Defense Date

2014

Document Type

Thesis

Degree Name

Master of Science

Department

Physiology

First Advisor

Janina Lewis

Abstract

Porphyromonas gingivalis, a gram-negative anaerobic bacterium, is a major etiological agent in the initiation and progression of severe forms of periodontal disease. Oral bacteria like P. gingivalis are subject to continually changing conditions as a consequence of host eating, oral hygiene patterns and subgingival temperatures. As such survival requires an adaptive response to environmental cues, but little is known about the mechanism by which P. gingivalis controls co- and post-transcriptional regulation of RNA levels and potentially protein expression. RNA-binding proteins (RBPs) are evolutionarily conserved across species and are involved in such regulatory mechanisms. However, P. gingivalis currently has no identified RBP. Recently, PG0627 has become an ideal candidate for a putative RBP due to its sequence homology to RBPs across various species. By characterizing PG0627, we can gain better insight into the function of this hypothetical protein and determine if it indeed behaves like an RNA-binding protein. A host of studies were done on a PG0627-deficient P. gingivalis mutant, V3139, in order to determine the biological role of the protein encoded by the gene. Our bioinformatics analysis indicated that PG0627 had sequence homology to several RNA recognition motifs or RBPs. Furthermore, our PG0627-deficient mutant, when compared to W83, exhibited decreased cell-associated iron content, decreased total interactions and invasions with eukaryotic cells, and decreased protease activity. Conversely, our PG0627-deficient mutant displayed slightly increased growth in the presence of nitrosative stress, and in hemin-depleted conditions. In conclusion, our results support that PG0627 is a valid candidate for an RNA-binding protein in P. gingivalis.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

8-18-2014

Available for download on Saturday, August 17, 2019

Included in

Physiology Commons

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