Open Access. Powered by Scholars. Published by Universities.®

Medical Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

Medical Biochemistry

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1231 - 1260 of 1322

Full-Text Articles in Medical Sciences

Immunologic Effects Of Gliotoxin In Rats: Mechanisms For Prevention Of Autoimmune Diabetes Mellitus, Honggang Liu, Susan H. Jackman, Henry Driscoll, Bryan Larsen Oct 2000

Immunologic Effects Of Gliotoxin In Rats: Mechanisms For Prevention Of Autoimmune Diabetes Mellitus, Honggang Liu, Susan H. Jackman, Henry Driscoll, Bryan Larsen

Biochemistry and Microbiology

Various fungal products, such as gliotoxin (GT), have immunomodulating activity, a fact exploited previously by our group for prevention of autoimmune diabetes mellitus in BB/Wor rats. To understand better the immunologic effects in GT-treated rats, splenocytes from 65-day-old prediabetic diabetes-prone rats were phenotypically characterized after chronic treatment with GT. A parallel study examined the direct effects of GT on splenocyte preparations incubated with the mycotoxin. In vitro treatment of splenocytes with GT revealed relative decreases in CD4+ and increases in CD8+ T-cell subsets, whereas in vivo treatment with GT did not result in detectable alterations in relative CD4+ and CD8+ …

Go to article

Genomic Structure Of Murine Mitochondrial Dna Polymerase-Gamma., Justin L. Mott, Grace Denniger, Steve J. Zullo, H. Peter Zassenhaus Oct 2000

Genomic Structure Of Murine Mitochondrial Dna Polymerase-Gamma., Justin L. Mott, Grace Denniger, Steve J. Zullo, H. Peter Zassenhaus

Journal Articles: Biochemistry & Molecular Biology

We have sequenced a genomic clone of the gene encoding the mouse mitochondrial DNA polymerase. The gene consists of 23 exons, which span approximately 13.2 kb, with exons ranging in size from 53 to 768 bp. All intron-exon boundaries conform to the GT-AG rule. By comparison with the human genomic sequence, we found remarkable conservation of the gene structure; the intron-exon borders are in almost identical locations for the 22 introns. The 5' upstream region contains approximately 300 bp of homology between the mouse and human sequences that presumably contain the promoter element. This region lacks any obvious TATA domain …

Go to article

Helicobacter Pylori Serology And The Diagnosis Of H. Pylori Infection In Children, Yoram Elitsur, Rafah Aflak, Cheryl Neace, W. E. Triest Sep 2000

Helicobacter Pylori Serology And The Diagnosis Of H. Pylori Infection In Children, Yoram Elitsur, Rafah Aflak, Cheryl Neace, W. E. Triest

Biochemistry and Microbiology

Serological screening accuracy rate may be dependent on clinical and pathological determinants. The aim of this study was to evaluate the accuracy of Hp serology test (Roche Biomedical Lab., Labcorp), In the diagnosis of Hp infection in 121 children who were seen in the Pediatric Gastoenterology Clinic at the Marshall University Joan C. Edwards School of Medicine In Huntington. Positive serology detected children with Hpassociated gastritis with a sensitivity of 51.6%. Positive serology significantly correlated with the degree of gastric inflammation and density of Hp organisms in the gastric mucosa (ANOVA p < 0.001). The Labcorp. Hp-ELISA test had a poor accuracy rate for the detection of Hp-gastritis in children. Gastric biopsies should always be performed to establish the diagnosis of Hp infection in children.

Go to article

A Ypt/Rab Effector Complex Containing The Sec1 Homolog Vps33p Is Required For Homotypic Vacuole Fusion, Darren F. Seals, Gary Eitzen, Nathan Margolis, William T. Wickner, Albert Price Aug 2000

A Ypt/Rab Effector Complex Containing The Sec1 Homolog Vps33p Is Required For Homotypic Vacuole Fusion, Darren F. Seals, Gary Eitzen, Nathan Margolis, William T. Wickner, Albert Price

Dartmouth Scholarship

Yeast vacuoles undergo priming, docking, and homotypic fusion, although little has been known of the connections between these reactions. Vacuole-associated Vam2p and Vam6p (Vam2/6p) are components of a 65S complex containing SNARE proteins. Upon priming by Sec18p/NSF and ATP, Vam2/6p is released as a 38S subcomplex that binds Ypt7p to initiate docking. We now report that the 38S complex consists of both Vam2/6p and the class C Vps proteins [Reider, S. E. and Emr, S. D. (1997) Mol. Biol. Cell 8, 2307-2327]. This complex includes Vps33p, a member of the Sec1 family of proteins that bind t-SNAREs. We term this …

Go to article

A New Role For A Snare Protein As A Regulator Of The Ypt7/Rab-Dependent Stage Of Docking, Christian Ungermann, Albert Price, William Wickner Aug 2000

A New Role For A Snare Protein As A Regulator Of The Ypt7/Rab-Dependent Stage Of Docking, Christian Ungermann, Albert Price, William Wickner

Dartmouth Scholarship

The homotypic fusion of yeast vacuoles occurs in an ordered cascade of priming, docking, and fusion. The linkage between these steps has so far remained unclear. We now report that Vam7p (the vacuolar SNAP-23/25 homolog) signals from the cis-SNARE complex to Ypt7p (the vacuolar Rab/Ypt) to initiate the docking process. After Vam7p has been released from the cis-SNARE complex by Sec18p-mediated priming, it is still required for Ypt7p-dependent docking and it needs Ypt7p to remain on the vacuole.

Go to article

Vitamin A And Cancer, Richard M. Niles Jul 2000

Vitamin A And Cancer, Richard M. Niles

Biochemistry and Microbiology

Vitamin A, its physiological metabolites and synthetic derivatives (retinoids) have been shown to have protective effects against the development of certain types of cancer. In addition, pharmacological amounts of retinoids have been used with some success in the treatment of a few human tumors. The chemoprevention effect of retinoids is most likely exerted at the tumor promotion phase of carcinogenesis. Retinoids block tumor promotion by either inhibiting proliferation, inducing apoptosis, inducing differentiation, or a combination of these actions. Clinically, isotretinoin (13-cis-retinoic acid) significantly decreases the incidence of second primary tumors in patients with head and neck cancer and also reduces …

Go to article

Effect Of Receptor-Selective Retinoids On Growth And Differentiation Pathways In Mouse Melanoma Cells, Sejal H. Desai, Goran Boskovic, Linda L. Eastham, Marcia Dawson, Richard M. Niles May 2000

Effect Of Receptor-Selective Retinoids On Growth And Differentiation Pathways In Mouse Melanoma Cells, Sejal H. Desai, Goran Boskovic, Linda L. Eastham, Marcia Dawson, Richard M. Niles

Biochemistry and Microbiology

Treatment of B16 mouse melanoma cells with all-trans-retinoic acid (ATRA) results in inhibition of cell proliferation and induction of differentiation. Accompanying these events is an induction of retinoic acid receptor β (RARβ) expression, an increase in protein kinase Cα (PKCα) expression, and enhanced activator protein-1 (AP-1) transcriptional activity. These cells express nuclear RARα and RARγ and nuclear retinoid X receptors (RXR) α and β constitutively. We tested the ability of receptor-selective retinoids to induce the biochemical changes found in ATRA-treated melanoma cells and also tested their effectiveness in decreasing anchorage-dependent and -independent growth. The RXR-selective ligand (2E,4E)-6-(5,6,7,8-tetrahydro-3,5,5,8,8-pentamethyl-2-naphthalenyl)-3,7-dimethyl-2,4,6-octatrienoic acid (SR11246) was …

Go to article

Asymmetric Requirements For A Rab Gtpase And Snare Proteins In Fusion Of Copii Vesicles With Acceptor Membranes, Xiaochun Cao, Charles Barlowe Apr 2000

Asymmetric Requirements For A Rab Gtpase And Snare Proteins In Fusion Of Copii Vesicles With Acceptor Membranes, Xiaochun Cao, Charles Barlowe

Dartmouth Scholarship

Soluble NSF attachment protein receptor (SNARE) proteins are essential for membrane fusion in transport between the yeast ER and Golgi compartments. Subcellular fractionation experiments demonstrate that the ER/Golgi SNAREs Bos1p, Sec22p, Bet1p, Sed5p, and the Rab protein, Ypt1p, are distributed similarly but localize primarily with Golgi membranes. All of these SNARE proteins are efficiently packaged into COPII vesicles and suggest a dynamic cycling of SNARE machinery between ER and Golgi compartments. Ypt1p is not efficiently packaged into vesicles under these conditions. To determine in which membranes protein function is required, temperature-sensitive alleles of BOS1, BET1, SED5, SLY1, and YPT1 that …

Go to article

Differential Expression Of Chemokines In A Mouse Model Of Wound Healing, Susan H. Jackman, Matthew B. Yoak, Shivaleela Keerthy, Bonnie L. Beaver Apr 2000

Differential Expression Of Chemokines In A Mouse Model Of Wound Healing, Susan H. Jackman, Matthew B. Yoak, Shivaleela Keerthy, Bonnie L. Beaver

Biochemistry and Microbiology

Macrophages have a multifaceted role in wound healing. While their initial activity may be in the degradation and elimination of damaged tissue, macrophages also produce and secrete a variety of mediators that can participate in the repair process as well. To perform these functions, macrophages must be recruited to a wound site. Our purpose was to examine the temporal and spatial expression of macrophage chemoattracting cytokines (chemokines) at a surgical wound site. A surgical wound was prepared on the dorsal aspect of B6AFI/J mice. Biopsies were obtained from the wound and a comparable nonwounded area between 6 and 72 hr …

Go to article

Membrane Cholesterol Content Modulates Activation Of Volume-Regulated Anion Current In Bovine Endothelial Cells., I Levitan, A E Christian, T N Tulenko, G H Rothblat Apr 2000

Membrane Cholesterol Content Modulates Activation Of Volume-Regulated Anion Current In Bovine Endothelial Cells., I Levitan, A E Christian, T N Tulenko, G H Rothblat

Department of Biochemistry and Molecular Biology Faculty Papers

Activation of volume-regulated anion current (VRAC) plays a key role in the maintenance of cellular volume homeostasis. The mechanisms, however, that regulate VRAC activity are not fully understood. We have examined whether VRAC activation is modulated by the cholesterol content of the membrane bilayer. The cholesterol content of bovine aortic endothelial cells was increased by two independent methods: (a) exposure to a methyl-beta-cyclodextrin saturated with cholesterol, or (b) exposure to cholesterol-enriched lipid dispersions. Enrichment of bovine aortic endothelial cells with cholesterol resulted in a suppression of VRAC activation in response to a mild osmotic gradient, but not to a strong …

Go to article

Fungal Ipc Synthase Assay, Jeffery Radding, Robert C. Dickson, Robert L. Lester Feb 2000

Fungal Ipc Synthase Assay, Jeffery Radding, Robert C. Dickson, Robert L. Lester

Molecular and Cellular Biochemistry Faculty Patents

The presently-disclosed IPC synthase-inhibitor assays comprise the steps of: (1) expression of the IPC1 gene in a cell; (2) introducing labeled starting substrates for ceramide conversion as well as potential inhibitor(s) of such conversion to the expressed gene product in an environment which allows time and conditions for conversion, and (3) identifying those potential inhibitors which actually inhibit conversion. The present invention also provides methods to determine the ability of a test compound to inhibit fungal growth, comprising the steps of (1) presenting active inositolphosophotidylceramide synthase in a manner such that synthesis of inositolphosphotidylceramide can occur; (2) introducing ceramide and …

Go to article

Auto-Inhibition Of Ets-1 Is Counteracted By Dna Binding Cooperativity With Core-Binding Factor Α2, Tamara L. Goetz, Ting-Lei Gu, Nancy A. Speck, Barbara J. Graves Jan 2000

Auto-Inhibition Of Ets-1 Is Counteracted By Dna Binding Cooperativity With Core-Binding Factor Α2, Tamara L. Goetz, Ting-Lei Gu, Nancy A. Speck, Barbara J. Graves

Dartmouth Scholarship

Auto-inhibition is a common transcriptional control mechanism that is well characterized in the regulatory transcription factor Ets-1. Autoinhibition of Ets-1 DNA binding works through an inhibitory module that exists in two conformations. DNA binding requires a change in the inhibitory module from the packed to disrupted conformation. This structural switch provides a mechanism to tightly regulate Ets-1 DNA binding. We report that the Ets-1 partner protein core-binding factor α2 (CBFα2; also known as AML1 or PEBP2) stimulates Ets-1 DNA binding and counteracts auto-inhibition. Support for this conclusion came from three observations. First, the level of cooperative DNA binding (10-fold) was …

Go to article

Vacuole Acidification Is Required For Trans-Snare Pairing, Lma1 Release, And Homotypic Fusion, Christian Ungermann, William Wickner, Zuoyu Xu Sep 1999

Vacuole Acidification Is Required For Trans-Snare Pairing, Lma1 Release, And Homotypic Fusion, Christian Ungermann, William Wickner, Zuoyu Xu

Dartmouth Scholarship

Vacuole fusion occurs in three stages: priming, in which Sec18p mediates Sec17p release, LMA1 (low Mr activity 1) relocation, and cis-SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex disassembly; docking, mediated by Ypt7p and trans-SNARE association; and fusion of docked vacuoles. Ca2+ and calmodulin regulate late stages of the reaction. We now show that the vacuole proton gradient, generated by the vacuolar proton ATPase, is needed for trans-SNARE complex formation during docking and hence for the subsequent LMA1 release. Though neither the vacuolar Pmc1p Ca2+-ATPase nor the Vcx1p Ca2+/H+ exchanger …

Go to article

Protein Adducts Of Iso[4]Levuglandin E2, A Product Of The Isoprostane Pathway, In Oxidized Low Density Lipoprotein, Robert G. Salomon, Wei Sha, Cynthia Brame, Kamaljit Kaur, Ganesamoorthy Subbanagounder, June O'Neil, Henry F. Hoff, L. Jackson Roberts Ii Jul 1999

Protein Adducts Of Iso[4]Levuglandin E2, A Product Of The Isoprostane Pathway, In Oxidized Low Density Lipoprotein, Robert G. Salomon, Wei Sha, Cynthia Brame, Kamaljit Kaur, Ganesamoorthy Subbanagounder, June O'Neil, Henry F. Hoff, L. Jackson Roberts Ii

Pharmacy Faculty Articles and Research

Levuglandin (LG) E2, a cytotoxic seco prostanoic acid co-generated with prostaglandins by nonenzymatic rearrangements of the cyclooxygenase-derived endoperoxide, prostaglandin H2, avidly binds to proteins. That LGE2-protein adducts can also be generated nonenzymatically is demonstrated by their production during free radical-induced oxidation of low density lipoprotein (LDL). Like oxidized LDL, LGE2-LDL, but not native LDL, undergoes receptor-mediated uptake and impaired processing by macrophage cells. Since radical-induced lipid oxidation produces isomers of prostaglandins, isoprostanes (isoPs), via endoperoxide intermediates, we postulated previously that a similar family of LG isomers, isoLGs, is cogenerated with isoPs. Now …

Go to article

Core-Binding Factor Influences The Disease Specificity Of Moloney Murine Leukemia Virus, Amy F. Lewis, Terryl Stacy, William R. Green, Lekidelu Taddesse-Heath, Janet W. Hartley, Nancy A. Speck Jul 1999

Core-Binding Factor Influences The Disease Specificity Of Moloney Murine Leukemia Virus, Amy F. Lewis, Terryl Stacy, William R. Green, Lekidelu Taddesse-Heath, Janet W. Hartley, Nancy A. Speck

Dartmouth Scholarship

The core site in the Moloney murine leukemia virus (Moloney MLV) enhancer was previously shown to be an important determinant of the T-cell disease specificity of the virus. Mutation of the core site resulted in a significant shift in disease specificity of the Moloney virus from T-cell leukemia to erythroleukemia. We and others have since determined that a protein that binds the core site, one of the core-binding factors (CBF) is highly expressed in thymus and is essential for hematopoiesis. Here we test the hypothesis that CBF plays a critical role in mediating pathogenesis of Moloney MLV in vivo. We …

Go to article

Three V-Snares And Two T-Snares, Present In A Pentameric Cis-Snare Complex On Isolated Vacuoles, Are Essential For Homotypic Fusion, Christian Ungermann, Gabriele F. Von Mollard, Ole N. Jensen, Nathan Margolis, Tom H. Stevens, William Wickner Jun 1999

Three V-Snares And Two T-Snares, Present In A Pentameric Cis-Snare Complex On Isolated Vacuoles, Are Essential For Homotypic Fusion, Christian Ungermann, Gabriele F. Von Mollard, Ole N. Jensen, Nathan Margolis, Tom H. Stevens, William Wickner

Dartmouth Scholarship

Vacuole SNAREs, including the t-SNAREs Vam3p and Vam7p and the v-SNARE Nyv1p, are found in a multisubunit "cis" complex on isolated organelles. We now identify the v-SNAREs Vti1p and Ykt6p by mass spectrometry as additional components of the immunoisolated vacuolar SNARE complex. Immunodepletion of detergent extracts with anti-Vti1p removes all the Ykt6p that is in a complex with Vam3p, immunodepletion with anti-Ykt6p removes all the Vti1p that is complexed with Vam3p, and immunodepletion with anti-Nyv1p removes all the Ykt6p in complex with other SNAREs, demonstrating that they are all together in the same cis multi-SNARE complex. After priming, which disassembles …

Go to article

Technique For Specifying The Fatty Acid At The Sn2 Position Of Acylglycerol Lipids, Robert C. Dickson, Robert L. Lester, M. Marek Nagiec Feb 1999

Technique For Specifying The Fatty Acid At The Sn2 Position Of Acylglycerol Lipids, Robert C. Dickson, Robert L. Lester, M. Marek Nagiec

Molecular and Cellular Biochemistry Faculty Patents

A method for specifying a fatty acid at the sn2 position of acylglycerol lipids including (a) transfecting a vector including the SLC1 gene or a variant thereof into embryonic biological material, and (b) allowing the SLC1 gene to specify the type of fatty acid at the sn2 position of acylglycerol lipids. Also provided for is an isolated SLC1 gene and a probe for its detection.

Go to article

The Seca Subunit Of Escherichia Coli Preprotein Translocase Is Exposed To The Periplasm, Jerry Eichler, William Wickner Nov 1998

The Seca Subunit Of Escherichia Coli Preprotein Translocase Is Exposed To The Periplasm, Jerry Eichler, William Wickner

Dartmouth Scholarship

SecA undergoes conformational changes during translocation, inserting domains into and across the membrane or enhancing the protease resistance of these domains. We now show that some SecA bound at SecYEG is accessible from the periplasm to a membrane-impermeant probe in cells with a permeabilized outer membrane but an intact plasma membrane.

Go to article

Exoy, An Adenylate Cyclase Secreted By The Pseudomonas Aeruginosa Type Iii System, Timothy L. Yahr, Amy J. Vallis, Michael Hancock, Joseph T. Barbieri, Dara W. Frank Nov 1998

Exoy, An Adenylate Cyclase Secreted By The Pseudomonas Aeruginosa Type Iii System, Timothy L. Yahr, Amy J. Vallis, Michael Hancock, Joseph T. Barbieri, Dara W. Frank

Dartmouth Scholarship

The exoenzyme S regulon is a set of coordinately regulated virulence genes of Pseudomonas aeruginosa. Proteins encoded by the regulon include a type III secretion and translocation apparatus, regulators of gene expression, and effector proteins. The effector proteins include two enzymes with ADP-ribosyltransferase activity (ExoS and ExoT) and an acute cytotoxin (ExoU). In this study, we identified ExoY as a fourth effector protein of the regulon. ExoY is homologous to the extracellular adenylate cyclases of Bordetella pertussis (CyaA) and Bacillus anthracis (EF). The homology among the three adenylate cyclases is limited to two short regions, one of which possesses an …

Go to article

A Vacuolar V–T-Snare Complex, The Predominant Form In Vivo And On Isolated Vacuoles, Is Disassembled And Activated For Docking And Fusion, Christian Ungermann, Benjamin J. Nichols, Hugh R. B. Pelham, William Wickner Jan 1998

A Vacuolar V–T-Snare Complex, The Predominant Form In Vivo And On Isolated Vacuoles, Is Disassembled And Activated For Docking And Fusion, Christian Ungermann, Benjamin J. Nichols, Hugh R. B. Pelham, William Wickner

Dartmouth Scholarship

Homotypic vacuole fusion in yeast requires Sec18p (N-ethylmaleimide-sensitive fusion protein [NSF]), Sec17p (soluble NSF attachment protein [alpha-SNAP]), and typical vesicle (v) and target membrane (t) SNAP receptors (SNAREs). We now report that vacuolar v- and t-SNAREs are mainly found with Sec17p as v-t-SNARE complexes in vivo and on purified vacuoles rather than only transiently forming such complexes during docking, and disrupting them upon fusion. In the priming reaction, Sec18p and ATP dissociate this v-t-SNARE complex, accompanied by the release of Sec17p. SNARE complex structure governs each functional aspect of priming, as the v-SNARE regulates the rate of Sec17p release and, …

Go to article

Title, Fergus Ryan, D Devaney, Caroline Joyce, A Nestorowicz, M Permutt, Benjamin Glaser, Paul Thornton, David E. Barton Jan 1998

Title, Fergus Ryan, D Devaney, Caroline Joyce, A Nestorowicz, M Permutt, Benjamin Glaser, Paul Thornton, David E. Barton

Articles

Persistent hypoglycaemia in infancy is most commonly caused by hyperinsulinism. A case is reported of the somatic loss of the maternal 11p in an insulin secreting focal adenoma in association with a germline SUR-1mutation on the paternal allele in a baby boy with hyperinsulinism diagnosed at 49 days old. A reduction to homozygosity of an SUR-1 mutation is proposed as a critical part of the cause of focal hyperinsulinism.

Go to article

Murine Transporter Associated With Antigen Presentation (Tap) Preferences Influence Class I-Restricted T Cell Responses., A J Yellen-Shaw, C E Laughlin, R M Metrione, Laurence C. Eisenlohr Nov 1997

Murine Transporter Associated With Antigen Presentation (Tap) Preferences Influence Class I-Restricted T Cell Responses., A J Yellen-Shaw, C E Laughlin, R M Metrione, Laurence C. Eisenlohr

Department of Biochemistry and Molecular Biology Faculty Papers

The transporter associated with antigen presentation (TAP) complex shuttles cytosolic peptides into the exocytic compartment for association with nascent major histocompatibility complex class I molecules. Biochemical studies of murine and human TAP have established that substrate length and COOH-terminal residue identity are strong determinants of transport efficiency. However, the existence of these specificities in the intact cell and their influences on T cell responses have not been demonstrated. We have devised a method for studying TAP- mediated transport in intact cells, using T cell activation as a readout. The approach makes use of a panel of recombinant vaccinia viruses expressing …

Go to article

Mitotic Spindle Poles Are Organized By Structural And Motor Proteins In Addition To Centrosomes, Tirso Gaglio, Mary A. Dionne, Duane A. Duane A. Compton Sep 1997

Mitotic Spindle Poles Are Organized By Structural And Motor Proteins In Addition To Centrosomes, Tirso Gaglio, Mary A. Dionne, Duane A. Duane A. Compton

Dartmouth Scholarship

The focusing of microtubules into mitotic spindle poles in vertebrate somatic cells has been assumed to be the consequence of their nucleation from centrosomes. Contrary to this simple view, in this article we show that an antibody recognizing the light intermediate chain of cytoplasmic dynein (70.1) disrupts both the focused organization of microtubule minus ends and the localization of the nuclear mitotic apparatus protein at spindle poles when injected into cultured cells during metaphase, despite the presence of centrosomes. Examination of the effects of this dynein-specific antibody both in vitro using a cell-free system for mitotic aster assembly and in …

Go to article

Sqt1, Which Encodes An Essential Wd Domain Protein Of Saccharomyces Cerevisiae, Suppresses Dominant-Negative Mutations Of The Ribosomal Protein Gene Qsr1., Dominic P. Eisinger, Frederick A. Dick, Elke Denke, Bernard L. Trumpower Sep 1997

Sqt1, Which Encodes An Essential Wd Domain Protein Of Saccharomyces Cerevisiae, Suppresses Dominant-Negative Mutations Of The Ribosomal Protein Gene Qsr1., Dominic P. Eisinger, Frederick A. Dick, Elke Denke, Bernard L. Trumpower

Dartmouth Scholarship

QSR1 is an essential Saccharomyces cerevisiae gene, which encodes a 60S ribosomal subunit protein required for joining of 40S and 60S subunits. Truncations of QSR1 predicted to encode C-terminally truncated forms of Qsr1p do not substitute for QSR1 but do act as dominant negative mutations, inhibiting the growth of yeast when expressed from an inducible promoter. The dominant negative mutants exhibit a polysome profile characterized by 'half-mer' polysomes, indicative of a subunit joining defect like that seen in other qsr1 mutants (D. P. Eisinger, F. A. Dick, and B. L. Trumpower, Mol. Cell. Biol. 17:5136-5145, 1997.) By screening a high-copy …

Go to article

Qsr1p, A 60s Ribosomal Subunit Protein, Is Required For Joining Of 40s And 60s Subunits., Dominic P. Eisinger, Frederick A. Dick, Bernard L. Trumpower Sep 1997

Qsr1p, A 60s Ribosomal Subunit Protein, Is Required For Joining Of 40s And 60s Subunits., Dominic P. Eisinger, Frederick A. Dick, Bernard L. Trumpower

Dartmouth Scholarship

QSR1 is a recently discovered, essential Saccharomyces cerevisiae gene, which encodes a 60S ribosomal subunit protein. Thirty-one unique temperature-sensitive alleles of QSR1 were generated by regional codon randomization within a conserved 20-amino-acid sequence of the QSR1-encoded protein. The temperature-sensitive mutants arrest as viable, large, unbudded cells 24 to 48 h after a shift to 37 degrees C. Polysome and ribosomal subunit analysis by velocity gradient centrifugation of lysates from temperature-sensitive qsr1 mutants and from cells in which Qsr1p was depleted by down regulation of an inducible promoter revealed the presence of half-mer polysomes and a large pool of free 60S …

Go to article

Hybrid Vector And Method Resulting In Protein Overproduction By Eukaryotic Cells, Robert E. Rhoads, Arrico De Benedetti Jul 1997

Hybrid Vector And Method Resulting In Protein Overproduction By Eukaryotic Cells, Robert E. Rhoads, Arrico De Benedetti

Molecular and Cellular Biochemistry Faculty Patents

A hybrid vector carrying a first and second DNA segments operationally linked thereto, the first DNA segment encoding a protein capable of cross-linking to the cap structure of mRNA and mediating ribosome-binding, and the second DNA segment encoding a polypeptide or protein, the vector being capable of replication, transcription and translation to express the factor and the polypeptide or protein upon transformation of a eukaryotic host, and the polypeptide or protein being expressed at a level higher than the level of expression thereof in the absence of the first DNA segment. A eukaryotic host is transformed with this hybrid vector. …

Go to article

Reference Serum Chemistry And Hematological Values For Spinal Cord Injured Patients, Michael S. Laymon, Antone L. Davis Ii Jun 1997

Reference Serum Chemistry And Hematological Values For Spinal Cord Injured Patients, Michael S. Laymon, Antone L. Davis Ii

Loma Linda University Electronic Theses, Dissertations & Projects

Serum chemistry and hematological values from 220 traumatic spinal cord injured patients (157 male and 63 female between the ages of 15-47, with greater than six months from injury) were compiled via chart review. Traumatic spinal cord injured patient’s reference ranges were determined and compared with the general population reference ranges. Reference ranges within the spinal cord population were compared by age, gender, level of injury and chronicity of injury. The reference ranges determined for all groups within this spinal cord population fall within the reference ranges of the general population. This supports recent research which suggests that a decrease …

Go to article

Identification Of A Novel Antiapoptotic Functional Domain In Simian Virus 40 Large T Antigen., Suzanne D. Conzen, Christine A. Snay, Charles N. Cole Jun 1997

Identification Of A Novel Antiapoptotic Functional Domain In Simian Virus 40 Large T Antigen., Suzanne D. Conzen, Christine A. Snay, Charles N. Cole

Dartmouth Scholarship

The ability of DNA tumor virus proteins to trigger apoptosis in mammalian cells is well established. For example, transgenic expression of a simian virus 40 (SV40) T-antigen N-terminal fragment (N-termTag) is known to induce apoptosis in choroid plexus epithelial cells. SV40 T-antigen-induced apoptosis has generally been considered to be a p53-dependent event because cell death in the brain is greatly diminished in a p53-/- background strain and is abrogated by expression of wild-type (p53-binding) SV40 T antigen. We now show that while N-termTags triggered apoptosis in rat embryo fibroblasts cultured in low serum, expression of full-length T antigens unable to …

Go to article

Dissection Of A Circadian Oscillation Into Discrete Domains, Martha W. Merrow, Norman Y. Garceau, Jay C. Dunlap Apr 1997

Dissection Of A Circadian Oscillation Into Discrete Domains, Martha W. Merrow, Norman Y. Garceau, Jay C. Dunlap

Dartmouth Scholarship

The circadian oscillator in Neurospora is a negative feedback loop involving as principal players the products of the frequency (frq) locus. frq encodes multiple forms of its protein product FRQ, which act to depress the amounts of frq transcript. In this scheme there are two discrete and separable steps to the circadian cycle, negative feedback itself (repression) in which FRQ acts to decrease the levels of its own transcript, and recovery from repression (derepression) in which frq transcript levels return to peak amounts. By introducing an exogenously regulatable frq transgene into a frq loss-of-function strain (frq9 …

Go to article

C-Terminal Truncations Of The Yeast Nucleoporin Nup145p Produce A Rapid Temperature-Conditional Mrna Export Defect And Alterations To Nuclear Structure., Thomas C. Dockendorff, Catherine V. Heath, Alan L. Goldstein, Christine A. Snay, C N. Cole Feb 1997

C-Terminal Truncations Of The Yeast Nucleoporin Nup145p Produce A Rapid Temperature-Conditional Mrna Export Defect And Alterations To Nuclear Structure., Thomas C. Dockendorff, Catherine V. Heath, Alan L. Goldstein, Christine A. Snay, C N. Cole

Dartmouth Scholarship

A screen for temperature-sensitive mutants of Saccharomyces cerevisiae defective in nucleocytoplasmic trafficking of poly(A)+ RNA has identified an allele of the NUP145 gene, which encodes an essential nucleoporin. NUP145 was previously identified by using a genetic synthetic lethal screen (E. Fabre, W. C. Boelens, C. Wimmer, I. W. Mattaj, and E. C. Hurt, Cell 78:275-289, 1994) and by using a monoclonal antibody which recognizes the GLFG family of vertebrate and yeast nucleoporins (S. R. Wente and G. Blobel, J. Cell Biol. 125:955-969, 1994). Cells carrying the new allele, nup145-10, grew at 23 and 30 degrees C but were unable to …

Go to article

First Prev Next Last