[Secreted proteins of Giardia duodenalis--characteristic and role in biology of the parasite].
The article presents the current knowledge on the proteines under question. The first analysed E-S products released by G. duodenalis was a polydisperse hydrophobic complex (16.5-225 kDa), protease VI sensitive, chloroform-methanol insoluble. Based on inhibition studies cysteine protease and metalloprotease were detected in the complex. The further analysis revealed that a 58 kDa heat stable as wall as protease sensitive glycoprotein secreted by G. duodenalis trophozoites is highly immunogenic for the hosts. Before encystation, G. duodenalis trophozoites secrete leucine-rich cyst wall proteins: CWP1, CWP2 and CWP3. Steady-state levels of CWPs gene transcripts are low in non-encysting trophozoites but increase more than 100-fold during encystation. Another protein, which expression also increases during encystation is gGSP (Giardia Granule-Specific Protein). The protein possesses typical strucutre of calcium-binding proteins. Inhibition of gGSP expression abolishes cyst wall formation, suggesting that this protein regulates Ca(2+)-dependent degranulation of encystation-specific secretory vesicles (ESVs) during cyst wall formation.
Zysiak
Dorota
D
Zakład Parazytologii i Inwazjologii, Katedra Nauk Przedklinicznych, Wydział Medycyny Weterynaryjnej SGGW, ul. Ciszewskiego 8, 02-786 Warszawa.
D000595:Amino Acid Sequence; D000818:Animals; D016829:Giardia lamblia / Q000276:immunology / Q000378:metabolism*; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism*; D022142:Secretory Vesicles
C094333:CWP1 protein, Giardia lamblia; D015800:Protozoan Proteins