Molecular Biology Commons^™

Characterization Of Arabidopsis Eukaryotic Translation Initiation Factor 2Α (Eif2Α) Mutants, Mark Edens

Masters Theses

Plants are stationary organisms that are charged with overcoming a multitude of biotic and abiotic stresses. The eukaryotic translation initiation factor 2 (eIF2) is responsible for charging the P-site of the forming 80S ribosome with the initiator methionyl-tRNA. Thus, eIF2 is a protein of utmost consequence in the growth and development of organisms. The eIF2 protein is also a mediator of global translational regulation in the eukaryotic integrated stress response (ISR), where the α-subunit is phosphorylated by protein kinases, such as the kinase GCN2. Here, five eIF2α allele mutants in Arabidopsis were found to be deleterious to plant growth, development, …

Manipulating Adipose Tissue Fatty Acid Oxidation To Reduce Fatness In Broiler Chickens, Tania Emmanuelle Torchon

Masters Theses

Compared to rodents, broiler chickens, those reared for meat, are an attractive model for studies of adipose biology, and obesity development in children. The broiler chicken lacks the gene for uncoupling protein 1, the hallmark for brown adipose tissue making them a useful model to study lipid metabolism in white adipocytes. Two studies were performed to investigate if white adipose tissue had the metabolic ability for fatty acid oxidation (FAO), and to investigate the effects of dietary fatty acids on abdominal fat development of young broiler chickens as a model for childhood obesity. In study one, chickens were fasted for …

Localization Of Chemoreceptors In Azospirillum Brasilense., Anastasia Aksenova

Masters Theses

In order to ensure their survival, bacteria must sense and adapt to a variety of environmental signals. Motile bacteria are able to orient their movement in a chemical gradient by chemotaxis. During chemotaxis, environmental signals are detected by chemotaxis receptors and are propagated via a signal transduction cascade to affect bacterial motility. In a model organism Escherichia coli, chemotaxis receptors, also called MCPs (for methyl-accepting chemotaxis proteins) sense changes in concentration gradients by making temporal comparisons about the chemical composition of their surroundings. Decreased attractant concentration or increased repellant concentration results in conformational changes in the MCPs that culminate …

Angiotensinogen Gene Silencing Reduces Lipid Accumulation And Inflammation In Cultured 3t3-L1 Adipocytes, Wenting Xin Carroll

Masters Theses

Obesity is characterized by metabolic complications which are related to several life-threatening diseases. Dysregulated inflammatory adipokines secretion from adipose tissue is believed as the major contributor to obesity-associated local and systemic inflammation, insulin resistance, and other metabolic dysfunctions.

Numerous studies in our lab and others pointed to the role of local adipose tissue renin-angiotensin system (RAS) in the pathogenesis of obesity, inflammation and insulin resistance. We hypothesized that adipocytes-derived angiotensinogen (Agt) played a critical role in adipogenesis and/or lipogenesis as well as adipose inflammation. To test, we established 3T3-L1 preadipocytes stably transfected with Agt-shRNA or scrambled sequence (Sc-shRNA). Transfected preadipocytes …

Elucidating The Effect Of Silver On Ethylene Signaling In Arabidopsis Thaliana, Brittany Kathleen Mcdaniel

Masters Theses

Ethylene, a gaseous plant hormone, is involved in numerous plant developmental processes such as seed germination, senescence, and fruit ripening. In Arabidopsis thaliana, ethylene is perceived by a family of five membrane-bound receptors, which upon binding ethylene trigger downstream effects. At the receptor level, it is known that the coordination of a copper ion is necessary for ethylene to bind, resulting in a conformational change of the receptor and the initiation of the ethylene signal transduction pathway. Interestingly, silver ions are also able to support binding of ethylene but ethylene responses are blocked in the presence of silver. When …

Examining The Roles Of Pstoc75 Potra Domains In Chloroplast Protein Import, Richard Franklin Simmerman

Masters Theses

During chloroplast formation via endosymbiosis most of the plastid genome was transferred to the host nuclear genome. Genomic and proteomic analysis suggests that >95% of the original plastid proteome is now encoded in the nucleus, and these now cytosolically fabricated proteins require a post-translational transport pathway back into the organelle. This process is not well understood, yet it has been shown to involve translocons at the outer and inner envelope of the chloroplast membranes (TOC & TIC). These translocons interact with a cleavable N-terminal extension of between 20 and 100 residues on chloroplast-bound precursor proteins known as the transit-peptide. Precursor …

Structural And Functional Analysis Of Toc75, Ashita Mukul Dave

Masters Theses

The majority of chloroplast proteins are nuclear-encoded and post-translationally imported into the chloroplast. These newly imported proteins are translocated from the cytosolic compartment to the stroma by the Translocons of the Outer/Inner membranes of Chloroplast (TOC/TIC). In order to understand protein transport across the chloroplast outer membrane, it is crucial to investigate the structure and function of these complexes. The TOC complex is composed of the beta-barrel channel protein Toc75 and the GTPase receptors Toc34 and Toc159.

Toc75 is a member of the OMP85 (Outer Member Protein, 85 kDa) superfamily. Other proteins of the OMP85 superfamily also exist in Gram-negative …

Studies On The Mechanisms Of Homolog Pairing And Sister Chromatid Cohesion During Drosophila Male Meiosis, Jian Ma

Masters Theses

Meiosis is a complex process involving one round of DNA replication followed by two rounds of cell divisions. The proper segregation of homologs at meiosis I and sister chromatids during meiosis II is essential for the survival of the offspring. Aberrant chromosome segregation at any stage of meiosis can lead to aneuploidy. Meiotic chromosome segregation without crossing over or chiasmata is a widespread but poorly understand chromosome segregation pathway. In male Drosophila meiosis the absence of recombination in chromosomes makes it easier to identify mutations which influence homologous chromosome pairing and segregation.

Modifier of Mdg4 in Meiosis (MNM), a protein …

The Effects Of Acute Ethanol Treatment On The Suprachiasmatic Nucleus In Adult Male Mice, Charles Andrew Mangrum

Masters Theses

Light is the primary entraining signal for the mammalian circadian clock located in the suprachiasmatic nucleus (SCN). Light entering the eye leads to release of glutamate directly onto SCN neurons where it binds to N-methyl D-aspartate (NMDA) receptors initiating a cascade of cellular processes that ultimately modulates clock phase. SCN neurons show a 24-hour rhythm in neuronal activity that peaks in the middle of the day when isolated in a brain slice preparation. Treatments that phase-shift the SCN clock in vivo have been shown similarly to shift this rhythm of neuronal activity in vitro. Here, I have investigated …