The RNA-binding protein Psc1 functions downstream of the NDR/LATS kinase Cbk1 to modulate CO(2) tolerance in Cryptococcus neoformans.

Psc1, an RNA-binding protein in Cryptococcus neoformans, suppresses CO2 tolerance by sequestering key mRNAs when unphosphorylated, impairing growth under high CO2 conditions.

• Why it matters: Understanding how C. neoformans adapts to high CO2 environments is crucial because this adaptation enables the pathogen to survive in the host and cause lethal infections, filling a gap in knowledge about post-transcriptional regulation of stress responses.
• What they did: The study identified Psc1 as a downstream target of the Cbk1 kinase, showing that phosphorylation by Cbk1 prevents Psc1 from binding to mRNAs necessary for CO2 tolerance; they used genetic and molecular approaches to analyze Psc1 interactions and condensate formation.
• The result: Findings reveal a novel post-transcriptional mechanism where Cbk1 phosphorylation inhibits Psc1’s mRNA sequestration, enabling Cryptococcus neoformans to adapt to high CO2, which could inform strategies to combat fungal infections.