Open AccessIdentification of two new polar tube proteins related to polar tube protein 2 in the microsporidian A ntonospora locustae
Author(s) -
Polonais Valérie,
Belkorchia Abdel,
Roussel Michaël,
Peyretaillade Eric,
Peyret Pierre,
Diogon Marie,
Delbac Frédéric
Publication year - 2013
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12198
Subject(s) - microsporidia , biology , antigen , obligate , serine , microbiology and biotechnology , biochemistry , spore , genetics , botany , phosphorylation
Microsporidia are obligate intracellular eukaryotic parasites with a broad host spectrum characterized by a unique and highly sophisticated invasion apparatus, the polar tube (PT). In a previous study, two PT proteins, named AlPTP1 (50 kDa) and AlPTP2 (35 kDa), were identified in A ntonospora locustae , an orthoptera parasite that is used as a biological control agent against locusts. Antibodies raised against AlPTP2 cross‐reacted with a band migrating at ∼70 kDa, suggesting that this 70‐ kD a antigen is closely related to AlPTP2 . A blast p search against the A . locustae genome database allowed the identification of two further PTP 2‐like proteins named AlPTP2b (568 aa) and AlPTP2c (599 aa). Both proteins are characterized by a specific serine‐ and glycine‐rich N‐terminal extension with elastomeric structural features and share a common C‐terminal end conserved with AlPTP2 (∼88% identity for the last 250 aa). MS analysis of the 70‐kDa band revealed the presence of AlPTP2b . Specific anti‐ AlPTP2b antibodies labelled the extruded PT s of the A . locustae spores, confirming that this antigen is a PT component. Finally, we showed that several PTP 2‐like proteins are also present in other phylogenetically related insect microsporidia, including A nncaliia algerae and P aranosema grylli .