Spitzenkörper assembly mechanisms reveal conserved features of fungal and metazoan polarity scaffolds

• Published in: Nature communications Vol. 11; no. 1; p. 2830
• Main Authors: Zheng, Peng, Nguyen, Tu Anh, Wong, Jie Yun, Lee, Michelle, Nguyen, The-Anh, Fan, Jing-Song, Yang, Daiwen, Jedd, Gregory
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05.06.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 14/19; 42/35; 631/326/193/2538; 631/326/88; 631/80/85; 82/58; 82/80; Accumulation; Actin; Analogies; Assembly; Calponin; Cell Polarity; Coils; Divergence; Domains; Fungal Proteins - chemistry; Fungal Proteins - metabolism; Fungi; Glycolysis; Grooves; Homology; Humanities and Social Sciences; Hyphae; Hyphae - cytology; Hyphae - metabolism; Kinases; Localization; multidisciplinary; Myosin; Myosin Type V - chemistry; Myosin Type V - metabolism; Neurospora; Neurospora crassa - cytology; Neurospora crassa - metabolism; NMR; Nuclear magnetic resonance; Nuclear Magnetic Resonance, Biomolecular; Polarity; Protein Domains; Protein interaction; Protein Interaction Maps; Proteins; Scaffolds; Science; Science (multidisciplinary); Secretory vesicles; Secretory Vesicles - metabolism; Vesicles
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-16712-9

The Spitzenkörper (SPK) constitutes a collection of secretory vesicles and polarity-related proteins intimately associated with polarized growth of fungal hyphae. Many SPK-localized proteins are known, but their assembly and dynamics remain poorly understood. Here, we identify protein-protein interaction cascades leading to assembly of two SPK scaffolds and recruitment of diverse effectors in Neurospora crassa . Both scaffolds are transported to the SPK by the myosin V motor (MYO-5), with the coiled-coil protein SPZ-1 acting as cargo adaptor. Neither scaffold appears to be required for accumulation of SPK secretory vesicles. One scaffold consists of Leashin-2 (LAH-2), which is required for SPK localization of the signalling kinase COT-1 and the glycolysis enzyme GPI-1. The other scaffold comprises a complex of Janus-1 (JNS-1) and the polarisome protein SPA-2. Via its Spa homology domain (SHD), SPA-2 recruits a calponin domain-containing F-actin effector (CCP-1). The SHD NMR structure reveals a conserved surface groove required for effector binding. Similarities between SPA-2/JNS-1 and the metazoan GIT/PIX complex identify foundational features of the cell polarity apparatus that predate the fungal-metazoan divergence. The Spitzenkörper (SPK) is a polarized accumulation of proteins and secretory vesicles associated with tip growth of fungal hyphae. Here, Zheng et al. study SPK assembly and dynamics, identify SPK protein scaffolds and associated proteins, and reveal similarities with other scaffolds from metazoans.