Cell surface protease PRT1 identified in the fungal pathogen Pneumocystis carinii

Lugli, EB Bampton, ETW Ferguson, DJP Wakefield, AE

Eb. Lugli et al., Cell surface protease PRT1 identified in the fungal pathogen Pneumocystis carinii, MOL MICROB, 31(6), 1999, pp. 1723-1733

63

INGLESE

Article

Microbiology

MOLECULAR MICROBIOLOGY

0950-382X → ACNP

31

6

1999

1723 - 1733

ISI

0950-382X(199903)31:6<1723:CSPPII>2.0.ZU;2-U

The subtelomeric regions of the chromosomes of many organisms contain gene families that allow adaptation to a changing environment. In a number of pa rasites, these subtelomeric gene families encode cell surface proteins that undergo antigenic variation. Proteases are another important virulence det erminant in pathogenic microorganisms. We report the localization of the PR T1 protease of the pathogenic fungus Pneumocystis carinii sp. f. carinii, e ncoded by a subtelomeric gene family, to the cell surface of both the troph ozoite and the cyst phase of the organism. Using anti-PRT1 antiserum, we de monstrated 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 ant iserum showed cross-reactivity with a number of P. carinii sp. f, carinii p roteins migrating between 185 kDa and 28 kDa, the majority migrating betwee n 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. carin ii.