Urease produced by Coccidioides posadasii contributes to the virulence of this respiratory pathogen.

ABSTRACT: Urease activity during in vitro growth in the saprobic and parasitic phases of Coccidioides spp. is partly responsible for production of intracellular ammonia released into the culture media and contributes to alkalinity of the external microenvironment. Although the amino acid sequence of the urease of Coccidioides posadasii lacks a predicted signal peptide, the protein is transported from the cytosol into vesicles and the central vacuole of parasitic cells (spherules). Enzymatically active urease is released from the contents of mature spherules during the parasitic cycle endosporulation stage. The endospores, together with the urease and additional material which escape from the ruptured parasitic cells, elicit an intense host inflammatory response. Ammonia production by the spherules o

SUBMITTER: Mirbod-Donovan F 

PROVIDER: S-EPMC1346605 | biostudies-literature | 2006 Jan

REPOSITORIES: biostudies-literature