The putative flippase Apt1 is required for intracellular membrane architecture and biosynthesis of polysaccharide and lipids in Cryptococcus neoformans.
However, there was no difference in growth, capsule size, or melanin production between the wild type and the apt1 mutant strains at either 30 degrees C or 37 degrees C. Despite the absence of an influence on these major virulence factors, Apt1 was required for survival during interactions with macrophages, and apt1 mutants exhibited attenuated virulence in a mouse inhalation model of cryptococcosis.