PMID:16368098

Citation	Peuvel-Fanget, I, Polonais, V, Brosson, D, Texier, C, Kuhn, L, Peyret, P, Vivarès, C and Delbac, F (2006) EnP1 and EnP2, two proteins associated with the Encephalitozoon cuniculi endospore, the chitin-rich inner layer of the microsporidian spore wall. Int. J. Parasitol. 36:309-18
Abstract	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.
Links	PubMed Online version:10.1016/j.ijpara.2005.10.005
Keywords	Amino Acid Sequence; Antibodies, Fungal/analysis; Cell Wall/chemistry; Chitin; Chromosomes, Fungal/genetics; Cysteine/analysis; Cysteine/genetics; DNA, Circular/genetics; DNA, Fungal/genetics; Electrophoresis, Polyacrylamide Gel/methods; Encephalitozoon cuniculi/chemistry; Encephalitozoon cuniculi/genetics; Encephalitozoon cuniculi/ultrastructure; Fluorescent Antibody Technique, Indirect/methods; Fungal Proteins/analysis; Fungal Proteins/genetics; Glycosylation; Mass Spectrometry/methods; Microscopy, Electron/methods; Microscopy, Immunoelectron; Serine/analysis; Serine/genetics; Spores, Fungal/chemistry
edit table

Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
ENCCU:SWP3	part_of	GO:0031160: spore wall	ECO:0000314: direct assay evidence used in manual assertion		C		Seeded From UniProt	complete
ENCCU:SWP3		GO:0031160: spore wall	ECO:0000314:		C		Figure 7E: E. cuniculus was treated with EnP1 antibody, a secondary antibody was conjugated with gold, gold particles were found inside spore wall	complete CACAO 10266

References

See Help:References for how to manage references in GONUTS.