, but the enzyme is structurally more related to the proton-pumping vacuolar ATPase found in the endomembrane system of eukaryotes. We have cloned, overexpressed and characterized the stator-forming subunits E and H of the A-ATPase from the thermoacidophilic Archaeon, Thermoplasma acidophilum. Size exclusion chromatography, CD, matrix-assisted laser desorption ionization time-of-flight mass spectrometry and NMR spectroscopic experiments indicate that both polypeptides have a tendency to form dimers and higher oligomers in solution. However, when expressed together or reconstituted, the two individual polypeptides interact with …

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Prostasin Is Expressed In Benign Prostatic Hyperplasia And Regulates Cell Proliferation And Invasion Via Inos, Icam-1, And Cycli, Meghan Hatfield Jan 2008

Prostasin Is Expressed In Benign Prostatic Hyperplasia And Regulates Cell Proliferation And Invasion Via Inos, Icam-1, And Cycli, Meghan Hatfield

Electronic Theses and Dissertations

Prostasin is expressed in normal prostate epithelial cells but down-regulated in prostate cancers, while prostasin re-expression in invasive prostate cancer cells reduced invasion. We examined prostasin expression and function in benign prostatic hyperplasia (BPH). We evaluated prostasin expression in 12 BPH specimens by immunohistochemistry, and evaluated the impact of prostasin silencing by siRNA on the expression of the inducible nitric oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1), and cyclin D1, as well as on cell proliferation and invasion, using the BPH-1 human prostate epithelial cell line model. Prostasin expression was localized in the glands of BPH tissues by immunohistochemistry, in …

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