Serine Protease-mediated Host Invasion by the Parasitic Nematode Steinernema carpocapsae

Duarte Toubarro, Miguel Lucena-Robles, Gisela Nascimento, Romana Santos, Rafael Montiel, Paula Veríssimo, Euclides Pires, Carlos Faro, Ana V. Coelho, Nelson Simões

Producción científica: Contribución a una revistaArtículoInvestigaciónrevisión exhaustiva

45 Citas (Scopus)

Resumen

Steinernema carpocapsae is an insect parasitic nematode used in biological control, which infects insects penetrating by mouth and anus and invading the hemocoelium through the midgut wall. Invasion has been described as a key factor in nematode virulence and suggested to be mediated by proteases. A serine protease cDNA from the parasitic stage was sequenced (sc-sp-1); the recombinant protein was produced in an Escherichia coli system, and a native protein was purified from the secreted products. Both proteins were confirmed by mass spectrometry to be encoded by the sc-sp-1 gene. Sc-SP-1 has a pI of 8.7, a molecular mass of 27.3 kDa, a catalytic efficiency of 22.2 × 104 s−1m−1 against N-succinyl-Ala-Ala-Pro-Phe-pNA, and is inhibited by chymostatin (IC 0.07) and PMSF (IC 0.73). Sc-SP-1 belongs to the chymotrypsin family, based on sequence and biochemical analysis. Only the nematode parasitic stage expressed sc-sp-1. These nematodes in the midgut lumen, prepared to invade the insect hemocoelium, expressed higher levels than those already in the hemocoelium. Moreover, parasitic nematode sense insect peritrophic membrane and hemolymph more quickly than they do other tissues, which initiates sc-sp-1 expression. Ex vivo, Sc-SP-1 was able to bind to insect midgut epithelium and to cause cell detachment from basal lamina. In vitro, Sc-SP-1 formed holes in an artificial membrane model (Matrigel), whereas Sc-SP-1 treated with PMSF did not, very likely because it hydrolyzes matrix glycoproteins. These findings highlight the S. carpocapsae-invasive process that is a key step in the parasitism thus opening new perspectives for improving nematode virulence to use in biological control.
Idioma originalInglés
Páginas (desde-hasta)30666-30675
Número de páginas10
PublicaciónJournal of Biological Chemistry
Volumen285
N.º40
DOI
EstadoPublicada - oct 2010

Huella

Profundice en los temas de investigación de 'Serine Protease-mediated Host Invasion by the Parasitic Nematode Steinernema carpocapsae'. En conjunto forman una huella única.

Citar esto