Genome-wide functional analysis of phosphatases in the pathogenic fungus Cryptococcus neoformans

Abstract

Phosphatases, together with kinases and transcription factors, are key components in cellular signalling networks. Here, we present a systematic functional analysis of the phosphatases in Cryptococcus neoformans , a fungal pathogen that causes life-threatening fungal meningoencephalitis. We analyse 230 signature-tagged mutant strains for 114 putative phosphatases under 30 distinct in vitro growth conditions, revealing at least one function for 60 of these proteins. Large-scale virulence and infectivity assays using insect and mouse models indicate roles in pathogenicity for 31 phosphatases involved in various processes such as thermotolerance, melanin and capsule production, stress responses, O- mannosylation, or retromer function. Notably, phosphatases Xpp1, Ssu72, Siw14, and Sit4 promote blood-brain barrier adhesion and crossing by C. neoformans . Together with our previous systematic studies of transcription factors and kinases, our results provide comprehensive insight into the pathobiological signalling circuitry of C. neoformans .

MoWhi2 regulates appressorium formation and pathogenicity via the MoTor signalling pathway in Magnaporthe oryzae

“…In Colletotrichum orbiculare , CoWhi2 interacts with CoPsr1 and is involved in the biotrophic infection stage (Harata et al, 2016 ). Systematic analysis of phosphatases in the wheat head blight pathogen Fusarium graminearum and human opportunistic fungal pathogen Cryptococcus neoformans revealed that Psr1 homologs are involved in infection‐related development and virulence (Jin et al, 2020 ; Yun et al, 2015 ). In our study, we found that MoWhi2 colocalized with MoPsr1 on the plasma membrane and functioned together during appressorium development and invasive growth.…”

Targeting Unconventional Pathways in Pursuit of Novel Antifungals

“…In the field, significant progress has been made in the characterization of enolase, an enzyme implicated in tissue invasion, as well as enzymes from the mannitol biosynthesis and de novo purine biosynthesis pathways in many pathogenic fungi. In addition to the pathways explored in this review, de novo pyrimidine biosynthesis enzymes, intracellular redox environment regulators and key phosphatases, kinases and transcription factors that form cellular signaling networks have been explored as potential antifungal drug targets (Oliver et al, 2016 ; Marshall et al, 2019 ; Jin et al, 2020 ). Altogether, these experiments lay the foundation for antifungal drug discovery projects that target unconventional, but promising, pathways.…”

The Anti-Fungal Activity of Nitropropenyl Benzodioxole (NPBD), a Redox-Thiol Oxidant and Tyrosine Phosphatase Inhibitor

“…Microscopic fungi show lower conservation and greater diversity in phosphoproteins compared to higher eukaryotes, with the functionally important phosphoproteins being the more highly conserved [ 6 , 7 , 8 , 9 ]. Kinase and phosphatase orthologs are heterogeneously distributed across fungal species and often show diversified functions depending on habitats and activities [ 10 , 11 , 12 , 13 ]. Orthologs of protein tyrosine kinases of higher eukaryotes are lacking in unicellular fungi [ 14 ].…”

“…The Mpk1 ‘cell wall integrity’ pathway, the ‘high osmolality glycerol’ (Hog1) stress response pathway and the Fus3/Kss1 mating and filamentation pathways, independently and cooperatively, play essential roles in fungal growth, development, virulence and adaptation to stress [ 15 , 16 , 18 ]. Fungal MAP kinases are generally highly conserved but show considerable functional divergence in number of MAPK genes and in activation loop motifs [ 6 , 11 , 19 ].…”