Heterologous Expressed NbSWP12 from Microsporidia Nosema bombycis Can Bind with Phosphatidylinositol 3-Phosphate and Affect Vesicle Genesis

Abstract

Microsporidia are a big group of single-celled obligate intracellular organisms infecting most animals and some protozoans. These minimalist eukaryotes lack numerous genes in metabolism and vesicle trafficking. Here, we demonstrated that the spore wall protein NbSWP12 of microsporidium Nosema bombycis belongs to Bin/Amphiphysin/Rvs (BAR) protein family and can specifically bind with phosphatidylinositol 3-phosphate [Ptdlns(3)P]. Since Ptdlns(3)P is involved in endosomal vesicle biogenesis and trafficking, we heterologous expressed NbSWP12 in yeast Saccharomyces cerevisiae and proved that NbSWP12 can target the cell membrane and endocytic vesicles. Nbswp12 transformed into Gvp36 (a BAR protein of S. cerevisiae) deletion mutant rescued the defect phenotype of vesicular traffic. This study identified a BAR protein function in vesicle genesis and sorting and provided clues for further understanding of how microsporidia internalize nutrients and metabolites during proliferation.

Host and transmission route ofEnterocytozoon hepatopenaei(EHP) from dragonfly to shrimp

“…The fat body function in insects is similar to that of the hepatopancreas of shrimp [25] . The microsporidium Nosema bombycis mainly infects the fat body, midgut, silk gland, and gonad of the silkworm [7] . Paranosema locustae , an entomopathogen of grasshoppers and locusts that mainly infects the fat body tissue, remains the only microsporidium registered and available for long-term pest control [8] .…”

“…Microsporidians can infect a wide variety of animals ranging from invertebrates to vertebrate hosts, including humans and arthropods like insects and crustaceans [6] . Many microsporidia, including Systenostrema alba , Amblyospora connecticus , Paranosema locustae , Brachiola algerae , Nosema bombycis , and Nosema carpocapsae , have been reported in insects, but EHP has not been previously reported in insects according to the best of our knowledge [7–9] . Microsporidia have different transmission strategies, including horizontal transmission (the oral transmission of spores through contaminated food and water) and vertical transmission (from parents to offspring) [10] .…”