Functional glycosylphosphatidylinositol anchor signal sequences in the Pneumocystis carinii PRT1 protease family

Palmer, RJ Wakefield, AE

Rj. Palmer et Ae. Wakefield, Functional glycosylphosphatidylinositol anchor signal sequences in the Pneumocystis carinii PRT1 protease family, AM J RESP C, 25(4), 2001, pp. 466-473

49

INGLESE

Article

da verificare

AMERICAN JOURNAL OF RESPIRATORY CELL AND MOLECULAR BIOLOGY

1044-1549 → ACNP

25

4

2001

466 - 473

ISI

1044-1549(200110)25:4<466:FGASSI>2.0.ZU;2-R

Pneumocystis carinii is fungus which is a frequent cause of severe pneumoni a in immunocompromised individuals. The P. carinii genome contains the PRTI subtelomeric multigene family that encodes a kexin-like serine protease wh ich is expressed on the surface of P. carinii. Analysis of the sequence of the carboxy-terminal sequence of many copies of PRTI showed that they conta ined motifs characteristic of a glycosylphosphatidylinositol (GPI) anchor s ignal sequence. The ability of the C-terminal sequences of PRT1 to direct t he addition of a GPI anchor was tested. CD14, a GPI-anchored monocyte glyco protein antigen, was used as the basis of a heterologous system. CD14 was t runcated to remove the carboxy-terminal sequences responsible for GPI-ancho r addition. Addition of carboxy-terminal sequences from PRT1 restored high- level surface expression to the truncated CD14. Further, the majority of CD 14-PRT1 recombinant protein was removed from the cell membrane by treatment with GPI-specific phospholipase C. These results suggest that the carboxy- terminal residues of most of the members of the PRT1 family of proteases ha ve the potential to form a functional GPI-attachment signal.