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TUP1 disruption in Cryptococcus neoformans uncovers a peptide‐mediated density‐dependent growth phenomenon that mimics quorum sensing
Author(s) -
Lee Hyeseung,
Chang Yun C.,
Nardone Glenn,
KwonChung Kyung J.
Publication year - 2007
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2007.05666.x
Subject(s) - cryptococcus neoformans , biology , phenotype , quorum sensing , microbiology and biotechnology , yeast , oligopeptide , peptide , strain (injury) , repressor , saccharomyces cerevisiae , gene , genetics , virulence , biochemistry , gene expression , anatomy
Summary Cryptococcus neoformans is a pathogenic yeast that causes life‐threatening meningoencephalitis and grows well on mycological media regardless of inoculum size. Interestingly, a deletion of the global repressor TUP1 in C. neoformans uncovered a density‐dependent growth phenotype reminiscent of the quorum‐sensing phenomenon. An inoculum size of lower than 10 3 cells of the tup1 Δ strain failed to form colonies on agar media while inocula of 10 5 −10 6 cells per plate formed a lawn. This phenotype, expressed as the inability to grow at low cell densities, was rescued by the culture filtrate from a high cell density tup1 Δ culture and the active molecule in this culture filtrate was identified to be an oligopeptide composed of 11 amino acids. Activity assays, using a synthetic version of the peptide with strains harbouring a deletion of the corresponding gene, proved that the oligopeptide functioned as an autoregulatory molecule responsible for the density‐dependent phenotype. Although a density‐dependent growth phenotype has been reported in several species of Ascomycetes, no peptide has been reported to function as an autoregulator in the Kingdom Fungi. The identification of an 11‐mer peptide as an autoregulatory molecule in C. neoformans suggests that a diverse mechanism of cell‐to‐cell communication exists in the Kingdom Fungi.