W oronin bodies, their impact on stress resistance and virulence of the pathogenic mould A spergillus fumigatus and their anchoring at the septal pore of filamentous A scomycota

Summary Hyphae of filamentous A scomycota consist of compartments that are connected via septal pores. To avoid a dramatic loss of cellular content after wounding, fungi developed mechanisms to occlude their septal pores. In most P ezizomycotina , so‐called W oronin bodies are anchored in proximity to the pore. This is a prominent example for precise spatial positioning of organelles, but so far the underlying molecular organization has remained largely unknown. Using the pathogenic mould A spergillus fumigatus , we provide evidence that W oronin bodies are important for stress resistance and virulence. Furthermore the molecular machinery anchoring them at the septum is described. Namely, we have identified Lah as the tethering protein and provide evidence that the W oronin body protein HexA binds to the septal pore in a Lah ‐dependent manner. Moreover, we demonstrate that a striking poly‐histidine motif targets HexA to the septal cell wall. Thus, the axis HexA ‐ Lah is an excellent candidate for the tether linking W oronin bodies to the septum. This model applies to A . fumigatus , but most likely also to the vast majority of the P ezizomycotina . Our findings shed light on the evolution of W oronin body anchoring and provide a basis for the development of novel strategies to combat fungal pathogens like A . fumigatus .