Phosphorus-Rich Structures and Capsular Architecture in Cryptococcus Neoformans

Abstract

Intracellular and surface phosphorus-enriched structures were identified. These molecules were required for capsule assembly, as demonstrated in experiments using polysaccharide incorporation by capsule-deficient cells and mutants with defects in polyphosphate synthesis. The demonstration of intracellular and cell wall-associated polyphosphates in C. neoformans may lead to future studies involving their participation in both physiologic and pathogenic events.

A Predicted Mannoprotein Participates in Cryptococcus gattii Capsular Structure

“…(iv) Cell-associated cryptococcal polysaccharide diameter and thickness are influenced by the presence of Krp1. Polysaccharide thickness has recently been linked with capsular architecture and pathogenesis ( 66 ). Increased fiber thickness is indicative of higher levels of GXM self-aggregation, but other possibilities cannot be ruled out.…”

“…Sample preparation was conducted as described previously ( 80 ), and the capsular structures were visualized with an Auriga field emission gun scanning electron microscopy (FEG-SEM) microscope (Zeiss, Germany). The thickness of WT and KRP1 mutant fibers was measured in 20 to 30 cells with the ImageJ software as previously described ( 66 ).…”

Phosphate Acquisition and Virulence in Human Fungal Pathogens

“…Such roles in metal homeostasis are reminiscent of the well-established role of polyP in sequestering diverse cations in bacterial cells (reviewed in [ 62 ]). Intriguingly, in a recent study, polyP containing structures were located on the surface of C. neoformans cells [ 63 ]. In this regard, as polyP is known to induce blood clotting [ 64 ], this may underlie previous findings that wild-type but not vtc4Δ C. neoformans cells could increase the rate of blood clotting [ 44 ].…”

When green and red mycology meet: Impressions from an interdisciplinary forum on virulence mechanisms of phyto- and human-pathogenic fungi

“…The session was closed by Jim Kronstad from Vancouver, Canada, who demonstrated nutritional and proteostatic regulation of capsule formation in the opportunistic fungal pathogen Cryptococcus neoformans. Capsule size and morphology are influenced by a variety of factors, among them iron availability, surface polyphosphates, or cAMP signaling, 22,23 which underscores flexibility of this dynamic cellular shield.…”

“…Crossing path(ogen)s reveal the role for a natural product N. Keller (P) 15 The Cryptococcus neoformans capsule is a highly dynamic structure J. Kronstad (S) 22,23 Fusarium oxysporum acts as a true cross-kingdom pathogen A. Di Pietro (S) 31,32 Fungal spore components determine the interaction with immune cells A. Brakhage (S) 38 Regulatory networks of C. albicans morphogenesis are complex C. D'Enfert (S) 41 Experimental evolution reveals unexpected factors of fungal virulence S. Brunke (Y) 75,76 Candida albicans produces a toxic surprise: Candidalysin J. Naglik (S) 56 Coprinopsis cinerea produces potent fungal defense effectors M. K€ unzler (S) [59][60][61] The fungal cell wall acts as immunological & drug target N. Gow (S) 70 Copper detoxification supports A. fumigatus virulence N. Osherov (Po) 77 Note.…”