The interaction between the gelatin-binding domain of fibronectin and the attachment ofPasteuria penetransendospores to nematode cuticle

Abstract

Pasteuria penetrans is 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 of Meloidogyne javanica 2nd-stage juveniles. The results suggest that the structure of the nematode fibronectin is different to the fibronectins so far characterized. Pre-treatment of endospores of Pasteuria with 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.

THE CELLULAR IMMUNE RESPONSE OFDAPHNIA MAGNAUNDER HOST-PARASITE GENETIC VARIATION AND VARIATION IN INITIAL DOSE

“…Other studies add mechanistic support to the hypothesis that infection success is determined before the parasite reaches the host's hemocoel: Duneau et al (2011) observed attachment of P. ramosa spores on the esophagus of a susceptible D. magna genotype, but a distinct lack of attachment in a resistant genotype. A related parasite, P. penetrans , infects its nematode hosts by attaching to the heparin‐binding domain of the host cuticle (Sayre and Starr 1985; Mohan et al 2001; Schmidt et al 2008). To persist in the host population, such receptors would have evolved for another important purpose, perhaps for the recognition of nutrients, symbionts or commensal bacteria, and certain parasite strains may have taken advantage of these receptors by expressing chemical features that imitate food or commensal bacteria—“wolves in sheep's clothing.” The ability of a host to recognize and eliminate a parasite may depend on a lock‐and‐key mechanism where each receptor must effectively bind to a molecular feature on the parasite.…”

Genetic variation in the cellular response of Daphnia magna (Crustacea: Cladocera) to its bacterial parasite

“…The P. ramosa infection process may be similar to that seen in Pasteuria penetrans , a sterilizing parasite that initiates infections by attaching to the heparin-binding domain and gelatine-binding domain proteins on the cuticle of Meloidogyne nematodes (Sayre & Starr 1985; Mohan et al . 2001; Schmidt et al .…”

Bacteria used in the biological control of plant-parasitic nematodes: populations, mechanisms of action, and future prospects

“…The nature of the cuticle receptor(s) for Pasteuria adhesion is ambiguous. Persidis et al, (1991) showed that collagen may be responsible for the recognition process, because cuticle components involved in attachment are sensitive to trypsin and endoglycosidase F, and because gelatin (denatured collagen) itself can inhibit spore attachment (Persidis et al, 1991;Mohan et al, 2001). However, the incubation of second-stage juveniles in the presence of (Mankau et al, 1976;Sayre & Wergin, 1977;Morton et al, 2004;Huang et al, 2005).…”