Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

The subtelomeric regions of the chromosomes of many organisms contain gene families that allow adaptation to a changing environment. In a number of parasites, these subtelomeric gene families encode cell surface proteins that undergo antigenic variation. Proteases are another important virulence determinant in pathogenic microorganisms. We report the localization of the PRT1 protease of the pathogenic fungus Pneumocystis carinii sp. f. carinii, encoded by a subtelomeric gene family, to the cell surface of both the trophozoite and the cyst phase of the organism. Using anti-PRT1 antiserum, we demonstrated specificity to P. carinii sp. f. carinii in sections of infected rat lungs and, using immunofluorescence, we showed that the PRT1 protease has the characteristic distribution of a surface protein. The anti-PRT1 antiserum showed cross-reactivity with a number of P. carinii sp. f. carinii proteins migrating between 185 kDa and 28 kDa, the majority migrating between 42 kDa and 52 kDa, a region that has been shown by serological studies to contain important immunodominant P. carinii proteins. Cross-reactivity was also observed with P. carinii sp. f. hominis proteins. We have also cloned a portion of the catalytic domain of PRT1 from P. carinii sp. f. hominis, P. carinii sp. f. muris and P. carinii sp. f. rattus. Our data suggest that the PRT1 protease plays an important role in the pathogenicity of P. carinii.

Type

Journal article

Journal

Mol Microbiol

Publication Date

03/1999

Volume

31

Pages

1723 - 1733

Keywords

Amino Acid Sequence, Animals, Antibodies, Cloning, Molecular, Electrophoresis, Polyacrylamide Gel, Eukaryotic Initiation Factor-3, Fungal Proteins, Gene Expression Regulation, Fungal, Humans, Immunoblotting, Immunohistochemistry, Lung, Membrane Proteins, Mice, Mice, Inbred BALB C, Models, Genetic, Molecular Sequence Data, Plasmids, Pneumocystis, Polymerase Chain Reaction, Rats, Rats, Sprague-Dawley, Recombinant Proteins, Saccharomyces cerevisiae Proteins, Sequence Homology, Amino Acid