[log in to unmask]" type="cite"> Thesis Defense Announcement
To:  The George Mason University Community

Candidate: Sarah Hamer
Program: Master of Science in Biology

Date:   Wednesday April 25, 2012
Time:   10:00 a.m.
Place:  George Mason University, Prince William campus
	     Bull Run Hall, Room 247
 
Thesis Chair:  Dr. Serguei Popov
Thesis Director: Dr. Myung-Chul Chung

Title: "The S-nitrosylation of Peroxiredoxin 1 in Human Small Airway Epithelial Cells During Bacillus Anthracis Infection"

A copy of the thesis is on reserve in the Johnson Center Library, Fairfax campus.  The thesis will not be read at the meeting, but should be read in advance. All members of the George Mason University community are invited to attend.

ABSTRACT:
Bacillus anthracis, a Gram-positive soil organism, is the causative agent of anthrax.  Although the key virulence factor of anthrax is mediated by toxins (i.e. lethal toxin and edema toxin), it has proven that the bacterial nitric oxide synthase (bNOS) of B. anthracis, also, plays a role in pathogenesis.  Since B. anthracis infection produced bona fide nitric oxide that is responsible for protein modification by S-nitrosylation,  I hypothesized that bNOS-induced nitric oxide contributes to regulation of host cell function through protein chemical modification.  The nitrosproteomic analysis using the biotin-switch assay demonstrated that during B. anthracis infection, peroxiredoxin 1 (Prx1) was predominantly S-nitrosylated; there was a decrease in its peroxidase activity and an increase in its chaperone activity, which both affect cell viability.  Treatment with a nitric oxide donor in a high hydrogen peroxide environment decreased cell viability; while during B. anthracis there was an increase in cell viability, presumably due to increase of chaperone activity of Prx1.  These results suggest that during B. anthracis infection, bacteria-derived nitric oxide plays a role in oxidative or nitrosative stress-induced epithelial responses to the pathogen in the lung.

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