Premium
Proteomics of the Microsporidia Encephalitozoon cuniculi : from Proteins of unknown Function to New Cell Wall Ones
Author(s) -
BROSSON D.,
TEXIER C.,
PRENSIER G.,
VIVARES C. P.
Publication year - 2005
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/j.1550-7408.2005.05202003_3_6.x
Subject(s) - biology , encephalitozoon cuniculi , proteomics , polyclonal antibodies , microsporidia , cell wall , microbiology and biotechnology , computational biology , genetics , gene , antibody , spore
The microsporidia Encephalitozoon cuniculi , a human opportunist pathogen, is an obligate intracellular parasite, the nuclear genome of which has been fully sequenced. Our descriptive proteomic analysis of the late developmental stages showed that one‐third of the most abundant proteins are of unknown function. The spore, stage of resistance and dissemination, is protected by a wall, which plays the major role for survival in the environment. In order to find new spore wall candidates among the unknown proteins, a bioinformatic screening on the basis of the prediction of secretion, membrane anchoring and eventually of some domain homology was performed. In a first validation test, we used proteomics data to identify the target of a polyclonal antibody directed against the cell wall. The identified protein matched with criteria of selection and presented homologies with the polysaccharide deacetylase family, suggesting its implication in cell wall biogenesis. Its localization and the timing of its expression were studied by TEM immunocytochemistry. Screening was then applied to 44 expressed proteins of unknown function. Four of the nine potential cell wall components were demonstrated as being either endospore or exospore proteins, using polyclonal antibodies directed against GST recombinant proteins. The analysis of these new wall proteins should facilitate further bioinformatic screenings and should help in the better understanding of the structure and function of the microsporidian spore wall.