Molecular Biology Commons^™

Investigation Of Potentially Catalytic Residues Of Uba5 Through Mutagenesis, Purification, And Structural Characterization, Grant Bradley

Senior Honors Projects, 2020-current

Ubiquitin-fold modifier 1 (Ufm1) is a member of the Ubiquitin (Ub) family of proteins whose primary function is degradation of proteins through a sequential mechanism of chemical reactions. Though Ufm1’s specific roles are largely unknown, this family of proteins has shown to play a part in a wide variety of processes, including regulation of the cell cycle¹, secretory functions of cells^2,3, and blood clotting⁴. Ufm1’s mechanism of action proceeds with the aid of three enzymes: an E1, E2, and E3. Uba5 is the E1 activating enzyme that is specific to Ufm1, and its mechanism of …

Decrypting Female Attractivity In Garter Snakes, Holly Rucker

Senior Honors Projects, 2010-2019

Pheromones are utilized by many species as sexual signals driving mate choice, and pheromone production in vertebrates hinges on sex hormone action. Female red-sided garter snakes (Thamnophis sirtalis parietalis) produce a skin-based sex pheromone used by males for mate detection and selection. Estradiol is necessary for pheromone production, yet the specific mechanisms within the skin are unknown. Central to this is the metabolism of testosterone to estradiol via the enzyme aromatase. It is hypothesized that female garter snakes synthesize estradiol locally in the skin and maintain pheromone production via tissue-specific regulation of aromatase. Further, I hypothesize that female …

Anti-Crispr Vs. Crispr: The Evolutionary Arms Race Between Microorganisms, Rachael M. St. Jacques

Masters Theses, 2010-2019

CRISPR arrays are a defense mechanism employed by bacteria against viral invaders. Cas proteins do the work in detecting, capturing, and integrating the viral DNA into the CRISPR array (Barrangou et al., 2007). Anti-CRISPR proteins are produced by phages, viruses that infect bacteria, to stop the bacterial host’s CRISPR-Cas complex from interrupting the phage life cycle (Bondy-Denomy, et al., 2015).

SEA-PHAGES is a course-based bacteriophage research network composed of 120 colleges and known at James Madison University as Viral Discovery. JMU uses the unsequenced Streptomyces griseus ATCC10137 as a host for bacteriophage discovery and propagation, and in this study we …

Structure/Function Analysis Of Fega And Fhua In Bradyrhizobium Sp., Alexander James Herd

Senior Honors Projects, 2010-2019

Bradyrhizobium japonicum is a Gram-negative soil bacterium commonly known for its agriculturally significant mutualistic relationship with soybean. In this symbiosis, the bacteria and plant undergo complex molecular signaling characterized by sent and received signals resulting in the formation of infection threads and root nodules. This research aimed to compare two related bacterial outer membrane proteins, FegA and FhuA, associated with the molecular signaling between the bacteria and plant. Previous work has led to the hypothesis that the N-terminal domain (NTD) of FegA in B. japonicum is needed for a functional symbiosis to occur. Recombinant bacterial strains expressing altered FegA proteins …

An N-Terminal Acidic Domain In Β-Amylase2 Is Required For K+ Regulation., Jillian Breault

Senior Honors Projects, 2010-2019

In the chloroplasts of leaf mesophyll cells, β-amylase proteins (BAMs) are responsible for breaking down starch into maltose when the plant cannot undergo photosynthesis. BAM2, which was previously considered inactive, was recently shown to be active under stromal-like levels of salt and has optimal activity at 80mM KCl. In addition, BAM2 is active as a tetramer in vivo and displays sigmoidal kinetics due to a secondary binding site that is responsible for activating BAM2 when bound to starch. A hypothesized tetramer model was created using a homology model of a BAM2 monomer and the configuration of a crystallized sweet potato …

Epigenetic Characterization Of Human Retina Cells, Nicholas R. Dunham

Senior Honors Projects, 2010-2019

DNA methylation is an epigenetic modifier that modulates gene expression in plant and vertebrate genomes. The aim of this study was to characterize the role of DNA methylation in the human retina, particularly within rod and cone photoreceptor retinal neurons. Previous studies investigating DNA methylation in murine retinal cells and retina-derived human retinoblastoma immortalized cell culture lines demonstrate an inverse relationship between DNA methylation and transcriptional activity. Here, we used gene-specific bisulfite pyrosequencing analysis to measure DNA methylation in the genomes of human ocular cells in an effort to characterize the role of this important epigenetic modifier. These results can …

Searching For Potential Binding Partners Of Arabidopsis Β-Amylase2 Using Yeast 2-Hybridization, Megan E. Hines

Senior Honors Projects, 2010-2019

BAM2 is a chloroplast-targeted member of the β-amylase gene family that currently has an unknown function in starch hydrolysis. Previous research indicated that BAM2 did not have significant catalytic activity, but, because the gene is highly conserved and there is a starch-excess phenotype in older plants lacking BAM2, it was hypothesized that BAM2 may instead have a regulatory function. Many regulatory proteins function by interacting with other proteins, so we wanted to test for potential protein binding partners for BAM2 using the yeast two-hybrid system. A plasmid containing the BAM2 gene from Arabidopsis thaliana was co-transformed into Y190-strain yeast ( …

The Purification And Characterization Of Beta-Amylase6 In Arabidopsis Thaliana, Catherine E. Torres

Senior Honors Projects, 2010-2019

Experimental evidence indicates that the family of beta-amylase (BAM) proteins is largely responsible for the hydrolysis of starch in land plants. In Arabidopsis thaliana there are nine BAM genes, six of which are targeted to the chloroplast, but only four of those are presumed to be catalytically active: BAM1, -2, -3, and -6. Currently, little is known about the expression, characterization, or function of BAM6. Our study of starch accumulation in Arabidopsis indicates that BAM6 may be playing a role in older plants, although it has a minimal role in young plants. To further investigate the function of BAM6 we …

The Effects Of Chronic Partial Sleep Deprivation And Chronic Voluntary Alcohol Consumption On Δfos B Accumulation, Kristian Ponder

Masters Theses, 2010-2019

The present study explores the relation between sleep restriction and alcohol use and the neural substrates that result from chronic behaviors. Accumulation of the transcription factors ΔFosB is suggested as a possible outcome of chronic behaviors, such as addiction. Sleep is discussed as possible mediating factor in the relationship between ΔFosB and chronic alcohol consumption. There were four experimental groups in this study: Control (C), Sleep Deprivation only (SD), Alcohol Exposure only (AO), and both sleep deprivation and alcohol exposure (B). Levels of ΔFosB accumulation in the Nucleus Accumbens (NAc) revealed a significant main effect of sleep deprivation, but no …

The Effects Of Chronic Partial Sleep Deprivation On Alcohol Consumption And Delta Fos B Accumulation, Kristian Ponder

Showcase of Graduate Student Scholarship and Creative Activities

The present study explores the relation between sleep restriction and alcohol use and the neural substrates that result from chronic behaviors, such as transcription factors. Transcription factor activity is suggested as a possible outcome of chronic behaviors, such as addiction. Sleep is discussed as possible mediating factor in the relationship between specific transcription factors and alcohol. Analysis will focus on brain areas related to both sleep and reward.

Biophysical Characterization Of Naturally Occurring Titin M10 Mutations, Michael William Rudloff

Senior Honors Projects, 2010-2019

The giant human muscle proteins titin and obscurin are important for sarcomeric organization, stretch response, and sarcomerogenesis in myofibrils. The extreme C-terminus of titin (the M10 domain) binds to the N-terminus of obscurin (the Ig1 domain) in the M-line, an interaction that is critical for sarcomere stability. The high-resolution structure of human M10 has been solved, along with M10 bound to one of its two known molecular targets, the Ig1 domain of obscurin-like protein. Multiple M10 mutations are linked to limb-girdle muscular dystrophy type 2J (LGMD2J) and tibial muscular dystrophy (TMD), however the effect of the M10 mutations on protein …