Special type of pheromone-induced invasive growth in Saccharomyces cerevisiae

Area of Science:

• * Molecular and Cellular Biology
• * Mycology
• * Genetics

Background:

• * Fungal invasion of solid substrates is linked to pathogenicity.
• * The ISW2 chromatin remodeling complex subunit, Isw2p, influences Saccharomyces cerevisiae behavior.
• * Understanding gene regulation in yeast mating and invasion is crucial.

Purpose of the Study:

• * To investigate the role of Isw2p in the invasive growth of Saccharomyces cerevisiae.
• * To identify other factors influencing invasion in MATalpha cells lacking Isw2p.
• * To elucidate the signaling pathways involved in this invasive phenotype.

Main Methods:

• * Genetic manipulation of Saccharomyces cerevisiae strains (isw2Δ, MATalpha, deletion mutants for Dls1p, Dpb4p).
• * Phenotypic analysis of fungal invasion on minimal medium.
• * Microarray analysis to assess gene expression changes.
• * Examination of protein dependencies (Fig2p, Aga1p, Fus3 kinase, Kss1 kinase).

Main Results:

• * Absence of Isw2p in MATalpha cells promotes invasion, especially when Dls1p or Dpb4p are also absent.
• * The invasion phenotype resembles pheromone-induced invasion and depends on Fig2p.
• * Mating agglutinin Aga1p plays a role in agar adhesion for invasion.
• * Invasive growth of isw2Δ MATalpha cells specifically requires Fus3 kinase, with limited substitution by Kss1 kinase.

Conclusions:

• * Isw2p deletion in MATalpha yeast can lead to invasive growth, partially mimicking pheromone-induced invasion.
• * The pathway involves Fus3 kinase and Aga1p, suggesting a link to the mating response.
• * This study reveals novel insights into the regulation of fungal invasion and pathogenicity.