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

Molecular Biology Commons

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

Articles 1 - 8 of 8

Full-Text Articles in Molecular Biology

The Cdk-Resistant Prb-E2f1 Complex Recruits Chromatin-Organizing Proteins To Repetitive Dna Sequences, Charles A. Ishak Apr 2017

The Cdk-Resistant Prb-E2f1 Complex Recruits Chromatin-Organizing Proteins To Repetitive Dna Sequences, Charles A. Ishak

Electronic Thesis and Dissertation Repository

This thesis investigates mechanistic links between genome integrity and the recruitment of chromatin organizing proteins to repetitive DNA sequences mediated by the retinoblastoma tumor suppressor protein (pRB). I demonstrate that a CDK-resistant interaction between the pRB C-terminus and the E2F1 coiled-coil marked box domain establishes a scaffold that facilitates recruitment of multiple chromatin-organizing proteins to repetitive sequences across the genome throughout the cell cycle. Specifically, pRB recruits the enhancer-of-zeste-homologue 2 (EZH2) histone methyltransferase to establish repressive facultative heterochromatin at repetitive sequences, and the Condensin II complex to ensure proper DNA replication and mitotic progression. To disrupt the CDK-resistant pRB-E2F1 interaction ...


Investigating E2f Independent Cell Cycle Control And Tumor Suppression By Prb, Michael J. Thwaites Apr 2017

Investigating E2f Independent Cell Cycle Control And Tumor Suppression By Prb, Michael J. Thwaites

Electronic Thesis and Dissertation Repository

Cellular division is primarily controlled at the G1 to S-phase transition of the cell cycle by the retinoblastoma tumor-suppressor protein (pRB). The ability of pRB to restrict S-phase entry is primarily attributed to the repression of E2F transcription factors required to upregulate cell cycle target genes necessary for cellular division. Interestingly, while pRB is disrupted in the vast majority of human cancers, mutations typically target upstream regulators of pRB leading to inactivation through hyperphosphorylation. The rarity of direct pRB mutations suggests that the regulation of the cell cycle by pRB may involve additional mechanisms outside of E2F repression, as this ...


Characterizing The Human Vaginal Microbiome Using High-Throughput Sequencing, Jean Megan E. Macklaim Dec 2013

Characterizing The Human Vaginal Microbiome Using High-Throughput Sequencing, Jean Megan E. Macklaim

Electronic Thesis and Dissertation Repository

The human vaginal microbiome undoubtedly has a significant role in reproductive health and for protection from infectious organisms. Recent efforts to characterize the bacterial species of the vagina using molecular techniques have uncovered an unexpected diversity. Using high-throughput sequencing I sought to describe the structure and function of the vaginal microbiome under different physiological states including healthy, bacterial vaginosis (BV), post-menopausal vaginal atrophy, and acute vulvovaginal candidiasis (VVC).

Partial 16S rRNA gene sequencing revealed that healthy, asymptomatic women most often have vaginal biotas dominated by Lactobacillus iners or L. crispatus. In contrast, BV is a heterogeneous, highly diversified condition with ...


Exploring The Structure And Biochemistry Of Oxidation-Mediated Inhibitation Of The Peptidyl-Prolyl Isomerase Pin1, Brendan T. Innes Dec 2013

Exploring The Structure And Biochemistry Of Oxidation-Mediated Inhibitation Of The Peptidyl-Prolyl Isomerase Pin1, Brendan T. Innes

Electronic Thesis and Dissertation Repository

Pin1 is a phosphorylation-dependent peptidyl-prolyl isomerase that has been shown to be neuroprotective in aging-related neurodegenerative diseases such as Alzheimer's disease (AD). However, it is not active in AD brain, and a recent proteomic screen of Mild Cognitive Impairment (MCI) brain samples revealed that Pin1 is oxidized in the brains of these pre-AD patients. This suggests that this oxidation may be the cause of the loss of the neuroprotective Pin1 function in AD. The Pin1 active site contains a functionally critical cysteine residue (Cys113) with a low predicted pKa, making it highly susceptible to oxidation. We hypothesize that Pin1 ...


Human Adenovirus E1a Binds And Retasks Cellular Hbre1, Blocking Interferon Signalling And Activating Virus Early Gene Transcription, Gregory J. Fonseca Jun 2013

Human Adenovirus E1a Binds And Retasks Cellular Hbre1, Blocking Interferon Signalling And Activating Virus Early Gene Transcription, Gregory J. Fonseca

Electronic Thesis and Dissertation Repository

Upon infection, human adenovirus (HAdV) must block interferon signaling and activate the expression of its early genes to reprogram the cellular environment to support virus replication. During the initial phase of infection, these processes are orchestrated by the first HAdV gene expressed during infection, early region 1A (E1A). E1A binds and appropriates components of the cellular transcriptional machinery to modulate cellular gene transcription and activate viral early genes transcription. We have identified hBre1/RNF20 as a novel target of E1A. hBre1 is an E3 ubiquitin ligase which acts with the Ube2b E2 conjugase and accessory factors RNF40 and WAC1 to ...


Regulation Of Lipid Homeostasis, Inflammatory Signalling And Atherosclerosis By The Peroxisome Proliferator-Activated Receptor Delta, Lazar A. Bojic Jun 2013

Regulation Of Lipid Homeostasis, Inflammatory Signalling And Atherosclerosis By The Peroxisome Proliferator-Activated Receptor Delta, Lazar A. Bojic

Electronic Thesis and Dissertation Repository

The peroxisome proliferator-activated receptor (PPAR) δ is a ligand-dependent transcription factor that has been implicated in metabolic and inflammatory regulation. The molecular and physiological mechanisms by which PPARδ activation regulates lipid metabolism, inflammatory signaling and protection from atherosclerosis in states of metabolic disturbance such as insulin resistance and dyslipidemia, were investigated in a series of in vitro and in vivo studies. In vitro experiments demonstrated that PPARδ activation inhibits atherogenic lipoprotein-induced lipid accumulation and the associated proinflammatory responses. The primary mechanisms for these effects were increased fatty acid β-oxidation, decreased lipoprotein lipase (LPL) activity, reduced MAPK signaling and improved insulin ...


Involvement Of Interleukin-33/St2 In Myocardial Dysfunction In Murine Model Of Sepsis, Yoonmi Choe Dec 2012

Involvement Of Interleukin-33/St2 In Myocardial Dysfunction In Murine Model Of Sepsis, Yoonmi Choe

Electronic Thesis and Dissertation Repository

The disruption of myocardial extracellular matrix (ECM) has been implicated in myocardial dysfunction during sepsis. However, the underlying mechanism(s) are not clear. Interleukin-33 (IL-33) is a cytokine which regulates collagen synthesis in various cardiac pathologies. The purpose of the present study is to test whether IL-33 contributes to sepsis-induced myocardial dysfunction through regulation of matrix metalloproteinase-9 (MMP-9). The in vivo, feces-induced peritonitis (FIP) in mice and in vitro lipopolysaccharide (LPS) treatments to isolated cardiomyocytes were used. In FIP mice, myocardial IL-33 and MMP-9 expression were increased and myocardial contractility was decreased. Myocardial function in FIP mice was improved when ...


Characterization Of Cardiomyopathy In A Mouse Model Of Duchenne Muscular Dystrophy (Dmd) Using Echocardiography, Dce-Ct, And Pet-Fdg, Seyed Hamed Moazami Nov 2012

Characterization Of Cardiomyopathy In A Mouse Model Of Duchenne Muscular Dystrophy (Dmd) Using Echocardiography, Dce-Ct, And Pet-Fdg, Seyed Hamed Moazami

Electronic Thesis and Dissertation Repository

Duchenne muscular dystrophy (DMD) is an X-linked recessive neuromuscular disease that is the result of a loss of functional dystrophin, which causes cardiomyocyte fibrosis and death, leading to cardiomyopathy. In this thesis, I have utilized dynamic contrast-enhanced computed tomography (DCE-CT), positron emission tomography-fluorodeoxyglucose (PET-FDG), echocardiography, and traditional histology to longitudinally assess disease progression and degree of cardiomyopathy in a murine model of DMD (mdx:utrn-/-). No significant changes were observed in the blood flow, blood volume, or cardiac volume measured via DCE-CT, nor in standard uptake value (SUV) of glucose as measured by PET-FDG in the left myocardium between and ...