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

Biochemistry, Biophysics, and Structural Biology Commons

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

13,256 Full-Text Articles 28,720 Authors 1,658,542 Downloads 266 Institutions

All Articles in Biochemistry, Biophysics, and Structural Biology

Faceted Search

13,256 full-text articles. Page 470 of 471.

Unraveling The Molecular Mechanisms Of Insect Diversity, Steven Michael Hrycaj 2010 Wayne State University

Unraveling The Molecular Mechanisms Of Insect Diversity, Steven Michael Hrycaj

Wayne State University Dissertations

ABSTRACT

UNRAVELING THE MOLECULAR MECHANISMS OF INSECT DIVERSITY

by

STEVEN MICHAEL HRYCAJ

April 2010

Advisor: Dr. Aleksandar Popadic´

Major: Biological Sciences

Degree: Doctor of Philosophy

While it has long been recognized that the arthropods represent the most diverse animal phylum, the molecular bases defining these large-scale differences in body plans and appendages are only now becoming clear. Specifically, the recent merger between the fields of evolutionary and developmental biology ("evo-devo") have provided several examples illustrating that this extraordinary diversification may be due to evolved variation(s) in the developmental networks that control the formation of these structures. In addition, the ...


Single Molecule Studies Of Spliceosomal Snrnas U2-U6, Zhuojun Guo 2010 Wayne State University

Single Molecule Studies Of Spliceosomal Snrnas U2-U6, Zhuojun Guo

Wayne State University Dissertations

Spliceosomes catalyze the maturation of precursor mRNAs in organisms ranging

from yeast to humans. Their catalytic core comprises three small nuclear RNAs (U2, U5

and U6) involved in substrate positioning and catalysis. It has been postulated, but never

shown experimentally, that the U2-U6 complex adopts at least two conformations that

reflect different activation states. We have used single-molecule fluorescence to probe the

structural dynamics of a protein-free RNA complex modeling U2-U6 from yeast and

mutants of highly conserved regions of U2-U6. Our data show the presence of at least

three distinct conformations in equilibrium. The minimal folding pathway consists of ...


Meiotic Dna Re-Replication And The Recombination Checkpoint, Nicole Ann Najor 2010 Wayne State University

Meiotic Dna Re-Replication And The Recombination Checkpoint, Nicole Ann Najor

Wayne State University Dissertations

Progression through meiosis occurs through a strict sequence of events, so that one round of DNA replication precedes programmed recombination and two nuclear divisions. Cyclin dependent kinase 1 (Cdk1) is required for meiosis, and any disruption in its activity leads to meiotic defects. The Cdk1 inhibitor, Sic1, regulates the G1-S transition in the mitotic cell cycle and the analogous transition in meiosis. We have employed a form of Sic1, Sic1deltaPHA, that is mutated at multiple phosphorylation sites and resistant to degradation. Meiosis specific expression of Sic1deltaPHA disrupts Cdk1 activity and leads to significant accumulation of over replicated DNA ...


Creg1 And Its Enhancement Of P16ink4a-Induced Senescence, Benchamart Moolmuang 2010 Wayne State University

Creg1 And Its Enhancement Of P16ink4a-Induced Senescence, Benchamart Moolmuang

Wayne State University Dissertations

Bypassing cellular senescence, an irreversible growth arrest of cells that is activated in normal cells to become immortal is one of the prerequisites for carcinogenesis. Cellular senescence can be triggered by shortening of telomeres and certain cellular stresses. Using spontaneously immortalized Li-Fraumeni Syndrome (LFS) fibroblasts, we found that CREG1 (Cellular Repressor of E1A-stimulated Genes1) is one of genes whose expression fit the criteria of senescence-associated genes, decreased expression during immortalization and increased in senescence. Moreover, we found that epigenetic mechanisms regulate CREG1 expression in LFS fibroblasts. CREG1 is a secreted glycoprotein that was shown to bind Rb-family pocket proteins and ...


Evolution Of Lactate Dehydrogenase Genes In Primates, With Special Consideration Of Nucleotide Organization In Mammalian Promoters, Zack Papper 2010 Wayne State University

Evolution Of Lactate Dehydrogenase Genes In Primates, With Special Consideration Of Nucleotide Organization In Mammalian Promoters, Zack Papper

Wayne State University Dissertations

Concomitant with an increase in brain volume and mass, the allocation of energetic resources to the brain increased during stem anthropoid evolution, leading to humans. One mechanism by which this allocation may have occurred is through greater use of lactate as a neuronal fuel. Both the production of lactate, and conversion to pyruvate for use in aerobic metabolism, are catalyzed, in part, by the tetrameric enzyme lactate dehydrogenase (LDH). The two primary LDH genes, LDHA and LDHB, confer different rates of substrate turnover to the LDH enzyme, and these rates lend to the argument that LDHA supports anaerobic while LDHB ...


Enzymology And Medicinal Chemistry Of N5-Carboxyaminoimidazole Ribonucleotide Synthetase : A Novel Antibacterial Target, Hanumantharao Paritala 2010 Wayne State University

Enzymology And Medicinal Chemistry Of N5-Carboxyaminoimidazole Ribonucleotide Synthetase : A Novel Antibacterial Target, Hanumantharao Paritala

Wayne State University Dissertations

N5-Carboxyaminoimidazole ribonucleotide synthetase (N5-CAIR synthetase), a key enzyme in microbial de novo purine biosynthesis, catalyzes the conversion of aminoimidazole ribonucleotide (AIR) to N5-CAIR. To date, this enzyme has been observed only in microorganisms, and thus, it represents an ideal target for antimicrobial drug development. Here we report structural and functional studies on the Aspergillus clavatus N5-CAIR synthetase and identification of inhibitors for the enzyme. In collaboration with Dr. Hazel Holden of the University of Wisconsin, the three-dimensional structure of Aspergillus clavatus N5-CAIR synthetase was solved in the presence of either Mg2ATP or MgADP and AIR. These structures, determined to 2 ...


Regulatory And Functional Aspects Of Foxo3a Transcription Factor And Their Implications In Prostate Cancer, Melissa Elise Dobson 2010 Wayne State University

Regulatory And Functional Aspects Of Foxo3a Transcription Factor And Their Implications In Prostate Cancer, Melissa Elise Dobson

Wayne State University Dissertations

The P13K/Akt pathway is a critical mediator of growth factor signaling involving many cellular functions. The deregulation of this pathway has been shown to be involved in the development of various cancers. One of the main targets of this pathway is FoxO3a, a transcription factor whose target genes are involved in important cellular processes such as apoptosis, cell cycle control, and glucose metabolism. FoxO3a is regulated by various post translational modifications including acetylation, ubiquitination and phosphorylation. The transcription factor is directly phosphorylated by Akt on 3 residues: Threonine 32, Serine 253 and Serine 315. Phosphorylation by Akt generates binding ...


The Interictal State In Epilepsy And Behavior, Daniel Tice Barkmeier 2010 Wayne State University

The Interictal State In Epilepsy And Behavior, Daniel Tice Barkmeier

Wayne State University Dissertations

Epilepsy is one of the most common neurological diseases, affecting up to 1% of the world population. Epilepsy remains poorly understood and there are currently no medications to cure it. Patients with epilepsy have both seizures as well as another type of abnormal activity between seizures, known as interictal spikes. Interictal spikes have thus far been poorly researched, yet growing evidence supports an important role for them in epilepsy. In this project, we first show the high variability between reviewers in marking interictal spikes on intracranial EEG, and then develop and test an automated detection method to solve this problem ...


Molecular Mechanisms Of Pressure-Stimulated Cancer Cell Signaling, Christina Downey 2010 Wayne State University

Molecular Mechanisms Of Pressure-Stimulated Cancer Cell Signaling, Christina Downey

Wayne State University Dissertations

ABSTRACT

MOLECULAR MECHANISMS OF PRESSURE-STIMULATED CANCER CELL SIGNALING

by

CHRISTINA DOWNEY

June 2010

Advisor: Dr. Marc Basson, MD, PhD

Major: Cancer Biology

Degree: Doctor of Philosophy

Increased extracellular pressure stimulates cancer cell adhesion by a mechanism that is dependent upon beta-1-integrin activation, an intact cytoskeleton, and FAK and Src activation. By a different mechanism, increased extracellular pressure modulates cancer cell proliferation in a manner that is regulated by protein kinase C, but not Src or an intact cytoskeleton. Previous studies from our laboratory have shown that paxillin is a necessary mediator in the pathway by which pressure stimulates adhesion; however ...


Towards An Understanding Of The Etiology Of Abdominal Aortic Aneurysms: Identification Of Genes Implicated In Aaa Risk And Development, John Hunt Lillvis 2010 Wayne State University

Towards An Understanding Of The Etiology Of Abdominal Aortic Aneurysms: Identification Of Genes Implicated In Aaa Risk And Development, John Hunt Lillvis

Wayne State University Dissertations

Abdominal aortic aneurysm (AAA) is a common disease for which mechanisms of formation are still not well understood. Despite a strong genetic component to AAA risk, specific risk alleles are still largely unidentified. AAA is also a localized disease with a majority occurring in the infrarenal abdominal aorta and is six times more common than aneurysms of the thoracic aorta. To determine whether risk alleles are present in functional positional candidate genes. we: 1. performed a genetic association study using DNA from AAA cases and controls in ten candidate genes and 2. performed exon sequencing on three genes with evidence ...


Investigating The Metal Binding Sites In Znta, A Zinc Transporting Atpase, Sandhya Muralidharan 2010 Wayne State University

Investigating The Metal Binding Sites In Znta, A Zinc Transporting Atpase, Sandhya Muralidharan

Wayne State University Dissertations

ZntA from Escherichia coli is a member of the PIBtype ATPase family of transporters. The PIB-type ATPase pumps maintain cellular homeostasis of heavy metals such as Zn2+, Co2+, Cu2+, Cu+, and mediate resistance to toxic metals such as Pb2+, Cd2+ and Ag+. ZntA confers resistance to Pb2+, Cd2+, and Zn2+ by pumping these ions out of the cytoplasm. ZntA has two metal binding sites, one in the hydrophilic N-terminal domain and the other in the transmembrane region. The cysteine-rich N-terminal domain has ~110 amino acids and the conserved ...


Tracking Profiles Of Genomic Instability In Spontaneous Transformation And Tumorigenesis, Lesley Lawrenson 2010 Wayne State University

Tracking Profiles Of Genomic Instability In Spontaneous Transformation And Tumorigenesis, Lesley Lawrenson

Wayne State University Dissertations

The dominant paradigm for cancer research focuses on the identification of specific genes for cancer causation and for the discovery of therapeutic targets. Alternatively, the current data emphasize the significance of karyotype heterogeneity in cancer progression over specific gene-based causes of cancer. Variability of a magnitude significant to shift cell populations from homogeneous diploid cells to a mosaic of structural and numerical chromosome alterations reflects the characteristic low-fidelity genome transfer of cancer cell populations. This transition marks the departure from micro-evolutionary gene-level change to macro-evolutionary change that facilitates the generation of many unique karyotypes within a cell population. Considering cancer ...


Parity Is Associated With An Expanded Macrophage Population In The Mammary Gland, Wei Zhao, Clinton J. Grubbs, Ronald K. Myers, Marit Nilsen-Hamilton 2010 Iowa State University

Parity Is Associated With An Expanded Macrophage Population In The Mammary Gland, Wei Zhao, Clinton J. Grubbs, Ronald K. Myers, Marit Nilsen-Hamilton

Biochemistry, Biophysics and Molecular Biology Publications

Pregnancy is a well established protective factor against breast cancer. One explanation for protection is the increased differentiation status of the parous epithelium. However, this does not explain the association of parity with increased aggressiveness of breast cancers, particularly cancers that occur soon after pregnancy. Because tumor aggressiveness can be influenced by the cell population that surrounds the mammary epithelium, we examined the potential role of the immune system in establishing a long-term difference between the mammary glands of primiparous and virgin animals. Specific mRNA levels, enzyme activities and antigen expressing cells were quantified in primiparous and virgin mammary glands ...


Induction Of Interferon And Interferon Signaling Pathways By Replication Of Defective Interfering Particle Rna In Cells Constitutively Expressing Vesicular Stomatitis Virus Replication Proteins, Debasis Panda, Phat X. Dinh, Lalit Beura, Asit K. Pattnaik 2010 University of Nebraska - Lincoln

Induction Of Interferon And Interferon Signaling Pathways By Replication Of Defective Interfering Particle Rna In Cells Constitutively Expressing Vesicular Stomatitis Virus Replication Proteins, Debasis Panda, Phat X. Dinh, Lalit Beura, Asit K. Pattnaik

Papers in Veterinary and Biomedical Science

We show here that replication of defective interfering (DI) particle RNA in HEK293 cells stably expressing vesicular stomatitis virus (VSV) replication proteins potently activates interferon (IFN) and IFN signaling pathways through upregulation of IFN- promoter, IFN-stimulated response element (ISRE) promoter, and NF-κB promoter activities. Replication of DI particle RNA, not mere expression of the viral replication proteins, was found to be critical for induction of IFN and IFN signaling. The stable cells supporting replication of DI RNA described in this report will be useful in further examining the innate immune signaling pathways and the host cell functions in viral genome ...


Towards An Understanding Of The Herpes Simplex Virus Type 1 Latency-Reactivation Cycle, Guey-Chuen Perng, Clinton Jones 2010 Emory University School of Medicine

Towards An Understanding Of The Herpes Simplex Virus Type 1 Latency-Reactivation Cycle, Guey-Chuen Perng, Clinton Jones

Papers in Veterinary and Biomedical Science

Infection by herpes simplex virus type 1 (HSV-1) can cause clinical symptoms in the peripheral and central nervous system. Recurrent ocular shedding can lead to corneal scarring and vision loss making HSV-1 a leading cause of corneal blindness due to an infectious agent. The primary site of HSV-1 latency is sensory neurons within trigeminal ganglia. Periodically, reactivation from latency occurs resulting in virus transmission and recurrent disease. During latency, the latency-associated transcript (LAT) is abundantly expressed. LAT expression is important for the latency-reactivation cycle in animal models, in part, because it inhibits apoptosis, viral gene expression, and productive infection. A ...


Method For Identification Of Virulence Determinants, Raul G. Barletta, Beth Harris 2010 Lincoln, NE

Method For Identification Of Virulence Determinants, Raul G. Barletta, Beth Harris

Papers in Veterinary and Biomedical Science

Disclosed are methods for the determination of virulence determinants in bacteria and in particular bacteria of the genus Mycobacterium. Also disclosed are compositions and methods for stimulating an immune response in an animal using bacteria and virulence determinants identified by the methods of the present invention.


Inhibition Of Cell Invasion By Targeting Pld, Terry C. Farkaly 2010 Wright State University

Inhibition Of Cell Invasion By Targeting Pld, Terry C. Farkaly

Browse all Theses and Dissertations

Phospholipase D (PLD) is a crucial signaling enzyme involved in many cellular processes. The catalytic activity of PLD is essential for the production of Phosphatidic Acid (PA), a critical second messenger in cell signaling cascades downstream. Using the highly invasive rat mammary adenocarcinoma cell line mTLn3 as a metastatic model, we investigated the proficiency of these cells to invade using matrigels that mimic the basement membrane of the extracellular matrix (ECM), their activity through PLD enzymatic assays, as well as the potency of our potential inhibitors to inhibit PLD-mediated cell invasion and lipase activity. This study reveals that PLD-mediated cell ...


Genetic Studies Of Genes Involved In The Initiation Of Dna Replication In The Fission Yeast Schizosaccharomyces Pombe, Zhuo Wang 2010 Wright State University

Genetic Studies Of Genes Involved In The Initiation Of Dna Replication In The Fission Yeast Schizosaccharomyces Pombe, Zhuo Wang

Browse all Theses and Dissertations

The initiation of DNA replication is a highly conserved process in all eukaryotes. However, the underlying mechanism is not well understood. Genetic studies in the fission yeast S. pombe have contributed greatly to and will continue to provide insights to our understanding of this important biological process.

In the first chapter, we have used a complementary method to test three recently identified human replication proteins DUE-B, Ticrr/Treslin, and GEMC1 as the candidate functional homologue of Sld3 in S. pombe. Sld3 is an essential replication initiation protein discovered in yeasts. Since no apparent sequence similarity can be found, its homologue ...


Patterns Of Apoptotic Poly(Adp-Ribose) Polymerase Cleavage Induced By Laromustine And Its Analogs, Adam N. Paine 2010 Colby College

Patterns Of Apoptotic Poly(Adp-Ribose) Polymerase Cleavage Induced By Laromustine And Its Analogs, Adam N. Paine

Honors Theses

The anticancer prodrug Laromustine (VNP40101M) has produced promising remission rates in clinical trials among leukemic patients relative to currently available chemotherapeutics. Such improvements demand that the agent’s mechanism of action be elucidated. This study aimed to determine the role of poly(ADP-ribose) polymerase (PARP) in Laromustine-induced cell death. Previous studies indicated that the methyl isocyanate produced upon activation of Laromustine is largely responsible for its effective induction of apoptosis. Results reported herein strongly support the activation of a PARP-dependent apoptotic pathway by Laromustine’s carbamoylating and chlorethylating subspecies. Furthermore, it is evident that the Laromustine-induced PARP-dependent apoptosis is primarily ...


P450s In The Biosynthesis Of Diterpenoid Phytoalexins In Rice, Qiang Wang 2010 Iowa State University

P450s In The Biosynthesis Of Diterpenoid Phytoalexins In Rice, Qiang Wang

Graduate Theses and Dissertations

Rice (Oryza sativa) is an important food crop and produces more than fifteen labdane-related diterpenoid natural products as antibiotics against plant pathogens, for example, against the devastating blast disease pathogen Magnaprothe grisea. The biosynthesis of these labdane-related diterpenoid phytoalexins has been partially clarified, as early enzymatic genes involved in their biosynthesis have been identified, but the downstream pathways from the inactive diterpene olefin precursors to bioactive diterpenoid natural products have not been identified, which limits our understanding and ability to engineer production of these important natural products. Previous work defined two functional diterpenoid biosynthetic gene clusters in rice that include ...


Digital Commons powered by bepress