The Cytoskeleton and Polarity Markers During Polarized Growth of Filamentous Fungi

Filamentous fungi are highly polarized eukaryotic cells, which continuously elongate their hyphae at the tips. The extension of hyphal tips requires the continuous enlargement of the cell membrane and the extension of the cell wall. Both are achieved through massive vesicle fusion at the tip. Vesicle transport as well as all other dynamic processes related to polar growth, such as organelle duplication and distribution, or the transport of RNA, proteins, or lipids, requires cytoskeletal elements. The establishment and maintenance of cell polarity in fungi—as in higher eukaryotes—requires the interplay between the actin and microtubule cytoskeletons and landmark proteins at the cortex. Here we review recent findings unraveling the mechanism of polarized growth with special emphasis on the roles of the actin and microtubule cytoskeletons, polarity markers linking the two cytoskeletons.