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Chromatin Of Endoreduplicated Pavement Cells Has Greater Range Of Movement Than That Of Diploid Guard Cells In Arabidopsis Thaliana, Naohiro Kato, Eric Lam Jun 2003

Chromatin Of Endoreduplicated Pavement Cells Has Greater Range Of Movement Than That Of Diploid Guard Cells In Arabidopsis Thaliana, Naohiro Kato, Eric Lam

Faculty Publications

In the current model of chromatin organization in the interphase cell nucleus, chromosomes are organized into territories. Although constrained diffusion of chromatin in interphase cells has been confirmed in all cell types examined, little is known about chromatin dynamics in plant interphase cells. In this work, we measured for the first time interphase chromatin dynamics in plants using the green-fluorescent-protein-mediated chromatin-tagging system. Moreover, we compared the dynamics of diploid guard cells and endoreduplicated pavement cells. The movement of tagged loci in live seedlings shows constrained behavior in both types of nuclei. However, we found that the apparent confinement area for …

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Predicting Severe Wildfire Years In The Florida Everglades, Brian Beckage, William J. Platt Jun 2003

Predicting Severe Wildfire Years In The Florida Everglades, Brian Beckage, William J. Platt

Faculty Publications

© 2003 The Ecological Society of America. Wildfires result in important ecological benefits to many ecosystems, but have costs associated with fire fighting and property loss. Accurate, timely forecasts of the severity of upcoming wildfire seasons could facilitate wildfire management, limiting the most destructive aspects of fires, while preserving their ecological benefits. We demonstrate an approach where time series models are used to predict the severity of the wildfire season in Everglades National Park in southern Florida 3 months and 1 year beforehand. Model predictions contained all obserations within a 90% credible interval and also anticipated severe wildfire seasons. These …

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Comparing Regeneration Techniques For Afforesting Previously Farmed Bottomland Hardwood Sites In The Lower Mississippi Alluvial Valley, Usa, Brian Roy Lockhart, Bob Keeland, John Mccoy, Thomas J. Dean May 2003

Comparing Regeneration Techniques For Afforesting Previously Farmed Bottomland Hardwood Sites In The Lower Mississippi Alluvial Valley, Usa, Brian Roy Lockhart, Bob Keeland, John Mccoy, Thomas J. Dean

Faculty Publications

A study was implemented to test site preparation methods and artificial regeneration of three oak (Quercus spp.) species on four agricultural fields in the Lower Mississippi Alluvial Valley in Louisiana, USA. Six years after establishment, few consistent differences were found in oak density between sowing acorn methods (seed drill versus broadcast seeding), autumn sowing versus spring sowing, and sowing acorns versus planting oak seedlings. Results indicated that some degree of site preparation is needed to establish oak seedlings but few differences were found between site preparation treatments. These results indicate that no one prescription for oak regeneration fits all potential …

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High Affinity Ligand Binding By Integrins Does Not Involve Head Separation, Bing Hao Luo, Timothy A. Springer, Junichi Takagi May 2003

High Affinity Ligand Binding By Integrins Does Not Involve Head Separation, Bing Hao Luo, Timothy A. Springer, Junichi Takagi

Faculty Publications

Conformational change in the integrin extracellular domain is required for high affinity ligand binding and is also involved in post-ligand binding cellular signaling. Although there is evidence to the contrary, electron microscopic studies showing that ligand binding triggers α- and β-subunit dissociation in the integrin head-piece have gained popularity and support the hypothesis that head separation activates integrins. To test directly the head separation hypothesis, we enforced head association by introducing disulfide bonds across the interface between the α-subunit β-propeller domain and the β-subunit I-like domain. Basal and activation-dependent ligand binding by αIIbβ3 and αVβ3 was unaffected. The covalent linkage …

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Evidence That Acetyl Phosphate Functions As A Global Signal During Biofilm Development, Alan J. Wolfe, Dong Eun Chang, Jason D. Walker, Jeanine E. Seitz-Partridge, Michael D. Vidaurri, Charles F. Lange, Birgit M. Prüß, Margaret C. Henk, John C. Larkin, Tyrrell Conway May 2003

Evidence That Acetyl Phosphate Functions As A Global Signal During Biofilm Development, Alan J. Wolfe, Dong Eun Chang, Jason D. Walker, Jeanine E. Seitz-Partridge, Michael D. Vidaurri, Charles F. Lange, Birgit M. Prüß, Margaret C. Henk, John C. Larkin, Tyrrell Conway

Faculty Publications

We used DNA macroarray analysis to identify genes that respond to the status of the intracellular acetyl phosphate (acP) pool. Genes whose expression correlated negatively with the ability to synthesize acP (i.e. negatively regulated genes) function primarily in flagella biosynthesis, a result consistent with observations that we published previously (Prüß and Wolfe, 1994, Mol Microbiol 12: 973-984). In contrast, genes whose expression correlated positively with the ability to synthesize acP (i.e. positively regulated genes) include those for type 1 pilus assembly, colanic acid (capsule) biosynthesis and certain stress effectors. To our knowledge, this constitutes the first report that these genes …

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Production Of The Siderophore 2,3-Dihydroxybenzoic Acid Is Required For Wild-Type Growth Of Brucella Abortus In The Presence Of Erythritol Under Low-Iron Conditions In Vitro, Bryan H. Bellaire, Philip H. Elzer, Cynthia L. Baldwin, R. Martin Roop May 2003

Production Of The Siderophore 2,3-Dihydroxybenzoic Acid Is Required For Wild-Type Growth Of Brucella Abortus In The Presence Of Erythritol Under Low-Iron Conditions In Vitro, Bryan H. Bellaire, Philip H. Elzer, Cynthia L. Baldwin, R. Martin Roop

Faculty Publications

Production of the siderophore 2,3-dihyroxybenzoic acid (2,3-DHBA) is required for the wild-type virulence of Brucella abortus in cattle. A possible explanation for this requirement was uncovered when it was determined that a B. abortus dhbC mutant (BHB1) defective in 2,3-DHBA production displays marked growth restriction in comparison to its parent strain, B. abortus 2308, when cultured in the presence of erythritol under low-iron conditions. This phenotype is not displayed when these strains are cultured under low-iron conditions in the presence of other readily utilizable carbon and energy sources. The addition of either exogenous 2,3-DHBA or FeCl3 relieves this growth defect, …

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The Utility Of Single Nucleotide Polymorphisms In Inferences Of Population History, Robb T. Brumfield, Peter Beerli, Deborah A. Nickerson, Scott V. Edwards May 2003

The Utility Of Single Nucleotide Polymorphisms In Inferences Of Population History, Robb T. Brumfield, Peter Beerli, Deborah A. Nickerson, Scott V. Edwards

Faculty Publications

Single nucleotide polymorphisms (SNPs) represent the most widespread type of sequence variation in genomes, yet they have only emerged recently as valuable genetic markers for revealing the evolutionary history of populations. Their occurrence throughout the genome also makes them ideal for analyses of speciation and historical demography, especially in light of recent theory suggesting that many unlinked nuclear loci are needed to estimate population genetic parameters with statistical confidence. In spite of having lower variation compared with microsatellites, SNPs should make the comparison of genomic diversities and histories of different species (the core goal of comparative biogeography) more straightforward than …

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Linkage For Bmi At 3q27 Region Confirmed In An African-American Population, Amy Luke, Xiaodong Wu, Xiaofeng Zhu, Donghui Kan, Yan Su, Richard Cooper May 2003

Linkage For Bmi At 3q27 Region Confirmed In An African-American Population, Amy Luke, Xiaodong Wu, Xiaofeng Zhu, Donghui Kan, Yan Su, Richard Cooper

Faculty Publications

Significant and suggestive linkage for BMI on 3q27 has been reported by several groups, including our own study in African Americans. To further establish the linkage evidence on 3q27, we recruited an independent African-American sample comprising 545 individuals in 128 families. We genotyped 15 short tandem-repeat markers evenly spaced in the 112 cM region around the peak on 3q27 identified in our earlier study. Multipoint linkage analysis by GENEHUNTER2 gave the maximum logarithm of odds (LOD) score 2.4 at map position 188 cM in this sample. When we combined the two samples, linkage evidence was increased to a maximum LOD …

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Associations Between Hypertension And Genes In The Renin-Angiotensin System, Xiaofeng Zhu, Yen Pei C. Chang, Denise Yan, Alan Weder, Richard Cooper, Amy Luke, Donghui Kan, Aravinda Chakravarti May 2003

Associations Between Hypertension And Genes In The Renin-Angiotensin System, Xiaofeng Zhu, Yen Pei C. Chang, Denise Yan, Alan Weder, Richard Cooper, Amy Luke, Donghui Kan, Aravinda Chakravarti

Faculty Publications

The genes of the renin-angiotensin system have been subjected to intense molecular scrutiny in cardiovascular disease studies, but their contribution to risk is still uncertain. In this study, we sampled 192 African American and 153 European American families (602 and 608 individuals, respectively) to evaluate the contribution of variations in genes that encode renin-angiotensin system components of susceptibility to hypertension. We genotyped 25 single-nucleotide polymorphisms in the renin-angiotensin system genes ACE, AGT, AGTR1, and REN. The family-based transmission/disequilibrium test was performed with each single-nucleotide polymorphism and with the multilocus haplotypes. Two individual single-nucleotide polymorphisms were significantly associated with hypertension among …

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Protein Crystallography Retinol Dehydratase Y135f Mutant Project Expression, Purification, And Crystallization, Samuel Costa Araujo May 2003

Protein Crystallography Retinol Dehydratase Y135f Mutant Project Expression, Purification, And Crystallization, Samuel Costa Araujo

Honors Capstones

No abstract provided.

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The Identification And Isolation Of A Full Length Beta Carbonic Anhydrase Cdna In Arabidopsis Thaliana, Lisa Michelle Ballard May 2003

The Identification And Isolation Of A Full Length Beta Carbonic Anhydrase Cdna In Arabidopsis Thaliana, Lisa Michelle Ballard

Honors Capstones

No abstract provided.

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Characterization Of The Histone-Like Hu Protein From Helicobacter Pylori, Christina Chen May 2003

Characterization Of The Histone-Like Hu Protein From Helicobacter Pylori, Christina Chen

Honors Capstones

No abstract provided.

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Normal Proliferation And Differentiation Of Hoxc-8 Transgenic Chondrocytes In Vitro, Stephania A. Cormier, Maria Alice Mello, Claudia Kappen Apr 2003

Normal Proliferation And Differentiation Of Hoxc-8 Transgenic Chondrocytes In Vitro, Stephania A. Cormier, Maria Alice Mello, Claudia Kappen

Faculty Publications

Background: Hox genes encode transcription factors that are involved in pattern formation in the skeleton, and recent evidence suggests that they also play a role in the regulation of endochondral ossification. To analyze the role of Hoxc-8 in this process in more detail, we applied in vitro culture systems, using high density cultures of primary chondrocytes from neonatal mouse ribs. Results: Cultured cells were characterized on the basis of morphology (light microscopy) and production of cartilage-specific extracellular matrix (sulfated proteoglycans and type II Collagen). Hypertrophy was demonstrated by increase in cell size, alkaline phosphatase activity and type X Collagen immunohistochemistry. …

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Valuation Of Continuous And Intermittent Phragmites Control, R. Eugene Turner, R. S. Warren Apr 2003

Valuation Of Continuous And Intermittent Phragmites Control, R. Eugene Turner, R. S. Warren

Faculty Publications

Quantifying the relative value of Phragmites australis and Spartina alterniflora habitat is important to evaluate the benefits and risks of different attempts to address Phragmites expansion on the U.S. eastern seaboard. Two contrasting approaches commonly used to restore tidal marsh habitats invaded by Phragmites communities involve spraying Phragmites with herbicide only when its coverage of a particular marsh area is near or close to 100%. Alternatively, after the first application, herbicide is annually applied on any surviving patches of Phragmites present in a mosaic of other marsh vegetation. A model is introduced to evaluate the relative habitat value of these …

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Genetic Organization And Iron-Responsive Regulation Of The Brucella Abortus 2,3-Dihydroxybenzoic Acid Biosynthesis Operon, A Cluster Of Genes Required For Wild-Type Virulence In Pregnant Cattle, Bryan H. Bellaire, Philip H. Elzer, Sue Hagius, Joel Walker, Cynthia L. Baldwin, R. Martin Roop Apr 2003

Genetic Organization And Iron-Responsive Regulation Of The Brucella Abortus 2,3-Dihydroxybenzoic Acid Biosynthesis Operon, A Cluster Of Genes Required For Wild-Type Virulence In Pregnant Cattle, Bryan H. Bellaire, Philip H. Elzer, Sue Hagius, Joel Walker, Cynthia L. Baldwin, R. Martin Roop

Faculty Publications

Brucella abortus reportedly produces the monocatechol siderophore 2,3-dihydroxybenzoic acid (2,3-DHBA) in response to iron limitation. Nucleotide sequence analysis of the cloned DHBA biosynthesis locus from virulent B. abortus 2308 and genetic complementation of defined Escherichia coli mutants were used to identify the B. abortus genes (designated dhbC, -B, and -A) responsible for synthesis of this siderophore. Reverse transcriptase PCR analysis of total RNA with dhb-specific primers demonstrated that dhbC, -B, and -A are transcribed as components of an operon, together with dhbE, a functional homolog of the Escherichia coli entE gene. Homologs of the E. coli entD and Vibrio cholerae …

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Louisiana Agriculture Spring, 2003, Lsu Agcenter Apr 2003

Louisiana Agriculture Spring, 2003, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

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Interstrain Inhibition In The Sweet Potato Pathogen Streptomyces Ipomoeae: Purification And Characterization Of A Highly Specific Bacteriocin And Cloning Of Its Structural Gene, Xiujun Zhang, Christopher A. Clark, Gregg S. Pettis Apr 2003

Interstrain Inhibition In The Sweet Potato Pathogen Streptomyces Ipomoeae: Purification And Characterization Of A Highly Specific Bacteriocin And Cloning Of Its Structural Gene, Xiujun Zhang, Christopher A. Clark, Gregg S. Pettis

Faculty Publications

Strains of the sweet potato soil rot pathogen Streptomyces ipomoeae had previously been divided into three groups based on their ability to inhibit one another during pairwise cocultivation. While group I strains are not antagonistic to members of the other groups, group II and group III strains produce separate substances that are inhibitory to strains outside their respective cognate groups. Here, we purified the group III inhibitory substance from the culture supernatant of a representative strain and found that it consists of a single 10-kDa cationic protein which is bacteriolytic for S. ipomoeae group I and II strains but which …

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Y Chromosome Str Haplotypes And The Genetic Structures Of U.S. Populations Of African, European, And Hispanic Ancestry, Manfred Kayser, Silke Brauer, Hiltrud Schädlich, Mechthild Prinz, Mark A. Batzer, Peter A. Zimmerman, B. A. Boatin, Mark Stoneking Apr 2003

Y Chromosome Str Haplotypes And The Genetic Structures Of U.S. Populations Of African, European, And Hispanic Ancestry, Manfred Kayser, Silke Brauer, Hiltrud Schädlich, Mechthild Prinz, Mark A. Batzer, Peter A. Zimmerman, B. A. Boatin, Mark Stoneking

Faculty Publications

To investigate geographic structure within U.S. ethnic populations, we analyzed 1705 haplotypes on the basis of 9 short tandem repeat (STR) loci on the Y-chromosome from 9-11 groups each of African-Americans, European-Americans, and Hispanics. There were no significant differences in the distribution of Y-STR haplotypes among African-American groups, whereas European-American and Hispanic groups did exhibit significant geographic heterogeneity. However, the significant heterogeneity resulted from one sample; removal of that sample in each case eliminated the significant heterogeneity. Multidimensional scaling analysis of RST values indicated that African-American groups formed a distinct cluster, whereas there was some intermingling of European-American and Hispanic …

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A Causative Relationship Exists Between Eosinophils And The Development Of Allergic Pulmonary Pathologies In The Mouse, Hua Hao H. Shen, Sergei I. Ochkur, Michael P. Mcgarry, Jeffrey R. Crosby, Edie M. Hines, Michael T. Borchers, Huiying Wang, Travis L. Biechelle, Katie R. O'Neill, Tracy L. Ansay, Dana C. Colbert, Stephania A. Cormier, J. Paul Justice, Nancy A. Lee, James J. Lee Mar 2003

A Causative Relationship Exists Between Eosinophils And The Development Of Allergic Pulmonary Pathologies In The Mouse, Hua Hao H. Shen, Sergei I. Ochkur, Michael P. Mcgarry, Jeffrey R. Crosby, Edie M. Hines, Michael T. Borchers, Huiying Wang, Travis L. Biechelle, Katie R. O'Neill, Tracy L. Ansay, Dana C. Colbert, Stephania A. Cormier, J. Paul Justice, Nancy A. Lee, James J. Lee

Faculty Publications

Asthma and mouse models of allergic respiratory inflammation are invariably associated with a pulmonary eosinophilia; however, this association has remained correlative. In this report, a causative relationship between eosinophils and allergen-provoked pathologies was established using eosinophil adoptive transfer. Eosinophils were transferred directly into the lungs of either naive or OVA-treated IL-5-/- mice. This strategy resulted in a pulmonary eosinophilia equivalent to that observed in OVA-treated wild-type animals. A concomitant consequence of this eosinophil transfer was an increase in Th2 bronchoalveolar lavage cytokine levels and the restoration of intracellular epithelial mucus in OVA-treated IL-5-/- mice equivalent to OVA-treated wild-type levels. Moreover, …

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Stabilizing The Open Conformation Of The Integrin Headpiece With A Glycan Wedge Increases Affinity For Ligand, Bing Hao Luo, Timothy A. Springer, Junichi Takagi Mar 2003

Stabilizing The Open Conformation Of The Integrin Headpiece With A Glycan Wedge Increases Affinity For Ligand, Bing Hao Luo, Timothy A. Springer, Junichi Takagi

Faculty Publications

The affinity of the extracellular domain of integrins for ligand is regulated by conformational changes signaled from the cytoplasm. Alternative types of conformational movement in the ligandbinding headpiece have been proposed. In one study, electron micrograph image averages of the headpiece of integrin aVβ3 show two different conformations. The open conformation of the headpiece is present when a ligand mimetic peptide is bound and differs from the closed conformation in the presence of an obtuse angle between the β3 subunit hybrid and I-like domains. We tested the hypothesis that opening of the hybrid-I-like domain interface increases ligand-binding affinity by mutationally …

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Bacillus Anthracis Virulence In Guinea Pigs Vaccinated With Anthrax Vaccine Adsorbed Is Linked To Plasmid Quantities And Clonality, Pamala R. Coker, Kimothy L. Smith, Patricia F. Fellows, Galena Rybachuck, Konstantin G. Kousoulas, Martin E. Hugh-Jones Mar 2003

Bacillus Anthracis Virulence In Guinea Pigs Vaccinated With Anthrax Vaccine Adsorbed Is Linked To Plasmid Quantities And Clonality, Pamala R. Coker, Kimothy L. Smith, Patricia F. Fellows, Galena Rybachuck, Konstantin G. Kousoulas, Martin E. Hugh-Jones

Faculty Publications

Bacillus anthracis is a bacterial pathogen of great importance, both historically and in the present. This study presents data collected from several investigations and indicates that B. anthracis virulence is associated with the clonality and virulence of plasmids pXO1 and pXO2. Guinea pigs vaccinated with Anthrax Vaccine Adsorbed were challenged with 20 B. anthracis isolates representative of worldwide genetic diversity. These same isolates were characterized with respect to plasmid copy number by using a novel method of quantitative PCR developed for rapid and efficient detection of B. anthracis from environmental samples. We found that the copy numbers for both pXO1 …

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Human Population Genetic Structure And Inference Of Group Membership, Michael J. Bamshad, Stephen Wooding, W. Scott Watkins, Christopher T. Ostler, Mark A. Batzer, Lynn B. Jorde Mar 2003

Human Population Genetic Structure And Inference Of Group Membership, Michael J. Bamshad, Stephen Wooding, W. Scott Watkins, Christopher T. Ostler, Mark A. Batzer, Lynn B. Jorde

Faculty Publications

A major goal of biomedical research is to develop the capability to provide highly personalized health care. To do so, it is necessary to understand the distribution of interindividual genetic variation at loci underlying physical characteristics, disease susceptibility, and response to treatment. Variation at these loci commonly exhibits geographic structuring and may contribute to phenotypic differences between groups. Thus, in some situations, it may be important to consider these groups separately. Membership in these groups is commonly inferred by use of a proxy such as place-of-origin or ethnic affiliation. These inferences are frequently weakened, however, by use of surrogates, such …

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Preparation And Identification Of Anti-Transforming Growth Factor Β1 U1 Small Nuclear Rna Chimeric Ribozyme In Vitro, Ju Sheng Lin, Yu Hu Song, Xin Juan Kong, Bin Li, Nan Zhi Liu, Xiao Li Wu, You Xin Jin Mar 2003

Preparation And Identification Of Anti-Transforming Growth Factor Β1 U1 Small Nuclear Rna Chimeric Ribozyme In Vitro, Ju Sheng Lin, Yu Hu Song, Xin Juan Kong, Bin Li, Nan Zhi Liu, Xiao Li Wu, You Xin Jin

Faculty Publications

Aim: To study the preparation and cleavage activity of anti-transforming growth factor (TGF)β1 U1 small nuclear (sn) RNA chimeric hammerhead ribozymes in vitro. Methods: TGFβ1 partial gene fragment was cloned into T-vector at the downstream of T7 promoter. 32p-labeled TGFβ1 partial transcripts as target RNA were transcribed in vitro and purified by denaturing polyacrylamide gel electrophoresis (PAGE). Anti-TGFβ1 ribozymes were designed by computer, then synthetic ribozyme fragments were cloned into the U1 ribozyme vector pZeoU1EcoSpe containing U1 snRNA promoter/enhancer and terminator. 32p-labeled U1 snRNA chimeric ribozyme transcripts were gel-purified, incubated with target-RNAs at different conditions and autoradiographed after running denaturing …

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Carboxylate Groups On The Manganese-Stabilizing Protein Are Required For Efficient Binding Of The 24 Kda Extrinsic Protein To Photosystem Ii, Terry M. Bricker, Laurie K. Frankel Feb 2003

Carboxylate Groups On The Manganese-Stabilizing Protein Are Required For Efficient Binding Of The 24 Kda Extrinsic Protein To Photosystem Ii, Terry M. Bricker, Laurie K. Frankel

Faculty Publications

The effects of the modification of carboxylate groups on the manganese-stabilizing protein on the binding of the 24 kDa extrinsic protein to Photosystem II were investigated. Carboxylate groups on the manganese-stabilizing protein were modified with glycine methyl ester in a reaction facilitated by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide. The manganese-stabilizing protein which was modified while associated with NaCl-washed membranes could bind to calcium chloride-washed PS II membranes and reconstitute oxygen evolution in a manner similar to that observed for unmodified manganese-stabilizing protein (Frankel, L,K, Cruz, J. C. and Bricker, T. M. (1999) Biochemistry 38, 14271-14278), However, PS II membranes reconstituted with this modified protein …

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Salt Dependence Of Dna Binding By Thermus Aquaticus And Escherichia Coli Dna Polymerases, Kausiki Datta, Vince J. Licata Feb 2003

Salt Dependence Of Dna Binding By Thermus Aquaticus And Escherichia Coli Dna Polymerases, Kausiki Datta, Vince J. Licata

Faculty Publications

DNA binding properties of the Type 1 DNA polymerases from Thermus aquaticus (Taq, Klentaq) and Escherichia coli (Klenow) have been examined as a function of [KCl] and [MgCl2]. Full-length Taq and its Klentaq "large fragment" behave similarly in all assays. The two different species of polymerases bind DNA with submicromolar affinities in very different salt concentration ranges. Consequently, at similar [KCl] the binding of Klenow is ∼3 kcal/mol (150×) tighter than that of Taq/Klentaq to the same DNA. Linkage analysis reveals a net release of 2-3 ions upon DNA binding of Taq/Klentaq and 4-5 ions upon binding of Klenow. DNA …

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Climatic Influences On Riverine Nitrate Flux: Implications For Coastal Marine Eutrophication And Hypoxia, Dubravko Justic, R. Eugene Turner, Nancy N. Rabalais Feb 2003

Climatic Influences On Riverine Nitrate Flux: Implications For Coastal Marine Eutrophication And Hypoxia, Dubravko Justic, R. Eugene Turner, Nancy N. Rabalais

Faculty Publications

The average nitrate flux of the lower Mississippi River increased 3.3-fold between 1954–1967 and 1983–2000. During the same time period, the average nitrate concentration increased 2.3-fold while the average discharge increased 40%. Partitioning of the observed trend in nitrate flux among the two flux components, nitrate concentration and discharge, revealed that about 80% of the observed increase in flux could be explained by the increase in nitrate concentration. This indicates that a historical increase in the anthropogenic nutrient inputs has had a far greater impact on the lower Mississippi River nitrate flux than a change in climate. The influence of …

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Structure Of The Proline Dehydrogenase Domain Of The Multifunctional Puta Flavoprotein, Yong Hwan Lee, Shorena Nadaraia, Dan Gu, Donald F. Becker, John J. Tanner Feb 2003

Structure Of The Proline Dehydrogenase Domain Of The Multifunctional Puta Flavoprotein, Yong Hwan Lee, Shorena Nadaraia, Dan Gu, Donald F. Becker, John J. Tanner

Faculty Publications

The PutA flavoprotein from Escherichia coli plays multiple roles in proline catabolism by functioning as a membrane-associated bi-functional enzyme and a transcriptional repressor of proline utilization genes. The human homolog of the PutA proline dehydrogenase (PRODH) domain is critical in p53-mediated apoptosis and schizophrenia. Here we report the crystal structure of a 669-residue truncated form of PutA that shows both PRODH and DNA-binding activities, representing the first structure of a PutA protein and a PRODH enzyme from any organism. The structure is a domain-swapped dimer with each subunit comprising three domains: a helical dimerization arm, a 120-residue domain containing a …

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Stat5a Promotes Adipogenesis In Nonprecursor Cells And Associates With The Glucocorticoid Receptor During Adipocyte Differentiation, Z. Elizabeth Floyd, Jacqueline M. Stephens Feb 2003

Stat5a Promotes Adipogenesis In Nonprecursor Cells And Associates With The Glucocorticoid Receptor During Adipocyte Differentiation, Z. Elizabeth Floyd, Jacqueline M. Stephens

Faculty Publications

The differentiation of adipocytes is regulated by the activity of a variety of transcription factors, including peroxidase proliferator-activated receptor (PPAR)-γ and C/EBPα. Our current study demonstrates that ectopic expression of STAT5A, such as that of PPAR-γ and C/EBPα, promotes adipogenesis in two nonprecursor fibroblast cell lines. Using morphologic and biochemical criteria, we have demonstrated that STAT5A and the combination of STAT5A and STAT5B are sufficient to induce the expression of early and late adipogenic markers in BALB/c and NIH-3T3 cells. Yet, the ectopic expression of STAT5B alone does not induce the expression of adipocyte genes, but enhances the induction of …

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Methylation-Sensitive Binding Of Transcription Factor Yy1 To An Insulator Sequence Within The Paternally Expressed Imprinted Gene, Peg3, Joomyeong Kim, Angela Kollhoff, Anne Bergmann, Lisa Stubbs Feb 2003

Methylation-Sensitive Binding Of Transcription Factor Yy1 To An Insulator Sequence Within The Paternally Expressed Imprinted Gene, Peg3, Joomyeong Kim, Angela Kollhoff, Anne Bergmann, Lisa Stubbs

Faculty Publications

The 5�-ends of two paternally expressed mouse genes, Peg3 and Usp29, are jointly associated with a CpG island that exhibits allele-specific methylation. Sequence comparison of the regions derived from human, mouse and cow revealed the presence of two evolutionarily conserved sequence motifs including one that is repeated multiple times within the first intron of Peg3 in all three mammals. DNA mobility shift and chromatin immunoprecipitation (ChlP) assays clearly demonstrated that this motif is an in vivo binding site for the Gli-type transcription factor YY1. The YY1-binding site contains one CpG dinucleotide, and methylation of this CpG site abolishes the binding …

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Transcriptional Initiation Under Conditions Of Anoxia-Induced Quiescence In Mitochondria From Artemia Franciscana Embryos, Brian D. Eads, Steven C. Hand Feb 2003

Transcriptional Initiation Under Conditions Of Anoxia-Induced Quiescence In Mitochondria From Artemia Franciscana Embryos, Brian D. Eads, Steven C. Hand

Faculty Publications

In response to anoxia, embryos of the brine shrimp Artemia franciscana are able coordinately to downregulate metabolism to levels low enough to permit survival for several years at room temperature. In addition to dramatic decreases in free ATP levels and heat production, intracellular pH drops from 7.8 to 6.3 overnight. Use of isolated mitochondria to study transcriptional responses to anoxia offers several advantages: (1) the localized nature of transcript initiation, processing and degradation, all of which may be followed in organello; (2) the relatively simple cis- and trans-machinery involved and (3) the ability to provide relevant physiological treatments in vitro. …

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