Life Sciences Commons^™

Understanding The Impact Of Chlamydia Trachomatis Infection On Host Vesicular Trafficking, Lisa M. Jorgenson

Theses & Dissertations

Chlamydia trachomatis is a highly evolved obligate intracellular bacterial pathogen. During infection, organisms reside within a host epithelial cell in a membrane-bound vacuole called the inclusion. The inclusion membrane contains both pathogen and host components, including unique chlamydial type III effector proteins called Incs and host lipids like cholesterol and sphingomyelin. The inclusion membrane serves as the main barrier between the bacteria and the host cytosol, and thus, functions as the platform supporting host-chlamydial interactions. Via the inclusion membrane, C. trachomatis intercepts components of host vesicular traffic including many host SNARE proteins, which are a conserved family of eukaryotic proteins …

Metabolic Heterogeneity And The Roles Of Cody And Ccpa In Central Metabolism And S. Aureus Biofilm Formation., Logan L. Bulock

Theses & Dissertations

Staphylococcus aureus is a metabolically versatile human pathogen, causing disease in many areas of the body. Its versatility can be attributed to the fact that it utilizes a variety of tools to adapt to many different environments, including toxins to scavenge from the host and multiple transporters to compete for its preferred carbon sources. S. aureus can also survive in harsh conditions through biofilm development, which are notoriously recalcitrant to antibiotics and immune defenses. Biofilms exhibit marked heterogeneity, with division of labor for production of matrix components and differential gene expression among various niches within the biofilm.

In this study, …

Strainiq: An N-Gram-Based Method To Identify And Quantify Microbial Communities In Metagenomic Samples, Sanjit Pandey

Theses & Dissertations

Microbes are ubiquitous in nature, and they play vital roles in various processes associated with metabolism in the human body, photosynthesis in plants, or decomposition of waste in the environment. Hence, it is essential to understand how the composition of microbial communities affects the ecosystem of different environments ranging from ocean floors to hot springs to the human body. Microbial communities present in different human body sites are of particular importance due to their implications in the cause and prevention of human diseases. The traditional approaches limit microbial research to exclusively studying species that can be successfully cultured in the …

The Staphylococcus Aureus Lrgab Operon Encodes A Holin-Like Protein Involved In Pyruvate Transport, Jennifer L. Endres

Theses & Dissertations

The Staphylococcus aureus cidABC and lrgAB operons encode a well-conserved family of proteins involved in programmed cell death (PCD) during biofilm development. Based on the structural similarities that CidA and LrgA share with bacteriophage holins, we have hypothesized that these proteins function by forming pores within the cytoplasmic membrane. To test this, we utilized a “lysis cassette” system that demonstrated the abilities of the cidA and lrgA genes to support bacteriophage endolysin-induced cell lysis. In addition, the CidA and LrgA proteins were shown to localize to the surface of membrane vesicles and cause leakage of small molecules, providing direct evidence …

Role And Regulation Of Staphylococcal Cell Death, Abdulelah Ahmed Alqarzaee S

Theses & Dissertations

The transition from growth to stationary phase is a natural response of bacteria to starvation and stress. When stress is alleviated and more favorable growth conditions return, bacteria resume proliferation without a significant loss in fitness. Although specific adaptations that enhance persistence and survival of bacteria in stationary phase have been identified, mechanisms that help maintain the competitive fitness potential of non-dividing bacterial populations have remained obscure. This dissertation demonstrates that staphylococci entering stationary phase following growth in excess glucose undergo regulated cell death to maintain the competitive fitness potential of the population. Upon a decrease in extracellular pH, the …

Role Of Endocytic Machinery Regulators In Egfr Traffic And Viral Entry, Insha Mushtaq

Theses & Dissertations

STUDY 1: Role of endocytic regulator EHD1 and its binding partner RUSC2 in EGFR traffic

Abstract

Epidermal growth factor receptor (EGFR) is a prototype receptor tyrosine kinase and an oncoprotein in many solid tumors. Cell surface display of EGFR is essential for cellular responses to its ligands. While post activation endocytic trafficking of EGFR has been well elucidated, little is known about mechanisms of basal/pre-activation surface display of EGFR. Here, we identify a novel role of the endocytic regulator EHD1 and a potential EHD1 partner, RUSC2, in cell surface display of EGFR. EHD1 and RUSC2 colocalize with EGFR in vesicular/tubular …