Life Sciences Commons^™

Functions Of Fibroblast Growth Factor Homologous Factor 2 In Excitable Tissues, Christopher Marra

Dissertations, Theses, and Capstone Projects

Purpose: Fibroblast Growth Factor Homologous Factors (FHFs) are a group of proteins known to associate with and modulate voltage-gated sodium channels (Na_v) in excitable cells. The four FHF genes are differentially expressed in specific cell-types, with FHF2 expressed prominently in the hippocampus, cerebral cortex, heart and dorsal root ganglia. Due to previous unavailability of an Fhf2 knockout mouse, this gene’s functions have been understudied in comparison to other those encoding other FHFs. The purpose of this research has been to better understand the normal physiological functions of FHF2 at the cellular and system levels in the heart, sensory …

Employing High Probability Gene Choice Elements To Understand Singular Odorant Receptor Expression, Raena Mina

Dissertations, Theses, and Capstone Projects

The ability to detect odorous chemicals in the environment is the oldest of the senses necessary for survival, from escaping danger, finding mates, to locating food. It is said that humans can identify and discriminate up to a trillion different odor mixtures. For chemoreception to have such a high discriminatory power, would require a diverse population of cells dedicated for odor detection. These detector cells are the olfactory sensory neurons (OSNs), which express odorant receptors (ORs) that bind to chemical odors in the environment. In order to increase specificity and sensitivity, an essential property in olfaction is for each OSN …

Molecular Roles Of Small Inner Membrane Proteins In Escherichia Coli Cell Envelope Integrity, Aaron Mychack

Dissertations, Theses, and Capstone Projects

The biological membrane is an essential, defining feature of all cells. Biological membranes comprise phospholipid bilayers as well as a complement of proteins which are unique to a given organism. These proteins play a central role in dictating the biochemical state of the cell’s internal cytoplasm by controlling selective passage of solutes in and out of the cell, transducing signals in response to extracellular stimuli, and controlling the biogenesis of the bilayer itself which is critical towards barrier function. For most bacteria, the periphery of the cell is multi-layered, including both a biological membrane as well as a peptidoglycan cell …

Evaluating Satellite-Based Sea Surface Temperatures, In Situ Observations, And Coral Symbioses In Southwestern Puerto Rico, Andrea Michelle Gomez

Dissertations, Theses, and Capstone Projects

I examined the effects of in situ and satellite-based sea surface temperatures (SST) on the seasonal coral-algae symbiotic relationship in La Parguera, Puerto Rico. Climate change-driven rising sea temperatures are endangering most of the world’s reefs, which are currently in decline. Satellite remote sensing datasets support global-scale characterization and monitoring of risks to reefs associated with increasing temperatures. Corals’ unique symbiotic relationship with unicellular algae in the family Symbiodiniaceae is largely responsible for helping corals cope with increasing ocean temperatures, and some corals are able to adjust their symbiont species in response to temperature disturbances. My research had two components …

Protein Phosphatase 2a Suppresses Spindle Elongation In Saccharomyces Cerevisiae, Shoily P. Khondker

Dissertations, Theses, and Capstone Projects

Eukaryotic cell division is an essential process that is carried out by the cell cycle, a tightly controlled process that has been extensively studied in the budding yeast Saccharomyces cerevisiae. The cell cycle is driven by Cyclin Dependent Kinase (Cdk1) activity. Protein phosphatase 2A-Cdc55 (PP2A^Cdc55) reverses Cdk1 phosphorylation events during late stages of the cell cycle to ensure the correct order of events. This thesis presents evidence that the anaphase inhibitor Pds1 is a PP2A^Cdc55 target. Pds1 binds to and inhibits separase (Esp1). Esp1 triggers sister chromatid segregation by cleaving the cohesin complex that holds the …

Elucidating The Role Of Apl-1, The C. Elegans Ortholog Of The Human Amyloid Precursor Protein, Adanna G. Alexander

Dissertations, Theses, and Capstone Projects

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder, impacting approximately 6 million Americans. AD is the leading cause of dementia amongst the aged population. Post mortem analysis of the brains of AD patients shows high quantities of extracellular Aβ peptide deposits, which are derived from cleavage of the amyloid precursor protein (APP). Mutations in APP and proteins responsible for APP cleavage, PSENs, greatly increase the incidence of developing AD at an early age. Despite its strong correlation to the progression of AD, the role of APP remains unclear.

Here we investigate the role of the Caenorhabditis elegans ortholog, APL-1. We …

A Neural Mechanism For Capnotaxis In The Naked Mole-Rat, Michael Zions

Dissertations, Theses, and Capstone Projects

A Neural Mechanism for Capnotaxis in the Naked Mole-Rat

The Naked Mole-Rat (NM-R) is a small hairless rodent that has thrived underground in the Horn of Africa for the past 40 million years. It was first discovered in 1847, but has only been maintained in captivity and studied as a laboratory animal over the past 40 years. To date, more than 400 scientific papers have been published on this species. This is relatively few compared to established lab animals like rats and mice, but those papers contain a trove of information that has changed our understanding of the constraints of …

Through The Back Door: Proteins Escape Cells Without Conventional Permission, Michael J. Cohen

Dissertations, Theses, and Capstone Projects

Proteins secreted to the extracellular environment play a fundamental role as signals, in metabolism, and a variety of other processes. The process of secretion through the endoplasmic reticulum and Golgi to the plasma membrane is well documented, and all cargo in this pathway contains a signal peptide. However, a variety of proteins secreted from eukaryotes lack a signal peptide and are called unconventionally secreted proteins. Here we discuss known mechanisms of unconventional protein secretion, as well as model proteins which follow characterized pathways. Additionally, we summarize the roles various unconventionally secreted proteins play outside of cells and suggest criteria for …

Hur Ubiquitination By Brca1/Bard1 And Its Role In Controlling Gene Expression During Dna Damage Response, Gamage M. Aruggoda

Dissertations, Theses, and Capstone Projects

Despite our understanding of the biochemistry of the BRCA1/BARD1 E3 ligase, we know very little of the mechanism by which its cellular substrates, how they are chosen, how its E3 Ub ligase activity is regulated, which are the cofactors involved in this regulation, and how the substrates are modified during DDR. In this dissertation, I further evaluate BRCA1/BARD1-mediated E3 ligase activity and how CstF-50 and p97 regulate this reaction working as cofactors. My data show that BRCA1/BARD1 is an E3 ligase that ubiquitinates the RNA binding protein Human antigen R(HuR).

HuR is abundant in the nucleus and is transported to …