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Updated: Dec 18, 2025

Biolistic Transformation of a Fluorescent Tagged Gene into the Opportunistic Fungal Pathogen Cryptococcus neoformans
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Biolistic Transformation of a Fluorescent Tagged Gene into the Opportunistic Fungal Pathogen Cryptococcus neoformans

Published on: March 19, 2015

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Fbp1-mediated ubiquitin-proteasome pathway controls Cryptococcus neoformans virulence by regulating fungal

Tong-Bao Liu1, Chaoyang Xue

  • 1Public Health Research Institute, Rutgers University, Newark, New Jersey, USA.

Infection and Immunity
|January 31, 2014
PubMed

Insights

F-box protein 1 (Fbp1) is crucial for Cryptococcus neoformans virulence. Deleting Fbp1 impairs fungal spread and survival within macrophages, revealing a new mechanism controlling fungal infections.

Area of Science:

  • Mycology
  • Infectious Diseases
  • Molecular Biology

Background:

  • Cryptococcus neoformans causes life-threatening lung and brain infections, particularly in immunocompromised individuals.
  • F-box protein 1 (Fbp1) was previously identified as essential for virulence, independent of known factors, suggesting a novel regulatory mechanism.

Purpose of the Study:

  • To investigate the role of Fbp1 in the ubiquitin-proteasome system and its mechanism of action during Cryptococcus neoformans infection.
  • To identify Fbp1 substrates and elucidate the molecular basis of its function in fungal virulence.

Main Methods:

  • Time course infection studies in a murine inhalation model.
  • Cryptococcus-macrophage interaction assays.
  • Proteomic analysis to identify Fbp1 substrates.

Main Results:

  • The fbp1Δ mutant showed significantly reduced lung damage and failed to disseminate to other organs.
  • The mutant exhibited impaired intracellular proliferation within macrophages.
  • Isc1, involved in inositol sphingolipid biosynthesis, was identified as an Fbp1 substrate crucial for intracellular survival.

Conclusions:

  • Fbp1 is a component of the SCF(Fbp1) E3 ligase, regulating fungal virulence through posttranslational modification.
  • Fbp1 controls Cryptococcus neoformans-macrophage interactions and fungal survival by regulating inositol sphingolipid biosynthesis via Isc1.
  • Fbp1 represents a novel target for controlling cryptococcosis virulence.

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