Fungal cytoplasmic membrane ergosterol

Ergosterol is the primary sterol found in the cytoplasmic membranes of fungi, serving a role analogous to cholesterol in animal cells (Lofgren & Nielsen, 2017). It is essential for maintaining membrane integrity, fluidity, and the proper functioning of membrane-bound enzymes and transporters (Alvarez et al., 2007). Ergosterol-rich domains, often referred to as fungal lipid rafts, act as platforms for signaling and protein trafficking, including the localization of cell wall synthesis machinery (Douglas & Konopka, 2014). Because ergosterol is absent in mammalian cells, it represents a critical target for antifungal therapy (Odds et al., 2003). Polyene antibiotics, such as amphotericin B, exert their effect by binding directly to ergosterol, creating transmembrane pores that cause the leakage of essential intracellular components like potassium ions (Gray et al., 2012). Recent studies also suggest that polyenes act by sequestering ergosterol into 'sponge-like' aggregates, which physically extracts the sterol from the membrane and disrupts cellular function (Anderson et al., 2014). This dual mechanism leads to rapid fungicidal activity against a broad spectrum of pathogens (Ghannoum & Rice, 1999).

Other names

ErgosterolFungal lipid raftsErgosterol-rich domainsFungal plasma membrane sterolProvitamin D2

Direct binding to ergosterol molecules within the fungal membrane, resulting in the formation of aqueous pores that cause the leakage of intracellular ions (e.g., K+, Mg2+) and subsequent cell death (Gray et al., 2012). Additionally, the sequestration of ergosterol into large aggregates disrupts the organization of ergosterol-rich domains (lipid rafts), impairing the function of membrane-bound proteins (Anderson et al., 2014).