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2004

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Articles 1 - 30 of 56

Full-Text Articles in Molecular Biology

Isolation Of Cancer Stem Cells From Adult Glioblastoma Multiforme, Xianpeng Yuan, James Curtin, Yizhi Xiong, Gentao Liu, Sebastian Waschsmann-Hogiu, Daniel Farkas, Keith Black, John Yu Dec 2004

Isolation Of Cancer Stem Cells From Adult Glioblastoma Multiforme, Xianpeng Yuan, James Curtin, Yizhi Xiong, Gentao Liu, Sebastian Waschsmann-Hogiu, Daniel Farkas, Keith Black, John Yu

Articles

Glioblastoma multiforme (GBM) is the most common adult primary brain tumor and is comprised of a heterogeneous population of cells. It is unclear which cells within the tumor mass are responsible for tumor initiation and maintenance. In this study, we report that brain tumor stem cells can be identified from adult GBMs. These tumor stem cells form neurospheres, possess the capacity for self-renewal, express genes associated with neural stem cells (NSCs), generate daughter cells of different phenotypes from one mother cell, and differentiate into the phenotypically diverse populations of cells similar to those present in the initial GBM. Having a ...


Chromosomal Duplications And Cointegrates Generated By The Bacteriophage Lamdba Red System In Escherichia Coli K-12, Anthony R. Poteete, Anita C. Fenton, Ashwini Nadkarni Dec 2004

Chromosomal Duplications And Cointegrates Generated By The Bacteriophage Lamdba Red System In Escherichia Coli K-12, Anthony R. Poteete, Anita C. Fenton, Ashwini Nadkarni

Open Access Articles

BACKGROUND: An Escherichia coli strain in which RecBCD has been genetically replaced by the bacteriophage lambda Red system engages in efficient recombination between its chromosome and linear double-stranded DNA species sharing sequences with the chromosome. Previous studies of this experimental system have focused on a gene replacement-type event, in which a 3.5 kbp dsDNA consisting of the cat gene and flanking lac operon sequences recombines with the E. coli chromosome to generate a chloramphenicol-resistant Lac- recombinant. The dsDNA was delivered into the cell as part of the chromosome of a non-replicating lambda vector, from which it was released by ...


Global Expression Changes Resulting From Loss Of Telomeric Dna In Fission Yeast, Jeffrey G. Mandell, Jürg Bähler, Thomas A. Volpe, Robert A. Martienssen, Thomas R. Cech Dec 2004

Global Expression Changes Resulting From Loss Of Telomeric Dna In Fission Yeast, Jeffrey G. Mandell, Jürg Bähler, Thomas A. Volpe, Robert A. Martienssen, Thomas R. Cech

Chemistry & Biochemistry Faculty Contributions (1986-2018)

Background

Schizosaccharomyces pombe cells lacking the catalytic subunit of telomerase (encoded by trt1+) lose telomeric DNA and enter crisis, but rare survivors arise with either circular or linear chromosomes. Survivors with linear chromosomes have normal growth rates and morphology, but those with circular chromosomes have growth defects and are enlarged. We report the global gene-expression response of S. pombe to loss of trt1+.

Results

Survivors with linear chromosomes had expression profiles similar to cells with native telomeres, whereas survivors with circular chromosomes showed continued upregulation of core environmental stress response (CESR) genes. In addition, survivors with circular chromosomes had altered ...


Rhodobacter Capsulatus Porphobilinogen Synthase, A High Activity Metal Ion Independent Hexamer, David Bollivar Nov 2004

Rhodobacter Capsulatus Porphobilinogen Synthase, A High Activity Metal Ion Independent Hexamer, David Bollivar

Scholarship

No abstract provided.


Rhodobacter Capsulatus Porphobilinogen Synthase, A High Activity Metal Ion Independent Hexamer, David W. Bollivar, Cheryl Clauson, Rachel Lighthall, Siiri Forbes, Bashkim Kokona, Robert Fairman, Lenka Kundrat, Eileen K. Jaffe Nov 2004

Rhodobacter Capsulatus Porphobilinogen Synthase, A High Activity Metal Ion Independent Hexamer, David W. Bollivar, Cheryl Clauson, Rachel Lighthall, Siiri Forbes, Bashkim Kokona, Robert Fairman, Lenka Kundrat, Eileen K. Jaffe

David Bollivar

Background: The enzyme porphobilinogen synthase (PBGS), which is central to the biosynthesis of heme, chlorophyll and cobalamins, has long been known to use a variety of metal ions and has recently been shown able to exist in two very different quaternary forms that are related to metal ion usage. This paper reports new information on the metal ion independence and quaternary structure of PBGS from the photosynthetic bacterium Rhodobacter capsulatus. Results: The gene for R. capsulatus PBGS was amplified from genomic DNA and sequencing revealed errors in the sequence database. R. capsulatus PBGS was heterologously expressed in E. coli and ...


High-Resolution Serum Proteomic Patterns For Ovarian Cancer Detection, Keith A. Baggerly, Sarah R. Edmonson, Jeffrey S. Morris, Kevin R. Coombes Nov 2004

High-Resolution Serum Proteomic Patterns For Ovarian Cancer Detection, Keith A. Baggerly, Sarah R. Edmonson, Jeffrey S. Morris, Kevin R. Coombes

Jeffrey S. Morris

No abstract provided.


Embryonic Expression Of Pre-Initiation Dna Replication Factors In Xenopus Laevis, Brian Walter, Jonathan Henry Oct 2004

Embryonic Expression Of Pre-Initiation Dna Replication Factors In Xenopus Laevis, Brian Walter, Jonathan Henry

Brian Walter

We examined the expression of various DNA replication factors, including: cdc45, the factors of the GINS heterotetramer (Sld5, Psf1, Psf2, Psf3), and PCNA, in Xenopus laevis during embryonic development via whole mount in situ hybridization. For the most part, these factors were expressed in similar patterns, with some subtle variations, throughout development within the anterior CNS, pharyngeal arches, and various placodes. More significant variations were also observed, including expression of only Psf1 and Psf2 in the pronephros and unique Psf2 expression in the somitic mesoderm. Overall, these results suggest that common regulatory mechanisms are involved in the transcriptional deployment of ...


Short-Term Growth Responses To Ethylene In Arabidopsis Seedlings Are Ein3/Eil1 Independent, Brad Binder, Laura Mortimore, Anna Stepanova, Joseph Ecker, Anthony Bleecker Sep 2004

Short-Term Growth Responses To Ethylene In Arabidopsis Seedlings Are Ein3/Eil1 Independent, Brad Binder, Laura Mortimore, Anna Stepanova, Joseph Ecker, Anthony Bleecker

Brad M. Binder

Kinetic studies indicate there are two phases to growth inhibition by ethylene for the hypocotyls of etiolated Arabidopsis seedlings. Phase I is transient, while phase II results in sustained growth inhibition. The EIN2 membrane protein is required for both the first and second phases of growth inhibition by ethylene, while the transcription factors EIN3 and EIL1 are required for the second phase but not the first phase. The first phase lasts no more than 2 h. It is less sensitive to the ethylene response inhibitor 1-methylcyclopropene and more sensitive to ethylene than the second phase. The first phase shows adaptation ...


Structure And Bioactivity Of Neuropeptide F From The Human Parasites Schistosoma Mansoni And Schistosoma Japonicum, Judith E. Humphries, Michael J. Kimber, Yi-Wen Barton, Walter Hsu, Nikki J. Marks, Brett Greer, Pat Harriott, Aaron G. Maule, Timothy A. Day Sep 2004

Structure And Bioactivity Of Neuropeptide F From The Human Parasites Schistosoma Mansoni And Schistosoma Japonicum, Judith E. Humphries, Michael J. Kimber, Yi-Wen Barton, Walter Hsu, Nikki J. Marks, Brett Greer, Pat Harriott, Aaron G. Maule, Timothy A. Day

Biomedical Sciences Publications

The blood flukes Schistosoma mansoni and Schistosoma japonicuminflict immense suffering as agents of human schistosomiasis. Previous investigations have found the nervous systems of these worms contain abundant immunoreactivity to antisera targeting invertebrate neuropeptide Fs (NPFs) as well as structurally similar neuropeptides of the mammalian neuropeptide Y (NPY) family. Here, cDNAs encoding NPF in these worms were identified, and the mature neuropeptides from the two species differed by only a single amino acid. Both neuropeptides feature the characteristics common among NPFs; they are 36 amino acids long with a carboxyl-terminal Gly-Arg-X-Arg-Phe-amide and Tyr residues at positions 10 and ...


Nrage Regulates Life And Death Of Neural Progenitors, Stephen E. Kendall Aug 2004

Nrage Regulates Life And Death Of Neural Progenitors, Stephen E. Kendall

Electronic Theses and Dissertations

The development of the central nervous system requires the orchestration of numerous instructive and permissive cues. These factors are secreted from signaling centers and function in a concentration dependent manner that effects the proliferation, survival and differentiation of neural progenitors (NP) and their differentiated progeny. The family including bone morphogenetic proteins (BMPs) are key regulators of NP expansion and survival. However, once NP become committed to a neuronal fate and begin to differentiate they compete for limited amounts of neurotrophin that facilitate further growth and survival. Here we show that the p75 neurotrophin receptor interacting protein NRAGE is expressed in ...


The Euplotes Telomerase Subunit P43 Stimulates Enzymatic Activity And Processivity In Vitro, Stefan Aigner, Thomas R. Cech Jul 2004

The Euplotes Telomerase Subunit P43 Stimulates Enzymatic Activity And Processivity In Vitro, Stefan Aigner, Thomas R. Cech

Chemistry & Biochemistry Faculty Contributions (1986-2018)

Telomerase is a reverse transcriptase that synthesizes telomeric DNA repeats at the ends of eukaryotic chromosomes. Although it is minimally composed of a conserved catalytic protein subunit (TERT) and an RNA component, additional accessory factors present in the holoenzyme play crucial roles in the biogenesis and function of the enzyme complex. Telomerase from the ciliate Tetrahymenacan be reconstituted in active form in vitro. Using this system, we show that p43, a telomerase-specific La-motif protein from the ciliate Euplotes, stimulates activity and increases repeat addition processivity of telomerase. Activity enhancement by p43 requires its incorporation into a TERT•RNA•p43 ...


Liver-Specific Expression Of The Agouti Gene In Transgenic Mice Promotes Liver Carcinogenesis In The Absence Of Obesity And Diabetes, Alexander I. Kuklin, Randall L. Mynatt, Mitchell L. Klebig, Laura L. Kiefer, William O. Wilkison, Richard P. Woychik, Edward J. Michaud Jun 2004

Liver-Specific Expression Of The Agouti Gene In Transgenic Mice Promotes Liver Carcinogenesis In The Absence Of Obesity And Diabetes, Alexander I. Kuklin, Randall L. Mynatt, Mitchell L. Klebig, Laura L. Kiefer, William O. Wilkison, Richard P. Woychik, Edward J. Michaud

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Background

The agouti protein is a paracrine factor that is normally present in the skin of many species of mammals. Agouti regulates the switch between black and yellow hair pigmentation by signalling through the melanocortin 1 receptor (Mc1r) on melanocytes. Lethal yellow (Ay) and viable yellow (Avy) are dominant regulatory mutations in the mouse agouti gene that cause the wild-type protein to be produced at abnormally high levels throughout the body. Mice harboring these mutations exhibit a pleiotropic syndrome characterized by yellow coat color, obesity, hyperglycemia, hyperinsulinemia, and increased susceptibility to hyperplasia and carcinogenesis in numerous tissues, including ...


Food Based Approaches For A Healthy Nutrition In Africa, Mamoudou Hama Dicko May 2004

Food Based Approaches For A Healthy Nutrition In Africa, Mamoudou Hama Dicko

Pr. Mamoudou H. DICKO, PhD

The latest estimates of the FAO demonstrate the problems of the fight against hunger. These problems are manifested by the ever-increasing number of chronically undernourished people worldwide. Their numbers during the 1999-2001 period were estimated at about 840 million of which 798 million live in developing countries. Sub-Saharan Africa alone represented 198 million of those. In this part of Africa the prevalence of undernourishment ranges from 5-34%, causing growth retardation and insufficient weight gain among one third of the children under five years of age and resulting in a mortality of 5-15% among these children. Malnutrition resulting from undernourishment is ...


The Importance Of A Critical Protonation State And The Fate Of The Catalytic Steps In Class A Β-Lactamases And Penicillin-Binding Proteins, Dasantila Golemi-Kotra, Samy O. Meroueh, Choonkeun Kim, Sergei B. Vakulenko, Alexey Bulychev, Ann J. Stemmler, Timothy L. Stemmler, Shahriar Mobashery May 2004

The Importance Of A Critical Protonation State And The Fate Of The Catalytic Steps In Class A Β-Lactamases And Penicillin-Binding Proteins, Dasantila Golemi-Kotra, Samy O. Meroueh, Choonkeun Kim, Sergei B. Vakulenko, Alexey Bulychev, Ann J. Stemmler, Timothy L. Stemmler, Shahriar Mobashery

Biochemistry and Molecular Biology Faculty Publications

b-Lactamases and penicillin-binding proteins are bacterial enzymes involved in antibiotic resistance to b-lactam antibiotics and biosynthetic assembly of cell wall, respectively. Members of these large families of enzymes all experience acylation by their respective substrates at an active-site serine as the first step in their catalytic activities. A Ser-X-X-Lys sequence motif is seen in all these proteins and crystal structures demonstrate that the side chain functions of the serine and lysine are in contact with one another. Three independent methods were used in this report to address the question of the protonation state of this important lysine (Lys73) in the ...


The C. Elegans Heterochronic Gene Lin-46 Affects Developmental Timing At Two Larval Stages And Encodes A Relative Of The Scaffolding Protein Gephyrin, A. S.-R. Pepper, Jill E. Mccane, Kevin Kemper, Dennis Au Yeung, Rosalind C. Lee, Victor Ambros, Eric G. Moss Apr 2004

The C. Elegans Heterochronic Gene Lin-46 Affects Developmental Timing At Two Larval Stages And Encodes A Relative Of The Scaffolding Protein Gephyrin, A. S.-R. Pepper, Jill E. Mccane, Kevin Kemper, Dennis Au Yeung, Rosalind C. Lee, Victor Ambros, Eric G. Moss

Open Dartmouth: Faculty Open Access Articles

The succession of developmental events in the C. elegans larva is governed by the heterochronic genes. When mutated, these genes cause either precocious or retarded developmental phenotypes, in which stage-specific patterns of cell division and differentiation are either skipped or reiterated, respectively. We identified a new heterochronic gene, lin-46, from mutations that suppress the precocious phenotypes caused by mutations in the heterochronic genes lin-14 and lin-28. lin-46 mutants on their own display retarded phenotypes in which cell division patterns are reiterated and differentiation is prevented in certain cell lineages. Our analysis indicates that lin-46 acts at a step immediately downstream ...


Core Concepts In Biochemistry And Molecular Biology In An Integrated Mbbs Curriculum, M P. Iqbal Apr 2004

Core Concepts In Biochemistry And Molecular Biology In An Integrated Mbbs Curriculum, M P. Iqbal

Department of Biological & Biomedical Sciences

No abstract provided.


Toward Solving The Structure Of Cholesterol Oxidase H447e/E361q Double Mutant, Larryn Krause Apr 2004

Toward Solving The Structure Of Cholesterol Oxidase H447e/E361q Double Mutant, Larryn Krause

Life and Environmental Sciences Undergraduate Theses

Cholesterol oxidase, a bifunctional flavoenzyme facilitates the oxidation and isomerization of cholesterol. Wild type cholesterol oxidase has been crystallized, and its structure has been resolved to 0.95 A. Wild type cholesterol oxidase turns over cholesterol with such extreme efficiency that it is very difficult to crystallize the substrate-enzyme complex. Cholesterol oxidase H447E/E361Q double mutant, which binds cholesterol, but is unable to completely turn it over, was expressed, purified, and crystallized to obtain a crystal structure. Once solved, the structure of the cholesterol oxidase double mutant could then be used as a background structure for the crystallization of the ...


Origin Of Cooperativity In The Activation Of Fructose-1,6-Bisphosphatase By Mg2+, Scott W. Nelson, Richard B. Honzatko, Herbert J. Fromm Apr 2004

Origin Of Cooperativity In The Activation Of Fructose-1,6-Bisphosphatase By Mg2+, Scott W. Nelson, Richard B. Honzatko, Herbert J. Fromm

Biochemistry, Biophysics and Molecular Biology Publications

Fructose-1,6-bisphosphatase requires a divalent metal cation for catalysis, Mg2+being its most studied activator. Phosphatase activity increases sigmoidally with the concentration of Mg2+, but the mechanistic basis for such cooperativity is unknown. Bound magnesium cations can interact within a single subunit or between different subunits of the enzyme tetramer. Mutations of Asp118, Asp121, or Glu97 to alanine inactivate the recombinant porcine enzyme. These residues bind directly to magnesium cations at the active site. Three different hybrid tetramers of fructose-1,6-bisphosphatase, composed of one wild-type subunit and three subunits bearing one of the mutations above ...


Effects Of Estradiol And Tamoxifen On Leukocyte Distribution In Response To Restraint Stress In Mice (Mus Musculus), Julianna Duchesneau Apr 2004

Effects Of Estradiol And Tamoxifen On Leukocyte Distribution In Response To Restraint Stress In Mice (Mus Musculus), Julianna Duchesneau

Life and Environmental Sciences Undergraduate Theses

Selective estrogen receptor modulators (SERMs), drugs that either mimic or block the action of estrogen but do not have its side effects, have been under intense research since the early 20th century because of their distinct biological functions as antagonists and agonists in cells through their unique molecular conformations. Previous, unpublished research has found a correlation between a reduction in the leukocytic stress response in mice and injection with a natural form of estrogen, estradiol. The present study tested the effects of a SERM, tamoxifen, on the leukocyte distribution in mice after subjection to restraint stress. No difference was found ...


Molecular Profiling: Gene Expression Reveals Discrete Phases Of Lens Induction And Development In Xenopus Laevis, Brian Walter, Yimin Tian, Amy Garlisch, Maria Carinato, Matthew Elkins, Adam Wolfe, Jonathan Schaefer, Kimberly Perry, Jonathan Henry Mar 2004

Molecular Profiling: Gene Expression Reveals Discrete Phases Of Lens Induction And Development In Xenopus Laevis, Brian Walter, Yimin Tian, Amy Garlisch, Maria Carinato, Matthew Elkins, Adam Wolfe, Jonathan Schaefer, Kimberly Perry, Jonathan Henry

Brian Walter

No abstract provided.


Protein–Dna Hydrophobic Recognition In The Minor Groove Is Facilitated By Sugar Switching, Michael Y. Tolstorukov, Robert L. Jernigan, Victor B. Zhurkin Mar 2004

Protein–Dna Hydrophobic Recognition In The Minor Groove Is Facilitated By Sugar Switching, Michael Y. Tolstorukov, Robert L. Jernigan, Victor B. Zhurkin

Biochemistry, Biophysics and Molecular Biology Publications

Information readout in the DNA minor groove is accompanied by substantial DNA deformations, such as sugar switching between the two conformational domains, B-like C2′-endo and A-like C3′-endo. The effect of sugar puckering on the sequence-dependent protein–DNA interactions has not been studied systematically, however. Here, we analyzed the structural role of A-like nucleotides in 156 protein–DNA complexes solved by X-ray crystallography and NMR. To this end, a new algorithm was developed to distinguish interactions in the minor groove from those in the major groove, and to calculate the solvent-accessible surface areas in each groove ...


Beginning To Understand The End Of The Chromosome, Thomas R. Cech Jan 2004

Beginning To Understand The End Of The Chromosome, Thomas R. Cech

Chemistry & Biochemistry Faculty Contributions (1986-2018)

In their 1985 Cell paper, Greider and Blackburn announced the discovery of an enzyme that extended the DNA at chromosome telomeres in the ciliate, Tetrahymena. Since then, there has been an explosion of knowledge about both the RNA and protein subunits of this unusual ribonucleoprotein enzyme in organisms ranging from the ciliates to yeast to humans. The regulation of telomerase is now understood to take place both at the level of synthesis of the enzyme and via the state of its substrate, the telomere itself. The roles of telomerase in both cellular immortality and cancer are vibrant areas of current ...


Overexpression Of An Arabidopsis Formin Stimulates Supernumerary Actin Cable Formation From Pollen Tube Cell Membrane, Alice Cheung, H. Wu Jan 2004

Overexpression Of An Arabidopsis Formin Stimulates Supernumerary Actin Cable Formation From Pollen Tube Cell Membrane, Alice Cheung, H. Wu

Alice Cheung

Formins, actin-nucleating proteins that stimulate the de novo polymerization of actin filaments, are important for diverse cellular and developmental processes, especially those dependent on polarity establishment. A subset of plant formins, referred to as group I, is distinct from formins from other species in having evolved a unique N-terminal structure with a signal peptide, a Pro-rich, potentially glycosylated extracellular domain, and a transmembrane domain. We show here that overexpression of the Arabidopsis formin AFH1 in pollen tubes induces the formation of arrays of actin cables that project into the cytoplasm from the cell membrane and that its N-terminal structure targets ...


Effects Of Hu Binding On The Equilibrium Cyclization Of Mismatched, Curved And Normal Dna, Ishita Mukerji Jan 2004

Effects Of Hu Binding On The Equilibrium Cyclization Of Mismatched, Curved And Normal Dna, Ishita Mukerji

Division III Faculty Publications

No abstract provided.


A Hidden Markov Model Capable Of Predicting And Discriminating Β-Barrel Outer Membrane Proteins, Pantelis G. Bagos, Theodore D. Liakopoulos, Ioannis C. Spyropoulos, Stavros J. Hamodrakas Jan 2004

A Hidden Markov Model Capable Of Predicting And Discriminating Β-Barrel Outer Membrane Proteins, Pantelis G. Bagos, Theodore D. Liakopoulos, Ioannis C. Spyropoulos, Stavros J. Hamodrakas

Pantelis Bagos

BACKGROUND: Integral membrane proteins constitute about 20-30% of all proteins in the fully sequenced genomes. They come in two structural classes, the alpha-helical and the beta-barrel membrane proteins, demonstrating different physicochemical characteristics, structure and localization. While transmembrane segment prediction for the alpha-helical integral membrane proteins appears to be an easy task nowadays, the same is much more difficult for the beta-barrel membrane proteins. We developed a method, based on a Hidden Markov Model, capable of predicting the transmembrane beta-strands of the outer membrane proteins of gram-negative bacteria, and discriminating those from water-soluble proteins in large datasets. The model is trained ...


A Drosophila Protein-Interaction Map Centered On Cell-Cycle Regulators, Clement A. Stanyon, Guozhen Liu, Bernardo A. Mangiola, Nishi Patel, Loic Giot, Bing Kuang, Huamei Zhang, Jinhui Zhong, Russell L. Finley Jr Jan 2004

A Drosophila Protein-Interaction Map Centered On Cell-Cycle Regulators, Clement A. Stanyon, Guozhen Liu, Bernardo A. Mangiola, Nishi Patel, Loic Giot, Bing Kuang, Huamei Zhang, Jinhui Zhong, Russell L. Finley Jr

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Maps depicting binary interactions between proteins can be powerful starting points for understanding biological systems. A proven technology for generating such maps is high-throughput yeast two-hybrid screening. In the most extensive screen to date, a Gal4-based two-hybrid system was used recently to detect over 20,000 interactions among Drosophila proteins. Although these data are a valuable resource for insights into protein networks, they cover only a fraction of the expected number of interactions.

Results

To complement the Gal4-based interaction data, we used the same set of Drosophila open reading frames to construct arrays for a LexA-based two-hybrid system ...


Integrated Allosteric Regulation In The S. Cerevisiae Carbamylphosphate Synthetase – Aspartate Transcarbamylase Multifunctional Protein, Valã©Rie Serre, Bernadette Penverne, Jean-Luc Souciet, Serge Potier, Hedeel Guy, David Evans, Patrick Vicart, Guy Hervã© Jan 2004

Integrated Allosteric Regulation In The S. Cerevisiae Carbamylphosphate Synthetase – Aspartate Transcarbamylase Multifunctional Protein, Valã©Rie Serre, Bernadette Penverne, Jean-Luc Souciet, Serge Potier, Hedeel Guy, David Evans, Patrick Vicart, Guy Hervã©

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

The S. cerevisiae carbamylphosphate synthetase – aspartate transcarbamylase multifunctional protein catalyses the first two reactions of the pyrimidine pathway. In this organism, these two reactions are feedback inhibited by the end product UTP. In the present work, the mechanisms of these integrated inhibitions were studied.

Results

The results obtained show that the inhibition is competitive in the case of carbamylphosphate synthetase and non-competitive in the case of aspartate transcarbamylase. They also identify the substrate whose binding is altered by this nucleotide and the step of the carbamylphosphate synthetase reaction which is inhibited. Furthermore, the structure of the domains catalyzing ...


Dissecting The Loci Of Low-Level Quinine Resistance In Malaria Parasites, Michael T. Ferdig, Roland A. Cooper, Jianbing Mu, Bingbing Deng, Deirdre A. Joy, Xin-Zhuan Su, Thomas E. Wellems Jan 2004

Dissecting The Loci Of Low-Level Quinine Resistance In Malaria Parasites, Michael T. Ferdig, Roland A. Cooper, Jianbing Mu, Bingbing Deng, Deirdre A. Joy, Xin-Zhuan Su, Thomas E. Wellems

Biological Sciences Faculty Publications

Quinine (QN) remains effective against Plasmodium falciparum, but its decreasing efficacy is documented from different continents. Multiple genes are likely to contribute to the evolution of QN resistance. To locate genes contributing to QN response variation, we have searched a P. falciparum genetic cross for quantitative trait loci (QTL). Results identify additive QTL in segments of chromosomes (Chrs) 13, 7 and 5, and pairwise effects from two additional loci of Chrs 9 and 6 that interact, respectively, with the QTL of Chrs 13 and 7. The mapped segments of Chrs 7 and 5 contain pfcrt, the determinant of chloroquine resistance ...


Actr/Aib1 Functions As An E2f1 Coactivator To Promote Breast Cancer Cell Proliferation And Antiestrogen Resistance, Maggie C. Louie, June X. Zou, Alina Rabinovich, Hong-Wu Chen Jan 2004

Actr/Aib1 Functions As An E2f1 Coactivator To Promote Breast Cancer Cell Proliferation And Antiestrogen Resistance, Maggie C. Louie, June X. Zou, Alina Rabinovich, Hong-Wu Chen

Collected Faculty and Staff Scholarship

Overexpression or amplification of ACTR (also named AIB1, RAC3, p/CIP, TRAM-1, and SRC-3), a member of the p160 family of coactivators for nuclear hormone receptors, has been frequently detected in multiple types of human tumors, including breast cancer. However, its role in cancer cell proliferation and the underlying mechanism are unclear. Here, we show that overexpression of ACTR not only enhances estrogen-stimulated cell proliferation but also, more strikingly, completely negates the cell cycle arrest effect by tamoxifen and pure antiestrogens. Unexpectedly, we found that ACTR directly interacts, through its N-terminal domain, with E2F1 and is recruited to E2F target ...


Can Martian Life Exist Under Dry Conditions?, Michael Kendrick Jan 2004

Can Martian Life Exist Under Dry Conditions?, Michael Kendrick

Inquiry: The University of Arkansas Undergraduate Research Journal

Recently, we have begun to hear more and more about news coming from Mars. With the recent confirmation of evidence of liquid water in Mars' past, evidence indicating liquid water in Mars' present, and as many missions planned for this decade and the next than have successfully reached the planet in the last 40 years, life on Mars is beginning to become a more relevant issue in our study of the planet. Although there have been no indications of multicellular life on Mars, there may be a possibility of microbial life in the subsurface. Since it appears that all of ...