Molecular Biology Commons^™

Mechanisms And Dynamics Of Oxidative Dna Damage Repair In Nucleosomes, Wendy J. Cannan

Graduate College Dissertations and Theses

DNA provides the blueprint for cell function and growth, as well as ensuring continuity from one cell generation to the next. In order to compact, protect, and regulate this vital information, DNA is packaged by histone proteins into nucleosomes, which are the fundamental subunits of chromatin. Reactive oxygen species, generated by both endogenous and exogenous agents, can react with DNA, altering base chemistry and generating DNA strand breaks. Left unrepaired, these oxidation products can result in mutations and/or cell death. The Base Excision Repair (BER) pathway exists to deal with damaged bases and single-stranded DNA breaks. However, the packaging of …

Functional Consequences Of Ama1-Ron2 Interaction During Host Cell Invasion By Toxoplasma., Shruthi Krishnamurthy

Graduate College Dissertations and Theses

T.gondii is a model organism of the phylum Apicomplexa that infects one third of the human population. While the majority of infections are asymptomatic or manifest with mild flu-like symptoms, toxoplasmosis can be fatal in immunocompromised individuals and in the developing fetus. The lytic cycle of tachyzoite-stage parasites causes damage to the host by repeated rounds of host cell invasion, intracellular replication and lysis of the host cell upon egress.

Invasion is a key step for the parasite to maintain its intracellular lifestyle. Apical Membrane Antigen 1 (AMA1) is an adhesin released from a unique set of secretory organelles called …

Barcoding The Actin Track: Differential Regulation Of Myosin Motors By Tropomyosin, Joseph Emerson Clayton

Graduate College Dissertations and Theses

Myosins and tropomyosins represent two types of actin filament-associated proteins that often work together in contractile and motile processes in the cell. While the role of thin filament troponin-tropomyosin complexes in regulating striated muscle myosin II is well characterized, the role of tropomyosins in non-muscle myosin regulation is not well understood. Fission yeast has recently proved to be a useful model with which to study regulation of myosin motors by tropomyosin owing to its tractable genetics, well-defined actin cytoskeleton, and established actin biochemistry.

A hallmark of type V myosins is their processivity -- the ability to take multiple steps along …

Epicardial Cell Engraftment And Signaling Promote Cardiac Repair After Myocardial Infarction, Krithika Rao

Graduate College Dissertations and Theses

The epicardium is a single layer of epithelial (mesothelial) cells that covers the entire heart surface, but whose function in adult mammals is poorly understood. Defining the role of epicardial cells during homeostasis, growth and injury has potential to provide new treatment strategies for human diseases that result in heart failure, due to extensive loss of viable cardiac tissue. We hypothesized that epicardial cells contribute to repair as transplantable progenitor cells for cellular regeneration and as a source of secreted growth factors for cell protection after myocardial infarction.

Adult epicardial cells were prospectively isolated as uncommitted epithelial cells using epithelial-specific …