Heterologous Expression of an Encephalitozoon cuniculi Aquaporin in Xenopus Oocytes

The parasitophorous vacuole of Encephalitozoon cuniculi: Biogenesis and characteristics of the host cell–pathogen interface

“…After a trigger, which might involve changes in pH and ion concentrations, a sudden rise of the osmotic pressure occurs, which in some, but not all microsporidia species is mediated by the cleavage of trehalose (Undeen and Frixione, 1990;Keohane and Weiss, 1998). The sudden rise of the osmotic pressure mediates a unidirectional flow of water inside the spore through recently characterised aquaporins (Frixione et al, 1997;Ghosh et al, 2006). This process increases the mechanical pressure inside the spore and finally leads to the breakage of the spore wall at a defined position followed by the explosive discharge of the polar tube, a process known as germination (Bigliardi and Sacchi, 2001) (Fig.…”

Current Therapy and Therapeutic Targets for Microsporidiosis

“…Based on the osmotic pressure theory of spore germination, water flow across the spore wall and plasma membrane which is accompanied by swelling of the polaroplasts and posterior vacuole after germination, results in quickly increased osmotic pressure and the corresponding eversion of the polar tube and subsequent expulsion of the sporoplasm ( Frixione et al, 1997 ). To this end, aquaporins are also a potential target for inhibiting spore germination, because they are critical proteins for water flow across membranes ( Ghosh et al, 2006a , b ). The aquaporin inhibitor HgCl 2 has been shown to be effective in inhibiting A. algerae spore germination ( Frixione et al, 1997 ).…”