EnP1 and EnP2, two proteins associated with the Encephalitozoon cuniculi endospore, the chitin-rich inner layer of the microsporidian spore wall
Microsporidia are obligate intracellular parasites forming environmentally resistant spores that harbour a rigid cell wall. This wall comprises an outer layer or exospore and a chitin-rich inner layer or endospore. So far, only a chitin deacetylase-like protein has been shown to localize to the Ence...
Gespeichert in:
Veröffentlicht in: | International journal for parasitology 2006-03, Vol.36 (3), p.309-318 |
---|---|
Hauptverfasser: | , , , , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Microsporidia are obligate intracellular parasites forming environmentally resistant spores that harbour a rigid cell wall. This wall comprises an outer layer or exospore and a chitin-rich inner layer or endospore. So far, only a chitin deacetylase-like protein has been shown to localize to the
Encephalitozoon cuniculi endospore and either one or two proteins have been clearly assigned to the exospore in two
Encephalitozoon species: SWP1 in
E. cuniculi, SWP1 and SWP2 in
Encephalitozoon intestinalis. Here, we report the identification of two new spore wall proteins in
E. cuniculi, EnP1 and EnP2, the genes of which are both located on chromosome I (ECU01_0820 and ECU01_1270, respectively) and have no known homologue. Detected by immunoscreening of an
E. cuniculi cDNA library,
enp1 is characterized by small-sized 5′ and 3′ untranslated regions and is highly expressed throughout the whole intracellular cycle. The encoded basic 40
kDa antigen displays a high proportion of cysteine residues, arguing for a significant role of disulfide bridges in spore wall assembly. EnP2 is a 22
kDa serine-rich protein that is predicted to be
O-glycosylated and glycosylated phosphatidyl inositol-anchored. Although having been identified by mass spectrometry of a dithiothreitol-soluble fraction, this protein contains only two cysteine residues. Mouse polyclonal antibodies were raised against EnP1 and EnP2 recombinant proteins produced in
Escherichia coli Our immunolocalisation data indicate that EnP1 and EnP2 are targeted to the cell surface as early as the onset of sporogony and are finally associated with the chitin-rich layer of the wall in mature spores. |
---|---|
ISSN: | 0020-7519 1879-0135 |
DOI: | 10.1016/j.ijpara.2005.10.005 |