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Full-Text Articles in Molecular Biology

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

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

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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 ...


Characterization Of Three Mutations In Conserved Domain Of Subunit Iii Of Cytochrome C Oxidase From Rhodobacter Sphaeroides, Rachel Omolewu Jan 2010

Characterization Of Three Mutations In Conserved Domain Of Subunit Iii Of Cytochrome C Oxidase From Rhodobacter Sphaeroides, Rachel Omolewu

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Cytochrome c oxidase (COX) is the final electron acceptor in mitochondrial respiratory chain and in many bacterial species including Rhodobacter sphaeroides. Electron transfer is coupled with the pumping of protons across the membrane. Previous work has shown that reaction of beef COX with dicyclohexylcarbodiimide (DCCD) resulted in an inhibition of proton translocation by covalently binding to the conserved amino acid residue E90 located in a nonpolar region of subunit III (SIII). E90 is involved in a bonding pair with another conserved residue H212, possibly connected by a salt bridge or a hydrogen bond in the three dimensional structure of SIII ...


P63 And Vdr Are Regulated By Vitamin D (Vd3) And Uv Signaling, Andrew J. Whitlatch Jan 2010

P63 And Vdr Are Regulated By Vitamin D (Vd3) And Uv Signaling, Andrew J. Whitlatch

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Skin cancers, such as squamous cell carcinoma (SCC), develop from accumulated mutations as a result of excessive exposure to Ultraviolet B (UVB) radiation. Intriguingly, UVB also catalyzes the synthesis of 1alpha, 25-dihydroxy Vitamin D3 (VD3), the hormonally active form of Vitamin D. Downstream VD3 signaling has been associated with promoting the inhibition of cell cycle progression, regulating calcium homeostasis, and inducing differentiation and apoptosis. VD3 mediates these processes via genomic mechanisms through interaction with its cognate receptor, the Vitamin D Receptor, (VDR). In addition, it was recently discovered that VD3 reduces UVB-mediated phosphorylation of the SAPK/c-Jun N-terminal kinase (JNK ...


Dose-Dependent Effects Of Oxygen On Metabolism In Rat Cortico-Hippocampal Brain Tissue Slices, Jennifer Lynne Hollyfield Jan 2009

Dose-Dependent Effects Of Oxygen On Metabolism In Rat Cortico-Hippocampal Brain Tissue Slices, Jennifer Lynne Hollyfield

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Studies have shown that 95% oxygen increases neuronal excitability and ROS production. We wanted to investigate the dose-dependent effects of oxygen on brain slice metabolism. We exposed rat brain cortico-hippocampal tissue slices to 0.40, 0.95, and 4.50 ATA O2 for 60 minutes, made dual-phase tissue extracts, and used multi-nuclear NMR experiments to elucidate the slice metabolism. We found that low doses of oxygen may shift metabolism toward anaerobic glycolysis. Elevated lactate suggests this shift, along with elevated ratios of NAD+/NADH which may drive the reactions toward the production of lactate. The results also suggest that high ...


Due-B, A New Human Dna Replication Protein, Is The Functional Homolog Of S. Cerevisiae Sld3, Jianhong Yao Jan 2009

Due-B, A New Human Dna Replication Protein, Is The Functional Homolog Of S. Cerevisiae Sld3, Jianhong Yao

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DNA unwinding elements (DUEs) are commonly found at DNA replication origins. The DUE binding protein (DUE-B) is crucial for the initiation of DNA replication in eukaryotes. The unique 59 amino acid C-terminal part of DUE-B shares nearly 50% similarity with yeast the C-terminus of Sld3. DUE-B plays a key role in eukaryotic DNA replication because it is required for the loading of Cdc45, the MCM helicase activator, on chromatin. Here we show that DUE-B, just like yeast Sld3, binds to Cdc45 and TopBP1 through its C-terminus in Sf9 cells and in vitro. We also show that DUE-B, Cdc45 and TopBP1 ...


Mdm2 Amplification In Nih3t3l1 Preadipocytes Leads To Mdm2 Elevation In Terminal Adipogenesis, Vaughn Litteral Jan 2008

Mdm2 Amplification In Nih3t3l1 Preadipocytes Leads To Mdm2 Elevation In Terminal Adipogenesis, Vaughn Litteral

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The p53 protein is a tumor suppressor protein that is mutated or non-functional in nearly all cancers. The Mdm2 protein has the ability to functionally inactivate p53 and these two proteins have been studied extensively in the context of cellular proliferation. In this study, expression of the murine double minute 2 (mdm2) gene was examined in the mouse NIH3T3L1 cell line. Under the proper conditions, the immortalized NIH3T3L1 cells have the ability to differentiate from fibroblasts to adipocytes (Green et al., 1975). This well characterized cell line provides an excellent model to study mdm2 in differentiation. While evaluating the regulation ...


In Search For New P53 Regulated Genes, Meldrick Daniel Mpagi Jan 2008

In Search For New P53 Regulated Genes, Meldrick Daniel Mpagi

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The p53 tumor suppressor protein has the ability to transactivate its target genes whose gene products are involved in carrying out cell cycle arrest, apoptosis, DNA repair, and senescence. Here, I report that two genes may be p53 regulated. Utilizing a microarray method to search for novel p53 target genes, I was able to identify a possible transcriptional target of p53 being solute carrier family 1a1 (SLC1a1). Along with that finding I also identified an E2F-target gene, minichromosome maintenance 10 (MCM10), as being p53 regulated. Gene expression profiling of MCF7 breast cancer cells treated with RNAi targeting Hdm2 and HdmX ...


Validation Of A Custom-Made Microarray To Study Human Intestinal Microflora, Harshavardhan Kenche Jan 2008

Validation Of A Custom-Made Microarray To Study Human Intestinal Microflora, Harshavardhan Kenche

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Intestinal microflora refers to all the different species of bacteria that reside in the human gut and is an important organ of the human body because almost all the digestive reactions of the host occur in the intestine. The bacteria of the intestine play a key role in this process by supplementing the intestine with various enzymes and proteins that are required for the digestive process. At the same time, these bacteria were shown to be implicated in a variety of gastrointestinal disorders like Irritable Bowel Syndrome, Inflammatory Bowel Disorder and Gastrointestinal Cancer, but with the current knowledge about the ...


Nmr Analyses Show Tcdd Elicits Differences In Hepatic Metabolism In Female C57bl/6 Mice And Sprague-Dawley Rats, Meghan Katherine Makley Jan 2008

Nmr Analyses Show Tcdd Elicits Differences In Hepatic Metabolism In Female C57bl/6 Mice And Sprague-Dawley Rats, Meghan Katherine Makley

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TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) elicits tissue-, sex-, and species-specific effects. This study compares the hepatic response to an oral dose of TCDD in immature ovariectomized (i.o.) C57BL/6 mice (30 µg/kg) and i.o. Sprague-Dawley rats (10 µg/kg), at 72, 120, and 168 h post-dose. Hepatic lipid extracts were analyzed by 13C and 31P NMR, and aqueous extracts by 1H and 31P NMR.

Consistent with increased lipid content in mice (p≤0.05), TCDD induced increases in hepatic triacylglycerides (TAG), cholesterol, and fatty acids. Principal component analysis of 13C ...


Transcriptional Regulation Of Lamb3 By P53, Meghna Jani Jan 2008

Transcriptional Regulation Of Lamb3 By P53, Meghna Jani

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The p53 tumor-suppressor plays a very important role in the prevention of cancer and it is known that about 50% of all human tumors possess p53 mutations. Although mutations in p53 are most prevalent in human cancers, inactivation of wild-type p53 occurs through many different mechanisms that are independent of p53 mutation or deletion. In an effort to determine novel p53 target genes, our lab employed a microarray method in which p53 was re-activated by RNAi mediated knockdown of Hdm2 and HdmX in MCF7 human breast cancer cell line, harboring wild-type p53 and elevated levels of Hdm2 and HdmX. Gene ...


Due-B In Chromatin And Nuclear Speckles, Nadia Katrangi Jan 2007

Due-B In Chromatin And Nuclear Speckles, Nadia Katrangi

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The DNA unwinding element binding protein (DUE-B) was first identified by using a yeast one hybrid screen with the DNA unwinding element (DUE) from the c-myc origin as bait. DUE-B's orthologue in the yeast Saccharomyces cerevisiae lacks the last 60 C-terminal amino acids and has been identified as a D-tyrosyl-tRNA deacylase. A substantial group of evidence suggests a role for DUE-B in the regulation of replication initiation. Here we show that DUE-B is focused in nuclear speckles and colocalizes with spliceosome associated protein 145 (SAP145), an mRNA splicing factor 3B subunit. Mass spectrometry results show that SAP145 co-purifies with ...


Differential Effects Of Mutant Tap63Γ On Transactivation Of P53 And/Or P63 Responsive Genes And Their Effects On Global Gene Expression, Shama Khan Khokhar Jan 2007

Differential Effects Of Mutant Tap63Γ On Transactivation Of P53 And/Or P63 Responsive Genes And Their Effects On Global Gene Expression, Shama Khan Khokhar

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p63, a member of the p53 gene family, known to play a role in development, has more recently also been implicated in cancer progression. Mice lacking p63 exhibit severe developmental defects such as limb truncations, abnormal skin, and absence of hair follicles, teeth, and mammary glands. Germline missense mutations of p63 have been shown to be responsible for several human developmental syndromes including SHFM, EEC and ADULT syndromes and are associated with anomalies in the development of organs of epithelial origin. The contrasting phenotypes associated with the different classes of p63 mutations might be in part due to the differential ...


Detection And Destruction Of Escherichia Coli Bacteria And Bacteriophage Using Biofunctionalized Nanoshells, Joseph E. Van Buren Jan 2007

Detection And Destruction Of Escherichia Coli Bacteria And Bacteriophage Using Biofunctionalized Nanoshells, Joseph E. Van Buren

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The ability to detect chemical and biological agents is arguably one of the highest priority technical challenges today. The capability to obtain specific information at and near single-molecule resolution is the ultimate goal in chemical and biological agent detection. Metallic nanostructures, nanoshells and nanorods in particular, are attractive substrates because of their plasmonic properties. Combining the specificity of biomolecular recognition with these nanostructures might lead to increased sensitivity and selectivity. Localization of biological recognition motifs to the surface of these nanostructures could provide a mechanism for highly specific and directed energy transfer when bound to its target. This study utilizes ...


Characterization Of Photosynthetic Reaction Centers From Bradyrhizobium Strain Btai 1, Isaac P. Forquer Jan 2005

Characterization Of Photosynthetic Reaction Centers From Bradyrhizobium Strain Btai 1, Isaac P. Forquer

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Photosynthetic rhizobia have been studied for about 15 years now. They are now considered to be metabolically aligned with a relatively recently discovered group of bacteria, the anoxygenic aerobic phototrophs (AAP’s).Rhizobia form symbiotic relationships with plants from the Fabaceae family. Photosynthetic rhizobia not only nodulate the roots, as most other rhizobia do, but they also form nodules on the stems of certain leguminous plants. The plant provides carbon to the bacteria and the bacteria provides the plant with soluble nitrogen fixed from the biologically inert but abundant atmospheric N2. A key question regarding photosynthetic rhizobia and other AAP ...