Characterisation of novel-cell-wall LysM-domain proteins LdpA and LdpB from the human pathogenic fungus Aspergillus fumigatus

Abstract

Aspergillus fumigatus , a filamentous fungus that is ubiquitous in the environment, causes several human pulmonary disorders, including chronic and acute invasive infections and allergic diseases. Lysin motif (LysM) is a small protein domain that binds chitin, a major component of fungal cell wall polysaccharides. Several secreted LysM-domain proteins without catalytic function (LysM effectors) have been identified. They act as virulence factors in plant pathogenic fungi by preventing the immune response induced by chitin; however, LysM proteins in mammalian pathogenic fungi remain largely unexplored. We describe two novel LysM-domain proteins, LdpA and LdpB, in A. fumigatus . Functional analyses of single and double knockouts revealed no significant effects on cell wall chitin content, cell wall integrity, fungal morphology and fungal growth. Fluorescent signals from LdpA-green fluorescent protein (GFP) and LdpB-GFP were observed in cell wall and extracellular matrix. In a mouse model of invasive pulmonary aspergillosis, survival did not differ between ΔldpA/B and wild-type infection; however, further studies are required to reveal their functions in fungal−host interactions.

Size‐exclusion chromatography allows the isolation of EVs from the filamentous fungal plant pathogen Fusarium oxysporum f. sp. vasinfectum (Fov)

“…Other proteins in Fov EVs contained sequence domains that have been found in fungal effectors. These domains include LysM [66], NPP1 [67], and AltA-1 [68]. Our results support the recent discovery of potential effectors in EVs from the wheat pathogen Zymoseptoria tritici [29].…”

In silico comparative genomic analysis unravels a new candidate protein arsenal specifically associated with Fusarium oxysporum f. sp. albedinis pathogenesis

“…These include proteins having a LysM domain, given that several LysM effectors have already been identified as virulence factors in plant pathogenic fungi 60 . These proteins inhibit the chitin-induced immune response, which protects the fungal cell walls from host chitinases 61 . Another type of effectors secreted by Foa are belonging to the cystin-rich proteins family.…”

Endolysins against Streptococci as an antibiotic alternative

“…To date, several CBDs have been described, including the lysin motif domain (LysM), bacterial Src homology 3 domain (SH3b), choline-binding domain, and Cpl-7-like CBD which is also known as CW-7 repeats ( Bustamante et al, 2017 ; Chang and Ryu, 2017 ; Mitkowski et al, 2019 ; Muraosa et al, 2019 ). SH3b domains are present and well conserved in many staphylococcal phage endolysins.…”

“…It has also been shown to bind and recognize glycine cross-bridges for most staphylococci ( Chang and Ryu, 2017 ; Mitkowski et al, 2019 ). LysM domains were first found in the C terminus of a bacteriophage lysozyme which binds to GlcNAc residues in the cell wall peptidoglycan but has since been described in various prokaryotic and eukaryotic proteins including both bacterial and fungal proteins ( Muraosa et al, 2019 ). The choline-binding domain is mostly found in pneumococcal phages like Cpl-1 and Pal.…”