| Title: |
Two glutathione peroxidases in the fungal pathogen Cryptococcus neoformans are expressed in the presence of specific substrates. |
| Authors: |
Mussall, Tricia A.1, Cherry-Harris, Jocie F.1, Lodge, Jennifer K.1,2 lodgejk@slu.edu |
| Source: |
Microbiology (13500872). Aug2005, Vol. 151 Issue 8, p2573-2581. 9p. |
| Subject Terms: |
*CRYPTOCOCCUS, *IMMUNE system, *GLUTATHIONE, *PEROXIDASE, *METALLOENZYMES, *KILLER cells, *CRYPTOCOCCOSIS |
| Abstract: |
Glutathione peroxidases catalyse the reduction of peroxides by reduced glutathione. To determine if these enzymes are important for resistance to oxidative stress and evasion of the innate immune system by the fungal pathogen Cryptococcus neoformans, two glutathione peroxidase homologues. which share 38% identity, were identified and investigated. In this study, these peroxidases, Gpxl and Gpx2, their localization, their contribution to total glutathione peroxidase activity, and their importance to the oxidative and nitrosative stress resistance of C. neoformans are described. It is shown that the two glutathione peroxidase genes are differentially expressed in response to stress. While both GPXJ and GPX2 are induced during t-butylhydroperoxide or cumene hydroperoxide stress and repressed during nitric oxide stress, only GPX2 is induced in response to hydrogen perox-de stress. Deletion mutants of each and both of the glutathione peroxidases were generated, and it was found that they are sensitive to various peroxide stresses while showing wild-type resistance to other oxidant stresses, such as superoxide and nitric oxide. While the glutath-one peroxidase mutants are slightly sensitive to oxidant killing by macrophages, they exhibit wild-type virulence in a mouse model of cryptococcosis. [ABSTRACT FROM AUTHOR] |
|
Copyright of Microbiology (13500872) is the property of Microbiology Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) |
| Database: |
Academic Search Complete |
