The interaction between the gelatin-binding domain of fibronectin and the attachment ofPasteuria penetransendospores to nematode cuticle
Pasteuria penetransis a Gram-positive endospore-producing bacterium that is a parasite of root-knot nematodes. Attachment of endospores to the cuticle of the nematode is the first stage in the infection process. Western blot analysis with monoclonal and polyclonal antibodies that recognize the 30 kDa heparin-binding domain (HBD) and the 45 kDa gelatin-binding domain (GBD) fragments of human fibronectin (Fn) revealed a series of polypeptides of approximately 40, 45 and 55 kDa present in crude cuticle extracts ofMeloidogyne javanica2nd-stage juveniles. The results suggest that the structure of the nematode fibronectin is different to the fibronectins so far characterized. Pre-treatment of endospores ofPasteuriawith either the HBD or the GBD was found to inhibit binding to the nematode cuticle. The larger GBD fragment was the most effective at blocking adhesion. Pre-treatment of the GBD fragment with gelatin prevented the GBD fragment from inhibiting endospore attachment to the nematode cuticle.