The Spitzenkörper: a choreographer of fungal growth and morphogenesis.

The Spitzenkörper (SPK) is a multicomponent pleomorphic structure found at hyphal apices. It is necessary to maintain hyphal growth and morphogenesis in numerous fungal species, including plant and human pathogens. At the turn of the 21st century extraordinary advances in protein tagging technology and live microscopy allowed uncovering the main molecular constituents of the SPK. Distinct layers of macrovesicles and microvesicles, each carrying different cell wall synthetic enzymes, along with the actin cytoskeleton and related proteins are some of the components that make up the SPK. One of the biggest current challenges is to decipher the functional relationship between the SPK components and macromolecular complexes, such as the polarisome and the exocyst, which partially co-localize within the hyphal dome.