RESUMO
The description of Plasmodium ookinete surface proteins and their participation in the complex process of mosquito midgut invasion is still incomplete. In this study, using phage display, a consensus peptide sequence (PWWP) was identified in phages that bound to the Plasmodium berghei ookinete surface and, in selected phages, bound to actin and enolase in overlay assays with ookinete protein extracts. Actin was localized on the surface of fresh live ookinetes by immunofluorescence and electron microscopy using specific antibodies. The overall results indicated that enolase and actin can be located on the surface of ookinetes, and suggest that they could participate in Plasmodium invasion of the mosquito midgut.
Assuntos
Actinas/metabolismo , Aedes/metabolismo , Anopheles/metabolismo , Sistema Digestório/metabolismo , Estágios do Ciclo de Vida/genética , Peptídeos/metabolismo , Fosfopiruvato Hidratase/metabolismo , Plasmodium berghei , Aedes/genética , Aedes/parasitologia , Sequência de Aminoácidos , Animais , Anopheles/genética , Anopheles/parasitologia , Extratos Celulares , Células Cultivadas , Sequência Conservada , Sistema Digestório/parasitologia , Imunofluorescência , Malária/metabolismo , Malária/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica , Dados de Sequência Molecular , Biblioteca de Peptídeos , Peptídeos/química , Peptídeos/genética , Plasmodium berghei/genética , Plasmodium berghei/metabolismo , Proteínas de Protozoários/metabolismo , Doenças dos Roedores/metabolismo , Doenças dos Roedores/parasitologiaRESUMO
Salivary glands of female mosquitoes produce proteins, not completely described yet, that participate in carbohydrate and blood feeding. Here, we report an acidic glycoprotein of 35 kDa (GP35 ANOAL) secreted in the saliva of the malaria vector mosquito Anopheles albimanus. GP35 ANOAL is produced exclusively in the distal lateral lobes of adult female salivary glands, it has a pI of 4.45 and is negatively stained by regular silver stain. An 888 bp cDNA clone encoding a predicted product of 240 amino acids has a signal peptide, potential post-translational modification sites, and a disintegrin signature RGD. The GP35 ANOAL sequence depicts high similarities with the 30 kDa saliva allergen of Aedes aegypti, 30 kDa allergen-like hypothetical proteins, and GE-rich proteins present in several Anopheles species, as well as in Ae. albopictus and Culex pipiens quinquefasciatus. The function of this protein family is still unknown.
