title: Fungal MACPF-like proteins and aegerolysins: bi-component pore-forming proteins?
abstract: Proteins with membrane-attack complex/perforin (MACPF) domains are found in almost all kingdoms of life, and they have a variety of biological roles, including defence and attack, organism development, and cell adhesion and signalling. The distribution of these proteins in fungi appears to be restricted to some Pezizomycotina and Basidiomycota species only, in correlation with another group of proteins with unknown biological function, known as aegerolysins. These two protein groups coincide in only a few species, and they might operate in concert as cytolytic bi-component pore-forming agents. Representative proteins here include pleurotolysin B, which has a MACPF domain, and the aegerolysin-like protein pleurotolysin A, and the very similar ostreolysin A, which have been purified from oyster mushroom (Pleurotus ostreatus). These have been shown to act in concert to perforate natural and artificial lipid membranes with high cholesterol and sphingomyelin content. The aegerolysin-like proteins provide the membrane cholesterol/sphingomyelin selectivity and recruit oligomerised pleurotolysin B molecules, to create a membrane-inserted pore complex. The resulting protein structure has been imaged with electron microscopy, and it has a 13-meric rosette-like structure, with a central lumen that is ~4-5 nm in diameter. The opened transmembrane pore is non-selectively permeable for ions and smaller neutral solutes, and is a cause of cytolysis of a colloid-osmotic type. The biological significance of these proteins for the fungal life-style is discussed.
authors.affiliation: Department of Biology Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000, Ljubljana, Slovenia.
authors.forename: Katja
authors.initials: K
authors.lastname: Ota
authors.forename: Matej
authors.initials: M
authors.lastname: Butala
authors.forename: Gabriella
authors.initials: G
authors.lastname: Viero
authors.forename: Mauro
authors.initials: M
authors.lastname: Dalla Serra
authors.forename: Kristina
authors.initials: K
authors.lastname: Sepčić
authors.forename: Peter
authors.initials: P
authors.lastname: Maček
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015938:Complement Membrane Attack Complex / Q000737:chemistry / Q000502:physiology*; D005656:Fungal Proteins / Q000737:chemistry / Q000502:physiology*; D006460:Hemolysin Proteins / Q000737:chemistry / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D054353:Perforin / Q000737:chemistry / Q000502:physiology*; D010802:Phylogeny; D020076:Pleurotus / Q000235:genetics / Q000472:pathogenicity; D052899:Pore Forming Cytotoxic Proteins / Q000737:chemistry / Q000502:physiology*; D055503:Protein Multimerization / Q000502:physiology; D017386:Sequence Homology, Amino Acid
chemical_list: D015938:Complement Membrane Attack Complex; D005656:Fungal Proteins; D006460:Hemolysin Proteins; D052899:Pore Forming Cytotoxic Proteins; C461279:aegerolysin; D054353:Perforin